TR2/3/3A TR 3A engine run in specs.

[Tinkerman]

Getting to the point that I need to "run in" the engine. Would some info on the best way to do that. RPM's, time and so forth. The engine is essentially a new engine. Machined by a local shop, rebuilt by me. It has stock oversized pistons. The head has standard valves, delrin spacers and was ported and relieved and mildly shaved. The engine has a mild street cam in it.
Compression is as follows : Cylinders 1 through 3 are 170 psi and # 4 is 165 psi.
My questions are: run in at what rpm, for how long and any other tips and suggestions you might have.

Your thoughts greatly appreciated!

Thanks, Tinkerman

 

[Mickey Richaud]

Hey, Dick -

Advice generally is to run it at 2000 rpm for about twenty minutes to "bed" the cam. After that, drive it normally, taking care to vary the speed and load, but not overdoing it.

Mickey

 

[TomMull]

Mickey is right of course but Ive done a bunch of these engines in the past, before I ever heard about bedding the cam. Essentially ran it at a high idle to check for leaks and get things sorted out. No cam problems, perhaps just lucky. Tom

 

[FordFiesta]

GM has a break-in compound for cams to put in the oil when you first run the engine. Lots of ZDDP, etc. for the cam and other engine parts. The (old) container that I have is:

E.O.S. Assembly Lubricant
# 1052367

I'm sure that there are many similar products on the market.

 

[TR3driver]

I'm not sure if it was the original source, but Kas Kastner also recommended the fast idle (1500-2000 rpm) at initial startup. Certainly you can check for leaks and so on at the same time.

And there have been a lot of stories of "bad" cams over the years. My recollection is that they started well before the much publicized reduction in ZDDP levels, but the folks complaining of bad cams very rarely mentioned which oil they used (or which assembly lube) so it's hard to correlate the two items.