rebuilding engine, advice needed

[turbizzle]

ok, well starters i have a 94 laser with a 7 bolt and im getting ready to rebuild it. i was just wanting to get some opinions on what direction to take. my goal is 400whp and i know for the most part what im gonna need to reach it. but i was curious about internals and what shape piston to go with. should i stick with 8.5:1 compression or up it a bit. dome or flat top piston. should i have a long or short skirt piston. im pretty decided on i-beam rods but should i get a new crank or just have my crank refinished. i dont have the money for everything right now but im rebuilding the engine anyway and i want to do it right the first time. so wiseman this question is for you

 

[mattdev]

If your goal is 400whp, you shouldn't need I-beam rods or anything special. I know for MY build I will be going with the faithful Weisco/Eagle setup with 9:1 compression at .020" over. 400whp shouldn't require a heavy build, as a stock 6-bolt can handle that much...

 

[Boost92awd]

I'd say just keep your 2G pistons and match them with some 6 bolt rods. That will hold 400WHP all day long with a good tune.

 

[92ts1]

Honestly 400whp isn't much. Just go 2g pistons 1g big rods stock crank, arp head studs, arp main studs, and rod bolts and you have a good strong bottom end. Same setup I have with stock head and I'm at right around 350whp.. Good cheap setup also.

 

[turbo90gsx]

Stock pistons, stock connection rods, stock crank, stock block. ARP head studs, ARP rod bolts, re-serface your cylinder head and block and use a MLS head gasket. If you want your can balance the rotating assembly.

Unless your running a 16g with lots of nitrous or above a 50 trim there is no need to build a 4g63 with anything other than stock internals.

The thing you should be concerned with is killing the engine you build with spark knock. When you detonate, you destroy.

 

[GalantGreg]

My motor's not in yet, I have 9.1 .020 over Wiseco pistons with crower H beam rods. I should make 400 hp. Also...

ok, well starters i have a 94 laser with a 7 bolt

A 1g with a 7 bolt? Have you considered building a 6 bolt? I have an extra one.

 

[Boost92awd]

A 1g with a 7 bolt?

Yes 1990-1992 came with 6 bolts and 1993-1999 had 7 bolts.

 

[turbizzle]

thanks for all the input, just to be more descriptive im going to have a 650cc injectors, 255lph fuel pump, and a t04e-60 turbo from turbonetics. thats a t3/t4 hybrib with an ar of .68 i want to build it to hold upwards of 600 hp cause i know i'll get bored with 400. i have a mustang that run's deep in the 12's and im already bored of it so this car is going to need to have some serious potential. but the one thing that im aiming to do is make good power on pump gas. so i dont want to up the compression to much. so im curious if 9:1 would make that impossible.

 

[Nbayer1614]

The only time I would recommend using 9:1 is if u run e85. On pump gas u can run more boost and less timing with 8.5:1 than the other. The higher compresion on pump gas creates a lower threshold for knock. If u plan on doing e85 someday. Use 9:1, boost the crap out of it and blow every one away with your street car! TJ from english racing ran a 10.8 and 128mph with a 16g heavy ported and a stock lower end with 850cc injectors and 2000cc injection of meth with pump gas. No need to rebuild until you absolutley have to.

 

[Grimis]

Stock pistons, stock connection rods, stock crank, stock block. ARP head studs, ARP rod bolts, re-serface your cylinder head and block and use a MLS head gasket. If you want your can balance the rotating assembly.

Unless your running a 16g with lots of nitrous or above a 50 trim there is no need to build a 4g63 with anything other than stock internals.

The thing you should be concerned with is killing the engine you build with spark knock. When you detonate, you destroy.

thats what i did, but im going 18g and no Nos, so im good to go, now if i can get the dang thing finished....

good luck with what ever path you take.

 

[My1GLaser]

I am running 9:1 on pump with no issues. 19-20* timing, 11.3-11.5 AFR & 25-26 psi on an 18g. Wiseco pistons, Eagle H-beams, MLS HG, ARPs head studs. I was hesitant at first and was second-guessing the CR choice until I started tuning and realized that it was an excellent decision. YMMV, but I am having great luck!

Pay attention to all the details, polish the CC and make sure there are no sharp edges in the CC (HG edge, valve reliefs on pistons, etc.) Pay attention to the quench pad when setting up the motor...a search will explain why its important and what it is. But basically, its the distance from the top of the piston to the bottom of the head @ TDC. If it is built correctly, the mixture will get a violent swirl at peak compression and be less prone to preignition for many reasons.

Just polish the crank if its in spec.

The pistons will be dished with a long skirt for a 4G63.

BTW, I have 272s and the overlap reduces the dynamic compression slightly, which I'm sure helps with my motor's knock resistance.

 

[GalantGreg]

My platform is also 9.1 Wiseco pistons bored .020 over with a 16g turbo added. I haven't bought injectors yet. That will be the very last thing I get. Haven't decided what to get.

 

[turbizzle]

I am running 9:1 on pump with no issues. 19-20* timing, 11.3-11.5 AFR & 25-26 psi on an 18g. Wiseco pistons, Eagle H-beams, MLS HG, ARPs head studs. I was hesitant at first and was second-guessing the CR choice until I started tuning and realized that it was an excellent decision. YMMV, but I am having great luck!

Pay attention to all the details, polish the CC and make sure there are no sharp edges in the CC (HG edge, valve reliefs on pistons, etc.) Pay attention to the quench pad when setting up the motor...a search will explain why its important and what it is. But basically, its the distance from the top of the piston to the bottom of the head @ TDC. If it is built correctly, the mixture will get a violent swirl at peak compression and be less prone to preignition for many reasons.

Just polish the crank if its in spec.

The pistons will be dished with a long skirt for a 4G63.

BTW, I have 272s and the overlap reduces the dynamic compression slightly, which I'm sure helps with my motor's knock resistance.

thanks for the advice, im a technician at gm and i have to say this is some of the best tech ive heard on this site yet. but thanks to everyone who gave me input, its much appreciated