Thread: 383 400 rwhp build

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Appreciate that rodger. Never put that into perspective.... What is a good scr to run 87?

just remember when using the mildon Indian oil pump that you take it part and grind port the core sand out of the pump trust me it look s like rust it is not ......... thank god i still take every ones oil pumps part ..and i still can see geat out of one eye

Originally Posted by pat mccarthy

just rember when using the mildon Indian oil pump that you take it part and grind port the core sand out of the pump trust me it look s like rust it is not ......... thank god i still take every ones oil pumps part ..and i still can see geat out of one eye

Good word, Pat - I too disassemble oil pumps and clean them up. Unfortunately the quality control for a lot of companies has gone to pot with off shore manufacturing. I still use a glob of Vaseline when I put them back together - works great to assure a quick prime and it dissolves harmlessly in the oil.

As to the CR - you can go 10.5:1 on most 91+ octane premium pump gas but as Roger said, the octane varies greatly. I have a 5.0 Mustang that is 11:1 and it runs fine on Chevron or Shell.

It sounds like your rods will be fine but I would still encourage you to use a good machine shop and check all the clearances as you assemble.

Regards,
Glenn

yep i use a lube in the well so it gets fast prime ...what I beam rods GM late model or early style Gm ? if thin beam Gm ?? if so pitch them. i used the X and they say the Os are better used both in a Gm rods i rebuild them with ARP bolts new bolts small bolt head should not need the Nip or are they scats rods ? i will not say how much CH i got way with on street pump fuel but cam comes in to play and O deck

Originally Posted by jamesnelizabeth

Appreciate that rodger. Never put that into perspective.... What is a good scr to run 87?

I'm not smart enough to give you a hard & fast answer, as there are just too many variables involved - cam timing, operating temperature and head material to mention a few (aluminum heads help by dissipating heat faster). I'm running 10.3:1 and I drive 15 miles to get zero ethanol 91 octane most of the time, and buy premium on the road. If I were doing it over I would probably dial it back to around 9.5 to one and try to run 87 or mid-range 89 octane. One problem is that ethanol blends start breaking down after about two weeks in the tank, and once they do their phase separation they lose six to seven percent on the octane scale - 91 becomes more like 85, and there's no way to know it other than the ping. This is more of a problem for the occasionally driven "play car" than a driver. Others may be able to give a more technically sound answer on the best way to decide your static compression target.

Great info roger. Did not know that! And is real good to know as truck will be mostly a weekend driver! And gas will Likely to be in tank for a while.

So does that mean your going with the 302??.

I am building a pump gas friendly 383 that I could lay out for you with pictures. Post which way your going.

302 I'm building later. But gonna start 383 this spring.

Haven forgot you.Running off to the doctors this morning and working in the shop today.Will try to post my 383 build later tonight.

Well pictures first:

.030 over I-Con 18cc dished pistons with offset pins to limit cold piston slap:





Scat stroker clearanced press fit pin ARP bolt rods:







A Howards Track Smart 5.7 forged crank:





This is going into a 1995 roller 350 block the is decked .010 down. We figured the SCR with cut down to 67CC Iron Eagles with 180cc intake runners,with a .040 head gasket to have a SCR of 9.3 ish.

Here is the thread and my errors included in the math to figure this combo out.The goal here is to make a torque monster. The thread is a long read,but you might find it useful.

383 build-Something Caught My Eye