so heres the deal: its a 92 350 block, bored .060" crank cut .010/.010". it has a comp or crane roller cam of unknown specs. the pistons are Speed-Pro forged with .125" dome.

i baught the motor as is, so thats why its got the dome tops, and unknown cam. the motor is in my car and running so its not coming back out. i have 062 Vortecs and a SDPC TPI manifold.

what can i do to make this motor not be a pig? all the talk i heard is that the dome tops really suck. its got pretty good low end and its real crisp, but falls off fast. im not sure if thats a function of the TPI, or the actual engine build.

 

Without knowing specs, it's hard to give suggestions.

Sounds like the compression ratio is too high unless you're running premium gas. Change the pistons or the heads to lower compression.
Without knowing the cam specs, it's hard to know where the engine powerband is.
Fuel pump may not handle enough fuel for the engine at higher rpms.

Too many people try to put a race engine into a street car and are unhappy with the results.

 

yeah tell me about it...this thing still pings a fair amount even with premium. ideally id pull the engine and put a nice set of flat tops in. but, thats just not going to happen. is there any particular cam i can use? i know that a long duration can be used to bleed off the cylinder pressure.

id have to say the cam is a compucam or something along those lines. theres virtually no lope, and the heads have no machine work to them for larger springs. it could even be a stock cam for all i know.

would a GMPP Hot Cam work for this motor? i've installed 918 beehives, so i've got plenty of spring for that cam. or is that just too much cam for the long runner TPI?

 

you cant use a cam to make up for a bad choice of pistons the end result will be less then acceptable there really isnt any need for a .125 dome with a 64cc head that will be driven on the street change the pistons or the heads... either will make more power safer than swapping cams...
try and find a -7cc flat top KB makes a set for around $100 with floating pins

 

Some smogger heads will lower the compression ratio with big combustion chambers but flow poorly. Even aftermarket heads that flow better but have large combustion chambers will do. Lowering the compression ratio for a cam that wants a high compression ratio doesn't work very well. Without knowing exactly what cam is in it, a guess is just a guess. Cam specs are more than lift and duration. Mine is a full race cam and idles smoothly at around 1000 rpm. It also starts to build power at 4000 rpm.

Putting a street cam in that engine may have the same effect as putting a 4000 stall converter or 4.56 gears behind a street engine. It'll work but you still won't be happy with the results which will probably be worse than before.

Dome pistons have their place but it's not really in a street engine. I run the biggest domes possible to raise the compression ratio because I use large combustion chambers to unshroud the large valves. A BBC with canted valves isn't affected by a dome piston like a SBC is.

Best suggestion: Pull the engine and sell it. Buy a more streetable engine. You won't be able to change minor things to make it more drivable.

 

eh...figured as such. i should have ran when i heard dome tops. anywho i guess im just going to run what i have for the summer. the truck will be down all summer if i pull it now. maybe over the winter i can get flat tops in there and have a good little motor. keep in mind, im not racing or anything. just trying to fix a mismatched combo of parts.