318 build with dyno session

Stock stroke or 4" stroker?

  • Stock stroke 318

    Votes: 48 88.9%

  • 4" stroker 318/390

    Votes: 9 16.7%
  • Total voters
    54
  • Poll closed .
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I’ll be a dissenter (and probably ignorantly so) that if the heads can be worked a little bit that it’s worth doing. My stock 1.78 valved 72 heads were needing done, but I found some 302s with 1.88/1.60s already in them. Spent a lot of time on YouTube and here reading about porting them and gave it a go. Added headers. And the difference was unbelievable. Woke the car up more than when I swapped from 2.76 to 3.92 gears. Was the real difference bump in compression and bigger valves plus headers over manifolds? Very possible. But I spent a lot of time shaving out that iron and would be willing to do it to aluminum in a heartbeat. Anyway not trying to take away from the post. I don’t know anything about throat and valve ratio lol. Just saying a couple carbide bits and time in the shop to me was worth the effort.
 
i'll echo what the other's said up thread and say give them heads the hairy eyeball and ship 'em.

your idea of keeping this straight forward and within reach of joe weekend wrench by choosing value based components that don't require (much) additional work or expensive machine processes and are easy to obtain is an ideal approach.
 
In high school, I had a 2 bbl 318 in my Duster that came out of a '67 Fury. It ran great but of course I couldn't be satisfied and pulled the heads to put on a set of 340 heads and cast iron 4 bbl intake that I had laying around. It ran good even though I killed the compression with those heads. It will be good to see what one can really do with the right compression and all bolt on parts.
 
The CR and cam choice will big players in the final numbers.

Sure, that’s true for any build……… but I feel like as the heads get bigger, relative to the cubes, it’s even more true.
 
PRH said:
The CR and cam choice will big players in the final numbers.

Sure, that’s true for any build……… but I feel like as the heads get bigger, relative to the cubes, it’s even more true.
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I'm waiting on Jim at racer brown to call me back with his recommendation, but I was kinda thinking high 230s to low 240s .550 ish lift. (Sft) Compression target is 10.8
 
NC Engine Builder said:
I'm waiting on Jim at racer brown to call me back with his recommendation, but I was kinda thinking high 230s to low 240s .550 ish lift. (Sft) Compression target is 10.8
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I did a 70 318 9.8:1 comp with cleaned up 318 heads and a 230/236 and .525 (if I remember right) and it ran pretty good. I’d expect with a better head and more comp on yours, he’ll recommend the upper part of your range.
 
NC Engine Builder said:
I'm waiting on Jim at racer brown to call me back with his recommendation, but I was kinda thinking high 230s to low 240s .550 ish lift. (Sft) Compression target is 10.8
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He has a grind that's 236@.050 and I think it was .495? lift? if I remember. On a 108.
 
Between NC Engine Building's two threads, I keep getting mixed up. 318 thread to head testing thread.. lol 318 needs to keep his head on straight. :D
 
So this project has not died! Got the rodney dangerfield 318 block dug out of the core pile, this ones a '73 casting, just a garden variety nothing special block. Found a freshly turned 318/340 cast crank on the shelf, and the Icon forged pistons and scat I beam rods are allready here, so progress is starting.
 
Got the parts all weighed up, and started ballancing the rotating assembly, and this crankshaft was in a 340, so with the much lighter bobweight, (318 with scat I beams and forged icon pistons) it needed almost 150 grams out of both ends. I put it in the lathe and turned the counterweights down some, but that's a crazy time consuming process, so still gonna have to take some weight out with holes. Bobweight checks in at 1801 grams.

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CRAP!!!! Might have been smart to mic the bores before I started. This one is allready .040 over and well worn, so looks like .060 over it shall be. This block does have good sonic check numbers, the thinnest spot I found was .220 so I'm not worried at all.
 
NC Engine Builder said:
CRAP!!!! Might have been smart to mic the bores before I started. This one is allready .040 over and well worn, so looks like .060 over it shall be. This block does have good sonic check numbers, the thinnest spot I found was .220 so I'm not worried at all.
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Thought you already had pistons? Do you have a set of 060 over?
 
man you don't mess around... i called some shops today and most here are so busy they barely wanna take work.
 
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