setting driveline angle questions

[asifnyc]

Hi, I've read the 1st thread in this section and read up on setting pinion angles, etc. but I still have some questions. I'm putting a TKO 500 in my '73 AMC Javelin (street car). I didn't bother to measure the stock setup and now I'm trying to figure out what angles I want everything at so I can fab a tranny crossmember. Here are my questions:

Currently pinion points UP approximately .8 deg. The engine is pointing DOWN approximately 4 deg. The engine cannot come up anymore without clearancing the tranny tunnel more. I'm trying to figure out if that's what I need to do or if I can get the angles equal and opposite by adjusting the pinion angle...

1) is 4 deg DOWN ok for a street engine?
2) If not, what's a good angle to set at? If I need to get to 3 or 2 degrees I'll need to cut away the tranny tunnel more.
3) Is it a MUST HAVE for the pinion to have an equal and opposite angle from the engine? Someone on another forum said my 4 deg. down eng. and .8 deg up pinion sounded fine and to just put it all together and see if I get any vibration...
4) Is 4 degrees up an acceptable angle to put the pinion at?
5) If 4 deg. up for the pinion is ok then should I set the eng. to 4.8 down and stack (2) 2 deg wedge plates on the rear? Then I'd have the eng 4.8 down and the pinion 4.8 up.

Whew... thanks in advance for any insight you guys can shed on this topic.

[dennis68]

1) is 4 deg DOWN ok for a street engine?

Not acceptable, clearence the tunnel and get driveline down angle to about 2*

2) If not, what's a good angle to set at? If I need to get to 3 or 2 degrees I'll need to cut away the tranny tunnel more.

See answer to question 1

3) Is it a MUST HAVE for the pinion to have an equal and opposite angle from the engine? Someone on another forum said my 4 deg. down eng. and .8 deg up pinion sounded fine and to just put it all together and see if I get any vibration...

You will get mucho vibration and possibly tear up the trans output bearing or pinion bearing or both

4) Is 4 degrees up an acceptable angle to put the pinion at?

No

5) If 4 deg. up for the pinion is ok then should I set the eng. to 4.8 down and stack (2) 2 deg wedge plates on the rear? Then I'd have the eng 4.8 down and the pinion 4.8 up.

4.8 up and 4.8 down is insane. Common mistake performing the TKO swap...everybody tries to shortcut it by not cutting the tunnel. It needs to be cut, the WHOLE tunnel needs to be cut.
See example, this tunnel is still getting another few inches all the way around...

[asifnyc]

Thanks a lot for the help. Ok, so I've got more cutting to do. Once I get the engine to 2* down should I wedge the pinion? If I can find a 1* wedge that would get the pinion to 1.8* up (so I'd have eng. 2* down, pinion 1.8*up). Will that do it? Thanks again.

[dennis68]

Yeah, getting pinion angle with .2* of the opposing end will work fine. Make sure to put a gauge on the prop shaft to find the joint working angle as well.

[asifnyc]

Ok, I found and ordered 1* pinion wedges. Thanks again for the help.

[asifnyc]

Ok, I've gotten the engine to 2* down. I had to cut quite a lot to do it. I had to cut the tranny tunnel to clear not only the trans but also the u-joint at the yoke... So, now my question is, how much clearance do I need between the tranny tunnel and the u-joint? I have about 1/2" now. Is that enough? Here's a couple of pics of the carnage...

[paul67]

Don't forget to set the carb flat what ever you set the angle of the engine as it will either run rich or lean due to the float , also you will find most carb manifolds sit with a 4 deg angle .

paul67