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Discussion Starter · #1 ·
question 1 of 90 million :D

how much boost do you think i could run on 10.3:1 compresion before blowing it up? (20V)

i have 3 engines, so i wanted to first BUY that stage IIc, then get it fully functional on a NA engine.....then turbo the engine in my 1990 90 20VQ, and then start rebuilding the engine i have on my stand......then swap in the new engine and tune some more :)

but i need to go fast, quick so i want to turbo the engine i have without lowering compression.....a nice 220 HP would be a nice start :)

what do the other 4 members think? :lol:
 

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Curse you! You moved your topic as I was replying, and I lost everything I wrote. :x :p

Anyway, I would guess that you may be able to push 5-10psi on pump gas, you'll really have to watch your timing at these levels with this compression level, and have to have a good intercooler, maybe even water injection to reduce detonation as much as possible. The lack of sodium filled exhaust valves may become an issue to if you really try to push the NA setup. Good call on getting it running tip top in NA form first if you want to try to turbo the stock NA motor.

What are you going to be using for the IM/EM, intercooled?

Oh, and you have 3 7a's!? Want to unload a set of pistons? I'm in need of a set for another project :)
 

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Discussion Starter · #3 ·
i DO have sodium filled exhaust valves, oil squirters, and the high volume oil pump like the 20V turbo (3b and AAN)

only difference is the water manifold on the head has 1 port on the 7A and 4 ports on the turbo.....also, the bore is a bit bigger.....

ill think about the pistons......would prolly want to get rid of the short block as a whole unless you happen to have a set of NG engine code pistons that you would trade :)

NG pistons yield a nice 7.7:1......that should make all of 70HP off boost!!

i would want to use the NG pistons, and shave the deck, and the cyl head to regain some compression.....
 

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I do in fact have some NG pistons if you want to trade, I'm up for it. Since the 7a's would be going into my NG engine.

My bad about the valves I thought the NA's weren't sodium for some reason, time for sleep perhaps :p

I knew it had the squirters, and as for the water manifold, I think I would definately want it on a built engine, but if 220 is your goal you can prolly get along fine without it.

Heck you have 3 motors, just find out the limits then report back :D
 

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Discussion Starter · #5 ·
so what are your hopes with the 7a pistons in the NG?

how many miles on the NG pistons?

i have about 160000K on my 7a pistons....i would have to clean my garage, and set up an area to lay out the parts...

i think im going to go to my machinist and have him look up how much he can shave off the head :)

im thinking a SERIOUS interfearance typr of valvetrain :eek:

i have 20V manifolds, injectors, fuel rails etc....

i also have a 20V parts car.....i need to get my driver car working PERFETLY tho.....its got some MAJOR electrical issues

im going to go play with the compression ratio calculator now..... :bashtard:
 

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Discussion Starter · #6 ·
7A engine with NG pistons, and how much is shaved with respective comp ratio

0.000" shaved = 7.76:1
0.005" shaved = 7.83:1
0.010" shaved = 7.90:1
0.015" shaved = 7.97:1
0.020" shaved = 8.04:1
0.025" shaved = 8.11:1
0.030" shaved = 8.19:1
0.035" shaved = 8.27:1
0.040" shaved = 8.35:1
0.045" shaved = 8.43:1
0.050" shaved = 8.51:1
0.055" shaved = 8.59:1
0.060" shaved = 8.68:1
0.065" shaved = 8.76:1
0.070" shaved = 8.85:1
0.075" shaved = 8.95:1
0.080" shaved = 9.04:1
0.085" shaved = 9.14:1
0.090" shaved = 9.24:1
0.095" shaved = 9.34:1
0.100" shaved = 9.44:1

brings me to the next question.....do the NG pistons clear the 7A oil squirters?

and now what compression ratio above would i want if i had to pick? :p



doesnt look like too much available to shave off!!!!
hopefully i can shave the block!
 

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Hey, My project for this winter is building a 20v turbo using the 7A head. As far as pistons go, one problem with using the NG parts is the rods.. they really aren't as stout as the MC rods from the 10v. I want to go the full monty and use a eurovan 95.5mm crank to get ~2.6 liters of total displacement. We'll see though, it will be a lot cheaper to just build a straight 2.3l 20vt using a stock MC crank. Any way I slice it I'm going to need custom pistons.. unless someone has a solution that can utilize MC rods and give decent clearance using OE parts at reasonable junkyard prices? Reasonable, Ha! :lol:
 

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Discussion Starter · #8 ·
why cant you use MC rods???

dont the pistons pop odd the rod with a pair of circlips?

even if they are the press-in type, they still should come off......

im going to try to use 7A rods and NG pistons...

and why do you want to use an MC crank with a 2.3L 20v?
 

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SLAB said:
why cant you use MC rods???

dont the pistons pop odd the rod with a pair of circlips?
Apparently the wrist pins are a different diameter between the 7A and MC rods. Real bummer :(

im going to try to use 7A rods and NG pistons...
cool, that'll work. Just that the 7A rods aren't as beefy as the MC units. Should be good for 250hp no problem I would imagine. Go for 350-400 and tell us what happens.. maybe then I'll go for 7A rods/NG pistons ;-)

and why do you want to use an MC crank with a 2.3L 20v?
because I've already got a spare MC block and the crank I think is the same between the NG/MC (amongst others). I'll get the extra displacement by going to a 82.5mm bore.
 

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SLAB said:
all makes sense except for where the 20V head meets the 10V block....
at the deck? :p

the 20v head will bolt right up to any 10v block. it is all a mater of compression ratio.
 

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SLAB said:
o...i was told the water ports are slightly differewnt
they are 8)

it closes off some ports and opens up others.

I have BTDT with a 20v head gasket on my 10vt block and head so I'm certain it won't be an issue.

The only MAJOR difference that needs to (or should) be addressed (other than compression ratio) is the issue of the water manifold that exists on the 3B head but not on the 7A head. My plan is to simply tap for pipe threads and kludge together some type of collector. I'm definitely trying to save costs where it makes sense on this project. :D
 

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SLAB said:
so what are your hopes with the 7a pistons in the NG?

how many miles on the NG pistons?

i have about 160000K on my 7a pistons....i would have to clean my garage, and set up an area to lay out the parts...
I am going to try to fit them in the NG engine, and see if I can get away with a high compression ~14:1 NA motor for the rally car for a season or two, 'till it blows up :p

The mileage is pretty much exactly the same on my NG set, just a hair over 160k

SLAB said:
brings me to the next question.....do the NG pistons clear the 7A oil squirters?
Yes, the NG bottom end is almost identical to the 7A, except for the oil pan, and the 7a has a windage tray as well. The NG block has the same squirters, oil oump, crank, rods, etc. as the 7a.
 

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Discussion Starter · #15 ·
ok....can you post pics of the different areas on the head where the water can/cant exit on the 7a and 3b?

14:1 sounds fun....wonder if the starter will crank it over..... :)

BTW....whats shens mean?
 

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shens = shenanigans

she·nan·i·gan
Pronunciation: sh&-'na-ni-g&n
Function: noun
Etymology: origin unknown
Date: 1855
1 : a devious trick used especially for an underhand purpose
2 a : tricky or questionable practices or conduct -- usually used in plural b : high-spirited or mischievous activity -- usually used in plural

If thats not clear enough watch Super Troopers, it's explained in that movie as well :p
 

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You can get away with a lot more then 220hp on a stock 7a motor. Look at what the vw 16v guys are making on stock motors....
http://forum.vwsport.com/viewforum.php?f=20
I've seen guys on stock 2.0l 16v w/ t3/t4 turbo, stand alone... make 300+whp on pump gas.

You could easily run 10-12psi on pump gas with 7a if it was properly tuned and a good intercooler. Since your getting 034efi the tuning part shouldn't be a problem.

One thing you could try if your worried about the high compression is run stacked headgaskets. This may sound ghetto but it does work. You could run 15psi easily with that setup!
 

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STACKED HEADGASKETS !!! no way,that's a problem waiting to happen,it might work ok for a while,but with 15psi your stressin' the gaskets a lot.there's also 40psi(plus) of oil pressure and 14-16psi of coolant.no offense but I wouldn't even think about more than 4-5 seconds after realizing all those factors :)
 

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what motor are you looking for the manifolds for.i have a modified 5ks,stock 4ks,and stock 200 intakes and a couple of stock 200 exhaust manifolds laying around.i also have volvo and audi 200 intercoolers as well as some other odds and ends.
 

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Well,

1st off, there are tons of guys running stacked headgaskets WITHOUT problems. Plus, he said the setup was temporary, so its not like he's going to run stacked headgaskets forever.

I'm looking for a weld el header for my 2.2l 20v motor. I'm using a T61(600-700hp) and need a custom manifold for it. I'll most likely go with the 034efi 20v manifold when it comes out in a couple months.

I also need a intake manifold that places the throttle body at the front of the motor. I was trying to get a wagner intake manifold off of ebay, but I think I'm going to go with a custom built one.

derracuda said:
what motor are you looking for the manifolds for.i have a modified 5ks,stock 4ks,and stock 200 intakes and a couple of stock 200 exhaust manifolds laying around.i also have volvo and audi 200 intercoolers as well as some other odds and ends.
 
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