pdawk1

so a while back i finished putting together a 383. 63' block, 516 heads with larger valves, stock bottom end, .060 over bore, comp cams hydraulic flat tappet 292 magnum, and it ran decent for a bit. has about 700 miles on it and an intake valve broke right at the retainer, and dropped about half an inch into cyl. checked compression, and had several at 120 psi, one at 160 ish (this plug was very oily), and another in the 140 range which was also oily. will be pulling the engine, hoping pistons arent too messed up, (valve isnt bent too bad, i can even spin it). My main worry is compression and compression ratio. when i pull this engine, im ditching those iron heads and going with edelbrock performer rpms, a nice hydraulic or solid roller cam in the mid- high 500 lift range and 230-250 duration @.050. have a number of cams im looking at, mostly comps xtreme energy line. definitely am fine with spending the more money on a roller , no special break in , etc. chances are im gonna need new pistons and rings, especially the route im taking (maybe not?). what im hearing and reading everywhere is that these 383s are kinda difficult to make good compression with. ive though about doing a stroker which would make it easier but i really dont have that kind of money. ive searched around for some good forged pistons, and really all im coming up with are speed pro L2315NF60 and some expensive diamond DIA51903 pistons on mancini racing. can get the edelbrock heads in either 75cc or 84cc, my boss is wanting to go for the 84cc ones because he said the 75cc versions wont flow as good since theyre a small closed chamber design? with the 75cc in a compression ratio calculator i getting around 10:1 with a .020 steel shim head gasket. 10:1 would be ideal IMO but with the 84cc it drops a bit and with a cam of the size im looking at that lower compression ratio doesnt sound good. i would like to see high 400 to 500 hp out of this engine. what have all you other 383 folks ran/what are yall running and what compression ratio? i would also like to get the 84cc version of the heads since i also have a 440 block and down the road plan to build it up as a real hot engine and use these set of heads with it. give me yalls opinions on it all and what yall would do,much thanks in advance

RacerHog

Read The Hot Rod Magazine 383 build.... I think you are off base with this build and way under budgeted.....
I would save the money and do a 400 or a 440 stroker engine build myself.... Good luck... Keep us posted.

pdawk1

i have a 440 block, though im only 17 and dont have a high budget at all. would do the 440 if i had money for machine work etc.

Iowan

Pull the heads and look at the damaged to piston and cylinder, if its contained to a few marks on the piston it could be used ( take pictures and post) as far as the heads go the 516s can be fitted with the valves from 915 or 904s but the ports are slightly smaller. On the plus side you can cut the face and bring them down to 70cc but I would replace stock valves with SS from Manly or Mopar Performance and buy the appropriate sprining, retainer and keepers. You should also check for coil bind, the heads might need to be cut.

what is this motor for and how is it set up, headers, gears and transmissions.

RacerHog

Happy your learning... Dont get all bummed out.... I was 17 at one time also .. If you learn how to really build Mopars well,,,, You can build most anything after that...
I'm just not ok with starting with a .060 over 383 Block... But if your up to the task... Will help as much as we can... Iowan made a few good suggestions....

pdawk1

car is a street/strip car. has a 4 speed, 3.91s in a 8 3/4 and will have a 28 inch tall drag radial. has hooker comp headers and 3 inch exhaust that goes into 2.5 over the axle. high 11s in the 1/4 would make me happy considering everyone else around here have chevy big blocks going faster. also thinking of doing some juice

pdawk1

little update: havent pulled engine yet, though my boss came across a real good deal on a fully forged balanced rotating assembly thats .060 over. bought it, pistons are old TRW L2293 forged dome pistons that are rated at like 11:1. gonna throw that whole rotating assembly in it. looking at a howards solid roller cam with .600 lift and .250 range duration @.050. also looking at those trick flow 240 heads instead of the edelbrocks. boss is fine with lending me some money for this engine. opinions ? what do yall think hp wise?

RacerHog

My Guess...450+

Iowan

It has the potential for 500+ with proper assembly, 850 cfm carburetor and intake manifold with the Trickflow heads.

pdawk1

pdawk1

Iowan

There's only 6 to 8 peek hp difference between a 750 and a 850 carb.

RacerHog

Yes.. But hey.. If you want to work with what you have.. Nothing wrong with that.

pdawk1

Iowan

The 500 number depends upon how many compromises you make and how many times you go after five more hp. If you settle for a small carb that's not a race carb plus an older style intake plus 800 gram trw pistons plus a 3/8 oil pickup ( I consider it a parasitic loss ) iron rockers instead of rollers etc. you can cost your motor 50 hp.

As far as 11s go that's all chassis if you make the power, I've never used drag radials but what I've read is there more for an automatic transmission car and I think you will need a deeper gear , 4.56 so you can run through the traps at 6500 rpm. with the cam you have. Assuming it's 1/4 mile you're going to be running.

pdawk1

very late to responding, but I’ve been looking into getting the Indy and trickflow heads, maybe even going to the max wedge ports, using Indy max wedge intake, having the lower end professionally assembled and set up with those TRW pistons, what about that larger pickup?? Is that worth it for better oiling? I plan to spin that heavy rotating assembly up to over 7k Rpm, going for 550+, possibly even 600. Using a solid roller custom ground bullet racing cam, roller rockers, all the goodies for the top end. Any more advice ??