Lower Engine Mount Sources

[lookforjoe]

Getting to be time for replacement again...

No obvious signs of contact, but it’s definitely getting close

Last one came from EuroSport UK, but every email I’ve sent in the past year, they say no stock, waiting...

Anyone located another reliable source ?

 

[ng_randolph]

Doug/RX1900 found a batch of these and offered them for sale here. Perhaps he has a few left?

 

[Dr.Jeff]

There are a couple listings for them on eBay, as you have likely seen already. The prices are good, but no info on them is given. Although you won't get info on something like this from any source, so kind of a try it and see what you get.

I'd love to figure out a way to modify these mounts the same why the other mounts have been done. But the odd shape of this lower one makes that very difficult. Which is unfortunate because it is likely the one that would benefit the most from a upgrade, due to the weight/load it bears. I don't recall ever seeing a urethane or other 'heavy duty' version either.

Bjorn's post (above) just popped up as I was typing this. Did Doug find a way to get some HD ones made, or what were they?

 

[DanielForest]

Mine is solid. It came with a parts race car I bought in the past. Don't know how it was done and the picture doesn't show much since it's in place. Maybe I could have taken a better picture if I crawled Under the car, but I'm still wairing my office clothes...

 

[Donald Wetzel]

http://www.vickauto.com/newstore/index.php?main_page=product_info&cPath=5_7_68&products_id=2930

 

[Dr.Jeff]

Mine is solid.

Hey Daniel, is it solid rubber or solid metal or ?? Just curious as I have not seen any "performance" type lower mounts sold by anyone. So wondering if yours was something the prior owner of the race car made himself?

 

[DanielForest]

It's full metal. And I also guess it was "home made" by the PO.

 

[PaulD]

I'd love to figure out a way to modify these mounts the same why the other mounts have been done. But the odd shape of this lower one makes that very difficult. Which is unfortunate because it is likely the one that would benefit the most from a upgrade, due to the weight/load it bears. I don't recall ever seeing a urethane or other 'heavy duty' version either.

I have recently made a mold and cast a "new" transmission mount. It has worked out well, a good fit with a very firm casting material. It has no flex, although a softer casting material could be used. It is a complex (5 piece) mold. I will post a separate description of it soon.

Paul

 

[Dr.Jeff]

Thanks Paul, please post more about it when you can. If I'm not mistaken you also did the same for the 'snail mount', or maybe it was the 'dog bone' (or both)? If so, please include some details on those as well. Thanks

 

[Dr.Jeff]

Paul's post above reminded me of a product that was mentioned in the past. It is a liquid mix that is poured into a mold and forms a urethane casting. I'm sure there are many other similar materials out there, but here is the one that was discussed on the forum before:
https://www.smooth-on.com/products/task-16/

Maybe something like this is what Paul used, we'll see. But off the top of my head I imagine you could take a old mount, remove the rubber, set the remaining metal pieces in place, secure the openings and pour this around them. It seems doable. No idea how it lasts, how strong it is, if it is appropriate for this type application, etc...and it's not exactly cheap to experiment with. But possibly it could be a way to make a better lower mount.

I'm sure this is overly simplified. But starting with just the "cushion" half of the mount assembly, by separating it from the solid back-plate/inner post (the arrowed portion):

I did not find a picture of the "cushion" portion without the rear mounting plate, so just pretend it is separate from here on. [If I recall the two can be pulled apart, as the center post pivots within the sleeve.]

Remove the rubber from the metal frames that surround it, and the metal sleeve in the middle (arrows):

Set the surrounding metal frame flat on a board, blocking the back side and locating the center sleeve. Then pour the urethane mixture into the void area within the frame and around the sleeve (blue arrow):

In the above picture it looks like this manufacturer has used a thicker wall sleeve in the middle (red arrow). Seeing this makes me think you could make a solid "filler" section to locate within the urethane when it is poured. Either a heavy wall sleeve (like above) or even a larger 'oval' shaped piece to take up much of the area where the urethane goes. This would make the mount even stiffer/more solid if that was your goal. Otherwise, smaller metal "filler" pieces could be placed within it (sort of like rebar placed in concrete when it is poured) to add strength to the urethane (to prevent tearing/failure) if needed.

I imagine it will take a little more development, but really how hard can it be?

 

[lookforjoe]

It would be nice to redesign the mount so all the load isn't all bearing down from that central pin. One that the weight is spread like a conventional mount would be nice.

Bought the last one from Vick Auto for the meantime.

 

[LarryC]

The Honda et al forums are full of discussion about using various stiff compounds to re-enforce existing mounts. I tried them and they suck/don't last. Or perhaps I should say, I sucked at making them and making them last. In any case, as Hussein says, a better design is really the ultimate answer

 

[Dr.Jeff]

Good point about the whole redesign. What are some types of mounts that could be considered as a replacement? Ideas?

 

[lookforjoe]

I would go with Volvo based layout - because it's what I'm familiar with. All newer FWD models have the drivetrain suspended from the mounts, rather than sitting on them, and that can get complicated with bracketry/failsafes. (Best) Old school style rear wheel drive would be like this:

(These hold up very well. Most failures are due to tailshaft seal leakage, which kills the rubber).

which replaced all the earlier styles that were some variation on this diagonal setup:

The earlier style was also an inherently bad design as you can see from the load transfer. The mounts ALWAYS sag or shear over time.

Maybe Honda/Toyota etc., use a more compact version of similar design? The Volvo horizontal mount I believe is physically too large to integrate into the available space.

 

[Dr.Jeff]

Your second pic of the Volvo mount is very similar to the old (solid rubber) Fiat 124 mounts:

And that brings up the other style (with internal spring) 124 mount. Might be more 'compliant':

BMW also uses this style mount:

The newer BMW version is "hydraulic" (this type is also used on VW's):

And they are available in a variety of materials:

The Fiat 124 (and some others) also located these mounts at an angle like you noted with Volvo:

But I agree, having these types of mounts located at an angle induces shear loading and short life. So how about mounting them vertically. Bring a 90 degree plate off the X's cross member underneath it, and another parallel plate above it attaching to the transmission housing. Similar to the old Volvo/Fiat124 design but located vertical instead of at an angle.
This is similar to how the Honda K20 installation kits are for the X1/9:

Starting with the X cross member:

You could cut/weld the cross member to add the lower horizontal plate, or possibly fashion a "bolt-on" version from the stock mount's bolt-holes. I think it would have to drop down a little to allow more room for the mount to fit between it and a upper mount plate.
The upper plate would bolt to the transmission case at the same mounting points as the stock mount. Something of a "L" shape to extend across the top of the mount.

I need to continue this in the following post....

 

[Dr.Jeff]

Redesigned lower mount continued.
Here is a very crude example of how this might look for the X1/9 drive-train. Maybe someone with real graphics skills can made a better rendering:

The yellow portion is the upper "L" shape bracket, bolted to the transmission housing.
The blue portion is the Volvo/124/BMW style mount.
The red portion is the lower horizontal plate attached to the cross member.
And the shaded black box represents the cross member (end view).

As noted by Huss, there might not be enough room between the upper and lower plates for this style of mount to fit. So perhaps a typical transmission mount from other vehicles will offer a shorter option. An inexpensive and readily available mount from earlier American cars for example:

 

[Mxgrds]

The newer/later models have the holes lower and closer to the center. I wonder if that is not weaken the whole construction. Less rubber the center rod can lean on and thus will quicker start to hang.

 

[Dr.Jeff]

The newer/later models have the holes lower and closer to the center

There are two versions of the lower mount?

 

[lookforjoe]

There are two versions of the lower mount?

The late one has the arm extended to support the cat/exhaust. Don't think anyone makes that one though. There may be multiple format/variants of the 'early' version, since none of them are OEM....

 

[lookforjoe]

Redesigned lower mount continued.
Here is a very crude example of how this might look for the X1/9 drive-train. Maybe someone with real graphics skills can made a better rendering:
View attachment 11131
The yellow portion is the upper "L" shape bracket, bolted to the transmission housing.
The blue portion is the Volvo/124/BMW style mount.
The red portion is the lower horizontal plate attached to the cross member.
And the shaded black box represents the cross member (end view).

As noted by Huss, there might not be enough room between the upper and lower plates for this style of mount to fit. So perhaps a typical transmission mount from other vehicles will offer a shorter option. An inexpensive and readily available mount from earlier American cars for example:
View attachment 11133 View attachment 11134

The immediate problem with a right angle bracket off the trans is the propensity for flex/breakage. Unless it has some sort of webbing I wouldn't trust it. Webbing will likely interfere with providing a suitable surface for the mount. This would need some serious time devoted to it with parts on hand to play with. Need to ensure the mount attachment doesn't drop lower than anything else under there & create a dangerous 'hang' point. Definitely worth investigation when time permits.

Something like the front lower mount on older FWD Volvos may also be a possibility.
This uses vertical attachment and horizontal mounting.