ford 302 motor mounts?

[billy]

snapped off both motormount bolts flush on my engine block.
currently designing/modifying mounts to be able to handle the downward stress and take the load off those bolts.
this will be the 4th try.
does anybody have a photo or two showing how they did it?
as always thanks!

 

[donsrods]

Wow, Billy, that is weird. Post a few pictures of how yours looks so I can see what is going on and the angles we are dealing with. If those pictures are on a build thread just let me know the link and I will look at them.

Don

 

[Dirtyrat]

Are these solid mounts? Or are you using something to cushion the load?

 

[donsrods]

Yeah, I can't envision any design that would snap off the bolts. I have the same side mounts on my 27 and used the same setup on my Jeep with the 5.0 and never had an issue with those bolts breaking........and I put a LOT of strain on mine continually. I even drag raced my 68 Mustang with the 351 Cleveland (same mounts as 302) and never had an issue.

Need to see some pictures of what you have.

Don

 

[billy]

the earlier failures were the steel itself cracking/splitting.
yes i measured the holes for depth.
i replaced the bolts with hex heads that are supposed to be a bit stronger than grade 8's
the photos will show why the previous bolts failed.
they couldnt stand up to the leverage.

 

[Dirtyrat]

My suggestion would be to come off the frame with a mount, and get your isolator closer to the mount bolts which go into the block. The way you have it now, you have basically given the mount free reign to flex the bolts in the block or at the frame until they snap the heads off. Your line of force should be through the mount/isolator, not a lever type force with only 2 bolts into the block as in this situation.

 

[billy]

thanks rich
your pic set me on the right track.[cl

 

[donsrods]

Dirty Rat hit it right on the head, Billy. Your mounts are simply too long and are acting like a lever, prying upward on those bolts and snapping them off. With the mounts that long you will keep having that problem, it needs changed.

Either do it the way DR showed a picture of, if you want to use early Ford bisquit type mounts, or use factory Ford mounts and build a bracket off of each frame rail to take that mount.

Speedway makes a super nice crossmember that incorporates the tubes for bolts to go through Ford mounts and it not only takes the stress off of the mounts, but it stiffens the frame by adding another crossmember. I am using that setup with 1963 Falcon Sprint mounts and they hold up great. I will try and find a picture of mine and post it.

Don

This picture will show the Speedway crossmember I used. It really stiffens things up a lot and supports the weight of the engine very well.

 

[Bamamav]

Yep, way too long. I saw a 61 Ford pickup somebody had swapped a 460 into and built long mounts like that. They didn't box the frame, and it would twist every time you revved the engine, probably the only reason it didn't snap bolts like yours.

DR's pics look good, mount a stand inside the frame, and then shorten the block mounts to match and you should be fine.

 

[billy]

since i have the shop to myself today.
i am going to try and fab up some of these

 

[donsrods]

Good idea.

Don

 

[Dirtyrat]

I'd still get as close to the centerline of the two bolts that go into the block as you can with the isolator.

 

[billy]

i forgot about this thread.
here is what i did

 

[kkadams123]

We ran our 302 in an Engine Endurance activity at the State SkillsUSA Conference last week. We run engines at WOT without coolant to see what happens. It is a fun activity for all the kids that attend.

The week before, we got the engine running but it was knocking. We dropped the pan and found loose rod caps and pieces of a piston skirt. We torqued the caps and buttoned it up for the trip north.

Our motor mounts held, but you can hear the connecting rod snap, then see it fall out on the ground a few seconds later. After tearing it down, we found that 3 rods broke, one cylinder had a hole in it, and the cam was in 6 pieces.

Here is the video. Enjoy!

http://www.youtube.com/watch?v=VWS9wHBrfpQ&feature=youtu.be

 

[billy]

hey KKADAMS
dont hijack threads.
it isnt polite.