Triumph Repair: TR 4 Head gaskets and re-rings question, copper head gaskets, compression gauge

Question
QUESTION: Howard:
Do you have any experience using the solid copper over size(thicker) head gaskets to bring down compression on engines that have had the heads shaved to the point that compression is above normal and contributing to dieseling on shutdown? I'm reading 190 lbs. on three cyls and 160 on #4, which brings me to my next question.     
After installing new pistons, rings and sleeves and putting about 3k miles on the car #4 cyl. is reading 160lbs. compared to the others that are 190. After a "wet check" #4 came in at 190lbs telling me the rings are bad. I should also mention that the head was shaved, new valves, seats and exhaust guides installed. All I can think of is for what ever reason the rings didn't seat or possibly I broke one or maybe installed a compression ring or rings up side down?  
I'm tempted to just re-ring #4 and drive on. What would you advise?  Thanks; Ken

ANSWER: Hi Ken,
190 PSI on a dry compression test is high. Check the compression gauge first but yes 160 to 190 dry to wet test is normally a ring problem but I am worried about the 190 reading too. Normally you should not see more than 10% to 15% increase. With that kind of compression you need a racing gas or alcohol fuel so as not to get detonation.

I have seen thick solid copper head gaskets used on race engines. However they can only be compressed once with out needing to being annealed. Solid copper head gaskets were common on older British motorcycles too. An upside down scraper/compression ring will not usually show low compression, it will pump a lot of oil into that combustion chamber.

Howard



---------- FOLLOW-UP ----------

QUESTION: Howard:
Thanks for you speedy reply to my first question. I have another for you.
Moss motors sells a ("Shim Steel Head Gasket" P/N 694-505) described as a "Corgasy" head gasket used as a component of the compression lowering kit. Do you have any experience with shim steel head gaskets?
I'm asking you because the "Technical Rep." at Moss told me this steel shim head gasket was used for increasing compression! I'm not so sure I'm trusting them for technical advice! I'm considering useing the steel shim along with the stock gasket rather than the oversize copper gasket from Gasket Works. Your thoughts?   Thanks: Ken

Answer
Ken, very few that I have seen that stacked gaskets made it work.

I have always found Moss motors to know what they are doing. If they told you that using a steel shim type gasket would raise compression, than I would believe them as most steel shim head gaskets that I have used on other cars were thinner than the composite gaskets for that engine thus it would raise compression.

Did you test your compression gauge like I suggested? I have done a lot of compression tests on British cars over many years and not found a 190 PSI compression test.
Howard