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Patrick(333pg333) thank you for sticking to the topic. A wish the rest could do the same. Also did you make those headers? If so did you use burns 321 ss? Do you have a parts list for the pieces used on that exhaust crossover? I have a freind (brother from another) that is an awesome ss tig welder! I can puzzle it together and he can weld it for me. If I could buy some pieces from broadfoot that would be nice. I like the 1/2" flanges they use. I'm getting some 928 intake flanges this next week to match the intake port. I'll cut them to the flange and have my friend weld on a runner for them. I'll have 8 intake flanges so if anyone want to copy me I'll have four left over. I wish more info was out about the 924GTP 2.5 la mans engine. I wonder if they used the same design combustion chamber as this 85,86 9284V head? Only a few people in the world could answer that question, if they can remember anyways, or still alive. I'm sure they won't let me just walk up to the Porsche musium and start taking the head off that car. But if they did I would be the fastest irunner in he world holding a head I my hands! I would strap the intake to my back and the exhaust too! I would be passing Bolt! I would run right to a CNC shop and have them copy it! Before going to jail.
H/grin, those headers were made by my builder for another customer. Note, specific to RHD cars. Yes, I believe that is a Burns 321 collector and it took quite some time to be shipped down here, however the end results are very pleasing on the overall system. Clearly there's not a ton of room on the right hand side of the motor so making these headers as close to equal length while dealing with a steering shaft is a tight prospect. You guys with the wheel on the wrong side of the car don't have the same issue.
In terms of the overall build on your car, is it a full on trailer only track car, or a dual driver? Should be interesting if you can utilise common parts to make a sort of budget 16v conversion. As I mentioned previously, I am not entirely sold on the super low c/r but I don't think it sounds like you have many options if you aren't going to use any custom parts.
I'm going to use it as a dual driver. Not as close at all to your car in that video. That car is AWESOME!!!!! Not sure what's funner watching the car go around the track from an outside veiw or being inside the car going around the track veiw. Great driving!!!
Voith, thank for the info on the valves. Might just order 33 or 34 to be safe. Or if someone else wants to copy this idea I can have some already made.
Last edited by Humboldtgrin; 08-31-2015 at 09:26 PM.
I've been digging info up on this engine build. I found an exhaust valve from Ferra for the Ford 5.4 DOHC that might work. The valve keeper seat .69" higher (basically one valve keeper grove up) which would leave .13 valve stem tip on the Ford valve after bringing it to the proper height. I don't know if that's enough valve tip or not. Also could shim up the bottom of the spring to bring the valve spring to the propper seat pressure. Or leave it and run IRL valve springs(maybe shim them) with a huge exhaust cam and have a more aggressive cam. I would like to know how much .69" would effect the spring pressure, I'm sure quite a bit. If it had 85 to 95# lbs of seat pressure still and if worked with the followers, I don't see why not. But I don't know if there sutible for a turbocharged engine yet(especially our flame (torch)throwers). I don't know what triple alloy is but that's what there made of. Will ask Ferra tomorrow when the weekend ends.
Just got off the phone with Zeke at Ferrea. Custom valves will cost $62 each intake and exhaust. That's pretty good, about a grand in valves! So the whole ford valve thing is out of the question now. Stupid idea anyways! He said the stock NA exhaust valve usually can withstand up to 1300 degrees F. Ferrea exhaust valve can handle 1600 degrees F. He said turbo and supercharged exhaust temps are usually around 1300 to 1400 so it's wise to change them out. Maybe I could have them oversized. What is the 968 valve size? I thought it was 40mm for the intake and 36mm exhaust? If anyone knows please feel free to tell me. Thanks in advance.
Last edited by Humboldtgrin; 12-21-2015 at 07:36 PM.
Just got off the phone with Zeke at Ferrel. Custom valves will cost $62 each intake and exhaust. That's pretty good, about a grand in valves! So the whole ford valve thing is out of the question now. Stupid idea anyways! He said the stock NA exhaust valve usually can withstand up to 1300 degrees F. Ferra exhaust valve can handle 1600 degrees F. He said turbo and supercharged exhaust temps are usually around 1300 to 1400 so it's wise to change them out. Maybe I could have them oversized. What is the 968 valve size? I thought it was 40mm for the intake and 36mm exhaust? If anyone knows please feel free to tell me. Thanks in advance.
968 intake valves are 39mm iirc, should be good enough for your application, only the exhaust valve really needs to be upgraded if at all i'd think?
any progress on this
regarding the exhaust manifold..yes it bolts on to the head, but how will the alignment of the pipes be affected, im assuming the location/angle of the exhaust ports on the 4v head differs vs the 2v head.
on the 928, the guys that put 2v headers on the 85-86 "S3" 4v heads find that the headers/y-pipe get shifted about 1/2" out of alignment, requiring some bending...
No progress. Waiting on funds. The turbo exhaust bolts right up to the head. You can see in the photos I posted that the angle is the same from an 8v 944 head to this 928S3 head. I'm pretty sure it will work with out problems. I will find out when it get to it.
Check out M3 S14 valves [87-89?], you can get them long and oversize and in inconel.
So drill out the water passage
stock 8v exhaust fits
custom intake manifold or modded 8v
you need 16v cams
How does the timing belt route- same as 16v?
what would the CR be on a 2.5? on a 3.0? both with NA pistons
Check out M3 S14 valves [87-89?], you can get them long and oversize and in inconel.
So drill out the water passage
stock 8v exhaust fits
custom intake manifold or modded 8v
you need 16v cams
How does the timing belt route- same as 16v?
what would the CR be on a 2.5? on a 3.0? both with NA pistons
the chamber on this head is about the same CC as the 8v head. so the compression ratio would be pretty much the same with this 16v head vs the standard 8v.
this head won't fit on the 3.0 block though due to the water passage location!
The intake port is bigger then an 8v head and the exuast is the same size. It will be a while before I do anything with this idea. It cost money and that's the problem. But I have most of what I need. I could use a CAD file for the turbo intake to be cut up and welded back together to fit this head. I can change out the intake flanges at that point. I'm not a fabricator so this is the biggest problem for me on this project.
I need to make this intake manifold. If anyone has a CNC program for this I would really appreciate sending me the file.
Finally found the problem the the 928 guys were having. So beacause the turbo exhaust is for an 8 valve head and the exhaust post is over the exhaust valve, and the DOHC exhaust port is moved to the center of the valves, this makes the exhaust ports closer to the rear of the engine by 1/2" to 3/4" by eyeballing it on the DOHC head. So knowing that I will have to think of the best way to modify either the headers or crossover. I'm thinking the crossover would be easier to modify. Could even make a custom twin scroll setup off the factory turbo headers. Now that would be the ticket! But I'm just going to modify the crossover most likely for now. So close! But not bad.
Last edited by Humboldtgrin; 12-21-2015 at 07:40 PM.
Modifying crossover is obviously easier and 16v headers are perfectly suitable for turbo, why even mess with those?
Regarding intake, welding turbo plenum to 16v runners is wasting 16v head potential because iirc it has been proven many times that turbo intake is a serious restriction when using 16v head.
Have someone make a decent 16v plenum that you can either weld to 16v flange or attach with silicone couplers.
08-31-2015, 07:29 PM
