Setting pinion angle

[dadnova]

It seems if you talk to three people you will get three answers on how to set pinion angle.
Some say the difference from harmonic balancer to rear end. Some say the differance from the trans, driveshaft and rear end and so on.
Whice would be the proper way? What are your thoughts?

[sc racing]

Its the relationship between the drivshaft angle and the pinion.You have to check it with the car at ride height, full weight including driver.Example:pinion is 2*down and driveshaft is 2* down total is 4*. or pinion is 2*up and drivshaft is 2* down total is 0*.

[race9899]

SC is correct, for drag racing you want anywhere from 2-4 degrees dip in the relation of the pinion to the driveshaft, I do most performance street cars the same way, however for your everyday driver, You set up the rearend to have the same angle as the crankshaft/transmision.

[sc racing]

In the chassis-suspension section there is a post from June 12 called "pinion angle test" lors of good info there about pinion angle.

[sc68z28]

Dale, (dadnova) I'm sorry to hear about your bearing/crank problems, I hope that gets sorted out soon.

On pinion angle, after a long internet search I got 10 different answers. That was just for a ladder bar suspension.

What I think I have settled on is at the Mark Williams site, link http://www.markwilliams.com/driveshafttech.aspx

This makes the most sense to me. When my car is on level ground, in race trim, the engine and trans are level. The driveshaft has about a 2* drop from the trans. I'm going to set my pinion to pretty much level, maybe down a half degree.

Anyone see any reason why this wouldn't be the best way to set it up with ladder bars I'm all ears. ---Bill.

[dadnova]

I set my angle @ 2*. Drive shaft @ 0 from the trans and down 2*, pinon level.
The car smoked the tires down the track, a problem I was happy to have, but it only lasted six passes before the bearing went bad again.
Rudy @ Castell polished the crap out of the ---- crank and says its fine now, however he would have the blocked checked prior to assemble just to be sure all the problems are gone so their wont be a fifth build.
He recommended Rancho in Temecula.
To tell the truth after building, installing and removing this engine three times, not to mention the COST, I'm scared to build it again.

[sc racing]

Hey dadnova are you using main studs or bolts? Im asking because I built an engine with main studs once and the rear cap always got misaligned when I put it on it kept the bearing in the cap from having any thrust clearence.I assembled the engine with bolts in the rear cap and everything was fine.Just something else to check. Good Luck.

[dadnova]

The engine is fully studded with splayed caps. Last night I was playing with it and I did notice that when the studs are inserted you can still move the cap a little, thanks I think I will look into it further, the other caps seem to lock into place but the rear does not. That might be adding to the problem as the crank has been polished out correctly.

Thanks again.

[dadnova]

Was at another sight and someone stated the same thing you did, however I liked his solution, think Im going to try it. Pin it. He said he had the same problem with the dart blocks main cap moving so now he pins them and they cant move. My heads, intake and everything else is pinned in this engine, why not the main caps?
What do you think?

[sc racing]

Wouldnt you have to line hone it after you pin it just in case they moved . I would get some opinions from some engine builders.

[sixty_foot]

isn't pinion angle....the total angle of the pinion, irregardless of the driveshaft angle ? i see calculations of the pinion angle combined with the drive shaft angle.......that cannot be correct. setting the centerline of your engine and trans in relationship to the axle is done first. when that is established, the final adjustment is your pinion angle. ????? (hence, the ladder bar adjustments)
i am that far off on this ??

s f

[sc68z28]

isn't pinion angle....the total angle of the pinion, irregardless of the driveshaft angle ?
i am that far off on this ??

s f

I think you are right on.
Lets say you could angle the engine down at 2*, and it was aiming in a staight line with the pinion (driveshaft also at 2*). Then with ladderbars you would set the pinion at 1 1/2 to 2* positive to level, giving you 0 to 1/2 degree of negitive pinion angle (Negitive to the driveshaft).

Am I that far off on this?? ---Bill.

[Mike Peters]

Pinion angle = the measurement of the difference between the angle of the pinion and the angle of the driveline. The flex of various suspension components allow the pinion yoke to rise so, the pinion angle is set in a manner to allow the driveshaft to be in phase when power is applied.

driveline angle = the angle of the cranshaft C/L, trans output shaft

[Wayne Carroll]

RJ Race Cars sells a trick pinion angle scale, take a look at their website and use the keyword, you must have it within 1/2 a degree. It's about a 100 bucks to purchase the degreed scale, if you want to do it yourself. Angle finders work, but they not a vernier scale for accuracy, so think about the RJ piece, or something similar from S&W, A.R.T, etc.

Yes, 2 degrees negative at the pinion yoke bearing center in relation to the driveshaft is very close to 0 degrees when you are under power. Standard transmissions are more extreme, maybe 4 or 5 degrees. They slam harder and shock the car more than the softer trans brake cars with converters. Heavier cars might need a little more. But, 2 degrees sounds very close.

Call RJ Race Cars, Hansen Race Cars, or any doorslammer chassis shop in your area and tell them your complete combination for some tech advice. Quartermaster, Alston, all these guys will be happy to answer your e-mail if you give them some time. Think about using them to set up your car initially, so you can see what angles, preload, alignment, etc. they provide for your combination. Scale the car and preload the corners at each tire. It would be worth the 200 to 300 bucks to get the car perfect and then work with their specs after you leave the shop.

Remember to ask them to write down all specs and computer print outs in order to: scale all corners front and rear, preload each corner of the car, with the weight bias front to rear with your weight and fuel level at race trim. Also, shock compression and extension for maximum traction. All this with full race trim will allow for an accurate reading on the pinion angle. They can choose right rear preload (if any) depending on your instant center and center of gravity, etc.

Tell them this is what you want. They know the numbers and the mathematics, they have all the electronic scales to set your car up perfectly. They also know what your combination needs for maximum traction for all of the local tracks. Best of all, you can charge the lights without fear for the driveline. Just a thought...Good Luck.

P.S. Don't change anything once at the track...it will work, don't sweat it. You should be at maximum chassis performance once power is put to the ground. Remember, have them write down all the specs. Including, the front end alignment, caster, camber, toe-in. Hopefully, 3.5 to 4.5 degrees caster, O degrees camber (with a couple of inches of rise) and 1/16 or 1/32 of toe-in. Keep your chassis spec sheet and don't lose it and don't forget it!...you will always know how to set it up from there. Go Fast! Have Fun!

[1nicenova]

I talked with travis at calvert racing & he said that 2-4 degrees negative with the caltracs was what they recommend. But thay set them by reading the angle at the tailshaft of the trans and the angle of the pinion. The driveshaft angle does not come into play. Trans at 0 pinion at 2-4 negative. Trans plus 1 pinion would have to be 3-5 negative. Trans minus 1 pinion would be 1-3 neagtive. Thats how I set mine. My tailshaft was +1 so I set my pinion at -5, which was achieved using a 6 degree wedge. I checked the driveshaft angle while I was there and it was 0. Hope I did this correct. I get the same thing as was mentioned earlier. Talk to 10 different people get 10 different answers.