P&V Checking Crankcase Without Cylinder

[TheTone]

A situation that I run into sometimes is wanting to check the seals on a crankcase without a cylinder. It would be an easy task except for the connecting rod sticking up. The only way I know to do it is to put the right cylinder on it and block the intake and exhaust ports. Am I overlooking something?

 

[Sam R]

I'm interested to hear answers to this, too. Because it sounds like the nonsensical ravings of a lunatic mind... But maybe someone has figured out how to do it.

 

[kuhndog]

What about a heavier sandwich bag (gallon ?)stuffed in cylinder and ends pulled out to bolt down?

 

[Deleted member 117362]

What about a heavier sandwich bag (gallon ?)stuffed in cylinder and ends pulled out to bolt down?

Make a plate with hole in middle, four case bolt holes, use that plastic and seal it down under plate and over rod sticking into bag. May take a little work and thought, but anything is possible with trial and error. Or just cut the rod off and weld it back on after test.

 

[CsClimbr]

I’m not at all familiar with this tool (maybe someone else could chime in?) but if by chance they’re sealed on the interior.. stick that bad boy (girl) on there and apply pressure during testing

Worth a shot, and if not, could always find another use for it

 

[TheTone]

I’m not at all familiar with this tool (maybe someone else could chime in?) but if by chance they’re sealed on the interior.. stick that bad boy (girl) on there and apply pressure during testing
Worth a shot, and if not, could always find another use for it
View attachment 663489

I can always count on this group for imaginative suggestions.

 

[Thommo]

You could always just make a plate up with a hole cut in the middle for the rod and weld a bit of pipe over the hole and then weld a cap on the pipe with a fitting screwed into it for the pressure tester

 

[drf255]

Cheapest AM jug you can find. Have a member weld up the intake and Exhaust ports shut. It works, but need one per model line.

 

[deezlfan]

What's the point of all that effort to do it without the cylinder in place? Seems like a bunch of work for nothing since you should be testing it before tear down to get the correct diagnosis and testing it after assembly to confirm proper assembly. You are just adding an unneeded step to the process.

 

[grizz55chev]

^^^^Occam’s razor.

 

[TheTone]

What's the point of all that effort to do it without the cylinder in place? Seems like a bunch of work for nothing since you should be testing it before tear down to get the correct diagnosis and testing it after assembly to confirm proper assembly. You are just adding an unneeded step to the process.

True, if you start out with the cylinder on the case. What I'm talking about is a crankcase received in good shape without a cylinder. If the bearings are good, it would be helpful to know if you need to order seals. I would replace them at that point to get a closeup look at the bearings and to make it easier to clean them up a bit. If you know you are going to split the case anyway, it's a moot point.

You could always just make a plate up with a hole cut in the middle for the rod and weld a bit of pipe over the hole and then weld a cap on the pipe with a fitting screwed into it for the pressure tester

Yeah, that sounds like a good approach. The problem with any kind of blockoff is the variable bolt pattern and piston size. I doubt if I will try to fabricate something; I was mostly trying to see if anyone had an ingenious solution that would make me do a Homer Simpson "Doh!!"

 

[grizz55chev]

True, if you start out with the cylinder on the case. What I'm talking about is a crankcase received in good shape without a cylinder. If the bearings are good, it would be helpful to know if you need to order seals. I would replace them at that point to get a closeup look at the bearings and to make it easier to clean them up a bit. If you know you are going to split the case anyway, it's a moot point.



Yeah, that sounds like a good approach. The problem with any kind of blockoff is the variable bolt pattern and piston size. I doubt if I will try to fabricate something; I was mostly trying to see if anyone had an ingenious solution that would make me do a Homer Simpson "Doh!!"

Just install the cylinder back on minus the piston and use the regular block off methods, I have a couple of plates the fit the popular size exhaust and intake ports. Doesn’t matter if the cylinder is good or bad, and you can also put the piston on temporarily minus the rings to get a good idea where your squish is. Keep it simple.

 

[atpchas]

What I'm talking about is a crankcase received in good shape without a cylinder.

When I get a toasted cylinder for a model I encounter frequently, I fill the intake/exhaust ports with JB and keep the jug on the shelf for just the situation you describe.