Broken motor mounts.....here's the fix

[Chatt69chgr]

The motor mounts attach to the steel plates that attach to the engine on one side and the other attaches to the K-frame.  Attached is a picture.  You can get them at most every auto parts place.  They don't cost very much.  Same one fits 66-72 big block B-body as well as some e-bodys and c-bodys.

[FLG]

Tar,

How bad is shipping prices from here to norway? I mean i could pick up the mounts for about 5$ or so a piece and ship em to ya.

[Tarzan]

That would be REALLY nice of you. Would help me alot.


It depends on the weight, but should not be too much.

How would I pay you?

[road/track]

  No need to go all the way over to US for this, the mounts are available in most Swedish speed shops for a couple of hundreds Swedish Krona, I think they where around 200 SEK last time I bought them at Hansen Racing.

[rav440]

is there anything that can be done to the SPOOL type mounts and what about the mounts on the K frame ?

[firefighter3931]

440 Source sells the biscuit style mount pretty cheap ($14.95) as well. 

http://www.440source.com/enginemounts.htm



Ron

[Nacho-RT74]

Dunno up there but down here there are a kind of buiscuit mounts what does have "ears" that hooks up between both metallic sections and prevents from get far away of what rubber mount is able to stretch.

[RTPTRON]

i have solid mounts, that fixes everything......no drilling, no buying bolts, just buy em and slap em in

After breaking my third motor mount in as many years back in the late 1990s I went with solids.   However, now I am ready to go back to rubber because my car has developed bad rattles and I have a few lose fillings .  The solid mounts allow the vibration from the 440 to transmit through the car body and your body. The power transfer to the rear wheels without having to move the engine first is pretty cool too.

We Chevy guys  :slap:back in the 60s used to do the bolt through the mount trick.  We still broke a mount now and then but the bolt kept the damage to a minimum.

Anyway I am older now and more responsible so I shouldn't have to worry about breaking mounts anymore, RIGHT?

[Plumcrazy R/T]

Hey Firefighter3931
Where can I get these bolts (a pair of 3/8 x 21/2 in grade 8 flathead bolts) to modify my mounts? I have looked on E-Bay and called around to some hardware stores but with no luck so far.

[Steve P.]

I have bought them at both ACE HARDWARE  and LOWES home stores.


On the 62-65 mounts I use Allen bugle style heads. I bought a special chanfer bit for my drill press. This is necessary to keep the mount flat on these years.

[squeakfinder]

 Sorry if this is has been answered. But I can't tell from the picture. Is it necessary to counter sink the holes for the head of the bolts?  Larry

[firefighter3931]

Sorry if this is has been answered. But I can't tell from the picture. Is it necessary to counter sink the holes for the head of the bolts?  Larry

Nope....just drill the 3/8 holes.

Countersinking them increases the chances of "pull-through" and failure. 




Ron

[squeakfinder]

Sorry if this is has been answered. But I can't tell from the picture. Is it necessary to counter sink the holes for the head of the bolts?  Larry

Nope....just drill the 3/8 holes.

Countersinking them increases the chances of "pull-through" and failure. 




Ron

I had thought it would weaken things. So, the head of the bolt's rest on the perch? I'm probably making this more difficult than it needs to be with these questions.

[firefighter3931]

I'm probably making this more difficult than it needs to be with these questions.

Yes, you are....no need to reinvent the wheel Larry. 

So, the head of the bolt's rest on the frame?

Yes, the bolt heads just sit on the k-frame mount. Grade 8 bolts will not break....the ear will break off the block or the bolts will pull through the engine mount before that happens. I know many using this mod with success...one guy has an 800hp Hemi in his race car and still uses the stock mounts with this upgrade. 


Countersinking the bolt heads just increases the probability of pull through. This has happened in the past with countersunk bolts used on the Schumacher high dollar mounts. It was posted earlier in this thread.




Ron

[dstryr]

Any risk of the nylock nut being a failure point on this setup?  I modified my motor mounts and ended up using 2 grade 8s cinched down on each other because I wasn't sure about the nylock strength. 

[Steve P.]

I've used the nylocks for years on many different motors and never had a failure. This fix is pretty much bulletproof. The cast iron ears are weaker than the steel bolts and nuts.

[dstryr]

Thanks, Steve.

[HeavyFuel]

Do you recomend this modification if I am running "only" a rebuilt stock 440 HP?  Well, it's got a CH4B intake, but that's about it.

I was just going to reuse the original mounts, they appear to be in good shape.  Bad idea?

[Brock Samson]

if it's a daily and your not a lead foot you might get away with it... but why chance ruining your day?.. 
first time i launched mine many years ago I broke a mount and had to limp home from the track..

[Steve P.]

 I agree... If they are out or you know it's getting time to change them it IS time to make them better than stock.... Any time you make something better is a good thing... For a few bucks and a few minutes work, why not?? 

[shadango]

I'm probably making this more difficult than it needs to be with these questions.

Yes, you are....no need to reinvent the wheel Larry. 

So, the head of the bolt's rest on the frame?

Yes, the bolt heads just sit on the k-frame mount. Grade 8 bolts will not break....the ear will break off the block or the bolts will pull through the engine mount before that happens. I know many using this mod with success...one guy has an 800hp Hemi in his race car and still uses the stock mounts with this upgrade. 


Countersinking the bolt heads just increases the probability of pull through. This has happened in the past with countersunk bolts used on the Schumacher high dollar mounts. It was posted earlier in this thread.




Ron

Hi folks....new to this forum -- I found this awesome tip on mounts and am going to try it on my e-body.  I started a thread on cuda-challenger.com and linked to this topic (hope you dont mind).

But anyways...I went to buy bolts and all I could find are standard hex head bolts in grade 8.   

I noticed that you say to use "flat head bolts", but not to countersink...that means the head of the flat head bolt will stick up, right?  Now, when I held up a flat head stove bolt next to the hex head, the hex head was actually LOWER.....will I be ok?

I guess I don't know how much clearance there is for the bolt heads??? Will the hex head bolts I bought work?

Sorry for digging up an old thread with a dumb question....LOL...but this is a great way to go I think.

Thanks in advance for the help!

[firefighter3931]

I've allways used the "cone head" bolts and been able to get the motor mount to sit properly in the k-frame. 

You could try with the hex head bolts and see what happens. 



Ron

[Chatt69chgr]

They make socket head style bolts that have flattened shaped heads.  I've got a feeling you will find unusual bolts like this at a industrial or mill supply.  I doubt seriously you will find them at your local Ace Hdwe.

[Troy]

I can't seem to find those bolts either and have been meaning to ask about them. I'll need at least 3 sets and have been checking locally and online. If there's anyone who can get them easily and would like to buy a pile for me I'd be more than happy to supply them to anyone else interested.

Troy

[69rtse4spd]

3/8-24 fine thread flat head Allen bolt. Fine thread is always stronger then a course thread. You can also drill & tap the mount & then run a nylock nut also.