Bent valve cover

[CliffordK]

AliBaba has this, which is close but not right:

Valve Cover For Yangdong 4cyl Engine - Buy Cylinder Sleeve seal Liner shelf Liner Product on Alibaba.com

Valve Cover For Yangdong 4cyl Engine - Buy Cylinder Sleeve seal Liner shelf Liner Product on Alibaba.com

www.alibaba.com

Alibaba is not the same as AliExpress. You can negotiate a bit on the offer. It is possible they have, or could get different valve covers.

However, that page did list a minimum order quantity of 6. Enough for you to break a few.

 

[quicksandfarmer]

I'm gonna repeat myself and suggest aluminum solder again. Really. If you have a decent propane torch you can do it. Vee out the crack some, clean the area real well with brake cleaner, let it dry, and solder away. And also apply solder to the outside of the valve cover along the line of the crack. Or, if you don't like this solution, get a piece of aluminum plate that will make up the thickness difference between the different model valve covers. Then use a band saw or a jig saw or whatever you have and cut the plate to resemble the gasket. Drill any necessary holes. And use two gaskets instead of one. Or, you could just use several gaskets to make up the difference. But really, it is easy to solder aluminum with the aluminum solder rods that are sold at any good hardware store. I tested the stuff and it is not only easy to use it is quite strong. You just need enough heat. Pre-heating in an oven or with a weed burner is acceptable. Be careful with a weed burner though because it could melt the cover. It only needs to be just a little too hot to touch, like 250 degrees F. Then solder away. My opinion is to repair the valve cover so that it can be used in perpetuity without any extra gaskets, or sealant, or spacers. Even though I am a good TIG welder, and have two TIG machines, I would be sorely tempted to use aluminum solder just because my tests show that it is actually good stuff and quite strong.
Eric

I might try this. The thing is, it's not leaking through the crack. It's flexing at the crack and leaking around the gasket. So a repair would have to be quite strong and stiff.

Also, 250F doesn't sound very hot for an engine repair.

 

[quicksandfarmer]

I'm gonna repeat myself and suggest aluminum solder again. Really. If you have a decent propane torch you can do it. Vee out the crack some, clean the area real well with brake cleaner, let it dry, and solder away. And also apply solder to the outside of the valve cover along the line of the crack. Or, if you don't like this solution, get a piece of aluminum plate that will make up the thickness difference between the different model valve covers. Then use a band saw or a jig saw or whatever you have and cut the plate to resemble the gasket. Drill any necessary holes. And use two gaskets instead of one. Or, you could just use several gaskets to make up the difference. But really, it is easy to solder aluminum with the aluminum solder rods that are sold at any good hardware store. I tested the stuff and it is not only easy to use it is quite strong. You just need enough heat. Pre-heating in an oven or with a weed burner is acceptable. Be careful with a weed burner though because it could melt the cover. It only needs to be just a little too hot to touch, like 250 degrees F. Then solder away. My opinion is to repair the valve cover so that it can be used in perpetuity without any extra gaskets, or sealant, or spacers. Even though I am a good TIG welder, and have two TIG machines, I would be sorely tempted to use aluminum solder just because my tests show that it is actually good stuff and quite strong.
Eric

I have a box of Durafix brand aluminum solder rods. It says a melting point of 750F. I'm going to give it a try.

 

[etpm]

I might try this. The thing is, it's not leaking through the crack. It's flexing at the crack and leaking around the gasket. So a repair would have to be quite strong and stiff.

Also, 250F doesn't sound very hot for an engine repair.

The 250 degree temp is just so the valve cover doesn't suck all the heat away when soldering. I realize the crack isn't leaking, it just needs fixing so that the cover doesn't flex. Remember that the aluminum must get hot enough to melt the solder. Apply the flame to the valve cover, not the solder. Use a scrubbing motion with the solder stick to break through the oxide layer. Clean the area very well and then use a stainless wire brush to remove the oxide layer prior to soldering.
Eric

 

[BigGG]

I would use J B Weld or aluminum solder. Then see if you can find a place or two to place a cross rod or two without interfering with the valve train. If you could get an all-thread or two from side to side, it could take the spread load from tightening the nuts.

 

[etpm]

I would use J B Weld or aluminum solder. Then see if you can find a place or two to place a cross rod or two without interfering with the valve train. If you could get an all-thread or two from side to side, it could take the spread load from tightening the nuts.

I like that idea, the cross rods, wish I'd thought of it. It would be fairly easy to seal where the all thread penetrates the valve cover. Good hardware stores sell rubber and fiber washers that could be used as seals along with some silicone or thread sealant. I think I would use thread sealant. Less messy.
Eric

 

[quicksandfarmer]

I had some time today so I soldered it with a Durafix rod. I washed it with degreaser and then used a Dremel tool with a conical tip to follow the crack and widen it a little. It took a while but heating it from the other side I was able to get the solder to flow and laid down a pretty good bead:

The cover had taken on a bow, so I held it with the bar clamp to straighten it out while I soldered. After it had cooled I removed the clamp and it stayed straight so the solder is doing something. I put the cover on and tightened it what I'd consider medium-tight, it bowed a little, don't know if it's going to leak. I have to buy more oil.

Heating the other side did quite a number on the paint job. Now it has kind of a steampunk look.

If this doesn't work I think next up is to try cross rods.

 

[etpm]

I had some time today so I soldered it with a Durafix rod. I washed it with degreaser and then used a Dremel tool with a conical tip to follow the crack and widen it a little. It took a while but heating it from the other side I was able to get the solder to flow and laid down a pretty good bead:
View attachment 2676653
The cover had taken on a bow, so I held it with the bar clamp to straighten it out while I soldered. After it had cooled I removed the clamp and it stayed straight so the solder is doing something. I put the cover on and tightened it what I'd consider medium-tight, it bowed a little, don't know if it's going to leak. I have to buy more oil.

Heating the other side did quite a number on the paint job. Now it has kind of a steampunk look.

View attachment 2676655

If this doesn't work I think next up is to try cross rods.

I'm sorry to say but the solder didn't wet the metal very well, at least outside of the crack. Also, it looks like the crack appeared on the outside of the cover.
Eric

 

[piper184]

So an update on this:

I talked to Tommy at Affordable Tractor, he had a cover for a YD480. I have a YD485, but since they use the same gasket I thought I'd give it a try. Well, I tried it today, it doesn't work, it's not quite deep enough for the rocker valves.

So the cover from the YD480 fits, but it is not tall enough?
How much more height does it need?

would it be possible to make a spacer to make up that difference? It wouldn't have to be exactly the same shape as the cover as long as it was big enough to utilize a gasket on the head and another one on the YD480 cover. It probably wouldn't even have to be metal or all one piece.

If the problem is the clearance of the valve train to the sides of the cover, then, never mind....

 

[quicksandfarmer]

"Also, it looks like the crack appeared on the outside of the cover."

The crack was through before I started.