Motor and Transmission Mount Issues

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PostPosted: Wed Jan 13, 2016 7:21 pm
I am in the process of the GEN3 conversion on my car, chassis #389. Upon testing the fit of the new engine, I determined that the upper right mount bracket (where the new head mount bracket bolts up) was both too low (1.5") and not back far enough (11.0"), so I cut it off and ordered a new bracket. When I attempted a second fitting of the engine, I noticed that once connected to the three mounts other than the new head mount, the engine sat at an angle, with the left side of the engine being closer to the firewall than the right side. When I removed the engine again, I observed that the left upper transmission mount was 1/4" closer to the firewall than a friend's SRF who has already completed the GEN3 conversion (11 1/16" from bottom of hoop where it connects to the frame rail to the inner side of the upper transmission mount bracket, compared to my friend's 11 5/16"). Additionally, I noticed the bolt hole through the lower transmission mount were at a slight angle, basically the same angle as the mis-orientation of the engine.

I'm looking for information from anyone else that had to deal with replacement/relocation of the existing mounts (from the GEN2 setup) and any advice for how to resolve this issue. At this point, the leading solution seems to be to cut off both transmission mount brackets and replace with new, spotting them in the proper place once the engine is fitted in the proper position. I can honestly say that I'm not looking forward to this amount of work, but want it to be right. Let me know if you have any questions about my setup or any measurements that you'd like me to provide. BTW - I did check the frame and found it to be square in the engine box, so that's not the issue.
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PostPosted: Wed Jan 13, 2016 11:46 pm
I feel your pain. ;) I think Mike Davies told us that if the Gen2 engine was installed to spec, there would be no problems with the Gen3. But I think the Gen2 was a lot less fussy about it's mounting location and suspect a lot of folks just put Gen2 in the chassis and welded it in...

We screwed around a lot with our first one trying to make it fit without moving much, but ended up pretty much redoing all of the, IIRC. On the other one, we didn't screw around and just moved what needed to be moved right at the start.

But we have a bunch of cars of varying eras (the two Gen3's are sub-100 cars) and I don't think any two are exactly alike...

Dave
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PostPosted: Thu Jan 14, 2016 11:13 am
I had some weird alignment issues with mine, but it turns out most of those problem were due to my lower trans mount, which had been modified due to impacts with immoveable objects ;) I found the new one that has some adjustability to it made all the difference in the world, and things dropped in REALLY well. Once you know you don't have any height issues with the right side mount, the lower trans mount might be worth considering.
Dan

Formerly Teamwork Motorsports #99, Chassis #460

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PostPosted: Thu Jan 14, 2016 12:37 pm
Dave and Dan - thanks for the replies and the input. Part of me wants to just slap the engine in for the excitement of having it done, but the more logical part of me says that this is the time to make sure my car is right. Based on what you know from what I've told you so far, would each of you recommend that I cut off both tranmission mount brackets and install new and use the new lower transmission mount in an attempt to make it all easier? Right now, that's the option I'm leaning toward.
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PostPosted: Thu Jan 14, 2016 12:45 pm
IIRC, we'd always had a problem getting that transmission mount in with the Gen2, even with the adjustable mount. I had decided before we did the Gen3 conversions that we are going to (hopefully) have these engines for a long time and I'd rather spend the extra time up front then have to deal with it every time we had to pull the engine forever...

It seems like the position of the upper trans mount varies quite a bit, and I suspect the front engine mount. I also see cars with the rear transmission mount like 1/4" off the frame.

Dave
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PostPosted: Thu Jan 14, 2016 1:36 pm
Chances are, your car was originally a GEN1 to GEN2 conversion during which the person doing the conversion didn't follow, or even come close to following, the extremely precise engine mount location measurements in the Ford/Roush conversion manual. The reason for such exact mounting specs for the GEN2 were to ensure proper dynamic alignment of the CV joints to minimize premature wear.

That said, check with SCCA Enterprises for the exact correct positioning of all the engine mounts before re-installing them.

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PostPosted: Thu Jan 14, 2016 1:44 pm
Bob Devol wrote:That said, check with SCCA Enterprises for the exact correct positioning of all the engine mounts before re-installing them.


Bob - would that be Nikki or Mike Davies directly?

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PostPosted: Thu Jan 14, 2016 2:52 pm
I would encourage you to purchase the shorter top left adjustable transmission mount and the adjustable lower transmission mount, so you get the proper clearance from the right lower diagonal frame member.

In addition to that you need to make sure the two upper frame mounts are welded in the correct position. Either Nikki or Mike could give you the min measurement from the back horizontal frame member.

The final item is to make sure the right frame mount bolt hole is high enough so there is engine clearance from the right diagonal lower frame member. You can get that measurement also from Nikki or Mike. In my case the bolt hole was too low. There are two ways of raising or fixing this problem.

One way is taking the old welded right upper frame mount off and welding a new one on, making sure the bolt hole is in the higher proper spot from the the top of the frame rail.

The easier way is to weld a piece of heavy metal on each outer side of the hole mount and drill two new holes at the proper spot. Works great and it is easy to weld!

Finally save yourself some time and buy the new bent transmission linkage for less than $100 bucks.

Pat
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PostPosted: Thu Jan 14, 2016 3:33 pm
I think everybody's responses above hit all the high points, so I have little more to add. I know my car was a GEN1 that was converted to GEN2, but it sounds like that conversion was done pretty much in accordance with those conversion instructions. Other than having to deal with some pre-existing upward bowing of my diagonal bars in the engine bay, things went in real cleanly for me once I used the adjustable lower trans mount. Sounds like I got off easy!!! :-)
Dan

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PostPosted: Thu Jan 14, 2016 3:56 pm
Jparris wrote:
Bob Devol wrote:That said, check with SCCA Enterprises for the exact correct positioning of all the engine mounts before re-installing them.


Bob - would that be Nikki or Mike Davies directly?


I think Mike might even have the numbers for you off the top of his head. I've found him to be quite helpful.
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