318 heads

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dave ellis

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Looking to figure out which 318 heads to use to tune for mileage in an A body on a daily driver. Hydraulic cam also for that matter. Thanks in advance, Dave
 
Use what ever head you have. If I had to choose from the verity of 318 heads ready to run on a table, it would be 302’s. Use a piston that can get you some good quench. That might be a problem with the various cc amount of the 318 heads. Generally there all a closed chamber.

The stock cam is good for mileage. If your going to move away from a stock cam, you could look into the aftermarket since they actually have cams under that listing, “Mileage Cams.”

There was a thread over on MoPars a good while back where a guy went down this path. He used a high compression 318 and really tweaked the crap out of to the tune of (IIRC) 32pmg’s. *I Think* an overdrive was used.
 
Build a time machine and go back to when you could buy gasoline and not "some form of alcohol"
 
rumblefish360 said:
Use what ever head you have. If I had to choose from the verity of 318 heads ready to run on a table, it would be 302’s. Use a piston that can get you some good quench. That might be a problem with the various cc amount of the 318 heads. Generally there all a closed chamber.

The stock cam is good for mileage. If your going to move away from a stock cam, you could look into the aftermarket since they actually have cams under that listing, “Mileage Cams.”

There was a thread over on MoPars a good while back where a guy went down this path. He used a high compression 318 and really tweaked the crap out of to the tune of (IIRC) 32pmg’s. *I Think* an overdrive was used.
Click to expand...
Not all 318 cylinder heads are closed chamber right? I thought that only the '67 and the "302" heads are a closed chamber.
 
Rv Camshaft 800-5000 operating range advanced 4 degrees 302 heads and four barrel 500cfm with sp2p intake 3.23 gears and hot igntion msd box. Should have alot of torque and great mileage.
 
GTX JOHN said:
We are very partial to the 302 heads both for power and mileage by a wide margin!
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I think that as far as a budget cylinder head you can't go wrong with them. You can leave the 1.78" intake valve's as is and go with 1.600" exhaust valve's, do a good 3 angle valve job and clean up the bowl area a little bit. One machine shop suggested doing a back cut on both valve's using a 30* by 0.070" back cut. What intake manifold do you use with the 302's?
 
Slantsix64 said:
Rv Camshaft 800-5000 operating range advanced 4 degrees 302 heads and four barrel 500cfm with sp2p intake 3.23 gears and hot igntion msd box. Should have alot of torque and great mileage.
Click to expand...
What spec cam do you recommend? Is the 500 cfm carburetor enough? I haven't seen a sp2p intake manifold in years.
 
Slantsix64 said:
Rv Camshaft 800-5000 operating range advanced 4 degrees 302 heads and four barrel 500cfm with sp2p intake 3.23 gears and hot igntion msd box. Should have alot of torque and great mileage.
Click to expand...
Some on here say to use a 4 pin gm module and matching coil. I'm thinking that 3.23's are the way to go
 
We use the factory thermoquad amd manifold even thou it is a major
mismatch to the heads.
I still race a 318 small valve 302 4000Lb Aspen /Wagon with stock 390 lift cam and stock compression/
heads/manifold/ carb when I am not feeling good enough for the faster cars. I was shocked how well the stock 302 flowed compared to
my best 202 X heads up to max lift of 390 on the same bench even with the tiny valves (Hint: well over 200 CFMS's with the
right valve job.

The Wagon held the O/SA NHRA record @ 11.83 @ 109MPH. complete with Roof Race and Air Deflector
for years!

To see it Google: John Irving Drag Racer
 
Dan the man said:
Some on here say to use a 4 pin gm module and matching coil. I'm thinking that 3.23's are the way to go
Click to expand...

i have ran all those ignitions Hei, Mopar ecu, and Msd 6A, Hei is avaliable over the counter but get ready to keep a spare on hand they go out, mopar ecu lasts longer than a hei module, but my msd 6a box has never failed yet no complaints beside better cold starts and over all drive ability. just my opinion.
 
GTX JOHN said:
We use the factory thermoquad amd manifold even thou it is a major
mismatch to the heads.
I still race a 318 small valve 302 4000Lb Aspen /Wagon with stock 390 lift cam and stock compression/
heads/manifold/ carb when I am not feeling good enough for the faster cars. I was shocked how well the stock 302 flowed compared to
my best 202 X heads up to max lift of 390 on the same bench even with the tiny valves (Hint: well over 200 CFMS's with the
right valve job.

The Wagon held the O/SA NHRA record @ 11.83 @ 109MPH. complete with Roof Race and Air Deflector
for years! I'm going to check it out

To see it Google: John Irving Drag Racer
Click to expand...
 
GTX JOHN said:
I have seen nice sets without the valves sunk or the seats and guides beat up for $100. to 400. pr.
Click to expand...
Unfortunately I have a budget that I'm going to have to stick with and the 302 heads sound like that they will work well for me as I'm not going for a high horsepower build, 300-325 fwhp.
 
dave ellis said:
Looking to figure out which 318 heads to use to tune for mileage in an A body on a daily driver. Hydraulic cam also for that matter. Thanks in advance, Dave
Click to expand...

I highly doubt there's any noticeable mpg difference between any small block heads.Other than a basic tune it's hard to recoup money spent to increase mileage especially in a summer toy, cheaper usually to put it into the tank. How many thousands you willing to spend to at best save a few hundred a year??
 
GTX JOHN said:
We use the factory thermoquad amd manifold even thou it is a major
mismatch to the heads.
I still race a 318 small valve 302 4000Lb Aspen /Wagon with stock 390 lift cam and stock compression/
heads/manifold/ carb when I am not feeling good enough for the faster cars. I was shocked how well the stock 302 flowed compared to
my best 202 X heads up to max lift of 390 on the same bench even with the tiny valves (Hint: well over 200 CFMS's with the
right valve job.

The Wagon held the O/SA NHRA record @ 11.83 @ 109MPH. complete with Roof Race and Air Deflector
for years!

To see it Google: John Irving Drag Racer
Click to expand...

Now that's impressive!
 
GTX JOHN said:
We use the factory thermoquad amd manifold even thou it is a major
mismatch to the heads.
I still race a 318 small valve 302 4000Lb Aspen /Wagon with stock 390 lift cam and stock compression/
heads/manifold/ carb when I am not feeling good enough for the faster cars. I was shocked how well the stock 302 flowed compared to
my best 202 X heads up to max lift of 390 on the same bench even with the tiny valves (Hint: well over 200 CFMS's with the
right valve job.

The Wagon held the O/SA NHRA record @ 11.83 @ 109MPH. complete with Roof Race and Air Deflector
for years!

To see it Google: John Irving Drag Racer
Click to expand...
What gears and transmission/converter are you running in that tank? That’s definitely getting it done!
 
RustyRatRod said:
Finding a set of 302s with no cracks will be a feat in itself.
Click to expand...
I just need to walk out in my garage. I "had" 2 sets of Magnum heads with no cracks as well. The cracked stories give those heads a bad image.
 
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