Welcome to our resource for MG Car Information.



TR parts and Triumph parts, TR bits, Triumph Car Spares and accessories are available for TR2, TR3, TR3A, TR4, TR4A, TR5, TR6, TR7, TR8, Spitfire and Stag and other TR models are available from British car spares and parts company LBCarCo.

Triumph TR6 - Leakdown test results

For the record here are the results of my tests today. You can use it as a comparison if you wish should you ever do your own.

I did the test at 80 psi. Since 10% or better seems to indicate good results I am satisfied. Most air seems to escape from around the rings and into the crankcase when I did my test. I didn't notice any air from valves (at intake manifold or exhaust manifold) or any bubbling in rad (head gasket problem). A hi loss (>10%) reading with no air flow in the manifolds or bubbling in the rad would indicate rings.

Cylinder/hot engine compression test/ leakdown result@80psi
1/ 143/ 5%
2/ 160/ 5%
3/ 145/ 9%
4/ 150/ 10%
5/ 145/ 7.5%
6/ 150/ 6%

Anyone want to comment why cylinder 2 is so much higher in compression? It seems to be the odd one. The others are close to where they should be.
Michael Petryschuk

Michael, I would have expected the 143 to match up with the 10% loss. Curious. It seems your engine is generally healthy though that,s gotta make you feel good.

rw loftus

Mike. Wish that wasn't greek to me.


I was surprised at cylinders 1 & 4 although I may have not had the fitting as tight in cylinder 4 (causing more leakage in the leakdown test) since the distributor makes it tough to tighten the fitting with the homemade tester I had. (I hand tightened the fittings.)

I am very satisfied considering when I got the car the head had been off it for 20 years. The pistons were seized in the cylinders and the rings might have well been glued to the pistons (the carbon in the ring groove having essentially solidified). I don't exactly remember now but at least 2 of the valves were seized in the guides as well. I chipped out the rings, cleaned up the pistons, punched out the valves, reground the valves and installed (2) new valve guides in my basement. The only thing I had done by others was planing the head. I pleased as punch it has gone 6500 miles since without throwing a bearing or losing compression.

Don- do you want me to translate the Greek for you and elaborate more on what my gibberish means or do you prefer the "that's all I need to know for now" state of mind? Let me know.

Michael Petryschuk

Mike, with the engine in the state that it was in when you got it, you've done really well with it. I'd be pleased as punch! Keep 'er goin'.

rw loftus

Put together your results and what you just said and I would say you are doin' pretty good.
Go on out and have some fun with your car this summer.

Oh Ya.....160 is better that 80!

Rick Crawford

This thread was discussed between 01/05/2009 and 06/05/2009

Triumph TR6 index