TR4/4A Engine rebuild on a TR4

[Jerry]

I helped a friend pull his engine today. Everything went well and the engine actually looks very good for having 145K on it. I did notice signs of the engine being apart before. IE: flywheel lock tabs not on all the way, bolts on the sump are different. The engine is a baby blue color. My friend has owned the car since 1970 and has never had the engine out. He has only replaced the clutch and done other minor matainance. Anyone know a rebuilder in Northern California that used to paint the engines baby blue?

Jerry

 

[KVH]

No, but there might be one out there worried about being disciplined after all these years.

 

[glemon]

No but I have seen a lot didn't Ford paint their engines that color for a while, maybe people did it because they had some extra engine enamel sitting around.

 

[Jerry]

It does look like a Ford color! I would not pick on anybody who did this engine. 145K with no issues is quite good.

Has anyone installed the later TR4a radiator into a TR4? any issues?

 

[Healey_Z]

I was going to say, if I can get 145k out of an old motor, they can paint it any color they want.

 

[TomMull]

I was going to say, if I can get 145k out of an old motor, they can paint it any color they want.

True enough although at least one forum member has gotten that much. My experience is about half that does them in.

I've also heard that there were some engines originally painted body color (powder blue?). I've never seen one, though. Anybody else heard that rumor?
Tom

 

[mallard]

I read TR4 factory replacement engines were painted a light green. I found this out because I had one that I purchased to get the alloy sump that it had.

 

[Jerry]

I don't know on your light green but the transmission on my TR3A was painted morris green. Since the engine that came with the TR3A is a TR4 engine, I don't know where the transmission came from. Wish it had OD.
JErry

 

[Jerry]

I wanted to give you an update on this engine we tore down. 145K and the engine looked real good. Until, we pulled piston number one and four. The top rings were broken but still in place. I would say the cylinder walls were very smooth. He did have a problem with the car overheating and the top of the pistons and valves were white indicating a lean mixture. But the shafts on his carbs were noticibly loose so he had extra air coming in all over the place. Does anyone know if you can buy oversize shafts to Stronbergs? He is not a hard driver with his car, and it has lasted very well.
Even the bearings still looked good, but more than half worn through. He thought he was hearing a rod knock.

Jerry

 

[SteveBones]

Hi Jerry,

I would suggest using regular sized replacement throttle shafts. I have owned 5 Triumph TR's (TR4, TR4A x 2, TR250, and a TR3A) . All were "original" meaning they needed various items rebuilt. This included rebuilding the carbs and replacing the throttle shafts because of excess play. All of these did not require me to rebush the carb body, but just replace with new throttle shafts.

The first TR I bought in college and due to limited budget ended up just replacing the throttle shafts due to major issues at idle. I just finished a TR3A where the car had been sitting for over 10 years in a garage, and the carbs looked to be original including the throttle shafts. I was actually concerned that these TR3A carbs were in such bad shape that they would need to be replaced. The previous owner actually replaced them with webers so they were off the car when I purchased. After rebuilding the carbs, including replacing the throttle shafts, the carbs and the car run great.

I would check and see what others have to say on this, but for me I have replaced the throttle shafts on 5 Triumphs over 30 plus years and the results were very, very good.

Good luck,

Steve

I wanted to give you an update on this engine we tore down. 145K and the engine looked real good. Until, we pulled piston number one and four. The top rings were broken but still in place. I would say the cylinder walls were very smooth. He did have a problem with the car overheating and the top of the pistons and valves were white indicating a lean mixture. But the shafts on his carbs were noticibly loose so he had extra air coming in all over the place. Does anyone know if you can buy oversize shafts to Stronbergs? He is not a hard driver with his car, and it has lasted very well.
Even the bearings still looked good, but more than half worn through. He thought he was hearing a rod knock.

Jerry

 

[EV2239]

Triumph's reconditioned engines were painted baby blue and the original serial numbers ground off. Instead they had a riveted on plate with a recon number on it.

The main bearings don't usually wear much but the big ends do, as do tappets, camshafts and rocker shafts, so best check carefully. I've just rebuilt a couple of TR3A engines so it's fresh in my mind.

 

[KVH]

I too agree on the carburetor shaft issue--just put new ones in or re-bush, too. Any good machine shop could re-bush for you.

About the camshaft on a rebuild. It looks quite difficult to work with those pressed in bearings. I assume that requires bringing the block to a machine shop as well?

And where on the engine would you rivet a new serial number? The front plate?

 

[SteveBones]

Very interested regarding the Triumph reconditioned engines. Also the info on what to look for during an engine rebuild is helpful as well. It is something I will want to do in the near future.

Steve

Triumph's reconditioned engines were painted baby blue and the original serial numbers ground off. Instead they had a riveted on plate with a recon number on it.

The main bearings don't usually wear much but the big ends do, as do tappets, camshafts and rocker shafts, so best check carefully. I've just rebuilt a couple of TR3A engines so it's fresh in my mind.

 

[bgbassplyr]

ISTR that the cam bearings weren't all that much of a 'pressed' fit, more of just tight as they were/are held in place with a set screw. I think the Churchill tool used for the installation was a simple mandrel used to tap the bearing in place.

Serial number plate was riveted onto the boss where the original number was ground off, I think.

 

[Jerry]

How much reaming is usually required if you put in new cam bearings?

Jerry

 

[bgbassplyr]

How much reaming is usually required if you put in new cam bearings?

Jerry

AFAIK, none. The cam bearings are one piece with babbit inner surfacing, so any reaming will ruin the bearing.

 

[EV2239]

Here's the one I've just done for my TR3A

 

[martx-5]

Looks good...I see a narrow belt conversion and spin on oil filter. Any other mods??? And what happened to the chrome rocker cover??

 

[Don Elliott]

Ash - Is the valve cover from a TR2 by any chance ? The early TR2s had the valve cover painted black. But all the rest seems fine. Did you get it in and start it yet ?

Cheers

Don

 

[EV2239]

Mine is one of the last that had a black rocker cover and it's mostly standard apart from being 2187cc, fully balanced, having a lightened flywheel with TR4A spring diaphragm clutch and a fast road cam from Kent cams. It might be 120bhp, it doesn't tick over as smoothly as a standard car, but has more mid range and revs more freely, I don't know how far because I'm running it in.