Hich comp head

J

jimTN

Well-known member
Does anyone make a good HC head in alumn? Have seen the cast iron head that most peddlers have and would like to save that extra weight. If alumn heads are not available, what or who has the best iron head?
 
brumfield for aluminum , snyders for cast iron .................... steve
 
My two Brumfield 5.9 heads are cast iron - not aluminum. I did not know of any Brumfield aluminumun heads. ???????
 
I never knew Larry Brumfield made an aluminum head.Then again,I never paid attention as I have a pet cookie against using an aluminum head on an iron block.I have been ont the recieving end of too many disasters from that combination.Warped,blown gaskets,cracked,broken,corroded,worn contact surfaces under the bolt heads,manifold studs pulling out,valve seats falling out.Those were all on overhead valve engines,I would say you have a fighting chance with a flathead.I have one here that I just leave hanging up.I have no idea who made it,It was on a shelf at a junkyard that closed in 1970.It came with an aluminum water pump,side cover,water outlet,intake manifold,and carb(that really is pot metal).
 
Cast iron doesn't look as "cool" but is less of a headache in the long run. I'm talking flathead Model A's.
 
Aluminum heads do look cool on a hot rod, nothing wrong with that. The main problems with the aluminum heads are they have a different rate of expansion when hot than the cast iron block. This will cause problems with head gaskets. Aluminum heads corrode when they are in contact with dissimilar metals such as steel and iron. If special anti sieze compound is not used, the head will stick to the studs or bolts and in some cases you will destroy the head when you have to remove it and count on having to remove it often. These type problems are why Ford discontinued the use of aluminum heads on the early V8 engines. Another MAJOR problem with all of the aluminum heads that I know of is none of them have a counterbore. With the pistons rising above deck height. If you don't have some counter bore the pistons will strike the head at tdc, especially when the engine is hot or at high high rpm. You can have a counter bore mechined into the head at a higher expense to relieve this condition, but if you do, it will lower the compression ratio.

The Lion head in cast iron is probably the most accurate head because the combustion chambers are machined. It has fins and you could paint it with dull aluminum for the desired look. The Lion heads are probably the heaviest but this shouldn't be a problem unless you plan to use it in an air plane The Snyder 6.0 or their 5.5 in my opinion is the best way to go for the original look if you need a head right away, No hoops to jump through and NO extreme politics to endure.
 
I have a finned alunimum Weiand head and it works great, no problems. True, it has no flycut above the piston, but the easy solution is to measure the piston pop-up and mill the pistons to get about .040-050 clearance, figuring the gasket will be about .050 (or more, depending on the gasket) when compressed. Use a sacrificial zinc, which the suppliers have, and a composition gasket, to avoid the dis-similiar metal problem. (Everyone should use a zinc. Try a digital voltmeter with one probe in the water and the other to ground and you will see voltage, but that is another subject.) However, if you are fine tuning for real speed, use an iron head of the same CR because the aluminum dissipates the heat from combustion faster than iron. That's why they run cooler, everything else being equal, but you lose BTU's in the combustion chamber. I think Ed Winfield said something to the effect to use aluminum for looks, iron for power. The problem is finding an iron head with the same CR as the aluminun ones, except the old Winfields. Then you get into chamber flow design and that too is another subject.
 
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Not only steel and Iron, Aluminum and copper just don't get along. All kinds of electrolitic action, Never mix the two! Interestingly enough, Aluminum-Bronze is one of the toughest alloys you may ever encounter, go figure.
Terry


Purdy Swoft said:
Aluminum heads do look cool on a hot rod, nothing wrong with that. The main problems with the aluminum heads are they have a different rate of expansion when hot than the cast iron block. This will cause problems with head gaskets. Aluminum heads corrode when they are in contact with dissimilar metals such as steel and iron. If special anti sieze compound is not used, the head will stick to the studs or bolts and in some cases you will destroy the head when you have to remove it and count on having to remove it often. These type problems are why Ford discontinued the use of aluminum heads on the early V8 engines. Another MAJOR problem with all of the aluminum heads that I know of is none of them have a counterbore. With the pistons rising above deck height. If you don't have some counter bore the pistons will strike the head at tdc, especially when the engine is hot or at high high rpm. You can have a counter bore mechined into the head at a higher expense to relieve this condition, but if you do, it will lower the compression ratio.

The Lion head in cast iron is probably the most accurate head because the combustion chambers are machined. It has fins and you could paint it with dull aluminum for the desired look. The Lion heads are probably the heaviest but this shouldn't be a problem unless you plan to use it in an air plane The Snyder 6.0 or their 5.5 in my opinion is the best way to go for the original look if you need a head right away, No hoops to jump through and NO extreme politics to endure.
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I have been running a 7 to 1 Thomas fin head on a speedster for 12 years. I have about 8,000 miles on it and have never had or needed to take the head off. No problems.
 
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