Solid mounts

Well I finally completed the engine swap and fired up the old-school 347. A little more work than I anticipated. After heat cycling the engine a few times and listening to the normal sounds of metal expanding and contracting I developed a concern that I want some input on. The engine has 2 custom solid steel motor mounts the and tranny also has a custom steel mount, all of which are grossly overbuilt as only I can. My question: is this too rigid? Do I need to account for heat related expansion and contraction? I could put a nylon or rubber spacer and back off on the mounting bolt torque at the tranny mount. Is this a valid concern or me being paranoid? FMR

Frank,
At the temps that we run, I wouldn't worry about it... Worst case, put a poly trans mount on it somehow and call it a day. Mine has solid fronts and a poly trans and hasn't had any issues.

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Originally Posted by cobra132

Well I finally completed the engine swap and fired up the old-school 347. A little more work than I anticipated. After heat cycling the engine a few times and listening to the normal sounds of metal expanding and contracting I developed a concern that I want some input on. The engine has 2 custom solid steel motor mounts the and tranny also has a custom steel mount, all of which are grossly overbuilt as only I can. My question: is this too rigid? Do I need to account for heat related expansion and contraction? I could put a nylon or rubber spacer and back off on the mounting bolt torque at the tranny mount. Is this a valid concern or me being paranoid? FMR

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the general rule of thumb if you are running solid engine mounts, you MUST run poly or softer trans mount. something about broken bell housing and tailshafts. Seriously suggest a poly mount on the trans....

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Originally Posted by cobra132

Well I finally completed the engine swap and fired up the old-school 347. A little more work than I anticipated. After heat cycling the engine a few times and listening to the normal sounds of metal expanding and contracting I developed a concern that I want some input on. The engine has 2 custom solid steel motor mounts the and tranny also has a custom steel mount, all of which are grossly overbuilt as only I can. My question: is this too rigid? Do I need to account for heat related expansion and contraction? I could put a nylon or rubber spacer and back off on the mounting bolt torque at the tranny mount. Is this a valid concern or me being paranoid? FMR

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Jay had a Firehawk that kept breaking the trans mount. We installed a poly trans mount and the car almost shook apart. I don't know why but after changing back to a rubber mount everything went back to normal.

JJ

Thanks. I will soften the back mount a bit. FMR

I realize this is a completely different environment, but when I ran dirt we ran solid motor mounts and had to run a softer poly or even rubber transmission mounts. The torque would break transmission cases.

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Originally Posted by marshall_mosty

Frank,
At the temps that we run, I wouldn't worry about it... Worst case, put a poly trans mount on it somehow and call it a day. Mine has solid fronts and a poly trans and hasn't had any issues.

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No issues?

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Originally Posted by cjlmlml

No issues?

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Not that I can relate to the engine and trans mount...

Just like what was said already, Solid Front and Poly rear.. you have to run the poly in the rear of you will have problems.

I have been running Solid Engine mounts and Poly Trans mounts since my car was built, no issues with them at all.
DD

Done!

Thanks!