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Shag has gone Cleveland

daveSanborn

Active Member
I have no plans to use the rebuilt 4barrel heads.

Craig,

Very few, if any, aftermarket heads will outflow those 4V heads. I'd run those MF'ers in a heartbeat!

If you're dead set on not using those 4V heads, DO NOT give them away. Hey definitely have some value to them!
 

tarafied1

Well-Known Member
"daveSanborn" said:
Craig,

Very few, if any, aftermarket heads will outflow those 4V heads. I'd run those MF'ers in a heartbeat!

If you're dead set on not using those 4V heads, DO NOT give them away. Hey definitely have some value to them!
tHey are probably worth as much as the short block or more!
 

cmayna

DILLIGARA?
Donator
"daveSanborn" said:
Craig,

Very few, if any, aftermarket heads will outflow those 4V heads. I'd run those MF'ers in a heartbeat!

If you're dead set on not using those 4V heads, DO NOT give them away. Hey definitely have some value to them!

Dave,
Odds are I will be using the heads afterall. I'd love to stay as stock as possible and yet kick some buttock. Tomorrow I'm going to contact a local machine shop to see what it will cost to disassemble, check valve grind and reassemble the heads.

 

daveSanborn

Active Member
Craig,

Have the machine shop determine what the combustion chamber size is on those heads. They should be "quench chamber" heads at 58CC (?). With this said, be careful that the compression ratio does not rise so high that you'll need to either "de-tune" the motor (by retarding the timing) or run a higher than desired octane fuel.

I love the 4V Clevelands, but the stock "somewhat higher" compression ratios is something to keep your eye on.

The last 4V Cleveland I ran turned out to be a PITA as I had to retard the timing a hair unless I was feeding a 50/50 mix of racing fuel (109 Octane) and Premium Unleaded (93 Octane). Either way though, that motor in your car will burn through a set of tires easily.
 

cmayna

DILLIGARA?
Donator
Dave the machine shop had written on the valves numbers from 60, 60.5 & 61cc. This was on the larger valve which I assume is exhaust. The average is 60.62cc.
 

daveSanborn

Active Member
Well, you had a 50/50 shot.... the larger valve is the intake valve.

If possible, compare the exhaust ports (where the exhaust manifold/header bolts on) on the 4V heads with those of any aftermarket small block cylinder heads.

Notice that the exhaust ports are likely 50% larger than any other head.
 

cmayna

DILLIGARA?
Donator
Dave,
Just measured the width and height of the exhaust port openings on both Shag's 302 heads and the cleveland heads. These are approximate only.



Width Height
302 7/8" 1-1/4"
351 1-3/4" 2-1/8"

Diammm, Almost twice the size.
 

daveSanborn

Active Member
Width X Height = Square Inches of port area (approximate)
302 7/8" 1-1/4" = 1.09375
351 1-3/4" 2-1/8" = 3.71875


From just over 1 sq.in. with the 302.... to just under 4 sq.in with the 4V Cleveland. Do you now understand the term "the 4V likes to breathe"?
 

AzPete

Well-Known Member
A set of 5" stacks will do fine.....
mustang-small.jpg
 
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