compressor head gasket

I have no similar experience, but I think it would be wise to check surfaces for flatness. I can only assume that the problem shouldn't be happening and has a reason. Could be a minor adjustment of the head, or mating surface, could eliminate future occurrences.
Harold

Based on ease of scraping it off, the gasket seems to be compressed most around the bolt holes, ie the rather thin cast iron head deflects a little when I carefully and sequentially tighten the 6 bolts. I would like to try out gasket solutions before removing metal from the head or cylinders.
jw

Have to agree with Harold on this. I would suspect the head is warped. One solution is two gaskets, and/or gasket cement. When replacing the head, fallow the manufacturer's suggested torque pattern and approach the final torque in stages, by halves. Example: 16 lb-ft final, 8 lb-ft, 12 lb-ft, 14 lb-ft, finally 16 lb-ft. If you extend the gasket into the cylinders, you will increase the compression and place too much load on your bearings, thus wearing them out sooner ($$$).
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| > The latest replacement head gasket on my old Kellogg-American TVS201 2 | > cylinder air compressor blew out again at the narrow place between the | > cylinders last night. I'm thinking of making a new one with smaller | > holes to match the valve recesses instead of copying the old one which | > was cut out to the cylinder bore size. The pistons do not quite reach | > the top of the cylinders when turned by hand, and to check free play I | > could run it with a pencil lying across the open cylinders. If the | > pencil doesn't fly off then the pistons shouldn't hit my new gasket. | > Anyone else have experience with this? | > | > JimW | > | | I have no similar experience, but I think it would be wise to check surfaces | for flatness. I can only assume that the problem shouldn't be happening and | has a reason. Could be a minor adjustment of the head, or mating surface, | could eliminate future occurrences. | | Harold | |

In my opinion, more gasket material probably won't last longer in this application, since the aditional won't be compressed. If it's already been failing, higher compression would very likely increase the frequency of failure.
It could be that the surfaces are too slick to actually grip the gasket you replaced last. The surfaces shouldn't be too smooth (filled pores in the cast iron may offer no grip).
If the mating surfaces are remaining flat when the bolts are tightened, a better gasket material would perform better than more (square inches of ) gasket material. There are some severe conditions of heat, oil, air pressure and thermal cycling taking place in your situation (considerably worse if it's a 2-stage pump).
You might want to consult a gasket technical department. I would suppose that fully soft copper sheet would perform as well as almost any compound or synthetic/paper type, but possibly much better. Another consideration might be to O-ring groove (figure eight) the cylinder top or the head, and use a soft metal such as copper. I believe this O-ring grooving was sucessful in IC racing engines.
WB ...............

One of the Mechanical Engineers here suggested a small increase in gasket width in the area that blew out. I'll try a D shaped opening and HondaBond removeable engine gasket cement tonight.
The replacement was slightly narrower than the wall between the cylinders. I think the narrow section of the gasket works back and forth until it rips through. It ran OK at 120PSI for a while.
I know the compression ratio will increase but don't think the maximum cylinder pressure will, since it just vents into the big tank. The efficiency should improve.
Jim W

I'm with Harold.
Clean thoroughly to remove any old gasketing and then blue them up--rub some known flat surface against the block and head in order to find your high spots, and then lap / scrape the head or deck as needed.

JW With the head off lay a long file flat on the block and stroke it around a bit to see if the area around the bolt holes has pulled up a bit. A bit of judicious filing will tell you if there are any high spots on the block or head. If you have high spots then they are going to prevent enough gasket crush at the weak points your blowing out. As someone below said use the old racers trick of a copper wire laid around the cylinder. It is not necessary to grove the block, just use a ring of 22 or 24 gauge wire to increase the seal pressure. lg no neat sig line