What condition are your body bushings in?

Andrew

 

The engine is in the stock location, CTS-V oil pan, crossmember notched. I can get full lock turn to the left, about 90% turn to the right before the tie rod grease fitting hits the oil pan.

I have about 3.5" of clearance from back of head to the firewall.

I measured my angle at the front crank (5*), at the top of the engine (5*), at the top of the transmission (5*), at the transmission yoke (5*) and at the rear axle pinion (~1*).

I used the Tremec driveline finder tool and it says my angles are out of tolerance. The transmission yoke is raised to just below the floor. I used a piece of wood between the output of the transmission and the axle pinion to find the driveshaft angle.

All my body bushings appear to be fine, all still have some pliability and are about 1" thick.

Even if I get the Holley pan, that doesn't necessarily provide all that much more clearance than the CTS-V pan does it?

So what could I possibly do from here? I can't bring the engine any lower. I can't really raise the transmission much higher, unless I'm willing to cut more tunnel and floor out.

I'm kind of stumped.

 

Some additional photos...

 

Question.. what is the type of Motor Mounts and Frame Stands you are using?

Short/Wide or Tall/Narrow ? see page 15 of this :Link... as well as the matching frame stands.. These could alter the height of the engine...

Suggestion, talk to Todd about getting the complete Holley pan and mounts..

BC

 

Based on pics I've seen, I think I'm using tall/narrows...but really I'm not entirely sure.

I'm still a little skeptical that the Holley pan with be that much better than the CTS-V oil pan. Better as in will actually solve the tie rod end clearance problem.

 

These are the mounts I have.....

 

The depth of the front portion of a CTS-V oil pan measures 1.83" at its shallowest.

The depth of the Holley 302-2 pan measures 1.25". A difference of .58". I think I need more than that to clear the tie rod ends.

These measurements were found at Dirty Dingos site here: http://dirtydingo.com/store/pages.php?pID=27&CDpath=5

 

Believe me.. the Holley is a much better pan than the CTS-V.. I was running the CTS-V since I did my Chevelle (since late 06').. it hung below the cross member by about 1".. I had trouble with the Trans Tunnel and cut the top off and had my fab guy put a new top on. I had trouble with drive line angle and the Trans output yoke is very close to the floor board support... used a BFH on it to get a little clearance.

I bottomed out on the CTS-V pan many times and it finally cracked. I swapped in a Holley 302-2 and clearance was much better. I also tried a Notched F-Body pan..

BC

 

You know where I might be able to get one at a decent price?

Also, do you recommend I slide the engine back at all or just use the stock mounting holes on the crossmember?

 

About the Holley pan...does it need a dipstick tube that goes into the pan itself or can I use my CTS-V dipstick that goes through the block?

Also, I read that you have to use Hooker mounts and headers to make it all work right.

I'm using Dirty Dingo mounts and Sanderson LS swap headers.

Do I use the CTS-V Windsor tray or will it come with its own?

Im just trying to figure out how intensive a process it is to swap over to the Holley pan.

 

I measured the angle of the floor and the frame and came up with 1.7* down for the floor and 1.5* down for the frame.

Do those numbers mean or do anything given the other measurements that I have. I can understand the relationship, but does that really do anything to the operating angles of the trans and axle? My trans is sitting at 5* down, my axle pinion is sitting at 1* up...a difference of 4*. If the argument is to account for the floor and or the car angle, wouldn't I just subtract the 1.7* or 1.5* from BOTH the trans and axle pinion angle and get the SAME difference of 4*?

Given these measurements, is 4* my operating angle? Or can it truly not be measured until I have a driveshaft installed and in place? Is there any reason I can't cut a piece of 2"x2" wood and place in between the two yokes and get an angle that way? What happens if I operate the car with these numbers as-is?

How many degrees of adjustment can be garnered from adjustable control arms?

Thanks again for all the inputs, suggestions and questions guys. I know I'll find a resolution at some point. I just want to go about it smartly and not pull too much hair out trying to find the best answer.

 

I slid the motor back to about within 1" of the firewall and jacked the trans up to where it just makes contact with the floor.

My trans/yoke angle is now at 4.1* down. Axle pinion still at ~1* up. I mocked up a 2"x2" piece of wood as the "driveshaft" and it's measuring at 7.1* down. So what does this tell us?

Should I remove some more floor back to the floor cross brace? (see pics.)

 

Is the rear end positioned at ride height or is it drooping all the way down? You must have the rear end positioned at ride height because this alters the angle of the driveshaft.

With the measurements above your front operating angle is 3° but I suspect the rear is not at ride height.

Andrew

 

Andrew,
I'm not sure I understand what you are asking.

The car is sitting on the floor under its own weight as it would be driven. There is no droop. I have the Rearend posotioned where it's always positioned, I haven't sone a thing to it.

How did you calculate front operating angle at 3*?

 

Ok, good. So I gather the car is relatively stock and does not have dropped suspension, right?

The front operating angle was calculated as the difference between the driveshaft angle and the angle of the transmission. In your case that was 7.1 degrees for the driveshaft (slopping down from the trans to the rear), and the transmission at 4.1 degrees (also slopping down from the front to the rear).

If you don't plan on lowering the ride height of the car, you can probably drop the back of your transmission a bit. This will actually decrease the front operating angle. With the rear, you might be good to go, because under power the pinion will want to climb, which will increase the rear working angle and get more parallel with the front.

If you plan to lower the car, then I suggest you get that trans as high as possible and you get the front of the engine as low as possible.

My GTO rides low, and my front operating angle is 6 degrees. I solved this by using a driveshaft with a Rzeppa style CV joint in the front.

Here is an aluminum version that Kwhizz just installed in his LSA powered 66 Chevelle:



Mine is similar but uses a carbon fiber tube.

Andrew

 

Firstly, I do not intend to lower the car at all. I believe the car is a stock suspension setup except for the air shocks in the rear.

Okay, so using basic geometry, if I lower my tailshaft, I will decrease the front operating angle (closer to 0). Which is good, to get it let's say to 2*...?

But using that same logic, that means my rear operating angle is about 6*, which is bad? Is it acceptable? Devastating?

Am I then left with adjusting the rear pinion angle upwards more to close that 6* gap to something closer to 3*?

Can adjustable control arms get 3* of adjustment?

 

Is the pinion yoke pointing at the ground or to the sky? I read that your pinion yoke is pointing to the sky, in which case, you are right, the rear working angle is about 6 degrees.

The front and rear working angles need to be in opposite direction, but equal. I would actually leave the trans where it is.

You can get adjustable upper rear control arms and use them to adjust your pinion angle. As you lengthen the arms (from the current length) the rear operating angle will start to match the front, and the front angle will get less (this is all good).

I think if you keep this car at stock ride height, you are good to go!

Let's wait for ToddoKY to chime in here, just to double check me.

Todd, is my logic good here?

Andrew

 

Yes, the pinion yoke is 1* up towards the sky. So to decrease the 6* angle, the yoke would have to be adjusted downwards toward the ground correct?

Would I just need upper adjustable control arms? Lower? Both? And will I be able to get 3* to 5* of adjustment at the pinion?

 

No, the pinion needs to go up. Remember, the operating angles must be equal but opposite. Like this:



Using just upper adjustable control arms should be enough.

Andrew

 

Andrew identified a good solution to the rear pinion angle if it needs to adjust.

another way to think of the necessary angles is that the output shaft of the trans (and engine crankshaft) and input yoke shaft should both be parallel, but not co-linear (not in an exact line). Being exactly in a line causes problems too.

The planes each shaft make (when viewed from the side of the car) should be offset just a bit. This ensures the u-joints are always loaded. Strange vibrations (and wear on the u-joints) occur when they are co-linear.

As suggested, it does appear that you can just fit the driveline to the body as best as you are able and adjust the rear pinion from there.

Doug