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General Tech Assembly Lube and Zinc and New Cam--TR4A

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KVH

KVH

Obi Wan
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I'm told that if I rebuild with a new cam I need to run the car at startup at 2500 rpm for 30 straight minutes and then dump and replace all the oil even thought it's new; and then I need to use Zinc in the oil.

Is that right?

Also, if I just add 1 or 2 quarts of 50 weight oil that has zinc in it, will that substitute for adding zinc separately.
 
KVH, What happened to running an engine in. I always try to keep the RPM's under 3000 for the first 500 miles with a brief spirited acceleration thrown in once in a while. Then change the oil with one that has zinc or ZDDP additive. Why are you using 50 weight? The new recommendation runs in the 5-30 or 10-30 range. I'm sure lots of folks will disagree.

Wayne
 
IIRC, Kas Kastner recommended more like 1500-2000 rpm, and warned against going any higher even momentarily. The goal was specifically to let the cam lobes work harden and mate to the (new) lifters; rather than worrying about ring seating, etc.

This process would definitely be best using either a high zinc oil, or a zinc-bearing "break in" additive, IMO. Non-detergent oil does not belong in a car engine!

My feeling is that in general, it is far better not to mix different oil formulations. Motor oil blending is a complex topic, with research going on all the time; and additive packages are carefully compounded to work and play well together. For example, a low-zinc oil may have a calcium-based substitute for ZDDP (the zinc based "anti-wear" additive), that is not compatible with higher levels of ZDDP. I used to read some of the tribology (lubrication) journals, and one of the last ones I read had a research report about just that problem. The mixed additives performed worse than either one by itself.

But any Autozone or O'Reillys (do they still have Schuck's in AZ?) should have Valvoline VR1, which is a well-known brand with plenty of zinc (and what I use). If you watch their flyers, it goes on sale once or twice a year for about the same price as the cheap stuff normally sells for.
 
I am currently getting my TR6 motor done and the machine shop recommends 25 min @ 2,500 rpm. They recommend Joe Gibbs oil. It can be used for break in and regular use. After start up, then run in and drain after @500 miles. This oil also has the zinc and phosphorous needed. The reason to run it for 25 minutes at initial start is to not only get the cam work hardened with heat, but also the rings to heat up and bed in.
The Gibbs oil is spendy, @$9/qt, but at least for start up I'll use it to protect the investment.

Perry
 
The higher RPM is to make sure the crank kicks plenty of oil onto the cam lobes for initial lubrication. The higher the spring loads, the more important initial lubrication is.
 
I have always read about twenty minutes at 2000-2500 RPM, I have stayed closer to 2000 on my TR250 and Healey 100 engine rebuilds. I used Brad Penn oil when I did mine, another oil that has extra ZDDP, but is a little pricey.

I also try to dial in the timing and mixture as it runs, as you usually have to reset all the stuff after a rebuild, and you will probably have set it to some static ballpark benchmark for initial start up. Lastly, newly rebuilt motors can run hot, if it is a warm to hot day it helps to do it before the hood (bonnet) is back on the car, and if you have a big old room/garage fan, it doesn't hurt to stick it in front of the radiator.
 
Stock TR4A cam. I had the performance cam, or whatever they call it. I really did not like it. A bit choppy, and seemed noisier, and slower off the line.
 
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