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TR4/4A Oh crud - not encouraging...

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tdskip

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Hi guys - started in on pulling the head per Randall / Ken's suggestions on my stuck TR4 engine. When I started in it became apparent that this was apart, was put back together but not to run as there were no locknuts and manifold gasket etc and the head bolts were not fully tightened.

I have gotten to a point where the head - in theory - should want to come off but look at the condition of the push rods. Ugh, looks like dirt and rust on them to me.









I'm thinking it is full rebuild time - yes?
 
Depending on circumstances, I wouldn't pull the trigger just yet. The bit where the pushrods ride in the lifters looks like it might be OK and some light rust on the sides won't hurt anything. Get it apart, see all the bad news, then make a decision.
 
Got the head loose. First time taking a cylinder head off a car, kind of fun to learn a new thing (not that is difficult or anything).

No head gasket. Looks like this sat at least partially dissembled for some time.

Red liquid in the cylinders is MMO, apparently I got an adequate amount plus some down the spark plug holes. Ha.

Anything jump out at you on the underside of the head?



I don't have a good idea what I should be looking for here, but there looks to be red gasket flakes all over the place. Not sure if the liners are supposed to have openings and that crud means anything. #3 cylinder (3rd in from the front) has corrosion in the bore.







View of all four:

 
The head looks very clean, like it might have been rebuilt. Not so much the cylinders. It's hard to tell if the cylinders will clean up with a hone, or will require more attention.
 
That head could use a trip thru the plane at a machine shop. Pitting and general surface condition look unacceptable.
Bob
 
Thanks guys - to my eyes the valves look new-ish. Any way to actually tell?

Need to figure out why the engine is still stuck still.
 
Yes, those valves appear to be unused to me.

As for stuck - considering the reasonable price of liners and pistons I would just hammer out the old liners with their pistons still stuck in them and go with new. IMO #3 looks like a 'no-hoper'.
 
Thanks Geo.

Agreed - that looks pretty nasty. If I go with a stock size piston and liners I believe that's only around $500 but that assumes the crank and everything else is OK.

Assuming I'm going to put in new liners and pistons what's my next thing to check here?

Thanks!
 
Okay, you now have put your big toe in the water. It seems to me that you should be about ready to jump the rest of the way in. One more point regarding the head that appears to have new valves. Does it have hardened seats on the exhaust valves? These are needed so that use can save the engine while using today's gas.
Charley
 
I'd probably pop the rod & main bearing caps off, make a decision on whether the crank has to be ground or replaced. Lifters should fall out when you turn the engine over, if not you may have to apply some force from below to get them out. Then pull the cam for inspection.

Obviously you're in for at least a partial rebuild. Now you're just deciding which parts can be reused, which can be rebuilt (eg grinding the crank journals undersize) and which have to be replaced.

If your machine shop can handle it, I've heard it can be cheaper to have the old liners bored oversize and just replace the pistons. But I've just always bought the liner set. BTW, BPNW has the 87mm set listed for $450.
 
Hi Charlie, thanks for the note. I am prepared for a full swim if need be but am looking to minimize my exposure to water if that makes sense.
 
Last edited:
TR3driver said:
I'd probably pop the rod & main bearing caps off, make a decision on whether the crank has to be ground or replaced. Lifters should fall out when you turn the engine over, if not you may have to apply some force from below to get them out. Then pull the cam for inspection.

Obviously you're in for at least a partial rebuild. Now you're just deciding which parts can be reused, which can be rebuilt (eg grinding the crank journals undersize) and which have to be replaced.

If your machine shop can handle it, I've heard it can be cheaper to have the old liners bored oversize and just replace the pistons. But I've just always bought the liner set. BTW, BPNW has the 87mm set listed for $450.
Click to expand...


Good morning Randall, thanks for the help. So I have not taken the lifters out, but I should be able to pull them up and out at this point. Correct? I need to keep those in the same order as the pushrods if I intended or use any of that, is that right?

as far as the bottom end of the engine goes my next step is to get the car securely I open the air so I have room to way underneath it and have a oil and dirt falling to my face. Then oil pan off and the rod and bearings should be visible, right?
 
tdskip said:
... my next step is to get the car securely I open the air...
Click to expand...

Got it -- 'up in the air' -- I love autocorrect.

There are several ways to do this but for a long term project one way is using cribbing:

Crib2_zps180a0dd8.jpg


Tom Mink also used cribs in his well documented TR4 project: https://www.britishcarforum.com/bcf/showthread.php?95332-Your-thoughts-value-of-this-TR4/page10
 
When I get the car securely up in the air and pull the oil pan off someone walk me through what I'm specifically looking for? When I take the bearing caps off am I looking at whether the bearings are spun? Am I using plastic gauge at that point to check tolerances?
 
Right, lifters should be ready to lift out and it's best to keep them in order. Pushrods aren't so important to keep in order, but it certainly won't hurt.

Plastigage is probably a waste, unless the bearings are new. I'd plan on replacing them if the engine has been driven at all. But you can use a mic to check the rod journals condition, as well as visually inspecting them and the main journals. Rods typically wear faster, so if they are OK, chances are the mains are fine too.
 
Sure. Note that there is supposed to be a fiber washer on the support post, that frequently gets left out. My gasket set didn't have one, so I cut a corner off one of the unused carb-manifold gaskets and used that.
 
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