7000+ RPM requirements

[Blue89rs]

Alright, this is what I have so far:


Crank
-Use the 2.8L crank, because it has a shorter stroke.

Springs
-LS2/6 springs, good for 6500+ rpm in a V8
-Crower 1.46" springs part # 68380-2.

Pushrods
-Chromoly CRN-25621-12

Cam
-solid lifter cam - 251241

Heads
-Gen III heads
'96+ 3400 and '00+ 3100


This certaintly sounds like a formula for a pretty hot motor. MUAHAHAHAHAHAHA!

Now if I can modify the oil passages and crank bearing to keep enough oil in the there I think it will work good. That cam that betterthanyou says it floats at 8000 so I should be good to go up there. Could I have problems with the oil pump spinning that fast???

[v6h.o.]

Wont be able to use those pushrods with the Alum heads. Those are Iron headed Pushrods If its got a -12 behind it...

Gen2/3 heads have splayed valves which use different length pushrods compared to the Iron headed engines. which also use different lengths for the intake and exhaust valves.

I would use the LS6 springs myself if i was doing your build up. Get the Crane solid roller lifters, have Crower grind you a Solid roller camshaft, and use the good large valve large port 3X00 heads which you have listed. Maybe even a 3500 upper plenum?

minimum 12:1 compression

[Doubt_Incarnate]

im not sure if the base 2.8 camaro's have the 8.5cr or the 8.9cr like the fwds. if its the 8.5 then just bolting on the aluminum heads gives you right at 12:1cr, and the crane h272 cam seems to run up to 7K (according to DD2K).

[Blue89rs]

Hmmm.... 12:1cr needs rocket fuel huh....... maybe that won't be such a good idea. So should I just go with the 3.1 crank then so I can put the 3.1 dished pistons on it? I know it has a longer stroke but you figure that it will still work? I guess if I go with the 3.1 crank I'll loose the compression but I'll keep the option open of a turbo someday.
I like the custom 3500 idea...hehe....that would be kewl. I was going to put my 3100 cavalier intake on with the heads that I have as well. This is in a camaro so I have plenty of hood space to do something crazy. I'll have to get the right push rods for sure. I forgot to change that number. I'll talk to my machinist hopefully today. I'm trading a 1965 396cuin motor for all the labor of building a solid bottom end and head work.

What cars have the '96+ 3400 and '00+ 3100 Gen III heads in them? Would it be any Lumina, Beretta, Cavalier cars? Do you have a GM PN I could have? Then I can check to see what I've got at home.

[Ja[M]z]

I am sorry to tell this to you but , all this money on a 2.8 just to make it do 7000+ rpm can be invested in a godamn good 350 engine ...


just my 2 cents tho

[bszopi]

3400s were only in the vans from 96-99. After 99, then cars like the Alero and GAGT got the 3400s.

[Blue89rs]

Not really. My car is a stock V6, so I would have to buy a tranny, ecm, wire harness, fuel pump and lines, upper intake, exhaust, suspension. I could get a whole setup for $1200 bucks down at the junkers, but then what would I have? A STOCK V8! I would rather spend about $500 to get a rather cool 2.8 custom engine setup. Anyway, when a V8 car is shifting into 3rd, I'll still be in 1st. We'll see at the track. Plus this motor/tranny setup will be 300lbs lighter than any V8 setup. And the whole cool factor is way higher.

[geoffinbc]

Hmmm.... 12:1cr needs rocket fuel huh....... maybe that won't be such a good idea. So should I just go with the 3.1 crank then so I can put the 3.1 dished pistons on it? I know it has a longer stroke but you figure that it will still work? I guess if I go with the 3.1 crank I'll loose the compression but I'll keep the option open of a turbo someday.
I like the custom 3500 idea...hehe....that would be kewl. I was going to put my 3100 cavalier intake on with the heads that I have as well. This is in a camaro so I have plenty of hood space to do something crazy. I'll have to get the right push rods for sure. I forgot to change that number. I'll talk to my machinist hopefully today. I'm trading a 1965 396cuin motor for all the labor of building a solid bottom end and head work.

What cars have the '96+ 3400 and '00+ 3100 Gen III heads in them? Would it be any Lumina, Beretta, Cavalier cars? Do you have a GM PN I could have? Then I can check to see what I've got at home.

12:1 compression with a cam like you are buying will not require special fuel. 91 or above fuel should be good.

Do remember that this thing will be lumpy at idle. So I hope you are aware that it will be a very fun car but will also loose the street manars you are use to.

[keithcar72]

I am a little confused? I am building a 2.8 to go in a fiero for the sm2 class. I have already finished the short block, stock crank, stock rods w/arp bolts, fwd pistons, ari no3 cam, hv pump. I was under the impression that the al heads and the fwd pistons made for something like 15 to 1. which is way to high for the motor to live. I would love to have something around 12 to 1 with just a head change. I work at a salvage yard so getting the heads would be easy. I will not drive it everyday so I don't mind running racing fuel only in it. it is a auto-x car so it will see a lot of high revs. I would rather have a high compression na motor than a turbo since they are easier to drive.(you don't have to keep the turbo spooled up) But I'm running with corvetts, miatas, rx7s and all other 2 seaters so I need a good bit of USEABLE hp.

[RacerX11]

According to my numbers, aluminum heads on a 2.8 HO iron-head shortblock will get you ~13.6 with 0.060" head gasket, ~12.6 with 0.040" gasket. Using the low-output 2.8 pistons with 0.020" shorter compression height get you ~12.6 with 0.040" gasket, or ~11.8 with 0.060" gasket.

Marty

[Blue89rs]

Wouldn't a shorter gasket get you a higher compression?

"~13.6 with 0.060" head gasket, ~12.6 with 0.040" gasket"

I found this GM part number for the aluminum heads, 10048649. Does it sound right?

Hey Kieth, in the GM Performance book I got, it suggests to add more oil holes in the crank bearings and leadin's on the crank holes if you want to rev it up. I intend on doing it so I feel better about floating the valves hehe....

[RidgeRunner]

According to my numbers, aluminum heads on a 2.8 HO iron-head shortblock will get you ~13.6 with 0.060" head gasket, ~12.6 with 0.040" gasket.

I assume you got those two numbers mixed up?

(edit: I should read page 2 before replying!)

[Blue89rs]

Haha! Its all good.

I have another interesting question.....is there a difference between a 3.1L RWD crank/piston and a 3.1L FWD crank/piston? Cuz I know that the camaro 3.1L have iron heads.....aren't they the same iron heads from 86 to 92? If that is true, then if I put any aluminum heads on my 3.1L crank I am going to have high compression right? Maybe I should figure out what I have before I put this together huh?

[RacerX11]

I assume you got those two numbers mixed up?

(edit: I should read page 2 before replying!)

Yep...sorry...got them switched.

Marty

[geoffinbc]

Haha! Its all good.

I have another interesting question.....is there a difference between a 3.1L RWD crank/piston and a 3.1L FWD crank/piston? Cuz I know that the camaro 3.1L have iron heads.....aren't they the same iron heads from 86 to 92? If that is true, then if I put any aluminum heads on my 3.1L crank I am going to have high compression right? Maybe I should figure out what I have before I put this together huh?

Cranks are the same. Pistons are different. FWD pistons have a bigger dish. You DO NOT use 3.1L pistons on a 2.8L crank or vise-versa.