| Author | Message | ||
| myles kleinfelter (Gonzo350)
Junior Member Username: Gonzo350 Post Number: 54 Registered: 8-2002 |
OK....just got my gasket kit for Superperformance (great service!) does anyone know if the valves seals in that kit are good and worth using...or should I go with the 85 BMW M5 seals? | ||
| Jack Habits (Ferraristuff)
Member Username: Ferraristuff Post Number: 904 Registered: 4-2003 |
Judging by the condition of the piston in your picture, it looks like there is already deposit on the damaged areas which woul dindicate an older dame. It doesn't look like a piston that was "freshly hit". Jack | ||
| myles kleinfelter (Gonzo350)
Junior Member Username: Gonzo350 Post Number: 53 Registered: 8-2002 |
I guess I should clarify that.....I did not completely loose oil pressure. I had lower than normal readings. As to how low....my memory has faded...this is over two years ago. But i do recall it scared me into shutting the motor down. | ||
| Joe Craven (Rscapri2600)
New member Username: Rscapri2600 Post Number: 21 Registered: 7-2002 |
OK, perhaps the knocking noise you heard was the one bent intake valve. How did it get bent? What worries me more is that you reported that your motor lost oil pressure. Something caused it - I wonder what? Could it be coincidence that your pressure sender failed at this exact moment. 85 Mondial QV | ||
| myles kleinfelter (Gonzo350)
Junior Member Username: Gonzo350 Post Number: 52 Registered: 8-2002 |
Pulled the pistons out this evening and I'm very happy to report all on the bottom end looks fine. There is no vissible wear on the cylinder walls and all bearings look normal for having 81K on them. Is there anything I should be aware of before taking the block to the machine shop to be cleaned? Thanks everyone for all the help through this project! | ||
| rob guess (Beast)
Junior Member Username: Beast Post Number: 135 Registered: 5-2003 |
Myles; I know what you are feeling. At the age of 26 i was rebuilding the engine in my former bosses 308QV Have you found anything in the bottom end yet??? Rob | ||
| rob guess (Beast)
Junior Member Username: Beast Post Number: 134 Registered: 5-2003 |
Mitchell; There is the potential for a couple of problems with the method that you stated. 1. If the spring is starting to lose its tension it will continue to get weaker durring opreation. 2. If the spring is shimmed to much it can coil bind durring operation, fracturing the spring and allowing the valve to drop into the motor. The shimming process i am talking about is the shim used to adjust the valve clearance to allow for thermal expansion durring operation. the shims are avaliable in a certain size range as the seats wear , stems streach, and valve faces wear the clearances get tighter. durring the seat cutting process material is removed from the seat to clean up the surface. If to much metal is removed then you can no longer get the proper valve clearance because there is not a thin enough shim avaliable. At this point the seats have to be replaced. This very point i stress to my students. 1. Measure everything twice before it is sent to the machine shop. 2. Measure everything again twice once it comes back from the Machine shop. 3. if anything is wrong send it back now. If you put the part into service and it fails due to incorrect work at the Machine shop, It is your fault not the machine shops since you are also the quality control inspector for the rebuild. Rob | ||
| myles kleinfelter (Gonzo350)
Junior Member Username: Gonzo350 Post Number: 51 Registered: 8-2002 |
I cant believe at the age of 30 I'm rebuilding a Ferrari motor!  | ||
| Mitchell Le (Yelcab1)
Member Username: Yelcab1 Post Number: 616 Registered: 11-2001 |
Rob The machine shop I used had this spring force measuring gauge. It tells how much force was used to compress the spring to a certain range. The force / spring lengths specs are in the book. If the spring is "weak," they use one of the shims at the bottom of the spring to bring it back within range. That would take 10 minutes to check all the spings. Isn't that ... good enough? I suppose an absolute complete job would replace all the springs with new ones, but that would be an overkill. | ||
| Phil Hughes (Ferrarifixer)
New member Username: Ferrarifixer Post Number: 29 Registered: 7-2003 |
If you made your own tool for removing the nuts, be very careful when you refit the heads. it's very easy to get innacurate torque of the nuts as the tool can touch the head and feel tight before it really is, or a compound angle difference will amplify or reduce your true torque achievements from what you set the gauge to. I'd practise and test several times on a dummy stud/nut arrangement where you can compare torques achieved from direct access with a socket to your access using your tool. Very common to find under tightened QV/TR heads. Will damage if you overtighten them too.... When done properly, they don't need re-tightening. If you suspect the heads have already been removed once before, replace all the studs too. I reckon it's OK to re-use them once if you can be sure. If in doubt, change them. | ||
| Phil Hughes (Ferrarifixer)
New member Username: Ferrarifixer Post Number: 28 Registered: 7-2003 |
If you made your own tool for removing the nuts, be very careful when you refit the heads. it's very easy to get innacurate torque of the nuts as the tool can touch the head and feel tight before it really is, or a compound angle difference will amplify or reduce your true torque achievements from what you set the gauge to. I'd practise and test several times on a dummy stud/nut arrangement where you can compare torques achieved from direct access with a socket to your access using your tool. Very common to find under tightened QV/TR heads. Will damage if you overtighten them too.... When done properly, they don't need re-tightening. If you suspect the heads have already been removed once before, replace all the studs too. I reckon it's OK to re-use them once if you can be sure. If in doubt, change them. | ||
| rob guess (Beast)
Junior Member Username: Beast Post Number: 133 Registered: 5-2003 |
Mitchell; I would not count on it. For the shop to properly be able to do it they would need the head with the cams, shims, buckets Etc. Rob | ||
| Mitchell Le (Yelcab1)
Member Username: Yelcab1 Post Number: 615 Registered: 11-2001 |
Hell For a $500 valve job, I would expect the machine shop to measure the spring force and shim up everyone that is weak. This is standard practice, isn't it? | ||
| rob guess (Beast)
Junior Member Username: Beast Post Number: 131 Registered: 5-2003 |
Myles; Being that you only have one bent valve and you stated that all the pistons had impact marks on them i would be inclined to say that the marks are from a previous failure, not the one that you just had. Did the Machine shop check the shim thickness and the free length and spring rate for the valve springs???? if your shim thickness is on the low side of there size range you may not be able to set the correct valve lash clearance upon reassembly. I would go and have all of these items checked before having any of the valve seats cut. Rob | ||
| Mike Florio (Mike_in_nevada)
New member Username: Mike_in_nevada Post Number: 21 Registered: 6-2003 |
Have you determined exactly what caused the valve/piston collison? I think I would be reticient to reinstall the heads until I knew the bottom end was OK too. | ||
| myles kleinfelter (Gonzo350)
New member Username: Gonzo350 Post Number: 49 Registered: 8-2002 |
Well thats good to know...thanks for the tip on the QV head...haven't seen that before. Had to make my own wrench just like everyone else to get teh acorn nuts off....after that...heads came right off....no trouble what so ever. | ||
| Timothy Fulmer (Tf308)
New member Username: Tf308 Post Number: 42 Registered: 5-2002 |
PS...How difficult was it to get your heads off? | ||
| Timothy Fulmer (Tf308)
New member Username: Tf308 Post Number: 41 Registered: 5-2002 |
The QV heads never had sodium filled valves! It was only the two valve car...How long did you stress over this? | ||
| JohnR. (Rivee)
Member Username: Rivee Post Number: 252 Registered: 1-2002 |
This is the Fcar page. http://www.sivalves.com/ocforeign_valvessp_fer.html | ||
| Paul Hill (348paul)
Member Username: 348paul Post Number: 350 Registered: 12-2002 |
Simon, http://www.sivalves.com/contactus.html (Great day at Brands Hatch yesterday!) Paul | ||
| Simon Campbell (Simonc)
Junior Member Username: Simonc Post Number: 123 Registered: 2-2002 |
Anyone have an email address for SI Valves or a phone number please | ||
| myles kleinfelter (Gonzo350)
New member Username: Gonzo350 Post Number: 48 Registered: 8-2002 |
Good news Good news! The machine shop called and said only had ONE bent intake valve and it was only barely bent! Seats were still in good condition and the guides looked great! Also another bonus....sombody has already replaced the sodium filled valves with SS ones. Both heads will be complete with 3 angle valve job for $500! Whew! | ||
| Keith Mahan (Gyrokeith)
New member Username: Gyrokeith Post Number: 32 Registered: 4-2003 |
I've had some experience with stainless steel valves and regular steel valves in "identical" vw engines. I found that the ss valves were made thinner and flowed better, great for hp. They only tended to hold seal about half as long as the regular type. Their sealing surface receded more/faster and they eroded more quickly. Regular steel valves seem to be good for 150k plus miles in most engines. If you were only putting a on few thousand miles a year then ss is fine. I've just found then not to be reliable for high milage type engines. I'm not a metalurgist so I don't realy know why this happens.. one would assume they harden the ss valves, too... When I machine ss it seems to be more maleable but ss valves must be ground, indicating a hardening process.. | ||
| JohnR. (Rivee)
Member Username: Rivee Post Number: 251 Registered: 1-2002 |
Call SI valves. Their valves are Stainless Steel and are around $20-25/valve. Guides=$7.00 | ||
| William Henderson (Billh)
Junior Member Username: Billh Post Number: 73 Registered: 5-2002 |
just for sh*ts and giggles, how much for TR valves and guides? | ||
| Jeff Howe (Ferrari_uk)
Member Username: Ferrari_uk Post Number: 452 Registered: 12-2002 |
I said they weren't cheap! | ||
| William Henderson (Billh)
Junior Member Username: Billh Post Number: 71 Registered: 5-2002 |
you could probably get custom valves made for less than that.... sheesh. | ||
| Mitchell Le (Yelcab1)
Member Username: Yelcab1 Post Number: 607 Registered: 11-2001 |
Quote: Inlet #131198 $47.84 Exhaust #131199 $103.20 End of quote. If the prices above are the same for QV, then that is $2416.64 for valves, 10% inport duty fees, and shipping, will get you to $2700 just for valves. Plus $320 for valve guides (32 at $10 each), that will be $3000. My calculator works with a little fudging. | ||
| Tom Bakowsky (Tbakowsky)
Member Username: Tbakowsky Post Number: 491 Registered: 9-2002 |
I would check that piston with the damage very carefully. The ringland could be crushed. I would replace that piston and check all the rest. If all the rest are fine then clean them up and reuse them. You don't need to replace all the pistons. Yes replace the sodium filled exhaust valves with new valves form SIvalves. Might aswell slam new guides and seals in there as well. Inspect everything very carefully. If nesassary send the whole bunch out and have it inspected by a good machine shop. They will have more experiance finding the problem, as they deal with this type of thing everyday. | ||
| William Henderson (Billh)
Junior Member Username: Billh Post Number: 70 Registered: 5-2002 |
Ok, try this one on for size: are the valves actually bent? I haven't read anything stating such. Is it a prior owners "valve to piston" encounter? could your symptoms be related to something else? | ||
| Ken (Allyn)
Intermediate Member Username: Allyn Post Number: 1094 Registered: 10-2001 |
$3000 for valves (if true), plus labor, pistons, and everything else...hmmm if you do your own work it may make sense but if it goes to a shop you really just have a parts car. | ||
| Malcolm West (Ferrari_uk_tech)
New member Username: Ferrari_uk_tech Post Number: 2 Registered: 7-2003 |
Myles - At 81,000 miles I would replace all the valves and pistons, check the valve guides as well, I would expect you to find excessive wear there. The camshaft must have locked in order to have caused the damage as shown in your pictures, check the journals carefully. Also as the valves have hit the pistons with some force I would recommend that you check the four con-rods just in case they are bent. Good Luck | ||
| John Millard (Jmillard308)
New member Username: Jmillard308 Post Number: 43 Registered: 5-2003 |
Mitchell - we obviously have different calculators  | ||
| Mitchell Le (Yelcab1)
Member Username: Yelcab1 Post Number: 606 Registered: 11-2001 |
Jeff at Ferr UK just responded to the 328 valves... over $40 intake, over $100 exhaust. At those prices, $3000 for 32 valves, I would make sure the valves are toast before replacing them. | ||
| John Millard (Jmillard308)
New member Username: Jmillard308 Post Number: 42 Registered: 5-2003 |
My opinion - replace all valves - particularly if exhaust valves are still OE sodium. At 80K I'd do pistons too - and whatever else was needed (or looking a bit suss) while the engine is in bits | ||
| JohnR. (Rivee)
Junior Member Username: Rivee Post Number: 250 Registered: 1-2002 |
Miles, check with T Rutlands for a rebuilt short block. I bought one for $4,700.00 (short block only) with exchange for your block. Also SI Industries for valves. | ||
| JohnR. (Rivee)
Junior Member Username: Rivee Post Number: 249 Registered: 1-2002 |
wITH THE LOSS OF OIL PRESSURE IT SOUNDS TO ME LIKE YOU SPUN A ROD BEARING | ||
| Mitchell Le (Yelcab1)
Member Username: Yelcab1 Post Number: 603 Registered: 11-2001 |
No need to replace all 32 valves, but you will need the machine shop (who does your valve job) to check the valves for you. They will check to see if the valves have excessive run-out, have enough material for a grinding, and if not, they will tell you to get replacement for that valve. So, you just do not know how many to buy until they inspect them all. Ferrari valves are not cheap so I would not just go out and drop $1000 for all 32 valves unless there is a good reason to. I would not know about the pistons, but my guess is it can be repaired. Although, at 80,000 miles and 20 years old, you could conceivably change them without feeling too guilty. They are expensive though, aren't they. Maybe someone at Ferrari UK will take pity on you and offer you a big discount with the stock they have. Jeff? | ||
| myles kleinfelter (Gonzo350)
New member Username: Gonzo350 Post Number: 47 Registered: 8-2002 |
All four cams rotate freely and nothing has been sheared. Thank god the motor was shut down right away. Heads are off, however I dont have the cams out yet so I can not state what the journal surfaces look like. The motor will be torn down to the bare block and completely rebuilt. So what I am asking is....can the pistons be reused if they are filed and repaired, and do I need to replace all 32 valves or can I replace just the bent intake valves? Heads are going to the machine shop this week so I will keep everyone updated as to what I find there. Thanks for all the input! | ||
| Joe Craven (Rscapri2600)
New member Username: Rscapri2600 Post Number: 13 Registered: 7-2002 |
I think Verell's guess may have started the damage. It could have been a loose rod cap or perhaps just a rod bearing getting pounded out. the piston was allowed to move further up the bore, striking 2 valves which caused the cam locating mechanism to fail. The valves that touched the pistons are bent and will need to be replaced. The pistons might be salvageable if the damage isn't too bad. One can polish the piston to remove the sharp edges. However, I suspect that this motor suffered significant damage and the cost of new pistons will be relatively small part of the total rebuild cost. 85 Mondial QV | ||
| Henryk (Henryk)
Member Username: Henryk Post Number: 989 Registered: 8-2001 |
Rob: It seems we both agree that the problem was with the cam rotating at a different speed then the cam gear. However, he did state no oil pressure accured first....this could have helped to freeze the cam.......then the key let go......then the problem. Hence it would appear that there may be a problem with the oil pump, as the initial cause. The reason I asked where the oil sending unit was, because......if it is in the involved head, then the problem could be the cam going first, for whatever reason, and causing a no oil pressure reading. If the sending unit is elsewhere, then the problem was primarily a loss of oil pressure that caused the cam to start seizing...thus, a bad oil pump. | ||
| rob guess (Beast)
Junior Member Username: Beast Post Number: 122 Registered: 5-2003 |
Henry; I would be more inclined to think that the key that keeps the cam in alingment with the pulley had either sheared or got hammered by a loose pulley bolt than the cam siezing up. Myles; More pictures please as you get deeper into the engine. Rob | ||
| Henryk (Henryk)
Member Username: Henryk Post Number: 986 Registered: 8-2001 |
The cam actually had to be "partially" frozen, since all 4 pistons where involved. Since it happened at idle, and the engine was shut down, would explain why no further damage was done, such as the exhaust valves hitting, or the other side going. Is the oil pressure sender by the affected side of the engine? I love a Ferrari mystery!!!!!!1 | ||
| rob guess (Beast)
Junior Member Username: Beast Post Number: 121 Registered: 5-2003 |
Myles; Definatly go through the entire motor leaving no stone unturned. The worse thing you can do at this point is start replacing parts without finding the true cause of the failure, doing so will just result another failure. I would go through the entire motor and measure everything. I would have to agree with HenryK that the most probable cause would be something to do with the intake cam on the failed bank. But again do not stop searching once you found what may have been the smoking gun, The true cause may be another component that failed causing the damage to the other part. Rob | ||
| Henryk (Henryk)
Member Username: Henryk Post Number: 985 Registered: 8-2001 |
Loss of oil pressure could have "frozen" the cam in place, while the cam gear continued to turn. Again, just a shot in the dark. | ||
| Henryk (Henryk)
Member Username: Henryk Post Number: 984 Registered: 8-2001 |
Before you decide how to rebuild the motor, I would think it imperative to find the reason behind the disaster first!!!!!!!! Let's see: All 4 intake valves hit the pistons, only on one side; timing marks are dead on; knocking sound before disaster.......it appears to me that the knocking sound was that of the pistons hitting the valves, as they bent. With the timing dead on, then the cam must have broken loose off the cam gear. The cam had to be in a position to let the valves hit the pistons, therefore, with timing on, the cam had to be in a differennt position than the cam gear. The reason the exhaust valves weren't hitting the pistons, is that maybe there is a larger relief in the pistons for them. What do you think? Just my 2 cents worth!!!!!!!! | ||
| Jeremy Lawrence (F512m)
Junior Member Username: F512m Post Number: 160 Registered: 1-2002 |
At 81K miles I would do both sides while you have the engine out. Yes it will be more expensive, but, you will probably have another 80k miles, or more, before you will have to do that kind of work again. | ||
| Verell Boaen (Verell)
Intermediate Member Username: Verell Post Number: 1005 Registered: 5-2001 |
Since this is a street car, I'm not so sure the pistons have to be replaced. The pistons will certainly need some repair. I suspect that the valve dings could be welded up & then the piston re-faced for significantly less than new pistons. I'd certainly discuss it with experts tho. This is speculation as I haven't had to deal with this class of problem before(knock on wood). However, I've heard of it being done on motorcycles & 'pistons is pistons'. The real question is how did your valves come to ding the piston(s?) (If more than 1 piston, how many tapped valves? & which pistons were they? ) It takes being off more than 1 tooth to get piston-valve interference. I believe it takes being off at least 3 teeth, but haven't used the cam profile to work out the numbers. I suspect a clue to the answer lies in the loss of oil pressure. A piston tapping a valve will not affect oil pressure. My bet is on a con rod cap coming off or a con rod breaking along a bearing surface & letting the oil bleed out. | ||
| myles kleinfelter (Gonzo350)
New member Username: Gonzo350 Post Number: 46 Registered: 8-2002 |
Not much to tell....car was fine one day....knocking the next morning with a loss of oil pressure and here we are all of this happened at idle. Got the 2nd head off and there is no apparent damage...so only one side hit...and it was only the intake valves on that side. So....is it possible to get away with just replacing 4 pistons and 8 intake valves? What do you guys think? 81,000 miles. | ||
| Henryk (Henryk)
Member Username: Henryk Post Number: 983 Registered: 8-2001 |
Myles: Where you just driving along and then.....BANG? Did you run the revs up; engine cold; etc.? Could you shed some more light on what you where doing when this happened.......and what you heard, felt, at the time? This would be of interest to all. | ||
| myles kleinfelter (Gonzo350)
New member Username: Gonzo350 Post Number: 45 Registered: 8-2002 |
haven't gotten to the bottom end yet....just now getting the heads off. | ||
| Mark Collins (Markcollins)
Member Username: Markcollins Post Number: 303 Registered: 7-2002 |
Myles Has the conrod let go or the conrod bolts stretched? it's got to be that or a timing problem, maybe the belt has jumped and managed to finf it's way back into the right place, either way you need to check the bottom end. With the likely rebuild costs have you considered looking for a used replacement | ||
| Philip Airey (Pma1010)
Member Username: Pma1010 Post Number: 324 Registered: 7-2002 |
Myles Others are more qualified than me to answer this, but from what I know I think the answer to replacing pistons is "yes". As I understand it, any nick or scratch is going to the locus for any detonation effects (potentially leading to a hole in the piston). I expect there are specifications on the values, the amount they are out of round, seat conditions etc that can guide you on replacement. Given that it is an expensive job to pull it all apart, and you'll be investing in some expensive hardware already (pistons), it would seem prudent to go the extra mile and do the valves. Good luck | ||
| myles kleinfelter (Gonzo350)
New member Username: Gonzo350 Post Number: 44 Registered: 8-2002 |
well thats a bit of a curious question...obviously you'd think the timing belt jumped a tooth.....and it did have 20,000 miles on it. However all the timing marks were dead on. Your guess is as good as mine. 1984 308 qv...81,000 miles | ||
| Mr. Doody (Doody)
Intermediate Member Username: Doody Post Number: 1479 Registered: 11-2001 |
no help from me, unfortunately. but i am curious - how did this happen? doody. | ||
| myles kleinfelter (Gonzo350)
New member Username: Gonzo350 Post Number: 43 Registered: 8-2002 |
 | ||
| myles kleinfelter (Gonzo350)
New member Username: Gonzo350 Post Number: 42 Registered: 8-2002 |
try this again! | ||
| myles kleinfelter (Gonzo350)
New member Username: Gonzo350 Post Number: 41 Registered: 8-2002 |
popjpeg{289042,Upload} Well its official...the valves hit the pistons. Looking for opinions here....should I replace the pistons or are they ok with their newly found valve reliefs? If I replace them...who has had good luck with aftermarket manufacturers? What are costs....comp ratio's etc. This is a street driven car so I would want to keep comp ratios under 10.5. Should I replace the exhaust valves while I'm at it...they appear to be untouched? Just looking for thoughts here...thanks all! |