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Triumph Repair/compression test


Following up on my problem with regard to my tr7 maxing at 4000 rpm and rattle

I double checked the compression using two good gauges.  Using four good squirts of 30 weight in the cyls  I came up with the following results

Dry compression   110     105     113      101
wet test          130     120     130      100

what do you think,


If those readings are correct you for sure have a piston ring problem on # 1,2,3 and probably #4 too. Plus you for sure have a valve problem or a head gasket leak on # 4

If I got those readings in the dealerships I worked in, we would not consider looking at any tuning of the carburetors or ignition system until the engine was corrected. It would be a waste of time.

If you choose to do the work yourself there are some things in the TR-7 that are odd and will trip up even a good mechanic. So let me know and I will give you some of the odd things to watch for in it. If you have a machine shop do the job there are things you need to tell them because they may not know the TR-7 engine.


Triumph Repair

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Howard M. Fitzcharles III


Triumph TR-4 up & Spitfire, and Engine theory


Dealership line mechanic on MG, Triumph, Jaguar for 15 years, Instructor in commercial mechanics school 2 yr. Product information manager for piston and valve manufacture, Instructor & hotline answer man for import car parts importer 15 yrs.

Associate member SAE EAA member

Import Car magazine

ASE Master Auto with L-1 certification up to 2000

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