> I just put a new headgasket in my series IV, and the damn thing still
>pukes coolant out of the exhaust when it gets hot. I assume I have a
cracked head. Is there >any difference between a >1592 head and a 1725
head?
The thing to look for on Alpine heads is the round coolant passage tube located about the middle of the head face. The aluminum around the tube gets eroded away over time. This is accelerated when plain water rather than an antifreeze mixture approved for aluminum heads is used in the cooling system. There is a seal on the head gasket that surrounds this coolant passage, and when the head is OK, it doesn't leak. If the water passage is eroded enough, the coolant can leak into the cylinders or elsewhere. There are also crescent shaped water passages that can be eroded, but the tube is more often the culprit. Lay a head gasket on the head, examine the location of the copper seals around each of the coolant passages, and ask yourself if they would seal.
Opinion is divided on the fix. A good welder with a heli-arc can sometimes lay in enough material, and grind it back to the original grade. I am told that the coolant and oils trapped in the pores of the casting cause the arc to sputter, and this can make welding more difficult. Has anyone on the list had a head successfully repaired this way?
It seems like a head could also be machined by milling or boring out the eroded material and installing a doughnut-shaped aluminum patch plug around the pipe. A good quality epoxy such as JB Weld could be used to seal the plug and hold it in place. I have used this stuff to patch cracked blocks with good success. Such a joint would not be subject to extreme pressure like around the combustion chamber, and should hold. It should also expand and contract at about the same rate as the surrounding aluminum. Just a thought.
The surest cure is really prevention. Try to find a head whose water passages are not eroded away. My experience is that about 1 in 4 or 5 heads I find are still useable without repair. I have heard of people installing a small strip of zinc under a radiator hose clamp so that it protrudes into the coolant. Supposedly, the ions in the coolant that normally attack aluminum have more affinity for the zinc, and it is eroded rather than the aluminum. I understand it's a good idea to replace the zinc strip periodically. That would be a lot cheaper and easier than replacing a head.
The 1592 cc Alpine heads have slightly smaller valves than the 1725 cc head, and look somewhat different, but I understand that they can be interchanged. The head gasket set for both is the same. The S I, 1494 cc engine uses a different head gasket, and is probably not interchangable.
Good Luck,
Rex Funk
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> From: Dan Perry <dperry(at)pressenter.com>
> To: 'alpines(at)autox.team.net'
> Subject: bad head?
> Date: Tuesday, July 07, 1998 5:26 PM
Does anybody in the Northland have a decent engine for >sale? Thanks for
any input.
Dan Perry
> http://www.pressenter.com/~dperry