Blade

Hey guys ! The engine in my 92 Z28 "died" today. Stil driveable but not
fixable. The wrist pin on the #6 cylinder decided to walk out and carve a
nice deep hole in my cylinder wall.

Now I have a 91 350 truck block which is non-roller. (100654727). Problem
is.. I cant exactly use my roller CompCams XR270HR cam I had in there. It
was a pretty big cam too... Anyway, what I wanted to ask if what you
guys would recommend for this engine ? I'm gonna be using it with stock L98
ported and polished heads, and ported stock TPI intake and a stock TB. It
will have Edelbrock TES headers also. Any suggestions/recommendation would
be greatly appreciated

Randy92Z

iTrader: (3)

With th TPI system keep the duration under 220

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Convertible, L98, Edelbrock intake, runners & TES, SLP cam, Thin Head gaskets, March underdrive pulleys, Fastchips custom chip, Accel 300+ ignition, Relocated MAT sensor, TPIS airfoil & AFPR, K&N airfilters W/ chopped airboxs, Dynomax high flo cat, Flowmaster exhaust, MAC subframe connectors, B&M shift kit & XMSN cooler and NOS!!

Kevin G

I think you can use a roller cam in that block no problems. The bores are made to support roller lifters.

Matt98SS

I would tend to agree with Kevin G. Roller is just fine...use your existing cam or go LPE 219

Blade

Yeah I found out later that I Can drill the holes for the spider. It already has the bosses, all I would need to do is drill and tap. Thanx guys

TRAXION

If you are using the STOCK TPI intake and stock throttle body then I would choose a cam that is balanced with that intake. IMHO - 219 is too big for that setup ... heh heh - me and Matt have disagreed on this one since day one

If your intake could support upper RPM power then I would go with the 219. The 219 is a perfect match for a SuperRam setup where the exhaust port on the cylinder heads flows rediculously well. If your I/E ratio on your heads isn't awesome then pick a split duration camshaft.

If you go with a STOCK long runner TPI setup and your ported heads I would recommend a cam that has about 214-216º of intake duration and an exhaust duration of around 220-222º duration.

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.587 @ 107.97mph (1.710 60ftr) on the long runner setup.
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels. Stock Wheels. No Weight Reduction.
Gunning for NA 11's with the MiniRam II and Hooker LT Headers.
-=ICON Motorsports=-

Blade

How about the cam I got in there now ? Is that good enuff ?

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92 Z28 L98 350
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Ported and polished heads, ported stock TPI base, ported plenum, Comp Cams XR270HR-10 cam (lift .495/.502 duration 218/224 lobe separation 110), Edelbrock TES headers, LT4 valve springs, Crane AFPR, Flowmaster catback with LT1 style tips, MSD coil & wires...

"Take that auto, drop it in first, hold the brakes, stomp the gas and grin from ear to ear! :-)

Ed Maher

I tried to start this discussion a while ago, but it was lost ona relatively non-looked at post. You guys are the ones i want to debate this with.
I was thinking about all the emphasis on split duration cams for TPI cars and it occurred to me. The stock intake doesn't flow that well. Even if you upgrade everything, teh long runners are a restriction in more ways then not being tuned to high rpms. So why wouldn't a single pattern cam be just the ticket for getting more air through the relatively restrictive intake.I mean, a 219' intake will make more torque then a 211' at any point in the curve past a certain point (which is probably lower than conventional wisdom would imply anyway.) And there can't be that much loss on the low-end. We're talking about port injection which will tame any low end loss anyway. And we're not talking a big cam anyway. 219' is very mild for a 350 in carbed circles, especially considering it's wide lobe seperation.
I don't know how much sense this is making, but hopefully it can start a good discussion. I guess my main point is, if you're talking about your basic L98 set-up with a base, LTRs, and headers, what part are you going to look at as your restriction. The exhaust is relatively good and the intake is relatively tight. So why would you need extra exhaust duration. i understand that higher rpms make the long runners more of a resttriction, but thats exactly why you need teh extra duration. Just saying that they won't make power past 5k rpms seems dumb. I don't think that the runners are going to completely stall and stop flowing air past that point. You just have to keep the valve open long enough to let it get the air it needs in.
enough of this ramble...anybody else have thoughts...ed

TRAXION

More than any other factor, the exhaust duration for a camshaft will be dependent on the exhaust port of your cylinder heads. That is the reason for the split duration. If you were running LPE L98 Corvette heads then I would recommend a single pattern cam.

It is well knows that if your exhaust port can't support the flow then you need a dual pattern camshaft because the exhaust port needs help. The extra exhaust duration gives it more time to scavenge the spent gases.

Tim