motor rebuild, what to replace?
 

I bent valve #2 and am getting a daily driver. Now my question is what should i replace while the motor is in pieces? I am not rich, and am actually getting a job to pay for this rebuild. So my question is, which would I get most benefit from and which would I be able to use forced induction w/ after the rebuild (i hope for turbo or nitrous at least in near future)

Crank?
Pistons?
I am getting dual coil valvesprings and rest of mods are in sig...

thanks for any suggestions

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

If $$$ is tight I am not sure forced induction is such a good thing to consider. But if that's your plan the thing to do is replace the pistons with forged, low compression "blower" pistons. The problem is that with the lower CR you will lose performance while the car is still NA. Other than that, now would be a great time to do a cam. There again though, an optimal blower cam is not optimal for NA.

Of course, a thorough inspection and replacing rings and bearings are basic rebuilding steps.

Rich Krause

im getting ready to have mine done im doing

pushrods
hotcam
lifters
timing chain
oil pan
headers
and motormounts

not all have hp gains but good things to replace well u have the motor apart.

I already have a mean cam, and stroking it is what I want to do for future (yr or 2 ahead) turbo.

the cam is a 230/236 112 LSA .585/.594 (w/ 1.6s) and I have valvetrain and am getting upgraded dual coil springs, so maybe heads will be ported too.

crank most important along w/ the pistons? what else?

As Rich mentioned, a blower cam is not optimal for a NA setup. Well the opposite is true as well. The 230/236 is a great NA cam, but it's not optimal for a turbo setup. A good turbo cam is generally lower duration with a reverse split and a larger LSA split (ie. 114+ degrees).

Depending on how much power you intend to make, you should probably look at doing an entire rotating assembly matched to your application. The stock rods are only good to 450-500 hp even with the bolt upgrade. Eagle makes a nice 383 blower setup with 4340 rods and crank and 33cc dished pistons that makes 9.0:1 compression with 58cc heads. It's about $1600 bucks. I think you should probably stick with the 230/236 and add a shot of nitrous. Much easier/cheaper than FI. :)

I know the cam isn't good for the turbo, but its good until I get the turbo slapped on, damn good N/A. I was asking besides the cam (which I will replace when doing the turbo install w/ a turbo cam) what should I replace, and a nitrous plan was already thought of... but I do EVENTUALLY want to go turbo (yrs ahead maybe). For nitrous I would need to replace all the internals? Say a 100 shot, what would need to be wrong w/ replacing the pistons, connecting rods, crank, heads, injectors, fuel pump... it starts getting expensive. Right now I want to run it N/A for a while and dont want big power losses on way low compression, isn't that how it goes?

I guess the 230/236 112 w/ what internals would run best for a yr or 2 while I get ready for the turbo? First/last to replace? I think crank, rods, pistons will be first, but do I need to bore the block for the pistons? and do I need to get 4bolt mains while I have the block in pieces?

thanks for the help 97ws6, that 1600$ package you said it comes w/ 58 cc heads? is that stock head combustion chambers or do they need to be milled out .030" over? I know it doesnt come w/ heads for 1600$. that does sound nice for the turbo tho, not so great for n/a... how much rwhp you think a 383 w/ 9.0:1 compression would get w/ ported heads and the 230/236? anybody?

You know, you could pick a setup that will give a slightly higher than stock compression ratio. A 383 with 58cc heads and a 14cc dished piston would produce around 10.8:1 compression. When you decide to build for a turbo, you could order a set of AFR heads with a 76cc chamber which should produce about 9:1 compression. You could have your cake and eat it too. ;)

As far as low compression and the 230/236 cam, I wouldn't want to try it. It was meant for higher compression ratios. :)

wow, thanks again, that idea kicks ass :)
so is 10.8:1 good for n/a? isn't stock about 11:1?

and thanks for the advice on the 14cc piston, that is exactly what I was looking for.

where can this kit be purchased?

10.8:1 works pretty well. Stock is 10.4:1. :)

Combination Motorsports (www.cmotorsports.com) sells that kit (seems it's actually -31cc), but it's a little more expensive than what I paid for it.

EG-37557-31

Eagle 383 cubic inch Low-Compression (blower/turbo) Rotating Assembly

4.030" Bore SRP -31cc dish pistons, 3.75" stroke Eagle forged crank, Eagle forged 5.70" H-Beam Rods

$1749.97

wow, so much good info :) thanks again 97ws6scharged.

For N/A and turbo applications, which type of piston is best? dished good for both?

also, what CC are stock heads and stock pistons?

and do those 31cc pistons give the 9:1 or 10.8:1 compression? or is it the head porting that lowers the compression?

thanks agian, sorry im kinda new to stroking the car, still tryin to learn a lot; really appreciate the help.

No problem. Questions are always welcomed. :)

As far as a FI application goes, you want a low static compression ratio. The lower the better because you can run more boost that way. With the stock heads and a stroker, you're going to have to run some sort of a dish to keep the motor alive on pump gas, with a FI stroker, you're going to need a bigger dish with the stock heads.

The stock heads are 58cc and the stock pistons are a 4 valve relief flat top piston. There's no dome or dish to them.

The dish in the piston is what lowers the compression ratio. Most likely, you will need to have your heads shaved a little bit to make sure they are flat and smooth, so you will loose a little bit of chamber volume which will up your compression a little bit. The 31cc dish should give ~9:1 with the stock 58cc heads. The 14cc dish will give ~10.8:1 with the stock heads, and ~9:1 with a set of AFR 76cc heads. Head porting merely opens up the passages that the air takes which allows the heads to flow more air. More air in/more air out equals more hp/tq. More hp/tq produces that :eek: feeling and leads to :D .

I honestly thing the best way to do a FI motor is to build one separately from what you're doing with the car now. Find a spare block and go to town. That way there's no compromises when it comes to parts.

:)

so that eagle kit, with afr heads would be a great combo, lets say with a D1 procharger?

wow, thanks again for the info on the piston dishes.
I am a college kid (without a job right now) and have to take apart the motor again (another bent valve? I think) so the heads are coming off for new valvesprings, I was just checking the difficulty in stroking it and what I could get out of it. I now think that I will wait till I do heads to do the stroker since it will be a big $$ project (need to save!!) but I am starting to think you are right about having a second motor to build to do this best.

changing the pistons sounds like a lot of work and I dont really want to do it twice... once when I stroke it initially and once again when I get heads/turbo or nitrous. It would be nice to stroke it though and spray the piss outta it :)
383 w/ heads/cam and 150 shot sounds fun.... but how much will the 383 lose N/A that it could have w/ a smaller(?) dish piston and higher compression? This FI the more I read seems like such a hard project that its not even worth it.... is that the truth?

Im off to do more research on pistons, thanks a bunch for the help.