Stoopid mount question
 

Hey, I know this is pretty remedial, but here goes.

Are the engine mounts for all/most of the conversions the same? I ask because there are diagrams, with sizings for making the mounts on pro-touring.com, but no mention of which vehicle they're for.

I want this for my 78 t/a. Also - in terms of just the motor mounts, is there much difference between the S&P and BRP style? One is more of a rectangle and the other is more of a trapezoid. I have a guy that can make these according to the diagrams, but before I send him off to do that I want to make sure he's making the right thing ....

Here's the diagram for the S&P style:

http://matt.undiagnosed.org/ls1/imag...ount_plate.jpg

And here's the BRP style:

http://matt.undiagnosed.org/ls1/imag...t_plate_V2.jpg

And does anyone know how these compare to the ATS mount?

The S&P style will set your motor back farther than the BRP style shown. I would measure my firewall clearence with the motor set in approximate place and decide which to use then. There are probably people who have the same combo who will chime in and tell you which work better.

Yeah, that's what I've heard, but I haven't heard what effect that has on the 2nd gens - whether it's better for it to be further back or not. Obviously for weight distribution, further back is better, but does it possibly fit better further forward?

And I suspect that the measurements given above were for a 1st gen conversion. Would they be the same for a 2nd gen conversion?

Not even close to ours. We have tested out mounts/oil pan on a 2nd gen, and the fitment was perfect.

Tyler

S&P claims their mounts put back of the LS1 engine in the same place a regular SBC would sit.... not sure if I said that right, but they're made so you can swap an LS1 in where a SBC was, and the trans should line up with the back of the engine.

I ordered some S&P mounts and the tech there said that the engine would sit exactly where the old SBC did allowing me to bolt it right up to my th350 without moving anything. He said he had a 71 camaro with a th400 and the engine went in with those adapter plates no problem. I haven't put the engine in yet but soon I'll find out if he's BSing or not.

Also, I had a set of S&P style plates made from that first drawing and the holes should not be 9 /16 dia. IMO. That size is way to big. The dia. of the bolt goung into the block is alot smaller and the plate won't be very secure.

The S&P style plate will put the motor and trans mount in the same place as it was on an original smallblock.

Regards, John McGraw

Ditto. I measured from the middle bolt on the engine mount of the SBC, to the rear of the block, and the same on my LS1 with S&P mounts, exactly the same. It was 16 or 14.5, I dont remember..
olly

Do you have to notch the frame for the a/c?

I also sent you a PM with a few other questions.

If you want it to stay in the stock location, yes.

Tyler

you can notch the frame and use the vintage air ls1 adapter bracket to mount the sanden compressor which will set you back close to 100.00 or you can pop for another 200.00 and mount it up top with the system from s&p. I have done it both ways and for the 200.00 difference I would recomend the s&p. And another thing to consider when notching is what motor mounts you use, the lower and farther back you sit the motor the larger notch you will have to make. Alot of the guys around here like to set the engine as far back and low as possible but when that is done it takes a huge notch(done it dont like it would not recomend it). Up top is well worth the dollars imo.

I have just purchased the s&p aluminum adapter plates and I am using energy suspension SBC motor mounts on a 68 corvette, but I can not get the holes to line up. I am off by about a 1/8" to 1/4" on both sides - the motor just will not drop down far enough to put a bolt through on both sides. s&p recommended using motor mounts off a 70 chevelle 305 - I purchased a set of these mounts and they are even worse. does anyone have any suggestions?

This probably isn't going to help you much since you've already bought the S&P plates, but after taking a look at ATS's mounts, I think that's the way I'm going to go. They look very nice. Check 'em out:

http://www.classicchevy5speed.com/Am...pecialties.htm

And maybe Tyler has some advice on the fitment in your 'vette.

It looks like I am going to have to switch to plates that are only 1/4" thick - the S&P plates are 1/2" aluminum.

I used the BRP mounts, and was able to get the motor about 2 1/2" from the firewall (measured from the pass. side head) This leaves about 1/4" of the motor plate hanging off the back of the sub-frame. Unless you want to notch the frame, this is about as far back as set it as the alternator is very close to the frame (f body pulleys) Besides, any further back and you won't have much access to the back of the motor for wiring fuel lines and such.

The S&P A/C bracket is the way to go. Spendy stuff, but it is much better (IMO) than notching the frame. Good luck!

I have purchased the s&p plates for my 71 camaro and I am having the same problem. But mine is a little farther off. I unbolted the frame mounts from the frame crossmember and moved them so the motor mounts would line up. This in return moved the motor down and now the alternator is hitting the top of the pittman arm of my steering. The only thing I thought of doing is maybe putting some metal plates in between the frame mounts and the frame to raise the motor back up. I thought I was the only one having trouble with these mounts.

Are you using the "preload plates"? They wont work with them, you have to use them without.
olly

a handful of threads talking about the same thing.
i had the same problem.
welded up my own.
as many people having this issue, why havent the the design of the mounts been changed?
:judge:

I am having the same problem fitting the LS2 into my Ultima GTR.... It all sounds a bit silly to me, I dont know why they are called adaptor plates when they are not.


Is there an off the shelf solution for this, or are ALL products "too wide" when you fit std SB mounts onto LS>SB adaptor plates.


I dont understand why they have adaptor plates for use with SB mounts when they dont fit anyway.... why not just make a mount that works.

Does anyone make a 1 piece mount? I know this question has been asked before, and the answer has been no. But hoping that someone might be doing it by now.

Strange, the OTHER ultima guy was thinking of producing them. :jest:

that's funny..

https://ls1tech.com/forums/showthrea...r+mounts+piece

ultima guys think alike, I think.

olly