318 Build - Expert Review Needed

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69cudaownr

69cudaownr

FABO Gold Member
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I have spent quite a bit of time reading FABO on small block builds and believe I have made some good decisions but I would appreciate input from the experts. This is a street car that will never see a track.

Here is what I have;
Stock 1969 318 bored .020 over
Competition Cam – XE262H (Lift intake .462, exhaust .470/lobe .308 & .313 /Duration 262 & 270)
302 heads milled to 58cc (milled for intake fit too)
302 heads have stock valves 1.78 intake and 1.50 exhaust
Head gasket – Mr. Gasket 1121G with .028 thickness (is this ok?)
Edelbrock Performer Intake
Heads and intake have not been ported but was planning to do that.
Holley 4160 - 600 CFM Carburator
Hedman Headers
833 four speed
8¾ rear with 3:23 suregrip

Please let me know if you see any concerns in the combination or recommended changes. If anyone can estimate compression ratio and horsepower for this setup it would be appreciated.
 
Well, because you asked about "horsepower" guesses, then I'll just add if it's power you want, the heads would be the first that would get my attention. 302's in stock form aren't anything to get excited about.
 
Don't neglect the port matching and runner blending. It will really pay off. Lots of good threads on how you can do it, just don't go overboard.
 
OP. looks like you have done your homework. Do you have the piston part number to share? If just guessing a standard stock replacement piston type, I get right at 9:1 static CR and 7.5 dynamic CR. So it ought to work decently well down in the low RPM's, with better DCR than stock, which you will appreciate IMHO with the manual trannie. Ought to run on regular pump gas with reasonably tuning care.

I personally would not touch the intake; IMHO it will quite handily outflow the heads and valves.
 
The “what I would do” response:

Have the heads machined for 1.88 intake valves and pay someone who knows what they’re doing blend that into the bowl, and mildly relieve the chamber around the the intake valve.
This would be no more than 1cc worth of material removal.
 
69cudaownr said:
I have spent quite a bit of time reading FABO on small block builds and believe I have made some good decisions but I would appreciate input from the experts. This is a street car that will never see a track.

Here is what I have;
Stock 1969 318 bored .020 over
Competition Cam – XE262H (Lift intake .462, exhaust .470/lobe .308 & .313 /Duration 262 & 270)
302 heads milled to 58cc (milled for intake fit too)
302 heads have stock valves 1.78 intake and 1.50 exhaust
Head gasket – Mr. Gasket 1121G with .028 thickness (is this ok?)
Edelbrock Performer Intake
Heads and intake have not been ported but was planning to do that.
Holley 4160 - 600 CFM Carburator
Hedman Headers
833 four speed
8¾ rear with 3:23 suregrip

Please let me know if you see any concerns in the combination or recommended changes. If anyone can estimate compression ratio and horsepower for this setup it would be appreciated.
Click to expand...


With the milled heads and thin head gasket, you may have to get the intake milled....

If you don't have a carb yet, I like the Holley 80457... It's a 600 vacuum secondary with electric choke that's calibrated for a late 60's engine... Plus reasonably priced....

Holley 4160 Aluminum Street Carburetor

Your cam is fine...
 
Heads are the power bigger valves may sure u have unleaded seats in the heads for our junk gas now days
 
PRH said:
The “what I would do” response:

Have the heads machined for 1.88 intake valves and pay someone who knows what they’re doing blend that into the bowl, and mildly relieve the chamber around the the intake valve.
This would be no more than 1cc worth of material removal.
Click to expand...

I'd do this in a nano second and add 1.6 exhaust valves, very much worth time and money........for valves, get used take outs, might be able to get them for free
 
The only issue with the 1.6’s on the exhaust is you’ll cut through the induction hardening of the casting and need to install exhaust seat inserts for unleaded fuel........ for what would amount to what I consider a very minimal gain in that combo.
 
sell the 302's, and buy a set of magnum heads. More flow, bigger valves, still closed chamber for your compression.
 
318willrun said:
sell the 302's, and buy a set of magnum heads. More flow, bigger valves, still closed chamber for your compression.
Click to expand...
You need some different pieces to make the Magnums work though.
 
toolmanmike said:
You need some different pieces to make the Magnums work though.
Click to expand...

Pushrods.

I bet the lifters for that comp cam have the oil through lifters. He'll spend more than that trying to install bigger valves or if he pays somebody else to port them
 
318willrun said:
Pushrods.

I bet the lifters for that comp cam have the oil through lifters. He'll spend more than that trying to install bigger valves or if he pays somebody else to port them
Click to expand...
He's already got a intake?
 
toolmanmike said:
He's already got a intake?
Click to expand...
you can re-drill the mag heads or again, sell and buy mag intake. Just saying the heads seems to be topic of bottleneck, magnums are a fast, cheap way to fix it instead of installing bigger valves (buying valves, buying seats, paying somebody to do the work) and porting.
 
PRH said:
The only issue with the 1.6’s on the exhaust is you’ll cut through the induction hardening of the casting and need to install exhaust seat inserts for unleaded fuel........ for what would amount to what I consider a very minimal gain in that combo.
Click to expand...


Ok, point taken..........then based on above statement by OP that no track time will be seen by this combination he does not need 1.88 intakes.

To the OP, build it with what you have, put it into a car and drive it, have fun........it will make for a nice ride
 
318willrun said:
you can re-drill the mag heads or again, sell and buy mag intake. Just saying the heads seems to be topic of bottleneck, magnums are a fast, cheap way to fix it instead of installing bigger valves (buying valves, buying seats, paying somebody to do the work) and porting.
Click to expand...
Just more work. at the machine shop. A big horsepower build is not necessary here:

69cudaownr said:
This is a street car that will never see a track.
Click to expand...
 
He certainly doesn’t “need” the 1.88’s, but those can be installed without the need for additional machine work, other than cutting 8 seats to fit the valves.

And for sure, this would also only be worth a small gain....... but if you find 5-10 small gains....... they add up.

About 30 years ago I re-ringed a 318 that was already .040 over.
Mild port job on some mid-70’s 318 heads, stock valve sizes, performer intake, 340 cam, 1-5/8” headers....... tried a few different carbs on it...... it made solidly over 280hp.
 
I like your plan. I would do a little cleaning of the ports of the 302's. Good heads after some work to them. My experience with them also is that they like a little less initial timing. I played around with distributors, advance curves, springs and limits before I figured this out.
 
PRH said:
He certainly doesn’t “need” the 1.88’s, but those can be installed without the need for additional machine work, other than cutting 8 seats to fit the valves.

And for sure, this would also only be worth a small gain....... but if you find 5-10 small gains....... they add up.

About 30 years ago I re-ringed a 318 that was already .040 over.
Mild port job on some mid-70’s 318 heads, stock valve sizes, performer intake, 340 cam, 1-5/8” headers....... tried a few different carbs on it...... it made solidly over 280hp.
Click to expand...

I think the stock 340 cam is max for a lo compression 318 on the street.The old generic 204 \ 214 would surely have good lo end torque for a street driven 318.
 
I used a bunch of stuff I had laying around, and that used 340 cam needed a home...... and that’s where it went.
If I had been up for putting a new cam in it, I probably would have gone even bigger........ like a Comp 268h.
May have helped..... may not have, but I’ve had pretty good luck overall with that cam through the years.
 
PRH said:
The “what I would do” response:

Have the heads machined for 1.88 intake valves and pay someone who knows what they’re doing blend that into the bowl, and mildly relieve the chamber around the the intake valve.
This would be no more than 1cc worth of material removal.
Click to expand...

THIS!!!!! ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
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