20vt head on 10vt block? Possible?
12-31-2003, 09:07 AM
#12
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Re: 20V NA head or 20V Turbo head?
yeah, for you, you wouldn't even have to pull the block if you didn't want to. Your clutch would be an issue though. I'd go with a stronger Coupe Quattro clutch and pressure plate (thats what Javad is running in his 80t). I'm using the 5000 turbo flywheel, clutch, and pressure plate also with no problems.
yes, bolt on a turbo head/manifolds/etc and you'd have a 2.3L 8.65:1 CR 20vt.
yes it will fit under your hood.
Yes it will run great with EFI.
Boost? At least 20 psi on pump gas, 30psi on 116 octane race gas.
Power? There is a guy running this setup in a SCCA rally car pushing 500hp. It should be noted that the rings are not really setup for turbo use on these cars so if you detonate too often you WILL blow the motor. The turbo bottom ends will take a bit more of the abuse like that. The key is tuning the engine properly so you can hit the huge power levels without detonation. You'll probably want to run head studs too, especially if you want to try to use the stock NG head gasket.
yes, bolt on a turbo head/manifolds/etc and you'd have a 2.3L 8.65:1 CR 20vt.
yes it will fit under your hood.
Yes it will run great with EFI.
Boost? At least 20 psi on pump gas, 30psi on 116 octane race gas.
Power? There is a guy running this setup in a SCCA rally car pushing 500hp. It should be noted that the rings are not really setup for turbo use on these cars so if you detonate too often you WILL blow the motor. The turbo bottom ends will take a bit more of the abuse like that. The key is tuning the engine properly so you can hit the huge power levels without detonation. You'll probably want to run head studs too, especially if you want to try to use the stock NG head gasket.
12-31-2003, 02:05 PM
#13
Careful with the head...Those three extra ports on the 20vt water manifold are more than just holes
They have a lip in them at a certain depth to retain an o-ring type seal. The water manifold also has a specific contour/profile in order to get the proper seal crushed height and not leak.
You do NOT want to just drill the holes out, they MUST be done on a CNC machine with something around a 3/8" two flute end mill.
You do NOT want to just drill the holes out, they MUST be done on a CNC machine with something around a 3/8" two flute end mill.
12-31-2003, 02:06 PM
#14
The ONLY difference between a 20v and 20vt head is the water manifold
20v = single port
20vt = quad port
The valves and such are the same for both. Cam profiles are different (obviously).
Both will fit an MC, NF, NG, etc cylinder block. However, choose wisely due to resultant CR values (20v head on MC-1 block = roughly 6.3:1 which is WAY low and will result in poor running and emissions). Do a search, CGT20vt and I have discussed this in depth.
20vt = quad port
The valves and such are the same for both. Cam profiles are different (obviously).
Both will fit an MC, NF, NG, etc cylinder block. However, choose wisely due to resultant CR values (20v head on MC-1 block = roughly 6.3:1 which is WAY low and will result in poor running and emissions). Do a search, CGT20vt and I have discussed this in depth.
12-31-2003, 02:09 PM
#15
Re: So your going to turbo a 7A motor?
Watch your piston-to-valve clearance. The 3B, AAN, ABY, ADU, 7A, and NM all have reliefs cut in the piston "crown" to provide extra clearance as they are ALL interference on (at least) the intake side.
12-31-2003, 04:43 PM
#16
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valve c learance isn't a problem
As I mentioned before, this setup has been done and works.
Here is a pic of the 2.3 short block showing the valve pockets in the pistons: <img src="http://www.mswanson.com/images/generated/Audi/20vt_stroker_project/IMG_0387__scaled_640.jpg">
Here is a pic of the 2.3 short block showing the valve pockets in the pistons: <img src="http://www.mswanson.com/images/generated/Audi/20vt_stroker_project/IMG_0387__scaled_640.jpg">
12-31-2003, 04:57 PM
#18
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Re: Careful with the head...
I wasn't aware about the "stepped" hole but it makes sense. I'm not concerned however since I can either try to use two standard drill bits to acheive the same effect (if there is enough material on the head to do this) or simply go with plan B which would be some simple pipe thread tapered fittings. Easy, cheap, simple, and acheives the same result.
More than one way to uh.. skin a.. 20v head? :P
More than one way to uh.. skin a.. 20v head? :P
12-31-2003, 10:26 PM
#19
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Dude, you need to clean up that block!! I'll have to post some "cleaner" pics :-P
Those aren't valve reliefs either, they're actualy raised sections of the piston....
<img src="http://home.earthlink.net/~danaimee/engine%2010-22/IMAG0026.JPG">
<img src="http://home.earthlink.net/~danaimee/engine%2010-22/IMAG0025.JPG">
<img src="http://home.earthlink.net/~danaimee/engine%2010-22/IMAG0026.JPG">
<img src="http://home.earthlink.net/~danaimee/engine%2010-22/IMAG0025.JPG">
01-01-2004, 06:20 AM
#20
Re: Careful with the head...
Two drill bits would not give the proper profile for the seal. Go with an NPT fitting or something, or just get the head machined to use the factory seals. Either way you go, you should get it hot tanked afterward to get any metal shavings out of the head.