TR4/4A Triumph TR4 Oil Pressure

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To check the clearance, you disassemble the bearing and lay a piece of Plastigage across the face. Then reassemble, torque, and disassemble again. Compare the width of the crushed Plastigage to the bands on the wrapper to read the clearance. Plastigage should be available at any auto parts store. You'll probably want some of both .001-.003 for main bearings and .002-.006 for rods.

For a first timer - how much time should I budget for this job?

 

[prb51]

Randall,
Do you like the plastigage better than a micrometer?

 

[TheSearcherMan]

I would try another gauge first, and check the relief valve. I'd then check the oil pump. It is my opinion plastigauge is not that accurate. Also, I replaced the rod and mains in a TR6 with 80k miles. After a few miles, the oil pressure was back where it was before new bearings. The crank may be out of round from wear, also, its hard to check without micrometer, and you can't check the mains in the car with micrometer. If the engine is rebuilt, why would the bearings be worn out? If you check the gauge and relief valve, and the problem is internal, then the engine wasn't rebuilt, remove engine and rebuild.

 

[TR3driver]

For a first timer - how much time should I budget for this job?

Oops, my apologies, I misread the question the first time.

I'll agree, 5 hours seems like more than enough; even with time to remove and check out the oil pump.

 

[Bugeye58]

For a first timer - how much time should I budget for this job?

Tom, I'd think you should be able to do it in five hours or less. Probably much less.
Jeff

 

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Thanks Jeff.

 

[TR3driver]

Do you like the plastigage better than a micrometer?

IMO they serve different purposes; so I use different ones at different times. For the operation described (basically a quick check with the engine still in the car and mostly assembled), I like Plastigage better. Not quite as accurate as a good set of micrometers used skillfully (remember you need both inside and outside measurements to get the clearance); but cheap, easy to use, less error-prone (no math or calibration required) and accurate enough IMO.