chevy V-8 motor mount from JEGS # RM-6093

[dale]

Has anyone here installed the chevy rear motor mount from JEGS thats 1/4 inch thick and goes between the motor and the auto trns  with mounts on both sides.  It eliminates the need for a trans. cross member and mount..

[Branded]

Attachment doesn't  go to Jegs, and the mount shown in link is a Toyota Supra mount.

Edited December 8, 2016 by Branded

[wayfarer]

Now that is a great idea!!!! A turbo charged Supra I6 is a whole lot better idea than another shiverlay swap.....

[dale]

I see the attachment isnt right.  Try JEGS  RM 6093

[knuckleharley]

2 hours ago, dale said:

Has anyone here installed the chevy rear motor mount from JEGS thats 1/4 inch thick and goes between the motor and the auto trns  with mounts on both sides.  It eliminates the need for a trans. cross member and mount..

I don't believe for a minute it eliminates the NEED for a center crossmember. What's to keep the bottom of the chassis rails from wanting to twist?

What are you trying to put the GM engine into,and why do you want to eliminate the center crossmember?

[dale]

46 Ply convert. with the X frame.  The JEGS page mentions no need for the trns mount but yes there should still be a crossmember.. A front motor mount is a long way from the trns mount.  To long I think.

[knuckleharley]

45 minutes ago, dale said:

46 Ply convert. with the X frame.  The JEGS page mentions no need for the trns mount but yes there should still be a crossmember.. A front motor mount is a long way from the trns mount.  To long I think.

The GM motor mounts have been located at the center of the block since the late 50's. That was when they moved the trans mount to the tailshaft. When the motor mount IS up front you need a center mount for the transmission if it is aluminum. If it is cast iron,a rear mount is fine.

You should be able to easily modify the center crossmember you have to either weld a rear trans mount to it,or just drop it a little for clearance and fab a new crossmember behind it for the trans mount.

If  you are putting a 50's 265 or 283 in your car,you will need the front eng mount and the center trans mount,but if you are putting a 60's 283 or larger chebby engine in it,forget about rear engine mounts.

[dale]

This is a 1979 350 and the motor mounts on the sides of the block are only back about six nches from the front of the block not in the middle.. I have installed a mount that mounted to the front of the block so there is over 48 inches between that mount and the trns mount which is located right behind the drain pan.  This Im sure is way too much.  Thus the idea of the JEGS mount that installs between the motor and trns.  Even using the block side mounts it seems like alot.

[knuckleharley]

1 hour ago, dale said:

This is a 1979 350 and the motor mounts on the sides of the block are only back about six nches from the front of the block not in the middle.. I have installed a mount that mounted to the front of the block so there is over 48 inches between that mount and the trns mount which is located right behind the drain pan.  This Im sure is way too much.  Thus the idea of the JEGS mount that installs between the motor and trns.  Even using the block side mounts it seems like alot.

It's not a lot. GM has used that system to install literally millions of engines and transmissions with no problems.

[Branded]

1 hour ago, dale said:

This is a 1979 350 and the motor mounts on the sides of the block are only back about six nches from the front of the block not in the middle.. I have installed a mount that mounted to the front of the block so there is over 48 inches between that mount and the trns mount which is located right behind the drain pan.  This Im sure is way too much.  Thus the idea of the JEGS mount that installs between the motor and trns.  Even using the block side mounts it seems like alot.

If you are using the mounting point on the front of the block below the water pump like GM did 55-57 then you will need mounts at the bellhousing. If you attempt to only use a crossmember under the tail shaft of the tranny and nothing to support at the bellhousing there is a real good possibility that you will crack the bellhousing. This is a very common problem with the Tri-5 folks that go with a crossmember under the tail shaft of the tranny and eliminate the factory bellhousing mounts keeping the factory front  engine mount. There is no support in the center and it will crack.

[dale]

That would be catastrophic.. I have two differing opinions now..

[knuckleharley]

20 minutes ago, dale said:

That would be catastrophic.. I have two differing opinions now..

How? Branded wrote the same thing I wrote.

 

Unless of course you are using the yoke front mount that bolts directly to the front of the block. That's assuming the 350's even have the mounting holes for that mount. I'll have to try to remember to look when I got out to the shop tomorrow

Why would you do that? GM has been using the side engine mounts and the rear tailshaft mounts for decades now,and in tens of millions of cars. It ain't like it's experimental.

BTW,IIRC,MOST of the engine block/bellhousing mounts sold today are for use in all-out race cars that have the center engine and trans mount as a part of the chassis reinforcement. You don't  have to believe me,call Summit on their tech help line and ask them.

Edited December 8, 2016 by knuckleharley

[dale]

Branded said that could crack the trns flanges or block with mounts up front and trns mount.  I do have the front mount that bolts to the front of the motor so it looks like Ill have to use the rear motor mounts to be on the safe side.

[DJ194950]

Chev. small and big still had the front motor mount holes cast, drilled  and tapped to the 90's-just because I guess.?

Back in the mid to late 50's when the front mount was factory they had side bell housing mount cast in the bell with rubber insulators and no rear of trans mount.

Dale, if I were you I would use that rear mounting from Jegs (Sold now as a quick way to remove the trans for racing problems) if I ran the way forward engine mount and  your motor has much HP. The early engine side mounts should also be OK

with just a trans mount as they used that with up to 425HP apps. You got more than that??

My ideas for perusal.

DJ

1955-1994 Small Block Chevy Engine Mount.htm

Edited December 8, 2016 by DJ194950
add pic I hope

[DJ194950]

[knuckleharley]

1 hour ago, dale said:

Branded said that could crack the trns flanges or block with mounts up front and trns mount.  I do have the front mount that bolts to the front of the motor so it looks like Ill have to use the rear motor mounts to be on the safe side.

Only if you use a transmission with an aluminum case. Which is what I wrote,also. Chevy used cast iron Powerglides with the 265 and 283's in the 50's.

GM seemed to think the side mounts for the engine and the rear mount for the aluminum transmission were good ideas,but what do they know?

8 minutes ago, DJ194950 said:

Yup,those cradle engine mounts were used in thousands of old Fords . It even uses the Ford flathead "biscuit" cushions. That was THE mount to use in 30's and 40's Fords running the cast iron 3 speed. Lots of people got away with using them with Turbo 350's and aluminum case 4 speed manual transmissions,too. Or got away with it as long as none of the "biscuits" got torn or any bolts got loose.. Everybody sold that mount back in the 50's and 60's. I think I have one out in the shop somewhere for a Y-Block Ford. I hope I do,anyhow. My plan is to use a Y-Block in my 38 Ford humpback tudor if the flat 8 in it ever goes bad.

Edited December 9, 2016 by knuckleharley

[DJ194950]

The pictured one was aftermarket for Chev. v-8 as originals were Not connected through the center but only the side portion was similar and used the same bolts mounting position .I believe you are correct on the cast iron autos did Not have the side bell mounts. That 250 lb?. monster did not need them!  .

Like this I believe

 

[dale]

Missed the aluminum part.. Yes the trns bell housing is aluminum... The original setup was side mounts which were about six inches from the front of the block and a transmission mount just past the trns. pan. so Ill either have to add the rear mount plate I referred to or add the side mounts.. Thx

[YukonJack]

12 hours ago, dale said:

Has anyone here installed the chevy rear motor mount from JEGS thats 1/4 inch thick and goes between the motor and the auto trns  with mounts on both sides.  It eliminates the need for a trans. cross member and mount..

You can buy aftermarket trans mounts for GM automatic transmissions that bolt to the transmission bell housing bolts. These are designed for 55-57 Chevy's with the original front engine mounts to allow use of a later model automatic without a rear cross member. These new trans mounts bolt up to the 55-57 frame the same way the stock bell housing mounts did. It is my understanding that these mounts could be attached to the stock 46-48 Plymouth trans cross member but new holes would need to be drilled. Final result, front mounted Chevy motor, later automatic bolted at the bell housing and stock cross member without removing the stock cross member and weakening the structural integrity of the stock frame.  

[YukonJack]

See Ebay item #'s 331382050975 or 310978872506. Note: I haven't tried this myself but it does seem likely that it would work.