[billy zz]

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!

 

[timothale]

need picts

I looked at your project picts but no mounts shown, On the last SBF swap I did, I used maverick V8 mounts and made a bracket to use front to back bolts like most chevy mounts. I did a search for maverick V 8 motor mounts and got several images. the ink line drawing showed the 6038 ones I used.

 

[Irelands child]

I use all ARP bolts - never a problem. BUT - I have torn the so called bonded elastomer, made-in-Korea crap apart. Now I drill through the entire assembly, add two Gr8 5/16 or 3/8" bolts just snugged to the metal and use a nyloc nut. Solved that problem by limiting the travel compression/rebound. As far as adding any vibration - haven't noticed.

The new motor mounts - actually found some Trade # 2257/NAPA#602-1151 made in the USA replacements which are used in most Fords through '72.

 

[timothale]

no thru rivet

I thought the factory spec was for a thru rivet like your bolts to prevent full separation.

 

[66GMC]

I was a Ford partsman and HAD a 351C in a 68 Torino which used the early "sandwich" style mount, and pulled many of the FORD ones (presumably built in NA) apart, which always resulted in the fan blade cutting through the upper rad hose. ain:

I drilled and bolted them also ... and never noticed any vibration issues.

Since working for NAPA, I began to notice pictures of motor mounts and similarities in design..

NAPA BKP 602-1151
fit most of the older model Ford 90° and 335 series "small block" engines from about 1966 to 71 in the "B" & "F" bodies (eg. Fairlaine, Torino, Mustang, Comet, Montego, Cougar)

NAPA BKP 602-1253
I'd have a look at these ones which seem to fit the "bigger" B & F series from 72 to 76. (Also 77 - 79 LTD II / Ranchero.)

Edit:
Here's another possibility:

NAPA BKP 602-1152
1968 - 74 Custom 500

 

[billy zz]

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.

 

[timothale]

biscuit mounts

I don't like the biscuit type mounts, they worked on 40's fords because the enclosed drive line -torque tube tied the engine-trans and rear end all together. The out rigger angle iron style will work on a chevy because they have 3 bolts spaced far enough apart to spread out the leverage. I prefer the mount shown in the last picture, more compact and it HAS the safety rivet . The middle one with the safety strap just doesn't look neat enough when you can see everything. I would build new frame brackets to weld to the frame and use the ones in the last pict. All the leverage would be transferred to the frame which should be boxed from the firewall foreward at least when doing a swap.

 

[timothale]

mount picts

A couple weeks a go Newinteriors posted picts of some mounts he built for his C cab wagon project. I don't know how to link you to the picts but if you do a search her on HR for new interiors motor mounts you can see his. they are fancier than I build but an idea of what will work best. He also posted picts another time of the plane jane type.

 

[carolinacustoms]

What if you welded an angle brace to your current mounts that would bolt to the frame and essentially traingulate the current mounts you have already made and take away the up/down twisting that is breaking the bolts? You could also use the same type of rubber spacer for vibration where the brace bolts to the frame if that is a concern. But it would greatly strengthen your current mounts and eliminate the movement that is causing you problem without having to completely redesign anything. Also I highly recommend the bolt through the mounts as otehrs or atleast a chain from the driver side head to the frame to limit torque twist. Just a thought.

 

[geezer69]

i did my 65-66 mustang mounts just like irlelands child does. never had another problem.

 

[timothale]

motor mounts

Detroit did a lot of work designing motor mounts, I was there 15 years. I always try to use the basic factory design when doing an engine swap. Get a speedway catalog and see what they offer. The old Hurst style mounts, outrigger style is one piece that bolts to BOTH sides of the engine. I don't like them when using a modern transmission that has a rear transmission mount, the motor mounts at the front and back are too far apart and creats too much stress. Speedway builds a crosmember that you can use the mounts shown in the earlier picts 66 GMC posted The weight of the engine -force is down , NOT leverage shearing the block bolts. speedway also sells universal brackets you can weld to your frame for the factory mount. 910-1831. I have always built my own but I have lathe, mill, plasma, torchmate pattern style cutter, etc. factory style mounts with the safety strap or THRU safety rivet don't require a chain and turnbuckle for a street car. In the 60's the GM motor mounts would tear apart and the engine would move over on the steering shaft rag joint and you couldn't turn the steering wheel. GM got a lot of bad press when they had to send a crew to repair the POPES Caddy limo.

 

[billy zz]

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

 

[timothale]

biscuit mounts

Those rubber biscuit mounts work OK for an automatic trans, but some clutch chatter can result on a stick shift open drive line setup . They were designed for 1930's technology, My 2 cents worth, I would use the factory mounts with frame brackets you show but a tube for the front to back factory bolts.

 

[barrnone50]

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 4yth try.
does anybody have a photo or two showing how they did it?
as always thanks!

I am on my third try to make some mounts.Very similar to yours,the design has changed three times also.Here is my last one needs some more work. Like the saying goes 4th or 5th time charm..Ha Ha. George
Also these are made with 3/8 plate also going to gusset bottom with the same,more fine tuning,should work fine...

 

[billy zz]

i got my new mounts and steering box installed.

[/QUOTE]

 

[billy zz]

with my old steering box set up.
i did have a bit of bumpsteer.
and when i stomped on the brakes it wanted to go to the right.
after the reversed corvair install the bump steer issue is gone.
and i got it up to about 50mph then stomped the brakes.
the diving to the right issue is gone as well.

 

[billy zz]

i am installing these tomorrow

VROOM!
SKREE!
etc.

 

[barrnone50]

i got my new mounts and steering box installed.

[/QUOTE]

Those look pretty beefy. Very nice!! I might have to change mine will see.I did revise them. Hope they work!

 

[billy zz]

Those look pretty beefy. Very nice!! I might have to change mine will see.I did revise them. Hope they work![/QUOTE]

the more i looked at my old ones the more i realized that the design itself was flawed because it makes the bolts the weak link.
these are more like a bridge abutment or something.
it ties everything together so nothing can go anywhere.
engine weight pushing down and that pushes the mounts against the inside of the frame rails

 

[barrnone50]

The latest ones you made look like they will fit the bill. Again I am no engineer so make and test and see what happens. I to wonder the stress point or weakest link is at motor or at mount at the frame. Time will tell.