joelw83

Hello to all.
Recently put my 327 together and not that impressed with it. Its not in a vette, but this forum seemed to have the most knowledge of 327s I could find. i have it in a little 4x4 Nissan truck with 32" tires and 4.60 gears and 5 speed. Now down to the engine. Picked it up cheap was in a barn for many years. Its a 67 small journal 275 hp 327 with a forged crank, out of a 67 parisienne. Anyways tore it down , sent to local machine shop. Had it bored .030" and had crank turned .010". got it back installed l79 cam, picked up a set of 492 angle plug heads that had some mild port work, also installed 1.5 roller rockers. Now to where i think i went wrong, installed a new set of sealed power flat top pistons with 4 valve relief not knowing of the "rebuilder" piston compression length of the pin difference. Anyways motor sounds and runs smooth, but feels lazy, especialy down low. I never checked the depth of the pistons as i started to rush it together now regretting. So my pistons should be .025 in the hole , with the rebuilder ones they be .045, and i have a .041 head gasket. With my quench roughly at .080 , way outta spec , my compression ratio would probably be quite low as well. So would like to know your guys opinions on tearing it back down and puting some speed pro domed pistons, think it would make a big difference and be the worth the time? thanks

MelWff

have you done a compression test to see roughly what ratio you ended up with. I would say readings around 150 psi mean you have a low compression engine and have left 50 or more HP out of the engine.
what did you set the initial timing to and do you know your total mechanical advance?
what intake manifold and carburetor are you using?

MVR 155

Obviously check the compression....... I also agree with making sure your initial timing and advance are correctly set. The wrong carb and or carb jetting/tuning could be an issue as well as intake selection. With a 32" tire and aggressive 4.60 gearing, it should be fairly responsive???

joelw83

Checked the compression the other day between 130-140 psi. Have a old wieand 8004 intake and a brand new street demon 625. Intial timing is roughly set at 8* btdc' thats roughly because mu timing tab dont match the small balancer on it. Ive tried advancing it a hair more but then she starts pinging, id imagine my .080 quench doesnt help that any. It runs alright but just not what i was expecting, and knowing what i know now i can see why. Also seems to run out power at 5400, rev limiter set at 5700.

Closer_2001

Love the project - seems a late model 5.3 or L33 AL 5.3 would make that thing fly!

Racer86

Low mechanical compression is perfect for a pro charger supercharger

joelw83

Little update, hauled it out the other day. Put the .015 head gaskets and a comp xe262. Works amazing wouldnt even think its the same motor very impressed with it now.

cv67

Amazing what a little compression and a modern cam does no?

When I see people insisting that old stuff is best makes me cringe.

Glad to see youre enjoying it now
Get some AFR 180s on there it will really really wake up

Trick flow makes some aluminum double hump clones that work real well. Could be fun painting em up