>Dan Perry wrote:
>
>> 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
>
>
>
>
>----------
>> 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