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MG TD TF 1500 - Compression test

Well, she's been here 2 weeks and title, tags and insurance is in place and it hit 50 today so I took the afternoon off and went for our first real (better than just up and down the street) ride, about 25 miles.

First, 50 is cold at 50 mph.

Second, I have some work to do. Despite having rebuilt carbs and all that, balancing and tuning is sorely lacking. (Whoever did the rebuild didn't spend a lot of time test driving), but I had triple SUs on the E's 3.8, so I can get through that. Plugs show I'm a little rich.

My question: I performed a compression test and got 105, 110, 110, 115 on a warm engine. Does this seem about right?
MAndrus

Although consistent, that seems very low to me. When I replaced my rings last July I measured
170,160,170,165 psi.

Regards
Declan
D Burns

Time for new rings I reckon. Might as well do the big end bearings as as well. Gives you a good reason to have a look at the head, pistons, crank & the bores. Cheers
Peter TD 5801
P Hehir

Make sure you held the throttle wide open, and had a good battery to crank it over quickly. Good that they are close, but a little low. I would think at least 130-140 better. Had the car been sitting for a long time? If so may get better.
George Butz

Hi

Read here about halfway down, compression test interpretation.

http://www.chicagolandmgclub.com/techtips/mgt/tune_up1.html

Barry
B Bridgens

Your compression values are good for the standard compression ratio of the XPAG. Before pulling your engine apart check if you have a standard head or a planed one. The original depth of the head should be 3.022 inches or 76.75 mm.

John
J Scragg

I would not be concerned.

Barry thanks for leading to the T site. Well written and informative.

Joe
JWP Policastro

This thread was discussed on 07/02/2015

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