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TR2/3/3A Engine rebuild - looking for preliminary advice

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wifegonnakillme

Jedi Hopeful
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I picked up a '56 TR3 as a failed project from the previous, previous owner that has been sitting in a pile for several years. While I am fine with the body work etc. I have never rebuilt an engine. This one was bought in an unknown state, but to my surprise, it turns nicely and based on when the speedo was removed has about 87000 miles on it.

Since it's out, I will refresh the engine over the winter. I have had two 3's in the past and for this one I am interested in getting it up and running as a strong driver, I will not be showing it and am not interested in sinking huge cash into gaining a few extra HP. So, I would welcome advice on how to approach this. There appears to be a full engine rebuild kit from Rimmer, but no other full kits from the usual suppliers - is this because people just buy the piston kit, gasket kit and head kits separately? Should I do the head while I am at it (I assume yes).

I do think I will go with 87mm as I am not experienced enough to deal with the tweaking that appears to be associated the 89mm. So, if someone could point me generally toward what supplies I will need, I'd appreciate it. I will order them now and do my research as I await goodies to start arriving in the mail,

Cheers,
Kerry
 
I would definitely plan on hardened exhaust valve seats, and new valve springs. My "barn find" 56 suffered from severe valve seat recession, and I eventually had to replace them even with running lead substitute. Valves and guides will depend on condition, but with 87,000 on the clock, they are probably ready to be replaced as well. Probably best to have a machine shop do this for you, unless you already have the various special tools required. Also have them check it for cracks and flatness.

87mm is a good choice.

Check the cam & lifters; most likely they are ready to change as well, but they might be OK.

Obviously you'll want to change rod, main, and thrust bearings. But you won't know for sure what size to buy until you get the crank out for inspection. It may be fine, but it could just as easily be worn or scored enough to require grinding undersize. Or even have been ground before. Cam bearings are a maybe, but I'd change them for sure if you replace the cam.

Timing chain tensioner for sure. The chain and sprockets might be OK, though.

Be sure to get the right size mandrel for setting the rear main seal. The dimensions given in the shop manual are wrong. You can consider whether to upgrade to the "Mad Marx" contact seal, but the original type seal will work well enough if set properly. Oh yeah, you probably do want to replace the seal unless the main bearings are nearly perfect. It's hard to assess the condition of the seal itself, but if the mains are worn it's a safe bet that the crank has been rubbing the seal and it is worn as well. TRF has the updated mandrels and the Mad Marx seal; I don't think Rimmers does. Or you can get them from Joe Alexander at A.R.E. and possibly save a few $$.

If you have the 5/16" pushrods, you might want to think about replacing them. The 5/16" ones flex a lot in service, and eventually break. The 3/8" ones are a lot stronger.

There's probably more, but I need to go and that's all I can think of offhand.
 
Rebuild of four engines in our club, all TR3 or 4s. 3 of them had problems with the oil rings. These were the three piece type, thin ring top and bottom, with a spring in between. The cars burned oil after 1000 miles. Pulled out the pistons and replaced the oil ring with one from Hastings, and no more oil burn. So out of 4 kits, one had a one piece oil ring but the other 3 had a 3 piece oil ring. On two of the repaired cars, the tabs were broken on the spring piece when we took them apart.
The only other issue I had with the piston/liner kits is a ring gap that was upper edge of 13 thousand, which I would like less.
Jerry
 
All of the above...plus balancing of all rotating engine parts, lighten flywheel and balance, shave head for a little more compression, do away with the crank pulley and fan, fit harmonic balancer and thermo fan.
Mild camshaft with remetalled cam bearings fitted and line bored for accuracy. Use dual outlet exhaust manifold. Electronic ignition. Rebuild carbs. Be careful on what cylinder head gasket you use as some are a lot better fit than others.
You will achieve a nice engine without a great cash outlay....money well spent.
 
I would also suggest that you inspect the rocker shaft and replace any rockers if you are going to have the head done .

If you have the engine apart I would also recommend looking at a rear main oil seal conversion kit as its really annoying fining oil leaks after you have very thing back together and the engine in the car

cheers

Steve
 
Jerry said:
Rebuild of four engines in our club, all TR3 or 4s. 3 of them had problems with the oil rings. These were the three piece type, thin ring top and bottom, with a spring in between. The cars burned oil after 1000 miles. Pulled out the pistons and replaced the oil ring with one from Hastings, and no more oil burn. So out of 4 kits, one had a one piece oil ring but the other 3 had a 3 piece oil ring. On two of the repaired cars, the tabs were broken on the spring piece when we took them apart.
Click to expand...

I've never liked those 3 piece rings either but the cast ones seem to be hard to find. The 3 piece rings do work, however, if properly installed and are probably better than the cast ones. The problem I found was that the spring middle piece tends to want to overlap at the joint. Usually they have a bit of red and green paint on the ends which will show if they are correctly installed. Directions with the set are usually quite clear. Follow them. (I know this from experience).
Tom
 
Thanks guys, most appreciated. I will take your suggestions to my Canadian importer and start lining up parts... (and thanks in advance for when I come back with all kinds of dumb questions)
Cheers,
Kerry
 
Nobbster77 said:
I would also suggest that you inspect the rocker shaft and replace any rockers if you are going to have the head done .
Click to expand...
Better yet, send the whole thing off to Rocker Arm Specialists for rebuilding. Oops, I see they are now Rocker Arms Unlimited. https://www.rockerarms.com/pages/about.html

It's been a few years ago now, but when I sent them my shaft & rockers, the whole thing came back looking new and the cost (even with shipping) was only about what I would have had to pay for the shaft, bushings and adjusters. I'm still not certain if they reconditioned my old rockers or just replaced them, but they looked new right down to the copper colored coating. Only the pedestals and end caps were obviously still originals. (They were cleaned up nicely, but not bead blasted.)
 
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