Engine mount design feedback please

[TurboRA28]

Hi all, im in the process of setting up engine mounts for the 1mz rwd swap.. I am using an aftermarket LS1 whiteline mount the same as Jeffro used on the 1jz ra28.

I just want to check what i've done is acceptable. Angles are kinda all over the place due to the engine mount on the block angle one way and the xmember the other way.

I hope the beauty of these mounts is that they can happily accommodate for my farked up setup.

Please ignore the shabby bits of metal under the mounts, this is used just to get the height correct which it currently is..

Engine is sitting centered and feels good, doesn't rock around etc.
But after some feedback thanks.













Thanks!

[oldcorollas]

looks funny due to the angle the goldy bits bolt to the cast mounts, bit if bolted tight, they are effectively a single unit anyway, and the angle on the crossmember is more important.. or is it?
with that kind of mount, the angles are less critical than the old floppy rubber rectangular type..

she'll be roight (maybe)

[TurboRA28]

Thanks mate, with your blessing I will continue along on my merry way.

[oldcorollas]

I wouldn't trust my judgement ......
wait for someone with half an idea

[ed]

the bit youre building up off the x-member under the mount, why does it have to be square? why not wedge it so the bottom of the mount sits gravitationally vertical? thatll put the load/vector acting through the mount more inline. thats what id do anyway

cheers
ed

[Supra967]

I'd be inclined to go with ed's idea. Looks like unnecessary loads on the lower mount bolt. Are you at that angle to reuse the existing mount hole in the crossmember?

[TurboRA28]

Hey Ed, you are right mate I wasn't really thinking there..
So if I made it a wedge shape, the mount would angle in towards the engine .. Is that also ok?

[JustenGT8]

Joel, the loads on the bush part won't change no matter what angle the mount is at....that's partly why you go with this style of bush as it makes mounting easier.

the only load you need to worry about are going to be on the welds and/or mounting bolt. I'd weld that bottom mount in place if possible rather than just use that bolt system? So, is the setup straong enough to cope with the extra load from being on an angle? I'm with OC that yes quite likely it will be OK.

As Ed said, if you want to reduce the static load of just holding up the engine then get that lower part of the mount more vertical with a tapered mounting plate. Not teally much load to worry about there though. the real loads of concern are the torque loads from the engine, mostly because they are repeated 1000's of times which is what may eventually crack the welds.

To reduce these shear loads you'd actually angle the mount perpendicular to the V of the engine. On the GT8 i have used this style of mount and it's vertical to take the static load. I use 2 top mounted engine steadies to reduce the shear loads from the engine twisting. My mounts are also a little beffier as we made them ourslelve from poly Ford suspension bushes pushed into some turned down thick wall tube.

they have lasted 5 years so far and you've seen what the car goes thru when it's driven.

I think no matter how you use those mounts they will be fine but yes the design can be improved upon.

[ed]

the mounts will go through cycles of tension and compression

having their 3 points/pivots whatever in a straight line, or as close as possible to a straight line, will reduce flex, and stress on the bolts as the 'straighter' construct will not be exposed to torque/twisting loads on each cycle.

and justen, ideally you want the engine mount parallel to the tangent of rotation (ie crank centreline) which on a 90deg v8 is about the same as 90 to the side of the block. just being picky with your definition

[JustenGT8]

^^^ LOL yeah fair enough but you got the idea

[ed]

my version of the same thing youre doing:

[allencr]

Is it the picture angle making it look so off center, or is that mount's rubber stuff getting so deformed that it'll be metal to metal in a little while?
If it's really flexed that much, it'll need one about twice that size to carry the load.

[TurboRA28]

There is no preload on bushes.. pics must be playing games..

[Supra967]

and justen, ideally you want the engine mount parallel to the tangent of rotation (ie crank centreline) which on a 90deg v8 is about the same as 90 to the side of the block. just being picky with your definition

Any mount angle would be a parallel tangent. You want the shortest perpendicular distance from mount axis to centre of rotation

Joel, doesn't look like you have the sump clearance to make the top and bottom mounts a straight line? Or would be very close.