GL1200 overheating

[sidecarsusie]

Larry wasn't at meeting last night, but conferred with a couple other mechanics there and both, without hesitation, said the head has a crack in it....

 

[dan filipi]

Larry wasn't at meeting last night, but conferred with a couple other mechanics there and both, without hesitation, said the head has a crack in it....

To everyone here besides Susie and I, Larry is the guy that rebuilt the heads. Susie took a picture to a meeting he was suppose to be at last night.

Next step is a used head.

Am I thinking right here?
What I figger is there is probably enough back pressure in the exhaust to blow those bubbles into the reservoir which got worse when hot because the crack would open.
I'm not sure why I saw bubbles when running it with those 2 spark plugs removed though, still enough back pressure in the exhaust from the other side? The blue liquid would turn color when testing either side :Awe:
I sure hope this is it :beg:

Any other telltale signs of a block problem I could look for while this right head is off?

 

[mcgovern61]

Larry wasn't at meeting last night, but conferred with a couple other mechanics there and both, without hesitation, said the head has a crack in it....

Next step is a used head.

Am I thinking right here?
What I figger is there is probably enough back pressure in the exhaust to blow those bubbles into the reservoir which got worse when hot because the crack would open.
I'm not sure why I saw bubbles when running it with those 2 spark plugs removed though, still enough back pressure in the exhaust from the other side? The blue liquid would turn color when testing either side :Awe:
I sure hope this is it :beg:

Any other telltale signs of a block problem I could look for while this right head is off?

Dan,

Hand crank the engine and move the pistons as far back as possible and check the liner for cracks. A tin foil rub might remove any small imperfections and if there are any cracks, you might see them.

The radiator was a big problem! Cavitating the pump also caused some of the excess heat in the cooling water. If the radiator has been the problem from many moons ago, it may have been the reason the engine overheated in the first place before Susie got the bike.

The crack on the exhaust side definately will allow exhaust gasses to travel into the cooling system even when the plugs are pulled. The exhaust system does have a lot of back pressure.

The question I still have is, are we absolutely sure we know why the head cracked in the first place?

I know that aluminum engines do not tolerate overheating and quick cooling very well. Ask Ford! The 3.8 liter engine had aluminun heads and cast steel block and if the temps went beyond 245 degrees, it would blow the head gasket because of the rapid expansion in the aluminum heads. (Ford replaced our Windstar 3.8 liter engine 3 times under warranty for this!) As the heads cooled they would crack allowing coolant into the running engine which would bend the pistons!

 

[dan filipi]

I'll definately check the piston liners like you say Gerry.

Without a doubt it ran cooler with the 1100 radiator so I'm going to finish modding it to mount up even if it doesnt appear to need it right off when I get the engine buttoned up with a good head.

I'm tempted to pull the left head but after all this time and work I don't want to do too many things and confuse what the problem was so I think one head at a time then test is the way to go. I'll move the exhaust back to get a good look up into the exhaust port on the left side for sure.

We had the cams ground so I'm wondering if we can move this cam over to the used head without any break in problem.

 

[mcgovern61]

We had the cams ground so I'm wondering if we can move this cam over to the used head without any break in problem.

That is a tough one. I am under the opinion that a good used head will be worn in evenly. I believe that this engine has hydraulic lifters, so I think that any adjustment by the lifters will not be noticed. Changing the cam over will have a small break in period, although it should not effect too much.

 

[dan filipi]

Got a used head. One valve is stuck open of course, gonna run it over to the head shop here shortly but wanted to post a pic of the exhaust passage from the valve side.

Can see into that port it's white looking steam cleaned. The crack must be back in there somewhere.

I swapped the cam over for a test fit.
After snugging the holder bolts down not torqued the cam turned hard by hand but it would turn so I think it'll break in OK.

Got some pics of the cylinders. Look OK, don't see any signs of cracks.
Cyl 3

Cyl 1

 

[mcgovern61]

After snugging the holder bolts down not torqued the cam turned hard by hand but it would turn so I think it'll break in OK.

It'll break in all right! Just hope it doesn't "BREAK IN". :smilie_happy: :smilie_happy:

 

[sidecarsusie]

Oh, I hope it works!
Good weather is coming and a ride to Randsburg as well
.

 

[dan filipi]

Susie, Larry at the head shop says he's going to pressure test the suspect head either today or tomorrow and call me.
He seemed to think it might be repairable, sleeved or pressure sealed. Dunno if I'd go that route myself.
I left him the replacement head.

 

[sidecarsusie]

Well, hope something works in our favor... it is about time, ya think?
Thanks, Dan

 

[joedrum]

i didnt relize this is susie bike. nice bike, i would love to have one just like it for my wife to ride and me to. ive always been looking for one i think i would like it better than a trike . good job finding the problem that didnt want to be found

 

[sidecarsusie]

Grew up with sidecars, thought it was the normal way of life.
If you are in Indiana and interested in sidecars, here is the email for the Midwest Director of the United Sidecar Association.
He may be able to give you some local information.... his name Al "Fly" Butterfield email: [email protected]
susie

 

[dan filipi]

Well the head shop has "pressure tested the hell out of it" and found no leaks. :head bang:

They recommend pressure sealing it as opposed to taking a chance with a unknown used head.
They say pressure sealing uses a ceramic solution under pressure into the water jacket that heats the head to 100-120 degrees and seals any crack permanently.
Umm,,,,if pressure testing didnt reveal a leak then will the pressure seal find it to seal? I was told IF there is a crack it will seal it and temperature shouldn't make a difference whether the crack shows up or not.

We gave them the ok to seal it.
My fingers and toes are crossed. :beg:

 

[joedrum]

dan this has got to be a very small crack if they pressured tested it cold then i can see how it tested ok . i may have went the other way with the unknown head because the known head is diffinutly cracked. unless there is something visably wrong about used head i dont know why you didnt pressure test the used head that would have taken some of the unknown part aside. iguess we could have been fooled by those pics you had but i was convince that was the problem . idont know anything about ceramic coating deal but its diffinutly not heavy duty fix sounds way to thin in my thoughts dan

 

[dan filipi]

I know what you mean Joe.
I'm not sure pressure seal is the way to go with it either.
The used head is in pretty rough shape though.
This shop has been doing them for 30 years and stands behind it 100%, speaks very highly of the process but them not finding a leak when testing has me concerned.

 

[mcgovern61]

I am not surprised that they did not find a leak when pressure testing cold. As we have been discussing, it is a hot leak that will only show when the metal expands. I still think the only way you will find it is by using dye penetrant and a black light (like looking for a cracked block). One of my tug engineer buddies was here last night and I showed him the pictures. He said that it is definitly steaming and there is an obvious crack letting only drops of water out. He also builds hot rods and other fun things and has a tremendous amount of experience in this area. Looks like a duck, talks like a duck.......

The company I work for has done ceramic coatings for years, but nobody wants to do it. The coatings are usually on valves and the piston crowns. Once on, it will not come off, it is chemically bonded to the metal.

Ask if the shop will try dye penetrant. I agree that the crack must be identified prior to a fix that may not be the right fix.

(BTW, my buddy also looked at and listened to my '81 diesel Goldwing and agrees that the main bearings and wristpins have seen their time!)

 

[dan filipi]

Well a chemical bond sounds encouraging anyway.
Still..it seems like a bandaid fix.

 

[joedrum]

seems like youve jump in with both feet already so we all might learn something here. i think its diffinutly cracked but very small. what gerry said sounds encoraging to me as far as im concerned tugs are water tractors that operate under full load most of the time there running pulling with everything they got and lots of money on the line so if that industry is using the ceramic stuff to extend life of old parts its because it must work. piston crowns valves thats petty stout proving ground for a product to live up to.

 

[dan filipi]

Waiting on the head so I fitted the 1100 radiator.

No shots about my welds, not pretty but it aint goin nowhere.




















Just need to fit the rock guard and air deflectors and she's good to go.

 

[joedrum]

no cracks about the welding :cheeky: i guess your right this post has enough cracks in it. ithink rad mod was a great thing to do dan :good: k: