Greetings. Long time reader/poster, newbie to the FI world.

I have long researched and dreamed of building a boosted motor. Until recently I did not have the resources to do so, but now I can build the motor and have a mentor to help me Exploded a lifter and had to tear the motor down again, ditching the NA/nitrous route.

Please critique my plan:
SRP -24cc dish 4.030 piston (need)
eagle 5.7" h beams (have)
eagle forged 3.5" crank (have)
2 bolt studded mains (have)
stock heads ported, close to le1. Flow 260 up top and made 387hp with an 847. 60cc chambers.
230/230 550ish lift on a 114? Want to spin @ 6500 (need)
haven't set my heart on the turbos yet, but going twins
whatever FMIC meets my needs
megasquirt stand alone for fuel and spark control

Fairly budget minded and somewhat modest goals I think. Should be a mean street car.
Shooting for 8.6 - 8.7:1 compression, @ 15psi and 600-700 to the wheels.

A lot of my build will be following Wills twin setup.

 

If i may, please go large single...If i could do it again, i would go large single and keep my stock acc. bracket, abs, etc.

and dont use Master Power turbos...other than that, go for it!! were all here to help!

keep us updated on your progress!

 

Will, I know you don't have current dyno numbers and everything, but why one big.

My goals are for a fun street car, not a race car. I would think that 2 small ones just big enough to make the power would spool much quicker and be a lot more fun on the street. And it looks sexy

And is the bracket giving you trouble? It looked pretty clean.

So far my black list includes
-master power
-ssautochrome (ebay)

 

Simplicity is the only reason i would stay single...easy to package, and you can use your stock accesory bracket. My bracket works great, it just wasnt easy to design, find room for, and make...etc. Now that i have a CAD model of it, it will be easy for others to copy...but haha, it wasnt easy first time around.

 

So what would a pattern or a replica cost ?

I can see the arguments, but so far I think I will be stuborn. Going for 2 still.

I'll shoot some pics soon of the "progress"

 

Couple of comments:

- Ditch the SRP pistons. They are very unforgiving.
- Install ARP 2000 or L19 bolts. The 8740's that come in the Eagle rods are junk.
- 2 bolt main is probably not adequate, even with studs. Strongly recommend a 4 bolt conversion.
- That cam will not support 6500 rpm. Expect hp peak to be around 5600 - 5800.

Mike

 

Well, JE has the -22 dish. I guess I will call them up and see what a custom set will run. If I am going to spend more than the SRPs, I think I want to drop that compression a bit more.

The argument about 4 bolt seems to still have people on both sides. I have no doubt that the conversion is a good move, but many have said it is no stronger than the 2 bolt stud. I guess I need to do more searching on it. Its only a few hundred more in the long run I guess.

**Edit** Also could someone give me suggestions on the cam. Turbo cams seem to behave a bit different than NA ones. If the one I have listed peaks @ 5800, then I could see spinning it to 62-6300. I know with boost I don't have the scream the motor to make power, so what should I do?

 

ive never heard anyone say a 2 bolt studded is as strong as a 4 bolt splayed conversion, and its not that much to do really.

talk to cam motion about your cam...theyll set ya up

 

Not going to chime in on the SRPs?

 

I don't think you'll have any real issues with the SRPs on a 355. Most of them that break are on 383s.

Pick a cam that will give you good drivability. You can always turn the boost **** a little more.

 

Tech at JE is saying that with my rods typically max dish is 25-28 on a set of their customs. It would cost 2x as much to go with the customs and if it will only pick up a cc or two,,,,

Anyone know another company that will make a bigger dish. I have seen 383 pistons with 31+ dish, but not in a 355.

I didn't want to buy another set of heads. So will 8.7:1 get my goals or do I need to shoot for lower? Shop that does my heads claims he can get 63cc out of the chambers, but they already look pretty worked over. Going to see if he can get me a bit more wiggle room.

SRP -24CC @ 8.7:1
JE -22CC @ 8.9:1
SRP -24CC w/ 63 Chambers ~ 8.5

 

I broke more SRP 355 and 383 pistons than I care to remember. I got a set of custom Ross pistons for around $650 and you can specify the size of the dish to them. I believe I got them through gofaststuff.com.

About the 4-bolt versus 2-bolt issue... I'm running 4-bolt steel main caps on my ~900 hp motor and mine are fretting where they meet the block. This means that even with 4-bolts, the caps are walking. Whoever said that 2-bolt studded is as strong as 4-bolt is wrong. 2-bolt studded is maybe 10% stronger than 2-bolt bolted. 4-bolt is nearly double the strength and holding power.

Don't bother with Cam Motion. Your 230/230-114 will be fine, but you'll have to shift around 6200. Actually, I would recommend 230/236-114 or 115.

 

As always thanks for the advice, I'll check with ross now too.

 

So what happened that caused the piston failures? Just curious cause i'm running a -31cc dish SRP in my setup. First theres the ATI BB/SB broken hub discussion, and now the broken SRP discussion. All parts that i have. Sheesh.... Its been a nail biting week on the board for me and my setup....

Ken R.

 

How much boost are you running now with the ttrim?

I try to take everyones knowledge into consideration when doing a project. I cheaped out and ran srp pistons on my 600hp nitrous setup. JE techs even told me they didn't suggest an srp for a 200 shot.

I'm guessing since you have the -31 and by checking your sig that you have the 3.75 stroke pistons. I don't understand why we can't have that deep of a dish in a 355 piston.