engine supported by yoke with two studs only?

[mark '87 930]

I received a proper yoke for our 911 engines yesterday and put the engine together with it today up on the engine stand. I'm surprised that it is supported by only two studs.. seems to work.

I'm curious about the 'flex' or sheer strength of the studs coming out of the case that we use to bolt the yoke onto. I slide in a pipe and a washer on both ends and torqued it down pretty good. The studs (especially the long one near the oil thermostat) seems to now go off at an angle since it's bearing a lot of weight.

I'm afraid that the stud or the case section will deform or worse case, the stud would snap. Thoughts?

[Wayne 962]

The weight of the engine is actually supported by the lip on the yoke - not the studs. They are doing a big job by holding the engine on the lip, but they alone are not supporting all the weight. Make sure that you have the lip / yoke installed properly (you might want to post a pic).

-Wayne

[mark '87 930]

Pictures are worth a thousand words I guess! Thanks Wayne, makes sense.

[dtw]

Assuming you are using the correct yoke (looks like you have some eBay special - does your yoke have a lip on it that mounts flush to the lip on the engine case?):

Aluminum case - don't worry about it.

Mag case - time-sert the transmission studs before mounting the yoke, then don't worry about it.

I've had two magnesium case 911 engines fall off the stand, due to pulled studs.

[mark '87 930]

I have no idea what kind of case this is, but the yoke does have a lip, flush mounted on the case.

[dtw]

I can see a 930 casting number down there, that is aluminum. You're all good.

[lindy 911]

I had the same concerns with my yoke; it's the one you get from Pelican with a pretty beefy "lip". I removed the studs (very easy to do) and used bolts with heavy washers. This eliminates any movement in the stud and pipe set-up. My complete motor does not flex at all with this method.

Lindy

[cmcfaul]

DTW, Old post but glad to hear I am not the only one to have an engine fall off the stand. In your case was their damage to the engine other than the bolts / holes.

Mine pulled a previously helicoiled bolt out and landed the engine on the tray below.

What the best fix.

Thanks,

Chris

73 911 E Mag 7R Case

[dtw]

Originally Posted by cmcfaul

DTW, Old post but glad to hear I am not the only one to have an engine fall off the stand. In your case was their damage to the engine other than the bolts / holes.

Mine pulled a previously helicoiled bolt out and landed the engine on the tray below.

What the best fix.

Man, sorry to hear about this. I am a fan of helicoils, but I never trust them for critical or heavy load-bearing jobs like this. With your application where the insert has stripped/pulled/failed, I believe there are oversize Time-Serts available that should do the job. Give your machine shop a call, they can probably supply them for you.

When it happened to me, it was on disassembly (both times). I carefully inspected the case, and there was no damage. Hopefully your engine mounting bracket took the brunt of the impact.

[cmcfaul]

Installed the Big Sert. Went so well installed a second one in the lower hole as well just to be extra strength.

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