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MG TD TF 1500 - XPAG crankshaft re-grind

Hello,
I am currently pursuing the restoration of the engine of my MG TD. I'm trying to inspect the crankshaft with the actually bearing (std. con rod bearing & 0.010" main bearing).
I have used the plastigauge method and the result is :
Main journal clearance = 0,063mm (0.0025 in.)
Crankpin journal clearance = 0,100 to 0,150mm (0.004 to 0.006 in.)
With the manual, I find that the crankpin is bad and the main journal is limit.
I have to put my crankshaft to the rectifier and my question is what diameter indicate to rectify the crankshaft to the upper side
On the XPAG engine data service, I read :
Main journal dimension for 0.0020 -> 51,5mm (2.0276 in.)
Crankpin journal dimension for 0.0010 -> 44,7mm (1.7598 in.)
Can you confirm this data ?
Roussel Didier

Roussel,

All the specs are located here: http://www.iot.ntnu.no/users/oddk/mg3/downloads/XPAGEngine.pdf
Gene Gillam

Thank you Gene but I know this doc. I have read the information I have write on this one.
Roussel Didier

I recall from the 1960s, when as a boy helping my father in his garage, that engine machinists would often grind a crank to suit bearings they had in stock. Thus a crank thank could have taken a -10 thou ended up -30. It didn't really matter in those days but I wonder how many cranks are now at maximum undersize.

Jan T
J Targosz

Roussel,

I'm not sure what you're asking for then. That info is all you should need to have your crankshaft ground.

See II-2 (page 8) for all the journal grind sizes.

Gene
Gene Gillam

We therefore agree, Gene. The only info I have to give to the rectifier is the regrind diameter, in my case, 44,7 mm and 51,5 mm. After, I have just buy bearing in 0.020 in. and 0.010 in. site.
What else ?
PS : sorry for my poor english but I am writting from France ...
Didier
Roussel Didier

Many of the experts on this bbs probably don't understand French but they understand car - a universal language - so I think you're doing OK.

Jud
J K Chapin

Roussel,

Yes, give them a copy of the page with the specs on it and tell them the size bearings you wish to use and they should grind it to that size. Don't order the bearings until it's been ground though...just in case they make a mistake.

Your English is fine...I just didn't understand the question.

Best,
Gene
Gene Gillam

Roussel, it's not at all uncommon for folks who are used to working/thinking in metric units to slip a decimal when going into inches, etc. It appears that you may have done so in your reference to the main journal dimension for the first regrind. 2.047 in. to 2.027 in. is 0.0200, not 0.0020. Likewise, the crankpin first regrind is for .010", not 0.0010". These 'errors' may be clouding your thinking. We run into the same thing when going the other way. Good luck. Bud
Bud Krueger

Thank you everybody for your answer. I have give the page to my rectifier (see picture). Now, wait and see ...

Roussel Didier

This thread was discussed between 10/09/2013 and 11/09/2013

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