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TR2/3/3A TR3 engine build

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J

jdavis

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actually the motor is from an early 4A. I have a couple motors to choose from for my 59 TR3A project, but the 4A engine turns easily and is complete. I've never done a wet liner engine before. I've built a couple of TR6 engines and a couple of small block Chevy motors over the years, and mostly, they held together. I've dismantled the engine, and am in the process of ordering some parts. The main pins looks like it is .20 thou under, and the crank pins are 10 thou under. I'm going to take the crank to a machine shop and see how out of round it might be before I order bearings. One of the con rods is obviously slightly bent. The corresponding cam lobe is a bit pitted, although the lifter looks fine. I've got another set of straight con rods I can use. Otherwise, I think I have a good pIatform from which to start, I've read a lot about these engines, and I'm confident I can build a good reliable engine. I'll have lots of questions from those of you who are willing to offer advice. The car is just for fun. I have no aspirations to do anything with it other than play with it. I know I need all the major internals including a new piston/liner set and cam. My question for the day is: If money is no object (of course it is) Is there any reason NOT to go with 89 mm pistons? Rimmer brothers has an AE 89mm set for basically the same price as the 87mm county brand that TRF sells, and only slightly more than the other brand 87mm piston/liner that BPNW and Moss sells. I figure the more displacement, the better I plan on increasing the compression only slightly, and using a 270 degree cam. I have a header, and I will do some porting on the head. Any advice about the 89mm AE piston/liners would be appreciated. I see that most of the vendors sell a head gasket to use with the larger displacement set. Are there any other problems?
Joe
 
Hi Joe,

Good luck with the engine build...take some videos :cool:

I think that I have read that one of the negatives of going to the larger Pistons/liners is a hotter running engine. That coupled with the header might give you some pretty hot temperatures under the bonnet so you may need to consider how you are going to cool it down as well. I believe I have 86 mm in mine as an FYI

Cheers
Tush
 
Don't forget, the TR4 has a different front plate. You'll want to build with a TR3 plate.

In addition to possible cooling issues (some have em, some don't), you'll also pick up some compression ratio with the bigger liners. You might want to check combustion chamber size.
 
Aother thing. I thought my crank and cam sprockets looked good and fit well to the new chain. So I only changed the chain. 3500 miles later, I had to replace the sprockets (and chain) when the chain started hitting the cover. A major job when the body is together.

Bob
 
Did you determine what caused the chain to hit the cover?

I did the same thing, just changed the chain as the sprockets looked fine.

David
 
jdavis, to add to TR3driver's comment, if you DO find you've installed a TR3 engine with a TR4 front mount, simply jack up the plate off the mounts and remove about 1.25" of the lower part with a sawzall then weld the old mount base plate onto the 'shortened version'. That works. (...Don't really want to talk about it...but did it).

Thom
1959 TR3
#34909L(O)
 
New cam should get new lifters. The 4A head will have the lighter 5/16" stems on the valves (better). You should get hardened seats in the valves . I use the 86 mm pistol because it gives me more distance between the coolant passages and the combustion chambers. I have had two head gasket failures even with the 86 mm Pistons.
though parts do add up I prefer to spend the money up front and get a reliable engine rather than gamble and pay later.
Charley
 
My engine was rebuilt 2 years ago after a crank failure. I went with 89 mm's and a slightly more agressive cam. Head was perfect so did not have to be machined. I was concerned about compression ratio but it has all gone well. We went with the lip rear seal, vernier timing gear and the engine was balanced, ARP head bolts, new lifters etc. I have an OEM rad with the crank hole and have had no heating issues for normal driving. In traffic with excessive idling, the temp does sneak up just like every other TR. Have not dyno'ed the car to determine power, but the torque is there well past 3500. Very quick car now. Watch out Tush!
 
Hi Joe, as Tush asked, if you could post pictures or video along the way, it would be most appreciated. I have to start a rebuild in the near future and while I have been all around the motor, I've never opened one up. If it helps, my supplier in Canada gave me a detailed parts list (Moss) that I would be happy to forward on,
Good luck,
Kerry
 
Frank_D said:
My engine was rebuilt 2 years ago after a crank failure. I went with 89 mm's and a slightly more agressive cam. Head was perfect so did not have to be machined. I was concerned about compression ratio but it has all gone well. We went with the lip rear seal, vernier timing gear and the engine was balanced, ARP head bolts, new lifters etc. I have an OEM rad with the crank hole and have had no heating issues for normal driving. In traffic with excessive idling, the temp does sneak up just like every other TR. Have not dyno'ed the car to determine power, but the torque is there well past 3500. Very quick car now. Watch out Tush!
Click to expand...
:cool: You will have to drive mine to compare!

Cheers
Tush
 
charleyf said:
I have had two head gasket failures even with the 86 mm Pistons.
Click to expand...
One thing I learned the hard way is to always check liner protrusion on both sides! Twice in a row now, I've found that the liner tops are not square to the block surface (apparently the block is not machined just right), and one side is low. Of course, I was always checking the other side ...

Of course, the right solution is to have the block machined; but this "shade tree" solution has served me well for a lot of years now.
 
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