TR2/3/3A Replacing the pistons and wet sleeves

Hi everyone...
So after a few months of thinking about it, i've finally started the tear-down of my 58' TR3a. I did have a few questions though for anyone who wanted to chime in. I'm pretty mechanically inclined and have done a ton of engine related work over the years on various cars but have never quite replaced pistons (and everything that goes with it). Soooooo... here it goes:

1.) Obviously if i'm going the distance and replacing the pistons and rings, I might as well replace the wet sleeve liners, correct? With that thought in mind... my TR3a has the stock 83mm pistons in it. Is it advisable to simply put the same type of piston back into it? I live in the hot Florida sun, so I'm thinking that going up a few sizes really isn't beneficial to me at all (heat). I'm not looking for more HP or torque... just looking for less smoke and more compression. I was originally thinking that heck, since I have it torn apart, I might as well go up to a higher mm size piston but after reading some threads and talking to people, I'm starting to wonder if I should just put the same back in, only brand new. Thoughts??

2.) Let's say I was going to go up in piston size: Since mine is currently stock 83mm... would I need to have the engine block bored out for larger wet sleeves?? From what I understand, the outside diameter wet sleeve is the same for all piston sizes. I don't think I would have to do that, correct? Just pop the new sleeves and pistons right into place?

I already have the cylinder head off. getting ready to go from underneath and do the piston removals (I"m not taking the engine out. I'm doing this all with the engine in). Any recommendations on a good head gasket? The one that was in it that I took out yesterday was a copper head gasket... and in excellent condition when I removed it.

3.) Finally: after I drained the coolant and removed the cylinder head, I noticed that there is still a ton of coolant all around the wet sleeves. I cannot figure out how to drain the coolant from the actual engine block. I have a brass valve on the left side of the engine block near the carbs but when I open it, it only drips very so slightly and doesn't appear to be draining anything at all. Any ideas on draining the entire block before i start pulling wet liners and pistons?

Thanks so much... I'm REALLY enjoying this tear-down, believe it or not. Any thoughts/suggestions/experiences would be GREATLY appreciated!
Billy

Issue 1 depends on how the sleeves mic for diameter and roundness. You need a round piston that fits a round hole (ovoid won't do) within the specifications for clearance. On issue 2, the block does not have to be modified to fit the new liners. Issue 2.5, I like copper head gaskets. Issue 3, the drain valve is mostly clogged with particulates. The remaining water will come out when you pull the liners.
Good luck'
Bob

Thanks Bob. I noticed that when I pull the head off and inspected the liners on two of the pistons that were "down" in the sleeve, there are some heavy grooves in them about an inch and a half below the top of the sleeves. I'm assuming that if I buy new pistons and sleeves, the clearance will be OK since they are brand new? Meaning, I shouldn't have to do anything but put the sleeves in and install the pistons/rings correctly? That's probably my first newbie-piston-installation question of the day. lol

If the grooves are vertical, the engine had been dragging some metal up and down with the piston. If the grooves are around in the liner it is a sign of wear by intact rings rubbing the liner. A new piston /liner kit will fix either problem. I assume you have a shop manual to guide the new installation. E.g., liners have to stand proud of the block by a specified amount so the head seals against the tops of the liners.
Bob

yup... they are vertical. pretty wide and distinct as well. something was clearly dragging up and down with the pistons over the past 57 years. and yes, I have the manual and have a pretty firm grip on what i'm doing (i think). I just wasn't sure about if it would be beneficial to go up a few mm in piston size because I had it torn apart or if using the same stock size was the way to go. thanks a ton for the replies... definitely a huge help.

I built my first TR3 in the late sixties with 87MM bore. Ran it in Miami for several years without overheating problems. I ran that car, as I do my present one, without thermostat. There are several ways, often thrashed on this forum, to augment cooling. You will be measuring the crank for roundness and clearance? Probably going to be bad news there as well. You may need to machine the crank. (More work than you plan, but worth it.) Consensus on this forum is that new rod bolts are always in order.
Bob

I can think of a couple of benefits of replacing the liners. One, the new liners will be ready to install, so that will offset some of the cost of having the old ones bored/honed. Also, by removing the liners, you can really clean out the inside of the block. I probably close to doubled the volume of coolant in the head by grinding out all of the rust and scale. Of course, you could knock out the liners, clean the block and then put the old ones back, but seems silly. And there is a nonzero chance that you will break one of the liners getting them out.

I replaced my TR3A pistons and liners with an 86mm set - have observed no issues with cooling, even in Tucson summers. Depending on what you find around the old ones, your cooling may even improve with new liners.

Remove the brass petcock or plug on the side of the block and use something (bamboo skewer, drill bit by hand, etc) to poke around in that hole -- should free up enough crud to get it to drain. Yeah, it'll all come out when you knock the liners loose but you don't really need a green shower.

To knock the liners out I used a tip I got from Randall -- made a big drift from an 18" length of 3/4" iron pipe with an iron cap on one end and a brass cap on the other. Hitting that with a 3# hammer had them out in a jiffy.

Did the engine knock? Are you going to replace the rod bearings? You can take the chance and put new rod bearings and not deal with the crank and see what happens, but usually the engine life is short and they start to knock after a while. The path you are on with leaving the crank in place is not usually done, but you might get lucky if you take the rods out and have them rounded for trueness and replace the wrist pins and rod bearings. A local machine shop perhaps would charge less than 100.00 and again the motor might last for 50k depending how hard you drive. I would have the head rebuilt also and that could easily run 600.00, so you start to see why most people do a total first class rebuild. But again you might be able to just clean the carbon off the head with a wire brush and go for it. After all, a tr3 is a rough and ready kinda car and I have done the frugal rebuild and just drove them and enjoyed it.

There are two kinds of "copper" head gasket. Solid copper, and copper clad composite. The latter type is stock, and much preferable IMO (unless you are building a high compression race motor or plan to tear the engine down every few months). Payen was the best brand, but they don't make them any more. The "no name" I got from TRF seems to be working out fine, though (with the fire ring mentioned below).

Having gone that route myself more than once, I strongly suggest you bite the bullet and pull the engine out. As Bob noted, the crankshaft is very likely to be worn even if it isn't damaged like the cylinder wall and the crank cannot be removed (for machining) with the engine in the car. Plus, when you knock the liners out, all that crud from the cooling system is going to come raining down. At the least, you'll want to tie rags around the bare crank journals, so none of it falls into an oil passage or whatever. Also wear eye protection. Pulling the engine will also let you change the rear main bearing, which very likely needs it, and tend to the rear oil seal which is usually the major source of "marking it's spot".

I'll disagree on the rod bolts. I've been reusing the original bolts since 1975 or so (not all on the same engine of course) and never had a problem. In fact, that first engine I "rebuilt" after a blowup (with the engine still in the car) still runs today. However, don't try to reuse the lock tabs. Many (myself included) just leave them out entirely and use a drop of Loctite instead. If you do that, though, double-check that the bolts don't bottom in the threads.

Don't assume that the new components are right, just because they are new. In particular, check the end gap of each piston ring, preferably in the cylinder it will be installed in; and check the liner height on all liners, both sides. Twice in a row now, I've discovered engine blocks that were apparently not machined exactly right at the factory, leaving the liner height too low just on one side. Took me a long time to figure that one out! If you do find a problem, you can either pull it all apart and lug the engine block to a machine shop to be re-machined; or what I did was to add a ring of copper wire to the head gasket around each cylinder. Haven't lost a head gasket since I started doing that; before I used to have to change the gasket at least once a year.

When checking your old liners, you also need to check for wear. Usually you can estimate the wear by looking at how tall the ridge at the top of the cylinder bore is, but you can double-check by measuring the end gap of a ring at both the bottom and top of the cylinder. Generally the wear is concentrated at the top (just below the ridge), the bottom of the cylinder won't wear at all (unless the oil was dirty or contaminated).

The scored cylinder points to a ring likely being broken. Then, if there is enough scale around the sleeves to plug the block coolant drain, I think you would be much better off pulling the engine to work on it. The ledge in the block that holds the sleeves must be absolutely clean and free of scale. I just cannot imagine trying to clean the scale out while hanging over a fender.

I just put my motor together. Even after tanking and wire brushing, I still had to work for 2 hours with a scraper to get all the scale out for the new sleeves. A single chip of scale that falls down while you're installing the sleeves will be enough to ruin your rebuild.

As did Randall, I built my current engine reusing the rod bolts that came in it. I believe that Randall and I are among the minority of opinion on the issue on this forum, though.
Bob

bobhustead said:

As did Randall, I built my current engine reusing the rod bolts that came in it. I believe that Randall and I are among the minority of opinion on the issue on this forum, though.
Bob

Click to expand...

Here is an engineering perspective on rod bolts.

In order for metal to fatigue, there has to be a cyclic tensile load. At first glance, you would think the rod bolts are subject to an extreme cyclic tensile load...but they actually are not. When you torque the rod bolts, they are stretched. In operation in the engine, the only way they can see a cyclic load after the initial stretch is if the rod caps began to physically separate, therebye further stretching the bolts. The only way it is possible to physically separate the rod caps would be to significantly over-rev the engine, so the rods are subject to higher than designed loads...or if the bolts were not properly torqued to begin with.

So, the rod bolts do not fatigue in normal use, and can be reused almost indefinitely, so long as they are otherwise undamaged. But, if you know that an engine was ever significantly over-revved...trash the old bolts!

There is an exception to the above, but it only applies to later generation rod bolts. Many newer generation motors use rod bolts that are designed to be installed so tight that they permanently deform on the initial torquing. These type bolts are always throw away items. They cannot be reused even once...and that even applies if you never ran the motor and have to later remove the bolts!

Good stuff from John about the connecting rod bolts - to confuse things a little, later in TR4 development they eliminated the tabs, and went to a stretch style bolt that didn't use tabs - I think those are the bolts you would want to replace as John mentions. But on my 3A engine I reused the bolts and used fresh locktabs.

I totally agree and recommend that you pull the engine to do this work - the main issue is the scale between the liners - you have some for sure based on your difficulty to drain coolant. Its a much easier operation with the engine out, and given the work you are doing taking out the crankshaft and making sure it is in good shape is worth the effort.

CJD said:

Many newer generation motors use rod bolts that are designed to be installed so tight that they permanently deform on the initial torquing. These type bolts are always throw away items. They cannot be reused even once...and that even applies if you never ran the motor and have to later remove the bolts!

Click to expand...

However, I believe there is a certain amount of urban myth about which motors actually use TTY rod bolts. In many cases, while the manufacturer specifies to either measure bolt stretch or torque to a value and then turn an additional number of degrees; the bolt is not actually being torqued beyond it's yield point.

And of course all this assumes that the bolts were installed properly before. If some gorilla put it together with a breaker bar last time, then you probably do want to use new bolts, along with having the rod ends checked for roundness and so on.

One simple test is to spin a new nut of the appropriate thread up the bare bolt. If it binds partway down the threads, the bolt is likely distorted and should be replaced. Also a good test for head studs (which can be distorted the same way and should be replaced if distorted).

Just to add a data point - I replaced my sleeves and pistons with the engine in the car & re-used the rod bolts. Got such a smokin' deal on the piston/liner/rings set that this ended up being my $300 'rebuild'. So far so good at 3 years & 4K miles.

That said I was pleasantly surprised how clean the inside of the engine was (work was required due to a broken ring that damaged both the piston & liner in #4). I wrapped the crank journals in aluminum foil then wrapped tape over that to keep them clean.