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400 sbc into an 85 vette??

I

Igor

Guest
Hello everyone.

So I am going to buy a vette my friend is selling. I am not new to sbcs but i am new to TPI AND Y body.

Here is what the car has (1985 Z51 automatic):

a zz3 crate motor w/a nasty knock in it.
Accel lingenfelter intake, I assume a super ram (its the big flat looking intake on the top, like a box)
headman or hooker LT headers, dual 2.5" exhaust with off road x pipe and magnaflows
new built 700r4 with a 2400 stall converter
3.08 rear diff, i assume the weak dana 33 or whatever it is
I think a 52mm TB and 24lb injectors
a mail order chip with lifetime free updates (1985 style)

I had a few rides in the car just prior to the knock. Ran strong and tranny shifted real well.

What I Have:

.040 400 with 2 valve relief flat tops, forged, -5.4cc, molly rings
5.7 rods with arp hardware, cleranced for cam
stock crank cut .010/.010
arp main studs, arp head studs, full machine work inc. balancing
short block is done so i do not want to change it. I want to do this on a budget.

I need a set of 70cc aluminum heads, that should put me in the 10.5-10.6:1 CR depending on exact deck height of my 400. I am hoping this would work with TPI. If I went with 67cc around 11:0-11:1 CR which might be too much. What is a good CR to run with pump gas TPI motors?
I'd look at some eddy RPM heads (cheap, on budget) or maybe something else for a similar price, but like i said budget is key.

I wanted to stick with a hydro flat tappet cam due to cost and a modest power goal. I just want to make this 400 work with the tpi intake/1985 computer as best i can. I want a car that is easy to drive in traffic, and does not rev too hard, but still makes use of the 2400 stall converter. Hyro Roller i know is the way to go, but it adds to cost significantly. You need the retro cam, lifters, button, etc. I have a SR in my 383 in an 88 trans am, but for this car i just want a daily driver. I have broken in dozens of flat tappet cams, I know you run the risk of them going flat, but i think it would work OK for this combo. Any idea what grinds would work OK with the 1985 TPI computer and a 400 combo?
I am assuming I'd need 30lb injectors and a new fuel pump. I'd get the chip sent back for a reflash to new speks, so i can break in the motor and drive it to the dyno for a real tune.

What oil pan do I need? I am understanding I CAN run a 168 tooth fly (what i have) but will need a smaller then 8" (6.25 or whatever) balancer?

Anything else I might be missing?

Thanks a lot guys.
 

JAKE

Well-known member
Joined
Nov 10, 2006
Messages
313
Location
KEMPNER, TX
Corvette
1996 388 LT1
Hello everyone.

So I am going to buy a vette my friend is selling. I am not new to sbcs but i am new to TPI AND Y body.

Here is what the car has (1985 Z51 automatic):

a zz3 crate motor w/a nasty knock in it.
Accel lingenfelter intake, I assume a super ram (its the big flat looking intake on the top, like a box)
headman or hooker LT headers, dual 2.5" exhaust with off road x pipe and magnaflows
new built 700r4 with a 2400 stall converter
3.08 rear diff, i assume the weak dana 33 or whatever it is
I think a 52mm TB and 24lb injectors
a mail order chip with lifetime free updates (1985 style)

I had a few rides in the car just prior to the knock. Ran strong and tranny shifted real well.

What I Have:

.040 400 with 2 valve relief flat tops, forged, -5.4cc, molly rings
5.7 rods with arp hardware, cleranced for cam
stock crank cut .010/.010
arp main studs, arp head studs, full machine work inc. balancing
short block is done so i do not want to change it. I want to do this on a budget.

I need a set of 70cc aluminum heads, that should put me in the 10.5-10.6:1 CR depending on exact deck height of my 400. I am hoping this would work with TPI. If I went with 67cc around 11:0-11:1 CR which might be too much. What is a good CR to run with pump gas TPI motors?
I'd look at some eddy RPM heads (cheap, on budget) or maybe something else for a similar price, but like i said budget is key.

I wanted to stick with a hydro flat tappet cam due to cost and a modest power goal. I just want to make this 400 work with the tpi intake/1985 computer as best i can. I want a car that is easy to drive in traffic, and does not rev too hard, but still makes use of the 2400 stall converter. Hyro Roller i know is the way to go, but it adds to cost significantly. You need the retro cam, lifters, button, etc. I have a SR in my 383 in an 88 trans am, but for this car i just want a daily driver. I have broken in dozens of flat tappet cams, I know you run the risk of them going flat, but i think it would work OK for this combo. Any idea what grinds would work OK with the 1985 TPI computer and a 400 combo?
I am assuming I'd need 30lb injectors and a new fuel pump. I'd get the chip sent back for a reflash to new speks, so i can break in the motor and drive it to the dyno for a real tune.

What oil pan do I need? I am understanding I CAN run a 168 tooth fly (what i have) but will need a smaller then 8" (6.25 or whatever) balancer?

Anything else I might be missing?

Thanks a lot guys.

Here's what I found when I built a 415 for my 86.

5.7" rods caused me a clearance issue so I went with early, small journal Chevy rods. I recommend a mock-up just to see if you'll have clearance issues too.

Head studs will probably not allow you to pull the heads once the engine is installed in the car; ARP head bolts are the way to go; not studs.

I bought a 6 quart 400 Chevy pan from Scoggins-Dickey which fit like a glove. No chassis clearance issue.

An 8" balancer won't clear so you'll need to go smaller in diameter. Unless you have the crank internally balanced, be sure to specify both the damper and flexplate are for an externally balanced engine. Something around 7"-7-1/2" should clear.

A re-burned PROM is a definite necessity, and don't assume the injector size until you have finalized your part selections and run them by your PROM re-programmer. I used and HIGHLY recommend PCMFORLESS for the PROM tuning.

The stock TPI won't flow enough to allow the engine to make it's best power, just too restrictive. TPIS' mini-ram is what I ended up running, even after I ported the HE** out of the stock setup. You could go with a Super Ram, but it, too, won't be optimum. You can drive the car everyday with the stock TPI setup, but it just won't give best power.

Edelbrock sells a set of Performer RPM heads that have 70cc chambers and are around a grand, complete. There are others, but Edelbrock's price and quality control are hard to beat. Be sure your springs match your cam choice. Too much pressure will kill the flat tappet lobes.

Based on what you posted, I'd go 218/224 @ .050 on a 113/114 Lobe Separation Angle. I'd chose one with the fastest ramps (most aggressive) giving the most valve lift.

Roller rockers would be a nice addition if your budget can stand the cost.

10.5:1 is a safe bet on CR.

Just my thoughts.

Jake
 

Jesse@House of Hook

New member
Joined
Apr 21, 2008
Messages
3
Location
St Marys, PA
Corvette
89 corvette
If you follow my signiture links you can see exactly what i had to do with my 406 when I installed it. I just peened in the crossmember a little to give the balancer some room. Pretty easy to do, just very loud on the ears when your in here bangin. :upthumbs

Also the best pan I have found is the one summit racing sells as their kits - its basically a moroso pan and melling pump kit.

I have run Milodon 450+ dollar pans and they did not control oil as good as the one I mentioned here did. Now the 450dollar pan is setting on a shelf and the moroso is on the car.
 

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