Hi all,

I found a website that discusses creating steel adapter plates to convert gen 1 small block motor mounts to LS1 motor mounts here:

http://www.norotors.com/index.php?topic=3618.0


Other than having to source a new KEP adapter plate for the transmission, couldn't you reuse the small block cradle from RH and avoid buying a whole new conversion kit?


Those that have done the LS1 conversion, is there anything specifically unique about that kit over the small block?



Thanks,

Matt

RH setup uses adapter plates like shown in your link. But If I recall correctly, the SBC engine bars go straight across to the outer mounts. The RH LS1 bar is offset toward the rear of the car by a couple inches... perhaps to provide clearance for the LS1 accessories.

Thanks for the input Dave.

I could see the cross bar maybe being placed in a manner that would make room for a different oil pan design.

I can't imagine accessories being effected by the cross bar location.


Just found a company that makes the adapters: http://www.welderseries.com/blog/online-st...1-motor-mounts/

I don't think the oil pan is an issue, as most pans slope upward toward the front. The SBC cross bar should sit farther forward than the LS1 bar.

As far as accessories, the AC compressor that came on my Corvette LS1 would definitely not clear an SBC crossbar. It's a tight fit with the RH LS1 bar.

Yes

Ok so no A/C, which most of us don't have anyways.



Yes to my OP ?

The cross bar is very easy to fabricate. Buy the adapter and mock it up. Weld it in place. I did the same thing with every motor swap. Simple bars take only hours. My new one (secret design) will take much longer.

You could have it done in a weekend.

Wait a minute is the adapter plate the same on SBC as the LS1?

See OP. It is not.


Although I am willing to bet that the small block adapter plate could be made to work with an LS1.

Well my small block cross bar is not a standard RH bar ( In fact all the original engine mount components are missing on my car). The original owner welded in beefy plates on the outside of the motor mount box's. The cross bar has steel plates on each side that mount with big bolts.

Interesting set-up.

Mine is beefed up too. The first time I made a mount was a 5.0L mustang motor. I had the 914 on a lift and the motor on a cherry picker and me on my knees under the car fabricating the bar.

To start the fab on my Audi/Boxster setup, I intend to start the main section of the cradle before the motor goes in. I have the Boxster tranny mounts and cable shift setup the measure from. My cradle will connect the front cross mount to the rear tranny mounts. Once the main section is complete, I will hang the engine in place with a cherry picker and install the cradle. Then the engine and tranny mounts can be connected to the main section. I am using triangulated .75" and .5" DOM tubing (0.120 wall). Should be strong and light.

Click to view attachment

Click to view attachment

Super beefy is right! Glad to hear that your new secret project is in the works.

Were you able to sell your rotary set-up?

Matt

The rotary still runs/drives right now. I have procrastinated pulling it. Mostly I have been collecting parts.

Sorry for the short first reply. I'm posting from a mine in Peru south America and had a bad connection.

The Kennedy adapters are different for the LS engines. But I think you could make a sbc one work. You would first need to have the 1 piece seal flywheel. This is the same bolt pattern as the LS engine. Then you would need a piece that GMPP makes to space the flywheel out. This is listed in there catalog and costs $20 IIRC.

The mount pieces you had the link to are similar to the ones I maded. You can find to everywhere now. These will put your engine in the same place as the sbc.

Bob

You're posting from a what? In where?

200 miles down a dirt road outside of Lima

I guess now I can say Im really from down south and deep too!