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TR4/4A TR4 Seized [?] Engine

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TRDejaVu

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The barn find 62 TR4 that arrived yesterday sat without a cylinder head (I obtained one seperately) for nearly 3 decades. Today I dropped the sump and all the lower end had been sitting in oil and, without disassembling the big ends, appears to be good. The bores seems pretty good, but I am unable to turn it over manually using the fan or backdriving from the rear wheels with it in gear (it's up on jack stands). I poured oil onto the piston tops and #'s 1, 2 & 3 drain down, while it pools in #4. So I'm guessing that #4 rings are stuck.

I was wondering whether to put it back on its wheels and try gently moving it in gear. Any advice on freeing this up, or should I be resigned to disconnecting the pistons and pulling out the applicable liner?

Thanks
 
Try soaking the cylinder in Marvel Mystery oil for a while. Another option is to use diesel fuel to soak the cylinder. I've actually seen a mechanic fill the crankcase with diesel fuel, let it sit for about a week and then drain the crankcase and fill with fresh oil and fire the engine. We've done this with marine engines that had been submerged in river water.
 
With it being stored for 30 years w/o a head and you have the oil pan off; I would take the pistons out and all the bearings to see the status. No experience with liners but if they only need a hone and the pistons need rings, why take the liners out? Measure the journals, mains and rods, to see if the crank has been turned before and to see the bearing size you will need. The back of the bearings will tell you what size is currently installed. Oil pump is important as much as anything else you do to the motor, so look it over carefully. I would put in a new pump or at least rebuild the old one.

If your intent is to free up the bottom end with oil or what ever and bolt on the "new" head, I think it is a little aggressive on a motor sitting 30+ years especially opened with out the head.

I bet you have a great time with your new TR4; can't wait to see pictures!
 
Well if you just want to free it up...Shoot some penetrating oil(or marvel oil)down the cylinders...let it sit for a few days(add a little more each day) then drop the car on it's wheels and get a bunch of people to help push it with it in gear...rock it back and forth...that should free it(worked many times for me)
 
[ QUOTE ]
The barn find 62 TR4 that arrived yesterday sat without a cylinder head...The bores seems pretty good, but I am unable to turn it over manually using the fan or backdriving from the rear wheels with it in gear (it's up on jack stands)...I was wondering whether to put it back on its wheels and try gently moving it in gear. Any advice on freeing this up, or should I be resigned to disconnecting the pistons and pulling out the applicable liner?

[/ QUOTE ]I have to ask: have you been doing this with no cylinder head bolted on and torqued down? If so, I think you'll be wanting to take out all four pistons AND liners. Perhaps it's not very likely in a motor that has sat for so long, but at this point I'd already be worried about liner movement and disruption of the "figure eight" seals below them.
 
Thanks for the quick responses. While normally I would disassemble to find the cause, with this one I need to try to run it, as well as try out the transmission etc. so I can see what I have bought. If the engine seems to run OK (oil pressure, cooling etc) and doesn't have any bad knocks or noises then I will concentrate on areas that may have a more immediate need for attention.

I have a good view of both ends of the bores, so if I can free it with one of your magic potions I can check for surface marking when turning by hand. If that is OK and I get it loose enough I will fire it up.

Would the Diesel fuel cause any problems with internal seals or gaskets? Someone else suggested PB Blaster. However the most popular approach seems to be Marvel, which is a new one to me.

Andy, yes I did have the liners locked down just in case, but thanks for the reminder anyway. In the heat of concentrating on the problem at hand, it is all too easy to forget something like that.
 
I would have agree with Andrew. Your going to waste a lot of money putting the motor back together only to find you might need new pistons and liners. If your going to keep the car, do a complete rebuild. Pistons, pins, liners and rings are less than $500-, well worth the money.

Bill
 
I have run into this before. Both times they were really stuck bad. I had tried soaking them for weeks with no avail.

In both intances I removed the other three pistons and used a 20 ton hydraulic press to get it un siezed. The engine was rebored and rebuit afterwards.

Even if you do get it free with just oil, I would recommend that at you deglaze the cylinders and install new rings.
 
I had a similar problem with the engine in my TR4A when I aquired it - penetrating oil, ATF, coke, etc were all tried without sucess.

The problem is when the cylinder is exposed to the atmosphere and the oil has drained off corrosion sets up between the aluminum pistons and the iron liners, wedging it in tighter and tighter.

To free it you will have to remove the liner and piston. Set it up in a heavy duty press and apply pressure - if that doesn't pop it out, try using an oxy torch to heat the liner red-hot then try to press it out again.

When all else fails to free it, wack the side of the liner with a sledge hammer (doesn't have to be too hard) once the liner cracks, the pressure from the corrosion will be relieved and you can pull the piston and rod out. (can you guess how I know this?)
 
Thanks for the suggestions, it is always good to get different viewpoints to solving a problem. As I do all my own work (well almost all), my only investment at the moment is my time. The car has many other things that also need immediate attention, so I am going the penetrating oil route to start with.

Yesterday it was doused with Gibbs penetrating oil, which was recommended to me by my local NAPA dealer when I bought the Marvel Mystery Oil. He said that he had heard very good reports about Gibbs and gave me a free sample to try. Today I have doused it in Marvel and will continue to alternate them. Not a scientific approach, but I'll see what happens and let you all know. If there is no sign of improvement in a few days, then I will look at removing the piston.
 
Update - I gave it a day of Gibbs and then used some Marvel for a few hours. Then I tried carefully hitting the piston from below using an aluminum (I don't say aluminium any more) drift on the thick area that houses the gudgeon pin. It didn't take much force and the piston was free. It was badly gummed up (not corroded) from decades of not running, but it has all cleaned up well.

My immediate priority is trying to get a bit of driving out of it before winter (ambitious, but potentially do-able the more I look it over) when I will concentrate on preventing the body and frame from going beyond some surface rust. So if I can get a year or two out of the engine before replacing the liners etc. I will be happy. I have taken out all the pistons, which still look good, and will be replacing the rings. Bores are still good, so I have dressed the lip edge (very small) and will glaze bust them. Gudgeon pin bushes (little ends) seem good, but I will replace the conrod (big end) bearing shells and thrust washers.

I have been using the Gibbs and am quite impressed with it so far. I cannot compare it to the other products as I have yet to really try them.

Other tasks done this week include:
- cleaning up the brake and clutch master cylinders and replacing all the seals etc. The casings came up really well; I hope that I can keep them that way.
- removed and dismantled the pedal box to de-rust and repaint.
- de-rusted the pedal box support structure using the Eastwood product.
- general engine crud removal.

While I am waiting for the engine parts from Moss I will start on the brakes and brake lines as well as the clutch slave cylinder and lines.
 
DejaVu -- Go for it! These are tough engines and you may get years out of your one if you just do as you say and replace only some of the parts. If it doesn't hold up, well you are then where you would have been if you started the complete rebuild now. Good luck, I hope it starts up and you get a good ride for a while.
 
[ QUOTE ]
Update - I gave it a day of Gibbs and then used some Marvel for a few hours. Then I tried carefully hitting the piston from below using an aluminum (I don't say aluminium any more) drift on the thick area that houses the gudgeon pin. <Snip>

[/ QUOTE ]

You don't have to say aluminium so long as you keep saying gudgeon pin. /ubbthreads/images/graemlins/wink.gif /ubbthreads/images/graemlins/smile.gif
 
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