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MG TD TF 1500 - TD Compression

I am looking at a real nice TD (to purchase) and the engine compression ranges from 82 - 90 lbs. I feel it is to low. The oil pressure is 40 - 55 which is fine. In Dick Knudson's "The T Type Restoration Handbook" he mentions The Min should be 100 and max 140 and that anything under 100 lbs is due for a rebuild. Has anyone out there been driving or driven a TD, for any lenght of time, where the compression is below 100?.. My last TD cost $5,500 to rebuild the engine that had a new crank and that was 10 years ago. Any suggestions or thought are greatly appreciated.
David Honness

With oil pressure good, absent a crack you won't probably need a new crank.

My guess is honing the cylinders and doing the head will be enough to get you another 20,000 miles at least.

I drove a TD with a engine which was 140 on 2-3-4 and 70 on 1 for 25 years before I rebuilt it. By doing most of my own work, and preserving the crank, I got it done for about $3,500.

good luck
dave
Dave Braun

Compression may be a little low, but cheap and easy to fix compared to rotten wood, bad or unoriginal chrome, instruments, etc.
George Butz

PS- was the throttle held open when checking it, and was the battery strong enough to spin it over fast? How does it run also? George
George Butz

George, I am told (and I beleave he has been honest) that the car runs good and smooth. The car is driven from Georgia to Tenn with no problem. I have not physically seen or driven the car in person but I believe the current owner and mechanic.
David Honness

I have always heard that compression should be uniform between the cylinders, rather than looking for a specific pressure. While 100-140 is ideal, 82-90 is still good. Is the 82-90 dry, on a cold engine? Or after warmup, with oil circulating? If it were mine, the engine ran smooth, and seemed to adequately power the car, I would leave it alone until it showed signs immenent demise (oil pressure low, won't pull a hill, hard to start, etc.).
John Masters

Yes..even is good...even if a little low. If it runs good, DRIVE IT. You might try a can of CD-2 with your next oil change. This will free up the rings which sometimes get stuck, especially if the car has been sitting unused for a period.
SEAMUS
F. HEALY

This thread was discussed between 08/03/2007 and 09/03/2007

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