mounts and drivetrain angle

[GM Muscle]

ok ive researched a little and just want to verify some things. help me out guys.
LSX swap into my 69 camaro, i have solid engine mounts and solid body bushings.

Should i also run a solid trans mount?
i was leaning towards yes but this seems to be a mixed reveiw

since the trans mount isnt in yet i can still set the engine angle. from what ive read, anything between -3 and -5 should be ok.
Is this correct?
Also, to measure this angle, im assuming ill set the car to where the frame rails are at zero then point the trans down from there right?

Thanks in advance guys:lateral:

[Vegas69]

You need a poly trans mount with solid motor mounts. Personally I wouldn't run a solid motor mount. I hate mine and will be converting to poly when my motor goes back in. GM set the drivline angle at about 4 degrees in 69. Personally I would go with what makes the most sense at your ride height. Meaning level the rockers, get your rear end at ride height and experiment. You can shim the trans up and down easily with a spacer between the mount and trans. Your tunnel clearance will dictate it to some extent unless you modify the tunnel.

[dhutton]

I think if you run solid engine mounts with an LSX you will have problems with the knock sensors. Better to use poly engine mounts.

Don

[GM Muscle]

Well I already had a solid setup so it was just cheaper and more convienent. I'll try to find a poly trans mount.
As far as knock sensors... It's carbed:thumbsup:

btw. This is a 4l80e if it matters

[GregWeld]

This whole "angle" debate is very confusing.... and can cause major headaches and issues of drive line vibration to oil starvation...

The reason the motors were set at down angles (from front to rear - rear being down) was to get the drive line angle correct -- and that is some debate anymore as well... and to allow for the pinion angle to rise under heavy acceleration as it wanted to wrap up the leaf springs as it tried to climb the ring gear... (whew! Long sentence!)

David Pozzi has a very good discussion on his website about this - drive line angle/u joint etc. Very worth reading. THE PROBLEM IS AFTER LOOKING NOW I CAN'T FIND IT so maybe I have the wrong site...

Also -- the "new" suspensions (3 link - 4 link whatever) don't allow for the leaf spring wrap-up of the old days... so the pinion angle relationship to the engine angle (used to be - Motor down 3 degrees - pinion down 3 to cancel each other and wind up with zero)... can be set differently - with many now setting pinion angles at 1 degree or zero...

I would also respectfully disagree with leveling the frame or rockers to set these angles - and would instead suggest that the car be at ride height and with the weight on the suspension as it would be on the street. Let's take an example of a way to ruin a good motor.... level the car - then go down 3 degrees on the motor... now you put the car at ride height with "bigs and littles" - and you're rear end is higher than the front and your rockers are now raked nose down 5 degrees.... your motor ends up nose down 2 degrees... with oil running to the front of the pan (in a Camaro lets say with a rear sump)....

I'm always confused by all of this stuff ---- so lets hear the proper way to do this? :willy:

[70rs]

This is all very interesting to me. I have never had to set up a car like this, and will have to when (if) mine is at that point.
I would love to find out the right way to do this.

What is the proper way to do this with a TKO/T56 and a torque arm rear?

[Vegas69]

Most pro touring applications are going for a fairly level stance. Most intake manifolds are milled at 4 degrees to level the carburator. To do it in a conventional way, meaning driveshaft on a downward slope, you will need more like 2-3 degrees of driveline slope. With these low ride heights and 4 degrees of angle you can't achieve a downward slope in the driveshaft unless you set the pinion up at an angle not equal to your driveline. Now I agree when setting up corresponding driveline angles, the car being level is not important. My point is simply if you are going with a custom set up you have to start somewhere. I know on my car the rockers are wihin .5 degree of level at ride height. You can always figure that out and take that into account when setting your drivline angle.

[GregWeld]

Here's CAR CRAFT MAGAZINE version of a how to:

http://www.carcraft.com/howto/91758/index.html

[GregWeld]

Most pro touring applications are going for a fairly level stance. Most intake manifolds are milled at 4 degrees to level the carburator. To do it in a conventional way, meaning driveshaft on a downward slope, you will need more like 2-3 degrees of driveline slope. With these low ride heights and 4 degrees of angle you can't achieve a downward slope in the driveshaft unless you set the pinion up at an angle not equal to your driveline. Now I agree when setting up corresponding driveline angles, the car being level is not important. My point is simply if you are going with a custom set up you have to start somewhere. I know on my car the rockers are wihin .5 degree of level at ride height. You can always figure that out and take that into account when setting your drivline angle.

Good points Todd -- and that is why I tossed in the grenade... because it's something to think about IF your car is NOT going to sit pretty level... Many hot rods etc sit at some pretty good nose down rakes... and that needs to be accounted for.:cheers:

[DRJDVM's '69]

I'm really interested in this too because I'm going to have to make a custom trans crossmember....so I need to figure out the mount so the engine and trans sit at the right angle.

My plan was to tilt the engine/trans combo up and down until I got the engine/trans tilted downward about 2-4 degrees from horizontal....all this with the car sitting at ride height....then make my trans crossmember to keep it at that angle.

Does that sound about right?

[GregWeld]

Ned --

I'm thinkin' you've got the right plan. My bet is that the FACTORY leveled the frame - and then set the "down" 3 degrees... like Todd was saying to do. If you're not going to have a big rake - then that's what I'd do as well...

[GM Muscle]

I've never actually measured to see how "level" the rocker was. I usaully just make sure the wheel openings are all the same height. With that being said, I built the crossmember today(will post pics in my build thread), and used the energy suspension poly mount. I went ahead and measured the rockers to zero(level) and set the drive train at 4. I figure it will sag to 5 ant I can use the shim to put it back to three. As far as spring wrap, I think I'm going with the cat 5 spings. So hopefully spring wrap will not bee too much of an issue. Fir oil control, I'm using the aurocraft pan:unibrow: