Catmaigne

I'm getting ready to take my car to the next level. The current engine in my 96Z slaps (and always has) so I figured now would be a good time to build a proper shortblock to replace the leaky, tired motor. Current specs on my car:

96Z M6
CC503
1.6 Harland Sharps
Crane 10308-1 spring kit
36lb L36 injectors
Pacesetter LTs
Magnaflow catback
Jegs HD EWP
LT4 KM
OBD1 conversion
Walbro 255

I originally had planned on running a 355ci GM847/LE2 combo NA, but one thing led to another and now I find myself here. I didn't think it would be worth dumping all that money into machine work alone without some really huge gains and a bit of versatility, so supercharging is my best bet for a fun weekend car with room to grow. I understand that a number of parts on my car cannot be reused (cam and injectors, possibly springs), but luckily I have a friend with a 95Z who would be more than excited about some discounted performance parts.

Eventual goal is 550whp. I'm hoping this isn't another unrealistic "budget build..." I'm trying not to cheap out on the integral parts but I'll try to be as frugal as I can to a point.

Outline for the bottom end:
*4-bolt LT1/4 block (from a used Corvette that will be decked .010, bored .030, line honed)
*ARP main studs
*GM #14088532 crankshaft (1053 forged steel found in LT5, ZZ4, trucks, etc.)
*Scat #25700716 rods (forged 4340 I-beams with 7/16" ARP bolts, bushed)
*Probe #P2441F-030 pistons (forged with dish, 2 valve reliefs, -20.30cc)

There are people making extreme amounts of power on stock cranks and rods, but I want something a tad more secure. I think this will do.

Tentative top end:
*Comp XE 224/236 low lift (.535/.555 114 LSA) or similar
*Ported stock heads (I think LE1 will do)
*LS7 lifters
*~46lb injectors

I'd like to pair all of this with a used P1SC or Vortech T-trim and a decent sized a/a intercooler up front. Compression should be between 9.0-9.2:1 with Felpro gaskets and I plan on running anywhere from 6-10 psi. Is 550whp realistic without any water/meth injection? (something I'd like to avoid for now) There was a fella on here making 520whp with a Vortech T-trim on a stock headed 355 9:1cr @ 10 psi!

The cam will be purchased used and my CC503 will be sold. The heads might also be purchased used unless I can make a deal with Lloyd porting my stock 643s (yes, my '96 has them). Last time I checked, he was willing to give me a $300 discount on LE2 heads if I reused my Crane spring kit. I'd imagine LE1 heads with my Cranes would only cost around $650 or less.

I plan on reusing my springs after shimming them to 1.750" installed for added seat pressure. Will 145-150 lbs seat and 380 lbs open be good enough for the amount of boost I want to run? How much more psi do you think they could take?

Thoughts? If this is too close to the edge then I'll just go back to my dinky NA build.

Kevin Blown 95 TA

My opinion - I think you might need dual pumps and larger than 46# injectors if you want 10 psi on that setup. You will also probably have to retard the ignition a little too much unless you use an intercooler or water/meth spray. You limit it to 6 psi, and you might just be OK, but you aren't going through all that trouble just to run 6 psi, are you?

Catmaigne

I did say I wanted to run an air to air intercooler, probably a new cheapo OBX 4" or something nicer used. I know there will be a psi drop but I figured the D1SC or T trim would have enough headroom to make up for that.

One of the very few perks of having the Camaro... the FMIC looks AWESOMEEEEEEEEEEE.

Catmaigne

Would just the a/a intercooler be enough to keep the IATs reasonable at 10 psi or is that water/meth territory? I want these Probes to last.

INSANEZ

I'm not a fan of Probe pistons, Wiseco or Diamond is what we use on all our builds, Probe always have clearance issues and do not like boost.

Sent from my SGH-I747 using Tapatalk 2

Kevin Blown 95 TA

Sorry, I must have missed that - I'd say it would be OK in that case, but you will still have to take some timing out as usual.

Bigbadwhitey

Question, whats your budget around? I too am looking into a cheap(ish) 355 built to withstand 10 or so psi

Catmaigne

The only real failure I could find with the Probes was B4Ctom's Nova. Granted, this Nova had a gigantic turbo and was making 8 second passes with over 1200 horsepower at the wheels.

[autostream]http://autostream.com/camaroz28/?page_type=firebirdplayerthumbnail&framepage=2764& transactionid=1362621983-17349172119&posted_by=Catmaigne_www.camaroz28.com& youtube_video_id=LImnsM9YyAI[/autostream]

These are probably the SRS slugs which are only really about 70 bucks more which might be worth the investment. I'd like to make less than half of that kind of power reliably.

Catmaigne

And I don't really have a set budget for the 355 but I'm trying to keep costs down by doing a good amount of the work myself. I have access to some nice tools so the bearing clearances will be set by myself, the pistons will be floating so I won't have to get them pressed on, I might also try some homebrew electrolysis but it all depends on local prices. The nearest machine shop is pretty high dollar but hasn't really established a reputation because nobody builds anything interesting around here!

The forged crank is a reman that comes with a good set of bearings for a bit over $200. It's only really $40 more than the standard LT1 reman so I figured it was worth the upgrade. The rods seem to be heralded as the best set for the money (see 7/16 ARP cap screw). The pistons are up in the air but I haven't heard many complaints, nor have I seen many catastrophic failures among the big V8 crowd.

Purple Poncho

I think you have a good plan for 550rw. You'll need bigger injectors as mentioned. 72lbs would work and you will need dual pumps if you don't want to use meth.
I do think you will need 12-15# of boost to get it.
Why not pulley that bitch up as much as it'll take??? You paid for it for a reason.

97WS6SCharged

I'd look at a set of Wiseco pistons for a budget build. Just personal preference on my part really.

As far as fueling it... toss another 255 pump in the tank (or a single 340) and run some Motron 60's.

Add a big block hub to the mix along with the timing cover to support it.

Finally see what Lloyd recommends for a cam to go with the heads and 10 lbs.

Catmaigne

After a great deal of research, I've decided to get rid of the Probes. I don't feel too comfortable with their method of pin oiling for a high horsepower build so both the FPS (4032 alloy) and SRS (2618 alloy) series are out of question.

Now, this is supposed to be more of a street oriented build and I don't think running much over 10 psi would be wise on the pistons I would choose. This engine needs to go the distance if not pushed to its limits so the piston of choice will probably be the weaker 4032 alloy that won't slap like crazy. I understand that the added silicone won't be as friendly when the boost goes up, but I would rather not have some 2618 slugs scoring my cylinder walls every time the engine starts up cold. Anyway, the LS9 runs 10.5 psi stock and only has 4032 pistons which seem to do just fine.

I forgot to mention that a LE ported intake, 58mm throttle body, and a better flowing exhaust system (or cutout) will eventually be swapped in. Do you think a 9:1 355/LE1 intercooled with the right supporting mods could breach 550whp under 10 psi on a kickass tune? What if I stepped it up to LE2 or Trickflow heads?

Catmaigne

Anyone running a set of 2618 pistons? How noisy are they on startup? Will they last 50k+ if babied on cold starts?

97WS6SCharged

Just let the motor heat up a bit before you beat on it and it should last quite a while. Pretty much a good idea for any motor that uses different materials in the construction (iron, steel, aluminum, etc...) as they all expand at different rates.

Purple Poncho

I've run the SRP 4032 and the JE 2618 pistons and both seem the same to me ion start up and regular driving. The SRPs are good to probably 10-11 psi then I would move up to 2618 pistons above that.