Angle of engine and gearbox

[batdan]

Hi all,

I finally have the engine and transmission in the car and it is sitting correctly on the motor mounts with the gear box sitting on blocks, as I need to make up the cross member.

What is the correct angle for the gearbox and engine to be at ? Should the output shaft of the gearbox and the driveshaft flange on diff be at the same height? Or should the engine be level front to back - which pushes the trans further up into the tunnel and would put the driveshaft on an angle.

Any measurements for a 302 / T5 combo into a Torana based DRB would be very helpful.

I guess also the car should be loaded (i.e fuel / driver / trim) to get this right ??

Cheers,
Dan

[ksmiff]

I set mine up so the carb is level. This keeps the float levels right. I have a bit of an angle on the driveshaft, but that is corrected with the U-joints. I have never had a problem with binding.

[eschaider]

The centerline of the crankshaft and the centerline of the pinion should be co-linear if at all possible. If not then as close as possible. You may find you have to make accomodations for manifold/carb combos to achieve a level float bowl. My first choice would be co-linear and machine up an appropriate spacer for the carb to get it level.

Ed

<edit>

Don't worry about the car being loaded unless you are not running an IRS rear.

[Rebel1]

Dan, with the DRB using the live rear axle you need to get the drive line right or you will have problems with the universals.

Here is a site to follow:
http://www.drivetrain.com/driveline_angle_problem.html

I'd recommend getting the output from the box and the input to the diff as parallel as possible. Ideally, the operating angles on each end of the driveshaft should be equal to or within 1 degree of each other, have a 3 degree maximum operating angle, and have at least 1/2 of a degree continuous operating angle.

The problem with live axle cobras is the very short drive shaft . You don't want to get the situation where you have to set up the rear springing/damping so stiff that your ride quality suffers because of incorrect angle and phasing of the driveshaft.

[cameron02]

Hi Dan,

Good to hear you are progressing.

Be very carefull and research the advise you are getting.

My engineer told me that we definately do not want the diff and trans outlet to be in a straight line.

If they are in a straight line it can apparently cause the uni joints to lock causing dissaster.

If you are using the Torana diff you will find the center is off to the side anyway so all you have to do is ensure you are also a few degrease higher or lower. Mine trans is higher.

[batdan]

Hi Cameron,

Yes getting there slowly, just stumbled across an oil filter issue that I'l put a seperate post up for...

I am using a shortened VN commodore diff and the center is central to the car. When I raise the gearbox up to where it looks right I am probaby about 40mm higher than the diff. I'll take some exact measurements and do some calculations to see what my angles are like.

Do you know how much higher your trans was ?

Cheers,
Dan

[cameron02]

Cant remember how many mm. 40mm dosn't sound too bad. I think its better to measure in degree's (cant spell), maybe using a digital spirit level if you can borrow one. Try asking Peter at DRB he will know for sure.

Apparently the greater the angle the more power lost. But no angle = uni joint lock. So idealy you want a few degree up down and a few degree across but no more than necessary. That's about the total of my knowledge on the subject. I'd contact DRB if I were you.

[Asp302]

cant remember any of mine just put it all in looked good but i did not have body on ever so was a lot easyer to see the angel.have not had a problem in 4 years