| Author | Message | ||
| Philip Airey (Pma1010)
Junior Member Username: Pma1010 Post Number: 145 Registered: 7-2002 |
John Thanks. Yes, a priced parts list with identification of appropriate suppliers would be terrific. Good luck with the project | ||
| John Moretti (Moretti)
New member Username: Moretti Post Number: 39 Registered: 11-2001 |
JRV, I thank you sir for your input and the helpful URLs John | ||
| JRV (Jrvall)
Member Username: Jrvall Post Number: 995 Registered: 11-2002 |
John M, As for the Titanium valves, Del West is the major Manu/Supplier of Titanium Valves & Valve Blanks to just about the entire racing world. The other sellers/suppliers you might find use either Del West Valves or Del West Blanks. While looking for their website for you I noticed Manley is advertising a series of TV's also, but it would'nt surprise me if Manley started with Del West blanks like all the others. For stainless there is Manley..who manufactures most of the stainless blanks, and SI Valves.... The advantage Titanium has over Steel is it's considerable wieght difference...so that lighter spring pressures can be maintained even with more radical cam lifts and still achieve 8500-9000rpms without float worries.... very high seat pressures cause more rapid valve train component wear. I'm a fan of Titanium for anyone that has the resources to budget for them..... Another thing you might want to consider for a nice build-up is internal coatings of various components to reduce friction and heat. I've used various coatings with success like those offered by Poly-Dyn. As mentioned previously longevity & durabilty as well as insurance goes in on the front end of the project during the build phase. Once a quality build is complete tuning and heat control help insure the longevity of the engine and the internal coatings can help with the heat issues. Here's a few links: http://www.cnc-west.com/articles/cncwart19990607/F1Valves/formula.htm http://www.darcyracing.com/valves.html http://www.delwestusa.com/ http://www.manleyperformance.com/ http://www.sivalves.com/company.html http://www.polydyn.com/hpec.htm http://www.swaintech.com/ http://www.hpcoatings.com/engine_coatings.htm | ||
| John Moretti (Moretti)
New member Username: Moretti Post Number: 38 Registered: 11-2001 |
Philip, I have a friend in Melbourne, Australia who is ordering all the parts for me. I will ask him for all the suppliers names and send you an email with the list and approx costs. There are several of us doing this to our cars here in Australia and we are putting in a "mass" order  (well a couple a hundred valves, several sets of gaskets, etc) to bring down the cost for shipping. | ||
| Philip Airey (Pma1010)
Junior Member Username: Pma1010 Post Number: 143 Registered: 7-2002 |
John M. Can I ask where you are getting the components. At some point I am likely to pull the top end apart and do HC pistons, valves, cams etc. A source list would be helpful, along with your subsequent assessment of whether you were happy with them. | ||
| John Moretti (Moretti)
New member Username: Moretti Post Number: 37 Registered: 11-2001 |
Thanks JRV, it was the insurance factor I was after. I think these engines are closeto bullet-proof as I regularly take my cat to the track and thrash her very hard and it handles it very well. The rods and valves were my main worry and I think the Carrillo rods sound like a good peace of mind upgrade. Any personal preference for valves ? I'm leaning towards titanium but that is because of my aircraft background. I'm already ordering the other things you mentioned as they make sense, thanks for your time John | ||
| JRV (Jrvall)
Member Username: Jrvall Post Number: 992 Registered: 11-2002 |
John M, Building up a motor doesn't neccesarily overstress it. Part of the rebuild is just replacing old parts with new & better. The additional power is being extracted to a large degree by how much more we know and can do today. The durability and longevity by and large is determined by the quality of the parts and the perfection of the build. If you are worried throw in a set of Carrillo rods...I run Carrillo rods in race engines for two reasons..the old rods are old and I want extra insurance against failure..number two..they are race rods that have been speced & treated in every way so they will not break ... I helped a friend build some 308 motors for Sheehans IMSA racing team that put out 370-380HP normally aspirated..and they lived and lasted under the most brutal circumstances. So 300-320 is well below the limits of what a 308 can take as designed, with the proper tweeking. To get the upper limits on HP you will likely need the Flow Ability of Ind. Throttle Bodies and something on the order of Tech2-3 EFI management/ignition. The Race Engines used Slide Valve Injection not really suited for the street. Besides the Factory GT4 Lemans 308, Micheletto built 2-3 308 based raced cars as well as the IMSA Racers that were done here in the states, so quite a few radical build-ups have been tried and tested and the limits defined. Regards, JRV | ||
| John Moretti (Moretti)
New member Username: Moretti Post Number: 36 Registered: 11-2001 |
Gentlemen, I thank you for the input and I was aware of the strength of the bottom end but not how much more power it could take. JRV, I like the options you listed as I was thinking along these lines but is 320 possible without overstressing the engine ? I use the car on a fairly regular basis and track the car a lot so time between rebuilds must drop significantly with the more power ?? BTW Verell, thanks for info from another thread on steering column switches, the photos helped me put my car back together better than it was in the first place | ||
| Hans E. Hansen (4re_gt4)
Member Username: 4re_gt4 Post Number: 896 Registered: 4-2002 |
Thanks Matt. I guess it all makes sense if looked at from the perspective of the 'ending' of the event, rather than the beginning. | ||
| Matt Morgan (Kermit)
Junior Member Username: Kermit Post Number: 111 Registered: 8-2001 |
Hans, Yes it does make the intake later, and the exhaust as well. On the intake side, this keeps the valve open later too, which allows it to benefit from the ram effect of the intake charge at RPM. There is only so many degrees to the cam duration, so we move the events ( opening and closing) around to suit.. With the exhaust, it allows more of the combustion pressure to start the flow out the port and down the headrer. The more agressive flow here will encourage scavenging on overlap, even though the overlap is less. Here again it's all a trade off. and Philip for lift on street cams, 10mm (.394") or 10.5mm (.413")would be my choice. 11mm (.433") would probably cause interferance with the seals. | ||
| Hans E. Hansen (4re_gt4)
Member Username: 4re_gt4 Post Number: 892 Registered: 4-2002 |
Matt: Sorry, as I'm semi cam stupid. Wouldn't opening the intake at 30deg BTDC instead of 34deg BTDC make the event 'later'? This would seem to support low rpm. Also, closing exhaust at 31deg ATDC .vs. 38deg ATDC would seem to do the same thing. It would seem that doing the intake earlier and the exhaust later would help high rpm. What am I not understanding here? I'm about to have my valves adjusted and belts replaced, and this would seem to be a perfect opportunity to have the cams 'tweaked' a little. Thanks bunches, Hans. | ||
| Matt Morgan (Kermit)
Junior Member Username: Kermit Post Number: 110 Registered: 8-2001 |
Philip, It depends a lot on what else is done to the motor. It must work in harmony. My extensive time in flowbench developement of 308 heads showed a surprising differance in stock form. The 4V flow leveled off at .350", yet the stock 2V kept climbing significantly when it hit the seal at .450". I haven't done one yet, but I'm working with some parts people to produce a guide that is shorter. I'm curious what .500" would flow. Ported, that alone changes the whole picture. Stock Carb Cams work well if Dialed In to open the intake at 30 instead of the stock 34 degrees BTDC. Move the exhaust to close at 31 ATDC instead of the stock 38. This moves the events so that the power is upper RPM. For Street and a bit of track use, ported heads, good ignition,etc. I'd go with a Split pattern cam, with the exhaust haveing more duration. Standard cams usually are the same duration on both intake and exhaust. I would recomend intake open 25 BTDC, Close 50 ABDC exhaust opening at 53 BBDC, and closing at 25 ATDC. And Thank You , I'll be around, as I learn here too! | ||
| Philip Airey (Pma1010)
Junior Member Username: Pma1010 Post Number: 131 Registered: 7-2002 |
Kermitt Good luck with the new adventure. I hope you'll stay on this forum as I think we are richer for your perspectives. In general, what would you advocate for a high performance street cam? Stock or close to stock duration with 11 mm lifts? Philip | ||
| Matt Morgan (Kermit)
Junior Member Username: Kermit Post Number: 108 Registered: 8-2001 |
Philip, As I recall it was in repsonse to a post "If you want a real Fire breathing Cam" I've loaded a chart, the old style "pie chart" (hopefully it comes thru) based on Bishop's book. With the valve events as radical as they must be for top end power, suitability for street use is IMO not practical. The late closeing of the intake works well in higher RPM, where there is a ram effect working for you, on the lower RPM, it causes reversion, or the pushing of intake, and often exhaust gasses into the intake tract. Note the early opening of the exhaust, @64 degrees, this is wonderful at high Revs as it lets part of the combustion pressure start the exhaust flow. the down side is at low revs it "gives away" that pressure, which only lowers power at street RPM ranges. On a side note, I have branched off from Nick's as a builder, some 60 days ago, and will have my own site up soon. | ||
| Philip Airey (Pma1010)
Junior Member Username: Pma1010 Post Number: 130 Registered: 7-2002 |
Peter Thanks for spec. I asked Bill Pound (who, amongst others things, helped develop the 1974 308 GT4 for Le Mans) about cams. He described the P6s as quite mild on lift and that a custom grind could add a lot more lift. I believe Kermit (of NFF) has opined on the increase in lift possible elsewhere on this forum. Philip | ||
| '75 308 GT4 (Peter)
Intermediate Member Username: Peter Post Number: 2491 Registered: 12-2000 |
P6 Comp cam (both Daytona and 308): 290° duration, 9.25mm lift (with 0.020" valve lash) From an article written by Mark L. Dees included in Allen Bishop's book "Ferrari Guide to Performance". | ||
| Philip Airey (Pma1010)
Junior Member Username: Pma1010 Post Number: 129 Registered: 7-2002 |
JRV, P6 cams were a higher lift, higher duration cam produced by Ferrari for 308s and I believe Daytonas. Primary intent, as I understand it, was as a track modification - the reputation of the P6 was that it produced a lot more power higher up the band, with a lot less lower down. Anyone have the specs? Philip | ||
| JRV (Jrvall)
Member Username: Jrvall Post Number: 950 Registered: 11-2002 |
>> I have heard of P6 cams.<< describe what the P6 cams are please. | ||
| Philip Airey (Pma1010)
Junior Member Username: Pma1010 Post Number: 127 Registered: 7-2002 |
I have never heard of P4 cams. I haev heard of P6 cams. JRV, did you miss type or is there a P4? Separately, has anyone seen a set of specs for a more aggressive streetable cam grind? | ||
| Verell Boaen (Verell)
Member Username: Verell Post Number: 558 Registered: 5-2001 |
JRV, Please don't jump on me for something I didn't say or imply. Specificly, in my preceding post I didn't make a statement as to the crank's construction or the facts,veracity, etc. of the statements that were made. I just reported the fact that there was a thread discussing the crank, & that somewhere in the thread was a reasonably presented statement about the 308 the bottom end being plenty strong. Which was the only point I was trying to make as it directly related to John's question. | ||
| JRV (Jrvall)
Member Username: Jrvall Post Number: 943 Registered: 11-2002 |
>>There was a long discussion as to whether the 3x8 crank was a forging or was machined from a steel billet. <<< You weren't convinced it's solid machined billet by the direct quote from the book " Inside Ferrari" ??? So there was no argument only the facts and some bullshit! >>what is the most sensible upgrade for a 308 motor to get near 300hp without turboing the car ?<< P4 Cams, Stainless or Titanium Valves, Spings Reshimmed or Replaced, 9.8 - 10.5 comp. pistons, valve reliefs cut for 10MM lift, rework the carbs or Individual Throttle Body Injection. The bottom end is fine Solid Billet Machined Crank, Rods are plenting strong, although should be magnafluxed and then shot peened and Rod Bolts & Nuts need to be replaced. These mods puts it between 300-320HP. | ||
| Verell Boaen (Verell)
Member Username: Verell Post Number: 555 Registered: 5-2001 |
Search the archives. There was a long discussion as to whether the 3x8 crank was a forging or was machined from a steel billet. I'm pretty sure that someone in that thread (Ric Rainbolt maybe) made a convincing case that the 3x8' bottom end is essentially the same as the 288GTOs. ie: It's good for 400+bhp. | ||
| Philip Airey (Pma1010)
Junior Member Username: Pma1010 Post Number: 123 Registered: 7-2002 |
FYI, Bill Pound opined to me that the easiest way to 300 bhp was a set of cams where emissions testing is not an issue. | ||
| John Moretti (Moretti)
New member Username: Moretti Post Number: 35 Registered: 11-2001 |
Quick question for JRV as I'm sure you've had this asked many times: what is the most sensible upgrade for a 308 motor to get near 300hp without turboing the car ? I was thinking along the lines of Mahle or similar type HC pistons, dry sumping and FI as I am taking the car historic racing and the rules are being relaxed here in Australia to allow me to get this by the ruling body. Do I need to strengthen the conrods and bottom end or should the money and effort go towards the top end (please don't say both as the wife is already whining ) |