Hi all,
I am looking for a few pointers from the Hercules gurus on this site.
I am working on a Hercules JXLD engine which came out of an M20 armoured car I am restoring. The JXLD had obviously run in it at some stage, but I did not know when.
When I first looked at the engine some 15 months ago, I found that it was stuck, but I managed to free it up quite quickly with a short bar through the flange on the gearbox. The engine then turned quite freely after that. I dropped the oil and put some fresh oil in it pending further tests I was going to do on it. I removed the gearbox as I had to do a rebuild on that.
Fast forward some 15 months and I am at the point where I need to see what the state of the engine is, what the compression etc is like, and whether it will run. I had replaced the large oil seal in the flywheel housing as that had shown signs of leaking and otherwise it looked good to test out.
I tried the engine yesterday by hand and found it was stuck again. I initially used a tool on the crankshaft to try and rotate it by hand but couldn’t get any movement there. I then used a short lever on the flywheel and sensed a little bit of back and forward movement on the flywheel. I decided to soak the cylinders with penetrant overnight and have a crack at it again the next day.
The gearbox and clutch were ready to fit and I was reasonably confident this engine would be a goer so I fitted the clutch and transmission today. I then put the transmission into top gear and gently rocked the engine back and forth again using a short bar through the flange on the transmission. I also used a bar on the flywheel again. Within about ten minutes I had movement in the engine. However, that movement is limited to about ¾ turn of the flange on the transmission. The engine won’t turn beyond that and has a very ‘solid’ stop to it when you get to that point on the rotation.
The pistons in cylinders 2, 4 and 6 are moving up and down. There is no discernible movement in pistons 1, 3 and 5, but that is probably due to the rotation point in the cycle where the engine is stuck.
Valves 4, 6, 10, and 12 don't appear to move. They may be stuck but that maybe also a result of the position in the cycle. That is, Intake valve on Cylinder 2, Exhaust valve on Cylinder 3, Exhaust valve on Cylinder 5, and Intake valve on Cylinder 6.
I’m picking a stuck valve (or two) are what’s causing the very ‘solid’ stop on the rotation but would be keen to get anyone’s thoughts.
If indeed it is a stuck valve, what is the best way to unstick then on a JXD. Do I just need to continue with the penetrating oil , or do I need a bit of heat on some of those valve stems to free them up?
Is there another method to unsticking the engine which is better than what I am doing? I’d prefer the softly, softly approach.
I've attached a few photos. The valves that aren't obviously stuck have a tick on the block beside them.
Any ideas from the group would be great.
Hercules JXLD stuck engine tips
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- G-Captain
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Hercules JXLD stuck engine tips
Darryl Lennane
NZ
1943 Willys MB
1941 LP2A MG Carrier
1943 White M3A1 AOP
1942 Willys MBT
1944 Ford M8 Armoured Car
1945 Ford M20 Armoured Car
NZ
1943 Willys MB
1941 LP2A MG Carrier
1943 White M3A1 AOP
1942 Willys MBT
1944 Ford M8 Armoured Car
1945 Ford M20 Armoured Car
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- G-Lieutenant Colonel
- Posts: 1192
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- Location: Albuquerque
Re: Hercules JXLD stuck engine tips
My question would be entirely different. I would want to find the problem and correct it, and all the other problems that develop with an engine sitting for years. A lot of guys have an overwhelming quest to make an old engine run without going through the engine first. That usually does more damage than good. Abrasive substances develop in the engine when it has sat for years and years. Seals deteriorate. Oil passages get plugged. My advice would be to completely dismantle the engine and check, clean, repair, replace as needed. Along that road you will find the “stuck” problem, and probably others. I had a scout car that had been sitting in a farm field and was full of mice. They get in the valve chambers and pee in there. That will make the valve stems stick.
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- G-Lieutenant Colonel
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- Location: Albuquerque
Re: Hercules JXLD stuck engine tips
Just an observation: since the cover is off the transmission, its possible that two speeds of gears could be engaged at the same time. That could lock it all up. Maybe disengage the clutch and see if it turns. Also, if the transmission is in 1st or reverse it would be very difficult or even impossible to turn the engine by hand the way you have it configured. Make sure its in fourth gear.
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Re: Hercules JXLD stuck engine tips
Any possibility you installed the wrong clutch bolts? If bolts are too long and protrude through the flywheel they will contact the block and exhibit the symptoms you see.
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Re: Hercules JXLD stuck engine tips
I would pull the pan, head, pistons and valves. clean pistons, new rings, do valve job.
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Re: Hercules JXLD stuck engine tips
Hi all,
Thanks for your thoughts and comments. I know what you are saying about stripping down the engine. I may well get to that point but at this stage I would like to check this engine out properly first and gather up a bit more information about its condition. I want to first make sure that it pumps oil, and then do a compression test and may then do a cylinder leakage test. That way, at least I'll have a bit more information about what I'm dealing with.
Jesse – the transmission is definitely in top gear. It has a synchromesh and can quite easily be put into top gear with a big screwdriver on the selector. Agreed – there is no way it could be turned in reverse or first gear.
Sawbuck – I’ll double check on the bolts into the flywheel but I’m 99.9% sure they are the correct length.
Thanks for your thoughts and comments. I know what you are saying about stripping down the engine. I may well get to that point but at this stage I would like to check this engine out properly first and gather up a bit more information about its condition. I want to first make sure that it pumps oil, and then do a compression test and may then do a cylinder leakage test. That way, at least I'll have a bit more information about what I'm dealing with.
Jesse – the transmission is definitely in top gear. It has a synchromesh and can quite easily be put into top gear with a big screwdriver on the selector. Agreed – there is no way it could be turned in reverse or first gear.
Sawbuck – I’ll double check on the bolts into the flywheel but I’m 99.9% sure they are the correct length.
Darryl Lennane
NZ
1943 Willys MB
1941 LP2A MG Carrier
1943 White M3A1 AOP
1942 Willys MBT
1944 Ford M8 Armoured Car
1945 Ford M20 Armoured Car
NZ
1943 Willys MB
1941 LP2A MG Carrier
1943 White M3A1 AOP
1942 Willys MBT
1944 Ford M8 Armoured Car
1945 Ford M20 Armoured Car
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