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TR2/3/3A Questions about Breaking in a refreshed TR3 Engine

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MGTF1250Dave

MGTF1250Dave

Jedi Knight
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Aloha All,

My refreshed TR3 engine is started and running well. I have done an inital 20 minute run at about 20 minutes. Initially there was a lot of valve calter, Since readjusting valve clearance, I have gone on two drives of about twenty minutes each. Timing seems about right and I have varied engine rpm and conducted several sprints from about 25 - 30 MPH up to about 50 MPH to help seat the rings.

My questions are, when should I replace the engine oil and filter, how many heat cylces should I get before I check the torque on the cylinder head studs and when should I expect the rings to be worn in?
 
If it were me I would change the oil now. Then again in about 500 miles. I would also retorque the cyl head. I don't know if there is a number of heat cyces involved with when you do it. It may take the rings a while to break in especially if they are chrome.
 
Personally, I kinda baby them a little. I check the plugs a lot and change them a lot on a new engine. I told you about the rich fuel thing. I try and keep them in open air and not a bunch of idling, and I would change the oil.

steve
 
You could do a compression test now and do another in 4-500 miles to monitor the progression of the rings doing their sealing act.
I did 3 since last December on my TR6 at 500, 1500 and 6700. The average went from 155 to 166 to 176.
 
I'm more casual about the whole thing. Baby it a little for 500 miles, then retorque the head, run the valves, change the oil & filter, & drive it like you stole it.

It's not a Swiss watch, it's a TRactor motor.
 
TR3driver said:
I'm more casual about the whole thing. Baby it a little for 500 miles, then retorque the head, run the valves, change the oil & filter, & drive it like you stole it.

It's not a Swiss watch, it's a TRactor motor.
Click to expand...

:iagree:

And I'd add that I was always taught that the best way to break in an engine is to vary the speed on short trips, rather than taking a long easy cruise.
 
I love the way Randell thinks!!! We just came back from Triumpfest on Sunday, 450 miles and the 75 mph average was fun, but the 100 mph spurts for a few miles were a blast!!
 
Re: Questions about Breaking in a refreshed TR3 En

what is the recommend cylinder head torque for a Tr3? I've heard various opinions and wonder if there is a general consensus?
 
Re: Questions about Breaking in a refreshed TR3 En

Aloha Karl,

I used 100-105 Ft/Lbs for the cylinder head nuts. This is what is listed in the Workshop Manual, Haynes and Bentley.

I'm going to run a compression test today to establish a base line, change the oil (filter also) to a 10W40 and recheck engine timing. A plug read indicates fuel/air mixture is good and valve clatter is normal after last adjustment.

I'll run through a tank of gas before retorquing the head.

Initially the engine seems much more peppy and smoother. The vibrating review mirror is now usable. New exhaust system also makes the car alot quieter, so strange noises will be easier to hear.
 
Re: Questions about Breaking in a refreshed TR3 En

MGTF1250Dave said:
I used 100-105 Ft/Lbs for the cylinder head nuts. This is what is listed in the Workshop Manual, Haynes and Bentley.
Click to expand...
:iagree:

If you try to cheat and go higher, you'll wind up with distorted studs.
 
Re: Questions about Breaking in a refreshed TR3 En

Don't forget a little lube on those...
Though, I guess if you are retorqueing, there prolly is oil on em.
 
Re: Questions about Breaking in a refreshed TR3 En

Aloha All,

I changed the oil to 10W40, but still get up to around 80 PSI at around 2500 or so RPM. I think I'll back off the pressure relief some to lift around 70 PSI. I checked the torque on the head and the nuts out near number 1 and 4 needed to be tightened. Hap Waldrop has commented in other posts that the nuts out from the center often need tightening after a few heat cycles. Rings are still bedding in, readings where consistant at around 70 PSI, dry and engine cold. I adjusted the static ignition timing to about 8 degrees BTDC and it starts alittle quicker now. I just got back from a 35 minute drive through the neighborhood and all gauges where reading normal. So now all I need to do is continue to drive it.
 
Re: Questions about Breaking in a refreshed TR3 En

You might also think about using a 30w non-detergent oil AND add a ZDDP supplement.
I know 30w ND is old school...but we are talking about a TR3 engine
 
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