Daily driver head question

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mattsinger

mattsinger

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So I'm starting to see that dollar wise...I'm probably better off stepping up to a aftermarket head than trying to rebuild a set of factory heads for our 383 build. My question is when looking at the 440 Source Stealth heads...how big of an issue will not having a heat crossover be if the car will be a daily driver....including winter driving?
 
I'm usually a proponent of using new and better heads. But if it's a 383, in MI, and it has to run well in the winter, I think I'd run iron. They should be similar cost or cheaper to do properly, and the 383 will run well on them. If you want to try to build with quench in mind, get a set of 516 closed chambers, stick the 1.74 exh valve when the valve job's done.
 
Goood thinking Moper.

IMO, there is nothing wrong with iron heads, unless they do not fit the air flow requirements. Weight is seldom an issue with a street car, though, yes, I do agree, every little bit helps and even more so when you get serious.
 
moper said:
I'm usually a proponent of using new and better heads. But if it's a 383, in MI, and it has to run well in the winter, I think I'd run iron. They should be similar cost or cheaper to do properly, and the 383 will run well on them. If you want to try to build with quench in mind, get a set of 516 closed chambers, stick the 1.74 exh valve when the valve job's done.
Click to expand...

Thanks moper....any idea what the chamber Cc would be with a 516 head....also trying not to get the compression too high for pump gas and Iron head
 
Not moper, but the 516's list at 78 cc's I believe. The ones I have on my 383 have the 1.74" exhaust added, (flat valve heads with no "dimple"), and a very light cut to flatten them. They checked out at 74 cc's. With a no valve relief, stock piston at -.020" deck, it's pretty easy to hit 10.0 to 1 compression.
 
BBBCUDA said:
Not moper, but the 516's list at 78 cc's I believe. The ones I have on my 383 have the 1.74" exhaust added, (flat valve heads with no "dimple"), and a very light cut to flatten them. They checked out at 74 cc's. With a no valve relief, stock piston at -.020" deck, it's pretty easy to hit 10.0 to 1 compression.
Click to expand...
Thanks BBB....that is part of my concern....with castiron heads, and being used as a daily driver, I think I would be way high on compression. I am using Diamond Pistons with 440 rods...which put me at a .005 deck after cleanup on the block.
 
Assuming it's .030" over bored, still stock 3.375" stroke, at .005" in the hole, 4 cc valve notches, and using the common .039" compressed gasket, a 78 cc head produces 9.60 to 1 compression. Heads at 74 cc's will produce 9.99 to 1 compression. Sounds good to me. Mine with the no valve relief pistons checks right at 10.0, and seems content with pump premium.
 
mattsinger said:
guess I need to recheck my numbers...I thought I came up a bit higher
Click to expand...


Matt, the valve notch is the part that will throw off the readings, if entered incorrectly, it will think you have a dome, rather than a dish, and give a big number. In your case it will read almost a full point higher.
 
BBBCUDA said:
Matt, the valve notch is the part that will throw off the readings, if entered incorrectly, it will think you have a dome, rather than a dish, and give a big number. In your case it will read almost a full point higher.
Click to expand...

I'm using the calculator on the Diamond Racing web site. I had the valve notch part right....not sure what I was looking at ....going over all these numbers, I guess my head was swimming. The stock steel shim headgaskets were .020....so going to a composition gasket at .040, I need to mill the heads .020 just to stay stock. Then, if my calculator is correct, if I took .040 off, that should put me right about 82CCs on the heads, which show 9.55:1. I do need to get the heads CC'd to lock everything in. I think that will work for getting him back and forth to school.
 
9.5 should be excellent. I wouldn't have put mine together at 10.0 on purpose, thats just the way it ended up using the parts I had laying around.
 
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