86IROC305

I am planning on builing up a 355 this summer and had a few Q's before I started buying stuff.

This is my first engine build up and I'd hate to put a bunch of expensive, mis-matched parts together and have under performing engine.

I was wanting to go with this combo :
'90 350 block (allready have)
Edelbrock TPI Base/ AS&M LTR's
AFR 190 Heads (unsure about the cc)
Comp Cam's XR269HR (218/224 .495/.503 @112)
Some Keith Black or TRW Forged Pistons
Eagle SIR rods

I was looking to get about 10:1 CR and about 350+ HP. Would this combo work well togther and what kind of #'s should I expect?

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86 TPI 305 Iroc-Z
700R4 (rebuilt)
Accel HEI SuperCoil
Flowmaster
K&N Filters
Ported Plenum
Comp Cams H268 218@.050 454/454 110 LSA

mirage2991

I'd go AFR 190's since you are keaping the long tubes, the cam seems to be in the right ball game, I'd favorise higher lift over biger durtion (like the ZZ4 cam and 1.6 rockers...but I'm not saying the cam you want is bad or anything....). KB pistons are really good as long as the rig gap is set according to specs...that's what I run in my 69 BB...I belive they are lighter than forged, and retain a better wall sealing than forged and doesn't transfer as much head thru the skirts as a forged would...either way, you can't go wrong with either KB or TRW's...far as rods, you are fine too...sounds like a prety good start to me! don't forget headers and a good chip...
I'm no expert, but I have red alot from this board, and talked to some other TPI guys at the strip, and you have what they all suggest I should do with my 355...if only I could! haha... good luck!
oh yea, 350hp should be right there to!

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85 Z28, 355, edelbrock base, SLP runners (old style) 58mmTB, ported plenum, stock cam, fuel reg, TES headers, flowmaster, 3.23's posi, rear disc, shift kit, MSD 6a, 305 hypertech chip (YUUUCK!) best prior intake mods: 14.6 @ 94, 2.02 60' temp: 78deg, 80% moist, on radials.
69SS, black, 3,73's, TH400, 402 BB, roller everything (solid 246@50 622 lift)+stud-guirdle, 67 Vette heads ported and o-ringed, about 10:1 cr KB pistons, should be done this summer, goals: 500hp and lots of fun

IROCKZ4me

Your combo seems right on. the cam is a good match for the induction pieces you have planned. The duration numbers are good for the long runners and the lift specs are good for the AFR190s.
You could pick up a little more power with some more compresion. Aluminum heads suck heat energy from the combustion chamber. Because of this you need to run higher compression with aluminum heads (VS iron) to get the same thermal enegy applied to the piston. Running 10:1 compression with aluminum heads is comparable to running 9:1 with iron heads.
With good prep, you should be able to run at least 10.75:1, maybe 11:1 on premium pump gas. Of course these days racing fuel might be cheaper.

To optimize for best compresion:
Check into getting the tops of your pistons ceramic coated, & the skirts lube coated. You can buy them already done from many places.
Get the block decked so that the pistons are 0.005" in the hole when at top dead center. Use a head gasket 0.038" thick, for a total piston to head clearance of 0.043". Use heads with the smallest combustion chamber you can! and use dished pistons of the right CC to make the compression ratio you need. This will make the combustion area more of a sphere, which will make a faster/cleaner burn with more power and reduce the risk of detonation.
Also as long as you are getting aftermarket rods, longer rods (6.0") will also help with a better burn, making more power, and reducing detonation.

Make sure your air/fuel ratio is not too lean and that your timing advance is not to high. A good calibration will be important. A custom chip will do wonders, at least when/if it is correct.

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Tracy /AKA IROCKZ4me
'86 IROC-Z Camaro
"Cogito ergo zoom"

• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

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