Crankcase Leakage Check Methodology

[StarTech]

Now you got something to use that works. Good Job.

Just a suggestion though. On the adapter plug use some sealant as I see a slight possible leak there. Considering the metal thickness probably some blue Loctite to help seal the threading. Of course what I see may just be normal suds too.

 

[FuzzyDriver]

Now you got something to use that works. Good Job.

Just a suggestion though. On the adapter plug use some sealant as I see a slight possible leak there. Considering the metal thickness probably some blue Loctite to help seal the threading. Of course what I see may just be normal suds too.

Yeah, those are just suds from the soapy-water spray, there's no leak on this iteration. I tapped the plate for 1/4-NPT, but the plate is way too thin to get a good seal by itself. I tried an O-ring/washer combination and that leaked to the tune of a 2 inch bubble every 10 seconds or so. Not much, but my OCD kicked in. Then I went with pipe sealant, but the thinness left that leaking too. Finally I went after it with Teflon tape. Ten layers later the leak disappeared. What a pain that was.

For anyone interested, I cut the flanges from a knife-blade blank, annealed 1075 steel 1/8" thick.

I use blue and red Loctite sometimes, but never as a sealant. Have you had success with that usage?

 

[StarTech]

Yeah, those are just suds from the soapy-water spray, there's no leak on this iteration. I tapped the plate for 1/4-NPT, but the plate is way too thin to get a good seal by itself. I tried an O-ring/washer combination and that leaked to the tune of a 2 inch bubble every 10 seconds or so. Not much, but my OCD kicked in. Then I went with pipe sealant, but the thinness left that leaking too. Finally I went after it with Teflon tape. Ten layers later the leak disappeared. What a pain that was.

For anyone interested, I cut the flanges from a knife-blade blank, annealed 1075 steel 1/8" thick.

I use blue and red Loctite sometimes, but never as a sealant. Have you had success with that usage?

Yes I have on my air line couplers and plugs but I never use the red stuff. I learned my lesson on that one. Cat had me apply red Loctite on a pressure pump valve caps. The stuff lock so quickly I couldn't even get the caps on fully install before it setup. I tried about everything including heat which I was afraid would melt the plastic check valves which it did to get the caps back off. I round off the hex and I had remake the hex just to get the caps off. Now I just use the blue Loctite.

When tapping thin stuff just don't all the way with the taps as they are tapered. By going at shallower depth it makes a tighter fit. On that thinner piece of you might could have gone with the 1/4 BSP threads which little smaller diameter and is one TPI off. Now I don't a 1/4 BSP tap at hand but I do know the 1/8 BSP is a tighter fit here.

 

[FuzzyDriver]

Since it's tapered, at first I only drove down about half way. At that, I could barely get it started. I went after it some more - too enthusiastically - and when I tried it again it went all the way and didn't tighten until it hit the hex part. Which leaked, as I related. I wasn't about to make another flange so that's when the stop-the-leak saga began.

 

[StarTech]

Since it's tapered, at first I only drove down about half way. At that, I could barely get it started. I went after it some more - too enthusiastically - and when I tried it again it went all the way and didn't tighten until it hit the hex part. Which leaked, as I related. I wasn't about to make another flange so that's when the stop-the-leak saga began.

If you do this enough you will learn to sneak up on things like this in the future. When I resizing or making a bushing it might me quite a few trial fits to get where I need it to be. I just made a bushing for a Nikki two barrel carburetor used on a JD Z950R engine. I still thinking about how a choke shaft would wear completely in two which did a lot damage to the carburetor thru hole. So wear that I had resize a 1/8" Sch 80 brass pipe that I used for making the bushing.

 

[FuzzyDriver]

Wow, that seems like a strange failure. I'm not familiar with that kind of carburetor. By "choke shaft" are you talking about the shaft that the choke plate is attached to? Is the housing plastic?