| Author | Message | ||
| Sean F (Agracer)
Junior Member Username: Agracer Post Number: 233 Registered: 2-2003 |
LOL, I wasn't sure what you called it! ;) | ||
| Frank Parker (Parkerfe)
Advanced Member Username: Parkerfe Post Number: 2567 Registered: 9-2001 |
Sean, I do like Daytonas. But, for now I'll keep my little Fiat Boxer . | ||
| Sean F (Agracer)
Junior Member Username: Agracer Post Number: 230 Registered: 2-2003 |
Maybe you should buy a Daytona. Only then will you have a real Ferrari! | ||
| Frank Parker (Parkerfe)
Advanced Member Username: Parkerfe Post Number: 2553 Registered: 9-2001 |
JRV, he is pretty close. It seems like 90c to 100c is the range most everyone and every publication agrees on. Mr. Fritz says in his experience the temp will normally run around 95c most of the time. If you run it hard or get caught in stop and go traffic it will cycle up to 100c or a little more and then go back down to 95c and cycle back up to 100c and so on. I know I have gotten a little paranoid on this issue, but with such great potential consequences, I just wanted to make sure I left no question unasked. | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 1757 Registered: 11-2002 |
Well Frank, how does what Fritz says compare to the numbers from your other 6-12 sources and the 4-5 different manuals and books you were quoting? TIA btw: might not be a bad idea at this point to double check all the info gathered so far against whatever might be found in the Library of Congress...just to insure we get all the sources we can covered. | ||
| Frank Parker (Parkerfe)
Advanced Member Username: Parkerfe Post Number: 2552 Registered: 9-2001 |
For what its worth I just got off the phone with •••• Fritz of Amerispec. He was returning my car from a few weeks back regarding my question about the proper water and oil temp of my Boxer. For those of you who don't know, Mr Fritz is "Mr Boxer" and is responsible for not only bringing the first Boxers into the USA, but for ghost writing the DOT/EPA compliance specifications to have them converted for use in the USA. He says a Boxer's water temp should normally cycle between 95c and 100c with the a/c on and the oil temp should remain pretty constant between 100c to 110c. While my water temp seems to now be running between 90c to 95c, I just thought I would post his opinion for everyone's information. | ||
| Mitch Alsup (Mitch_alsup)
Member Username: Mitch_alsup Post Number: 775 Registered: 4-2002 |
OK, I found the relevent paragraph in Tune to Win 1978 edition Carrol Smith page 99 second paragrpah. Both sides are a little right and a little confused. "For a given heat exchanger, the rate of heat dissipation varies directly with the mean temperature difference between the cooling surface and the air stream, approximately with the 0.6 power of the airstream velocity and the 0.8 power of the air volume through the core. Both thermal efficiency and internal drag are reduced by slowing down the air velocity through the core. This means that we need high energy (i.e. laminar and high velocity) air into a duct and that we want to slow the air down before it gets to the core. In order to provide an extractor effect and to ensure that the exiting air is traveling at or near freestream velocity when it rejoins the freestream, we also want to accelerate the air after it has passed throught the cooler and before it rejoins the freestream. To achive this we need a duct." | ||
| Drew Altemara (Drewa)
Junior Member Username: Drewa Post Number: 163 Registered: 2-2002 |
James and Frank, I just had a good debate with the refinery guys about heat transfer characteristics of exchangers and their applicability to automobile radiators. Actually I run the marketing side; remember when I said I'm a long ways away from this; I wasn't kidding. Anyhow, the general concesus of the "take home" is that the higher the rate the better the cooling but only within a certain range. So yes James in general, with a lot of caveats, you got it. Frank the heat capacity of water is 1 BTU/#/Deg F. The heat capacity of ethylene glocol looks to be about 0.7BTU/#/Deg F. So water is the better cooling medium. Lawrence did I get this right? | ||
| Frank Parker (Parkerfe)
Advanced Member Username: Parkerfe Post Number: 2538 Registered: 9-2001 |
To all you scientist out there, is it true that an engine will run cooler with a ratio of more water than coolant ? I have heard from others that a 25% coolant and 75% distilled water ratio will cool much better than the traditional 50/50 ratio. | ||
| Drew Altemara (Drewa)
Junior Member Username: Drewa Post Number: 162 Registered: 2-2002 |
Lawerence you bring back old memories especially with the Navier-Stokes equation. Drew PS: Yes you're right. We did do it with pencil and paper in my days. | ||
| James Selevan (Jselevan)
Member Username: Jselevan Post Number: 603 Registered: 6-2002 |
Lawrence and Drew - for the benefit of others following this thread, is the take home lesson as I suggested, that to maximize cooling, one wants water and air to flow through and past a radiator as quickly as possible (for a given volume of flow)? Thanks. Jim S. | ||
| Lawrence Coppari (Lawrence)
Member Username: Lawrence Post Number: 670 Registered: 4-2002 |
Drew, the profile flattens (starts to look like a plug) when you go from laminar flow to turbulent flow in a pipe. The laminar solution gives the parabolic profile you mentioned. It is the simplest solution of the Navier-Stokes equation for fully developed (acceleration non-linear terms drop out)laminar flow and was pretty much the only solution one could do with paper and pencil in the old days. Now, we actually have software that solves the full blown NS equations in 3 dimensions, including shear dependent viscosity. Programs run for weeks on relatively powerful work stations. My speciality is diffusion of heat in solids - figuring out what the temperature inside something is and worrying about thermal stress or how to get things hotter or cooler either uniformly or not. | ||
| James Selevan (Jselevan)
Member Username: Jselevan Post Number: 602 Registered: 6-2002 |
James G. - One explanation for different exhausts for different tracks is the anticipated load and RPM specific for that track - analogous to selecting gear ratios for various tracks. As far as "back pressure" and the Duesenberg, as you force me to think (both a good thing and a bad thing), I come up with the engineering concept of a "standing wave" in each exhaust manifold pipe. Not unlike a "pipe organ", the length of each pipe results in a different frequency emitted. By adjusting the length, one creates a different tuned frequency. Constrictors would act to shorten the pipe by increase flow-rate at the constriction - effectively decreasing transit time through the pipe (as thus, seemingly shorter). This is fun stuff. Jim S. | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1729 Registered: 10-2002 |
James I agree but they seem to use different exhausts on different tracks. Some had crossover and some didn't. I have also been told that back pressure makes more low end and mid range torque. There is a adjustable lever in the cockpit of my Duesenberg that adds backpressure and for use "When climbing hills" | ||
| James Selevan (Jselevan)
Member Username: Jselevan Post Number: 601 Registered: 6-2002 |
James G. - I always thought that "tuning" of exhaust manifolds had to do with timing of the low and high pressure pulses exiting each cylinder. Ideally, one would like a high pressure "bolus" of exhaust gases to pass a junction just as the next high pressure bolus arrives at the junction, to "pull" (low pressure) gases out of the next cylinder. Most speak of "back pressure" which seems counter-productive. It's a timing thing, me think. Jim S. | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1725 Registered: 10-2002 |
While we're on this why does restricting the exhaust flow make more low and mid range torque? Note difference in P4 headers. One set used on short courses has extra crossover loop. LeMans long course headers don't. | ||
| Drew Altemara (Drewa)
Junior Member Username: Drewa Post Number: 161 Registered: 2-2002 |
Well Lawrence maybe its been too long. But I can remember studying plug and parabolic flow in fluids class. Maybe I got it mixed up. | ||
| Lawrence Coppari (Lawrence)
Member Username: Lawrence Post Number: 669 Registered: 4-2002 |
JRV, some engines will overheat without restriction due to the thermostat because the coolant can possibly bypass where it is supposed to be going. I have engine manuals for my Mercedes vehicles. The manual clearly says that under no circumstances should the system be assembled without a thermostat because the water will bypass the block if you do that. It'll go from the pump to radiator to pump with very little making the trip to the block. The constricting of passageways may be used to reduce horsepower losses due to excessive pumping of the fluid around. If you deadhead a pump meaning not allow it to pump a fluid, it uses less power than if you let it pump as usual. Place an ammeter on your vacuum cleaner. Run it and note the current draw. Then plug the end. Motor speeds up and amperage draw decreases. The water pump must run at all speeds. You don't want it consuming a bunch of power at the top end if it does not need to pump that much water. So you restrict the water. I have never heard the term 'laminar plug flow'. We have two fluid dynamicists here in the office who do fluid modeling in our chemical plant. They have never heard of it either. The flow regime changes from laminar to turbulent at about a Reynolds number of 2000 - 2200. 23,000 is highly turbulent. Look in any heat transfer text. To increase heat transfer from a solid to a fluid, you increase turbulence. You do that by roughening surfaces or by increasing velocities. The mathematical correlations for film coefficients all include the Reynolds number unless the flow is laminar. | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 1733 Registered: 11-2002 |
>>The discussion concerning flow rate and cooling is of particular interest to me, as I believe there is a widely held misconception (as discussed below). << Such as? One of the main points in regards to control & flow that gets bypassed with theories of quantum mechanics is that the water is not supposed to have infinite cooling capabilities in engines, but rather be kept in a very narrow and specific range (OWKA operating range). It's apparent (to me at least) from the success's driving down the highways & byways and on race tracks everywhere that a combination of characteristics are neccesary to achieve the job of cooling to a point with flow rate being only one of several factors (the list of factors is rather long, actually) involved.. | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1722 Registered: 10-2002 |
James The P4 water tube tuning seems to be for tuning purposes as far as I can see and both Wallace and Alberto remember that was the purpose. It also, as we talked about before, uses the fuel as a heat sink as does the TR. These nuances are way cool. These systems work and really don't like to be modified. I tried to put a thermostat in my MK-IV but could never get it to work as well as cardboard in the radiator. Best Jim Matt No it's not a clearance issue. In addition some of the tubes have internal restrictor washers welded in. The water line is also embedded in the fuel transfer pipe to transfer heat to the fuel as the ac lines flo through the fuel in the TR. Best | ||
| "The Don" (The_don)
Senior Member Username: The_don Post Number: 5346 Registered: 8-2002 |
Jim, Could the narrowing of the tube be more of a form of the frame rather then a function of the flow? M | ||
| James Selevan (Jselevan)
Member Username: Jselevan Post Number: 600 Registered: 6-2002 |
James - you raise some very interesting issues. The discussion concerning flow rate and cooling is of particular interest to me, as I believe there is a widely held misconception (as discussed below). However, your observation that the chassis may have been "tuned" to flow characteristics raises the issue of whether this was related to structural strength rather than tube diameter/flow. Again, a mechanical engineer is necessary, but as I recall, a diminishing radius tube will provide strength beyond a continuous radius tube because of the angle of the "beam" of each element of the side. Difficult to explain, but it can be illustrated on paper. The point of my digression is that, perhaps, the change in tube diameter had to do with things such as physical clearance, strength, weight, etc., and not an attempt to slow flow. In fact, by narrowing the tube, one would increase the rate of flow, assuming a constant flow pump (such as a water pump) due to the simple mass-flow equation. As an editorial aside, this is why I like this board. The intellectual capital available equals, at a minimum, the financial capital of the participants. Thanks. Jim S. | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1719 Registered: 10-2002 |
Drew What started me down this road was the restoration of the water tubes in my P4. I was also interested in forensic examination of the chasssis welds to determine when they were originally made. In the P4 the water and oil flow through the chassis tubes and I noticed these tubes were often "tuned" sometimes tapered down to reduce flow at certian points. Best Jim  | ||
| Frank Parker (Parkerfe)
Advanced Member Username: Parkerfe Post Number: 2531 Registered: 9-2001 |
I went to FOA to check on my car yesterday afternoon. While it is ready, I will wait until Friday to pick it up to give this bad weather a little more time to clear up. After it passed the pressure test they ran a carbon monoxide/dioxide test to see if there were any combustion contaminants in the cooling system. It passed with a reading of 0.2 . Passing is a reading of 10.0 or below per the test machine. I plan to drive it to the Swap Meet at TRutlands on Saturday. Thanks for all the info. | ||
| Drew Altemara (Drewa)
Junior Member Username: Drewa Post Number: 160 Registered: 2-2002 |
James, its been way too long but I think you're right. It does say that within a given flow range the more coolant you pass through the radiator the cooler the engine will run. Nice discussion. Regards, Drew | ||
| P. Thomas (Ferrari_fanatic)
Member Username: Ferrari_fanatic Post Number: 425 Registered: 4-2003 |
As the radiator becomes plugged up over time, the resistance increases. Perhaps by removing the restrictors the flow rate becomes closer to original engineering specs. The removal of the restrictor may just be compensating for a plugged radiator. One could always feel various parts of the raditor to see if there are hot spots. | ||
| Hans E. Hansen (4re_gt4)
Intermediate Member Username: 4re_gt4 Post Number: 1511 Registered: 4-2002 |
Just as a side note: My uncle created a homemade solar heater for his pool, consisting of black hose coiled up on the roof. When water flow was great, it had little effect on pool temp. Restricting the flow heated the pool considerably - so much so that it was too hot! He had to carefully modulate the restriction to keep the pool in a usable temp range. | ||
| James Selevan (Jselevan)
Member Username: Jselevan Post Number: 598 Registered: 6-2002 |
Drew - thank you for the equation. Addressing the issue of laminar versus non-laminar flow, my recollection is that once the Reynolds number is exceeded, and turbulent flow is expected, the force necessary to move the fluid is increased. However, given sufficient force (constant flow irrespective of force), then the heat transfer should follow your equation. Correct me if I am mistaken. Thank you. Jim S. | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1703 Registered: 10-2002 |
Drew That is perhaps why the systems are restricted to slow the flo to the pre turbulant point. There are defineately desinged in restrictions the question is why? | ||
| Drew Altemara (Drewa)
Junior Member Username: Drewa Post Number: 159 Registered: 2-2002 |
Q=m(dot)X C(sub p)X Delta T (ln mean) Rate of heat transfer equals the rate of mass transfer X heat capacity of the fluid X difference in temperatures. So rate of heat transfer is proportional to the rate of mass transfer which in this case is the amount of water moving through the radiator. The Reynolds number, which is dimensionless, only server to validate whether you have laminar or turbulent flow. If below 23,000, as in this case, you have laminar plug flow and can apply the above equation. So the faster the water flow the greater the rate of cooling so long as you don't go into the turbulent flow mode where another set of equations apply and cooling is less efficient. I'm a chemical engineer but have been non-practicing a long time but I believe the above is correct. | ||
| James Selevan (Jselevan)
Member Username: Jselevan Post Number: 597 Registered: 6-2002 |
Laminar flow, and its predictive Reynolds number, merely address the force required to move a fluid past a point. When laminar, the force required is less than when turbulent. If one wishes to cool something through convection, then the more air or fluid that passes in a given time, the better. It is a difficult, and perhaps counter-intuitive argument, but it can be explained in the following way. The slower the mass of water or air, the higher the temperature the air or water will achieve. It takes longer to raise the temperature 10 degrees, for example, than 5 degrees. Thus, the total energy, in the form of heat, removed per unit of time is less. High rates of airflow might result in the air rising 1 degree, for example, but as this takes a much shorter time, more BTUs are removed. Again, the Reynolds number and laminar flow issue speak only to the force to move the fluid past a point. In a vehicle moving down the road, one has a "constant pressure" system, that is, the car's speed is not influenced by whether turbulent or laminar flow exists at the radiator. This I remember from Fluid Dynamics and Thermodynamics. A mechanical engineer is needed here as an arbitrator. Jim S. | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1694 Registered: 10-2002 |
Lawrence I'm sure you're right but then why would they put in these restrictions right before the rad? These retrictions are in all of my race cars and seem to be the traps Matt mentioned as being in the boxer as well. | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 1716 Registered: 11-2002 |
>>In general, I don't buy the argument about slowing the flow down to get more heat transfer<< Engine designers "buy it" and install a flow speed resrictive device right on the engines, they call it a thermostat. And if you look carefully at one, it's readily noticeable they don't allow uninterupted flow when open. | ||
| Lawrence Coppari (Lawrence)
Member Username: Lawrence Post Number: 664 Registered: 4-2002 |
A laminar flow regime implies that heat transfer relies on diffusion across the laminar region. Diffusion is most inefficient mode of heat transfer. Every correlation I have ever seen or used involves the Reynolds number. The bigger the Reynolds number, the bigger the film coefficient which is what we are talking about. The film coefficient is a computed parameter that is indicative of how readily a solid either absorbs or passes its heat to a fluid moving by. The Reynolds number is the product of the density of the fluid, its velocity, and a dimensional measurement of the flow. The product is then divided by the absolute viscosity. The Reynolds number is a dimensionless parameter that reveals degree of turbulence. The film coefficient is then computed from this and other parameters that include the specific heat of the fluid and its thermal conductivity. In general, I don't buy the argument about slowing the flow down to get more heat transfer. I suppose some weird experiment could ge ginned up where you might get better heat transfer by slowing flows down (perhaps due to flow separation effectively reducing area), but in general, higher velocities mean higher heat transfer. | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 1714 Registered: 11-2002 |
I'm with Mr. G and Mitch on this and the Late Great Carroll Smith of course. The air & water flow rates are carefully designed for maximun heat transfer in the time alotted.. | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1692 Registered: 10-2002 |
Mitch What do you think about the internal traps/restrictors? | ||
| Frank Parker (Parkerfe)
Advanced Member Username: Parkerfe Post Number: 2517 Registered: 9-2001 |
So Mitch, the water and/or air flow has to be "just right", not to fast not to slow in order to extract the maximun heat from the engine ? | ||
| Mitch Alsup (Mitch_alsup)
Member Username: Mitch_alsup Post Number: 769 Registered: 4-2002 |
"Therefore, your suggestion implies that one should slow down the airflow to maximize heat transfer! Of course, we all know that this is folly." Actually, slowing the airflow IS part of a well designed heat exchange system. Air that flow too fast passes through the radiator without picking up as much heat as air that flow at the correct rate. See "Engineer to Win" and "Tune to win" Carroll Smith (may he rest in peace). Air that flow too fast has a turbulent boundary layer that encompases the entire distance between one radiator and the next. Slower airflow has a laminar boundary layer and this results in more heat transfer capability. | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1691 Registered: 10-2002 |
James Wouldn't more air flo and slower water flo remove more heat in the rad? If not why are there these traps? These traps/ restrictions are throughout the P4's cooling system. what is their purpose? | ||
| James Selevan (Jselevan)
Member Username: Jselevan Post Number: 596 Registered: 6-2002 |
James G. - it seems logical that slowing the flow would increase the heat carried away, but this is not correct. The faster the water flows through the radiator (volume per minute), the more heat removed from the system. There is a complicated explanation, but the simplest way to look at it is to become "relativistic". By this I offer that heat transfer from a radiator is dependent on the water flowing through it, and the air flowing across vanes. It is the instantaneous heating of air molecules (loss of heat from water molecules) that accomplishes the goal. Therefore, your suggestion implies that one should slow down the airflow to maximize heat transfer! Of course, we all know that this is folly. Hope I do not cause a cascade of religious ridicule. Jim S. | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1688 Registered: 10-2002 |
Matt I'm not sure I'd remove the traps. The traps tune the water flo slowing it down as it flows through the rad allowing more heat transfer. My P4,Lola, and MK-IV all do this. This is the problem I have with water wetters as well sometimes they get the flo going too fast and effect rad heat transfer as well. Others? Best | ||
| Frank Parker (Parkerfe)
Advanced Member Username: Parkerfe Post Number: 2509 Registered: 9-2001 |
James, 90c water temp amd 100c oil temp is what mine runs when I'm just cruising. It's when I am in heavy traffic or running hard through the gears that the temps will get up to 95c water and 105-110c oil. In any event, the car held pressure all night so all seems to be well. I will pick the car up from FOA as soon as this flooding rain stops. | ||
| "The Don" (The_don)
Senior Member Username: The_don Post Number: 5278 Registered: 8-2002 |
Jim, do you hear an echo? M  | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1687 Registered: 10-2002 |
I think Doug's readings and JRV's range is correct. | ||
| Doug meredith (Dougm)
Member Username: Dougm Post Number: 326 Registered: 2-2001 |
Frank I just got back from a 220 mile jaunt in my Boxer running between 3800-6000 rpm and full AC. Today was also very hot and humid. Oil never went above 100c and water never went above 90c. The only time it touched either was a 5 minute stretch where I kept the car between 4500-6000 rpm. | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 1709 Registered: 11-2002 |
Frank, Oil Temp should run in the 180F-210F (100c-110c) range...220F is acceptable when running hard for awhile. As long as the water temp is under control running at 195F (90c-95c) the oil temp should be a non-issue on the street imo. Correctly working Boxers have never had temp issues on the street, no matter the driving style or traffic conditions. Both gauge needles should stay right in the center and maybe a tick over center on the hottest days or worst traffic conditions. That's always been the easy way to know if all was A-OK or needed attention. | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2499 Registered: 9-2001 |
JRV, what do you view as the proper oil temp in the summer ? On the highway with the a/c off mine runs about 90c or so. On the highway with the a/c on mine will run 100c or so. If I run it hard or in stop and go traffic it will get up to 110c or so. As I posted earlier, while that is still way below the OM's stated oil temp max of 135c, I want to be sure based on what other posts indicate. | ||
| "The Don" (The_don)
Senior Member Username: The_don Post Number: 5239 Registered: 8-2002 |
Frank, My understanding is that there are traps on the inlet and outlet of the radiator. By removing them, it allows the coolant less resistance to flow allowing the waterpump to work better and allows the circulation of the coolant at a higher flow rate. It work in conjunction with a lower set thermo that opens sooner and a new sending unit that is calibrated to match the rad so the fans come on sooner. | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2493 Registered: 9-2001 |
Thanks JRV. TheDon, what are "traps", how does their removal help cooling and how are they removed . | ||
| "The Don" (The_don)
Senior Member Username: The_don Post Number: 5238 Registered: 8-2002 |
Frank, Could you also have a bad thermo or temp sending unit? My boxer did. They replaced both with a lower temp setting and removed the traps in the rad to allow it to run cooler. Matt | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 1708 Registered: 11-2002 |
Frank, it's unlikely the 12 oz of watter wetter had any effect on the engine one way or the other. you'll know the story when the car is back in service, if it runs at 195F-200F (90c-95c)everything is fine, if it runs over those #'s more indepth investigation will be warranted. Those are the bench mark numbers I use here in Texas, which is every bit as hot as Atlanta. | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2492 Registered: 9-2001 |
JRV, I did add a 12 oz bottle of Waterwetter the night before the water hose burst. Could that 12 oz extra volume in the system cause overpressure and bust a water hose ? | ||
| djmonk (Davem)
Member Username: Davem Post Number: 304 Registered: 1-2002 |
Regarding the accuracy of F-manuals an running temps. One can look at the conflicting schedules presented for timing belts changes as another example of contradictory info. | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 1707 Registered: 11-2002 |
>> indeed, my Boxer had a puffed expansion tank. So I know it happens. <, and it takes more than 1 Bar to puff up a metal tank..a lot more..my guess is a hydraulic hammer of somewhere around 40-50 psi | ||
| James Selevan (Jselevan)
Member Username: Jselevan Post Number: 593 Registered: 6-2002 |
James and JRV - indeed, my Boxer had a puffed expansion tank. So I know it happens. My question (for which I obviously do not have an answer) is "How?". Your suggestion, James G., that the volume of fluid pushed out of the overflow tube exceeds its ability to exit without "back pressure" that is additive to system pressure makes sense. This presupposes that the air sitting above the fluid level in the expansion tank has already escaped, and fluid cannot get out of its own way. As likely a stream of causality as one can imagine. Thank you. Jim S. | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 1705 Registered: 11-2002 |
>>I doubt JVR would have come up with a puffed out overflo tank unless he's seen one.<< More than one. Believe me, they can build more than the cap can handle. | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1674 Registered: 10-2002 |
James I think you may be wrong. If the drain tube is too small relative to a huge amount of imcompressable fluid that's trying to get out being driven by a plug of compressed steam being futher compressed by the engine through a failed head gasket I think you can generate more psi than the relief valve opening to a small exit tube which snakes around and can cause more back pressure. I doubt JVR would have come up with a puffed out overflo tank unless he's seen one. Another possibility is the tank as it gets older and corroded out can't take 15PSI. | ||
| James Selevan (Jselevan)
Member Username: Jselevan Post Number: 592 Registered: 6-2002 |
James G. - from an engineering perspective, if the cap is rated at 1 Bar (14.7 psi) or thereabouts, then the coolant system should never exceed that pressure. This is true even if a head gasket goes south. In fact, that is why they put a release valve on the system, so one does not blow hoses, clamps, expansion tanks, and radiators. (I try not to ask questions that I don't know the answer to). Jim S. | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1672 Registered: 10-2002 |
Frank I had a hose like that go on my TR once. WWOC repalced the hose, washed off the engine and all seemed to be fine. Hopefully your car will be too but I'd keep an eye on it. Watch the temp gagues for ANY sign of overheating. | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2490 Registered: 9-2001 |
TheDon, when I looked at the engine it didn't look like the t-belts got wet. It didn't leak out all the coolant and what it did leak out was dumped on top of the engine well forward of the t-belts. On the Boxer the t-belts have a metal cover that covers the top and sides pretty good although the back side of the cover is open for t-belt inspection. Per FOA a little coolant on the belts wouldn't cause a problem. They do get wet with soap and water when you wash the engine anyway. | ||
| "The Don" (The_don)
Senior Member Username: The_don Post Number: 5229 Registered: 8-2002 |
What did they say about hot, steamy coolant on the t-belts? | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2489 Registered: 9-2001 |
JRV, I just got off the phone with FOA. They said it was the water hose that ran through the firewall at the top of the engine that split for some unknown reason. They have already replaced it and all appears well. It passed a pressure test. I hope that means there is no head gasket leaking as that would cause it to fall a pressure test wouldn't it ? When I get the car back what symptom should I look for if I have a head gasket problem ? | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 1703 Registered: 11-2002 |
Frank, isn't the car in the shop now? what is their conclusion? | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2484 Registered: 9-2001 |
Question: if my engine had a head gasket leaking which over pressured the cooling system and burst the hose, wouldn't the water temp have went up before the hose burst ? Because in my case I saw steam coming from the engine compartment well before the temp gauge budged off 90c. So the hose must have already busted for steam to come out. It wasn't until I exited the highway and slowed down did the water temp start climbing all the while steam pouring out of the engine compartment. It was such a sad sight that I almost cried. | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1666 Registered: 10-2002 |
James That is a good question. JRV? Perhaps even though the cap vents it can't release enough PSI from a massive overheating/compressing the coolant from a head gasket failure fast enough. | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2483 Registered: 9-2001 |
P.Thomas, I agree that bad translations can be a problem in some areas. But, in this case all temps are listed in the OM in celsius and the gauges are in celsius so there should be no translation problems with that. And, the temps my car has been running have always been in the center part of the gauges or mayby the needles width to the right of center. In any event you guys are scaring me. I just spent over $5k for a major service and another $5k for a new clutch and some cosmetic/interior/paint work. The last thing I need/want is another big bill ! | ||
| P. Thomas (Ferrari_fanatic)
Member Username: Ferrari_fanatic Post Number: 417 Registered: 4-2003 |
Not to be funny, but if you gave them (Dealer/Mecahnics) the #s in C. versus F., it may not have occured to them how high the numbers really were. It is the old: "I did 145 KM on the way to work today." | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2482 Registered: 9-2001 |
TheDon, not being able to rely on your OM is a little scarey. And, it makes me a little mad too as I was told by my dealer and several independant Ferrari mechanics that those temps were fine when I called them last week before the busted hose problem. | ||
| James Selevan (Jselevan)
Member Username: Jselevan Post Number: 591 Registered: 6-2002 |
Just curious - why would the expansion tank "puff" out if the 15 psi release cap is working? Jim S. | ||
| P. Thomas (Ferrari_fanatic)
Member Username: Ferrari_fanatic Post Number: 415 Registered: 4-2003 |
It has been a long time problem with many of the European cars. Information gets lost or misconstrued due to language barriers and semantics. Anyone ever try to figure out the heater or a/c controls on any early P-car, or BMW???? | ||
| "The Don" (The_don)
Senior Member Username: The_don Post Number: 5228 Registered: 8-2002 |
Frank, The problem with Ferrari, historically, is there lack of correct information. To compound the issue, each car acts differently then the one built before it and the one after it. Hence, the OM is really a baseline reading for the car. It's a good place to start but I have never placed more faith it then what its weight is in paper. I have and always will follow good sound mech's advice before I would crack the OM to check myself. M | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2480 Registered: 9-2001 |
TheDon, I never "dismissed" you for what you posted. I only said that the water and oil temps on my car were within the min/max ranges as indicated in my owner's manual, service manual and on www.owners.ferrari.com. They were right up until the hose burst. I suppose that info could be wrong, I don't know? But, if an owner cannot rely on info in his owner's and service manuals, where is he to look for such info ? After all, isn't that where we all find out things like how much and what weight oil to put in our engines, what oil filter to use, how much coolant the system holds and so forth. | ||
| "The Don" (The_don)
Senior Member Username: The_don Post Number: 5227 Registered: 8-2002 |
Frank, Remember that the engine temp is 20 to 30 degree's higher then the indicated temp on the gauge. | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2479 Registered: 9-2001 |
James, the temp rose to 120c while I drove the approx. 1 mile to a safe stopping point. It was not that high for the entire mile. It was only at 90c or so when I started that way but rose rapidly to the 120c mark before I could shut her down. And yes, 135c max oil and 115c max water is too high to operate the car at. The manual indicates that if it reaches either of those temps to shut her off and carry her to a Ferrari Service Center. That's why they are the "max" temps in the range. I hope there is no head gasket or warped head damage. If so, and it can be traced back to FOA and the busted hose clamp I will require them to pay for the repairs. | ||
| "The Don" (The_don)
Senior Member Username: The_don Post Number: 5225 Registered: 8-2002 |
I called the temps has two high and was dismissed for it. Still think FoD was wrong? | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1665 Registered: 10-2002 |
Frank The figures you cite from your manual 135c max oil = 275F 115c max water = 239F remain IMHO too high. I also think that as your w gauge top # is 120 and you drove with it pegged for a mile (the temp may have been higher) you may have blown the head gasket and warped the heads. JRV's advice is good. Check the overflo tank. If its puffed out I'd worry. I also agree that the head gasket should be checked and if it's blown, the heads should be checked for warpage. I also agree with him on the proper operating temp for these cars. The suggustion about the crushable alum water tubes is interesting. I'd check that out as well. I still think bleeding is very important. | ||
| P. Thomas (Ferrari_fanatic)
Member Username: Ferrari_fanatic Post Number: 414 Registered: 4-2003 |
90 degrees c. = 194 degrees f. (90 times 9, divided by 5, plus 32.) At 194 degrees you should not be steaming over. If however, (as alluded to earlier,) you are leaking compression into your cooling system, you would definitely pop the cap or a hose. | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2478 Registered: 9-2001 |
JRV, thanks I will look at the cooling tank for budging later today. But, wouldn't there be some other symptoms of a blown head gasket ? I've had them on other cars and always noticed either the power was down, oil in the coolant, coolant in the oil or extra noise in the engine compartment. In this case none of that happened. The car was running great and then all of a sudden steam started coming from the engine compartment. P.Thomas, the 266f figure came from James not me. What I have posted was that my owner's manual indicates that the min/max range for water temp is 85c to 115c. 120c is the maximum number on the water temp gauge itself. The manual list the min/max range for the oil temp at 95c to 135c. 140c is the maximun number on the oil temp gauge itself. Prior to the water hose busting my water temp was running 90c. It rapidly went up to 120c in the less than one mile I drove to the Chevron station where I shut her down. | ||
| P. Thomas (Ferrari_fanatic)
Member Username: Ferrari_fanatic Post Number: 413 Registered: 4-2003 |
Frank, it was not until the impelmentation of all of the emission control devices that cars started running these exorbitant water temps. Prior to the emission controlled vehicles, cars ran in the 185 to 195 degree range. My point is that, is the 266 degree figure correct?? Without any additives, your boiling point is 9 degress lower (257 vs. 266) than your running temp. Never the less, regardless of your combination, you are at, or above the boiling point of your cooling system. You do not want boiling water trying to dissipate heat from your engine, correct? | ||
| Sean F (Agracer)
Junior Member Username: Agracer Post Number: 207 Registered: 2-2003 |
Actually, at 30psi (14.7psia + 15psig cap = 30psi) your water boiling point is closer to 250�F, which is right at the 120C limit (248�F). All that other stuff is not really going to raise your boiling point that much. Also, where is the water temp measured? I'm not familiar with the BB. Is it at the outlet of the engine (where it would be the hottest) or the outlet of the radiator, (where it would be coolest). | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 1702 Registered: 11-2002 |
Frank, Water Temp should NEVER be above 195F-200F, even on the hottest days. Boxers have HUGE Radiators & 3 Fans for a reason. Any WSM or owners handbook claiming Temps over 200F are OK should be thrown in the circular file where they belong. There will be no liquid mixing with Ferraris when Head Gaskits Blow. You must be thinking of other types of engines, as it does not occur in Ferrari engines under 99% of the circumstances. What does happen is Compression is pumped into the cooling system by the cylinders at the blown spot/s aireating the coolant which prevents the ability to absorb the heat and fills the radiator with air dropping the coolant level thus preventing adequate heat disapation. The conditions you're describing are very common on Ferrari engines that have been overheated once to often...that result in Blown Head Gaskits which could well be caused by Warped Heads like Mr. G. mentions. I'm not claiming to know for sure that this is your issue here, but it certianly sounds likely imo. What I suspect blew the hose is pressure from compression being pumped into the cooling system. See if your Coolant Tank looks bulged/pregnant, if it is then there is no doubt about what's going on. | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2477 Registered: 9-2001 |
P.Thomas, so with a 15lb cap and a 50/50 coolant/water ratio and Waterwetter added my coolant's boiling point should be well over the 120c my temp gauge indicated. But, what does that mean ? | ||
| David Feinberg (Fastradio2)
Junior Member Username: Fastradio2 Post Number: 222 Registered: 4-2002 |
Frank, As one BB owner to another...This is typical. I went through an extended period of blown (new) waer hoses on my 365BB. Water temperture was never an issue...The two most common reasons for blown hoses were 1) NOS Ferrari hoses...and the difficulty in getting some of the clamps tight (without crushing the thin-wall alu water tubes). To alleviate these problems, I have replaced all the aluminum tubes with updated ones from Ferrari (now reinforced where the nipples/clamps are...and replaced all the hoses with Gates green stripe. I recently (again) changed all the Green stripe hose after 10 years of use, just to be safe. No coolant leaks...even after all those years! BTW, with the coolant passages external on the BB, there are even more places for hoses to leak, split or blow off.... FYI...Green stripe runs about $30-45 for a three foot length...Throw in $5 for the special hose cutter...and your done, forever, with the coolant hose issues. Trust me on this one.... Best Regards, David | ||
| P. Thomas (Ferrari_fanatic)
Member Username: Ferrari_fanatic Post Number: 412 Registered: 4-2003 |
266 degrees?? 1 PSI of coolant system pressure raises the boling point of H2O by appx. 3 degrees. 3 degrees, times 15 Lb. system = 45 degree increase in boiling temp of H2O. 212 degrees plus 45 (from closed pressurized cooling system) equals 257 degree bliling point. Additives may raise the boiling point by X %, but 257 would be your boiling point of straight H2O with a 15 lb cap.. | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2476 Registered: 9-2001 |
James, maybe you're correct but what else can an owner go by ? The owner's manual, service manual and info on the www.owners.Ferarri.com all give the same min/max range numbers. | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1663 Registered: 10-2002 |
JRV If it got hot enough it may have warped the heads as well. What do you think about bleeding midengine cars? Frank 120c=248F 130c=266F I still think the upper limit in your owners manual is too high. (266F) | ||
| P. Thomas (Ferrari_fanatic)
Member Username: Ferrari_fanatic Post Number: 411 Registered: 4-2003 |
An infrared sniffer (ie, smog machine in manual mode) can be put up to the coolant tank to see if there are any hydrocarbons in the coolant (that enetered via the head gasket. | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2474 Registered: 9-2001 |
JRV, could a headgasket cause that problem ? The coolant doesn't look like it has any oil in it and the oil looks coolant free as well. And how would one tell if a headgasket problem was caused by the "shakedown" run or happened since I have been driving the car ? And, would it just now show up after I had driven the car over 1k miles with no problems. Any information or suggestions will be most appreciated . Matt, I never said nothing was wrong before, I only indicated that the oil and water temps were within the min/max ranges as given it the owner's manual which is true even up until the water hose burst . | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 1701 Registered: 11-2002 |
Wonder if it overheated on the shakedown run fiasco and caused a lingering Head Gaskit problem? It's still warranteed right? Nothing to worry about then. Snatch the engine real quick, yank the heads, stuff new head gaskits on, slam the motor home and off to the races again for free. | ||
| matt (The_don)
Senior Member Username: The_don Post Number: 5217 Registered: 8-2002 |
Frank, I told you something was wrong. M | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2472 Registered: 9-2001 |
James, it the oil temp max that is 130c in the manual. The water temp max is 115c. My car has never gotten that hot for either. At the time of the problem the oil temp was 100c and the water temp was 90c. Those temps are both on the low end of the range. It looked to me like the hose itself was busted and the hose looks new. FOA will do a pressure test and let me know what they find. I will post it once I find out. HaHa, you are quite correct. There is a God and He is WONDERFUL. Are you a coward and afraid to state your mind in the open or are you just to stupid to complete your profile info so everyone knows who you are ? | ||
| david handa (Davehanda)
Member Username: Davehanda Post Number: 995 Registered: 5-2001 |
Frank, Sounds strange, could be a defective hose, bad install or a hose they neglected to change. When I had all the hoses changed on my 308, and my current 328, both times (different shops) the hose clamps either where not tightened enough or worked loose so that many of the hoses began weeping. I ended up returning the 308, and in the case of the 328, it was faster for me to put it on the lift and do it myself. | ||
| James Glickenhaus (Napolis)
Intermediate Member Username: Napolis Post Number: 1661 Registered: 10-2002 |
Frank I still think the upper temp range that your owners manual shows is too hot. On the highway I would want to see 180 water and 200 oil. If it runs constantly at higher temps and at the upper limit you cited from your owners manual (130W ?) I think you're going to keep blowing hoses and damage your engine. I suspect the problem is improper bleeding. Hose water has encapsulated air that takes a long time to come out. I use distilled water. If I didn't need freeze protection thats all I'd use with just a trace of coolant. Water wetters can also cause problem as they upset the designed flow rates and can move the fluid through the rad too fast to transfer max heat out of the system. Mid engined cars are very hard to bleed and even good mechanics have trouble with that sometimes. It must be done several times, often after driving a bit. If I were you I'd fit a high output alternator, a high amp battery, new modern electric fans, and an oil cooler. Dispite what the factory may say these cars will work a lot better on the street with these modifications and a properly bleed system. Having driven my MK-IV over 20,000 miles on the street this is what I've found to be true. | ||
| Haha (Haha)
New member Username: Haha Post Number: 1 Registered: 6-2003 |
HA HA THERE IS A GOD!!! | ||
| TomD (Tifosi)
Advanced Member Username: Tifosi Post Number: 3861 Registered: 9-2001 |
isn't this the second time in a matter of months the hose broke?? when you say burst, you mean in the center of the hose, not at the connection? could be NOS parts with some age | ||
| Frank Parker (Parkerfe)
Intermediate Member Username: Parkerfe Post Number: 2470 Registered: 9-2001 |
On the way home from Wolf Mountain yesterday I started noticing what appeared to be smoke coming out from behind my car. I checked the gauges and the oil presure was 6.5 bar or so, the water temp was 90c and the oil temp was 100c. So, I pulled off the expressway into a Chevron station to check it out. By the time I got into the parking lot the water temp had go up to 120c ! I turned it off immediately and called a flat bed. It turned out to be steam coming from the engine compartment. After I opened the rear hatch I noticed what appeared to be a water hose going into the top of the engine that had burst. The car has been hauled to FOA for a diagnosis and repair. All the hoses were changed by FOA a couple of months ago. What would cause a hose to burst even though the water temp is fine ? |