Radical SR8 casting flaw oil leak

[parsonsj]

Here's a video showing how the crankcase casting on my Radical SR8 has an internal void leading to a bad oil leak. From everything I can tell, this leak has been there since the car was new... of course, nobody mentioned it when I bought the car:

https://youtu.be/sR16AnzLdYk

A replacement part is 3000 BP (pounds).

I'm working on other possible solutions now. I've done lots of welding on aluminum, but this engine costs roughly $25k new. I don't want to screw around and make the problem so much worse. Anybody have any suggestions?

[sccacuda]

Can you tube that passage? On Mopar small blocks, we drive a copper tube down the lifter galley to block off the lifter feeds. That is such a short section you have, I think you could tube that pretty easy.

[AU Doc]

I feel a little dirty even suggesting something like this, but could you just use an epoxy on the outside (I'm assuming the video is showing the outside of the block)? If it's not under a great deal of pressure, it may be enough to keep it from leaking. It would be a simple fix, with very little cost and time involved.

[parsonsj]

I'd thought about using a tube. It is a straight section, etc. Do you know the science about interference fit? The thing that I can't have is for the tube to move after installation, or it will go down into the main oil passage between the oil filter and crank main galley. If it does that, the porous area will be exposed again and it will leak. (Spray is a better description)

Another idea would be to block the passage. It's a perfect size for 1/4-20 tap, and I could put a 1.5" set screw into it with Loctite pipe sealant. The leaking passage is used for the piston squirter on that cylinder only (why a direct feed from the main oil galley?); all the other piston squirters get oil secondarily from the main galley.

See the hole next to it on the top surface? That's an oil feed for the cams. I could grind a little valley there to get oil back to that squirter after blocking the passage.

[AU Doc]

Could you live with reduced flow to the squirter? Put a 1/4-20 pipe plug in the passage like you described, but you can drill out the center so that it's a flow restrictor. Or a threaded sleeve (you could even drill out the inside threads to improve flow).



It seems like you would have to cut a pretty deep valley between the cam feed and squirter feed to get equivalent flow.

Is your concern with welding it up adding too much heat and warping a bearing saddle or gasket surface?

[sccacuda]

So if I understand the pic right, the leak is between the bed plate rail and filter housing, and your concerned that the tube would go toward the filter housing? I'd run a ream down it, making a small step where you stop, so the tube couldn't slip away from the rail. Turn a tube down to a press fit and install it. On the copper tubes, we leave them long and pound them in, which distorts the end, then cut off the tail flush with the rail. Don't know what a press fit would be between copper and aluminum, but it's such a small piece, I'd think steel or aluminum would be fine, or even bronze like a lifter bushing...which is essentially what you would be doing.

[parsonsj]

This is the main oil gallery, so it’s pressurized oil. Epoxy isn’t an option, I don’t think.

Welding is an issue since the casting is contaminated with oil that can’t be cleaned since it’s inside the material. It can be done but I’d prefer a machined method.

[parsonsj]

Craig, right, I’m worried that the tube could fall towards the filter passage. But I like the tube idea, for sure. Maybe just use a slip fit with some Loctite close fitting adhesive and a step on the bottom.. or flare the tube on the top and add a countersink?

[AU Doc]

Craig's solution is sounding like a winner.

[Kenova]

....... or flare the tube on the top and add a countersink?

There you go!

Ken

[sccacuda]

Craig, right, I’m worried that the tube could fall towards the filter passage. But I like the tube idea, for sure. Maybe just use a slip fit with some Loctite close fitting adhesive and a step on the bottom.. or flare the tube on the top and add a countersink?

I'd just use the step, then it can't go anywhere and your passage would only be minimally smaller. I'd want a press fit to "seal" the tube to the outer wall.

[andrewb70]

JP,

Don't make it over complicated. Craig's idea sounds relatively simple and solid. If you leave a step on the bottom, the tube will stay in place. Surely there are specification available for press fit tolerance given aluminum and whatever you make the tube out of.

Andrew

[parsonsj]

I called Southeast Cylinder Head here in Orlando and am taking the part over there tomorrow for a second opinion... They might have press-in tube I can use.

[andrewb70]

I called Southeast Cylinder Head here in Orlando and am taking the part over there tomorrow for a second opinion... They might have press-in tube I can use.

Keep us posted!

Andrew

[parsonsj]

I left the cover with Southeast Cylinder Head. The are going to ream the galley, press in an oversize sleeve, then ream it back to the original size. The sleeve will be cemented in place with a Loctite adhesive.

[parsonsj]

Disappointment is the word of the day.

I picked up my sleeved part today, but they only sleeved the first .600, rather than the whole oil galley. The problem is actually worse now. I'll be taking it back tomorrow.

[sccacuda]

So a misunderstanding with them on how far to sleeve, or it's leaking further down now?

[parsonsj]

The first. I showed them the leaks by marking on the casting with a Sharpie. They just didn't push the sleeve in far enough, or maybe they didn't have a longer one and thought it was good enough. Or maybe they couldn't press it in any farther.

The thing is -- I gave them my "testing rig" and they obviously didn't use it. It took me less than two minutes to know it was still leaking. I think the shop sent the part out -- that's where the disconnect happened I'll bet.

We all screw up occasionally. Hopefully they'll make it right.

[andrewb70]

Is it me or is incompetence rampant?

Andrew

[parsonsj]

The owner apologized and said they'd make it right. I hope to have it back tomorrow.