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-   -   Help with Push Rod Length SBC (http://www.hotrodders.com/forum/help-push-rod-length-sbc-229153.html)

Landshark928 02-03-2013 08:08 PM

Help with Push Rod Length SBC
 
Trying to dial in my push rod length.

Using the Comp Cams checker 8.150" gauge centers the wear pattern best, however the wear pattern seems pretty wide. Almost from 1/3 inboard to 1/3 outboard.

Also 8.150" seems rather long to me for a solid roller cam in a SBC.

Dart block zero decked.
Lunati Voodoo solid roller with 1.65 scorpion rockers. .660 adjusted lift .016" lash(60133 cam, I think it's a .9" base circle.)
Lunati solid roller lifters
Airwolf heads with +100 valve

Here are pics of the pattern with a 7.900 and 8.150 push rod. Pattern is more center and smaller with the 8.150. Should I try 8.200 to get it perfect. I was worried it seems too long already.

http://i48.tinypic.com/34gklg9.jpg

http://i49.tinypic.com/qr0wle.jpg




Also note the cheap Pro Comp 7.900" push rods I have do not match up to the Comp Cams checker. When both are set for 7.900 the Pro Comp is much shorter than the checker. Since it uses gauge length I would have thought it would be a tad longer. Guessing the Chinese crap is like playing the lottery?

http://i49.tinypic.com/jhshtx.jpg

Here are the push rods I am thinking of ordering:
COMP Cams Hi-Tech Pushrods 8478-16 - SummitRacing.com

8.100"- 3/8" 0.135 wall
or
8.280"- 3/8" 0.135 wall

So before I order, am I missing something? Seems like my Lunati lifters may be standard flat tappet height and not stock roller lifter height?

oldbogie 02-04-2013 10:25 AM

Quote:

Originally Posted by Landshark928 (Post 1642323)
Trying to dial in my push rod length.

Using the Comp Cams checker 8.150" gauge centers the wear pattern best, however the wear pattern seems pretty wide. Almost from 1/3 inboard to 1/3 outboard.

Also 8.150" seems rather long to me for a solid roller cam in a SBC.

Dart block zero decked.
Lunati Voodoo solid roller with 1.65 scorpion rockers. .660 adjusted lift .016" lash(60133 cam, I think it's a .9" base circle.)
Lunati solid roller lifters
Airwolf heads with +100 valve

Here are pics of the pattern with a 7.900 and 8.150 push rod. Pattern is more center and smaller with the 8.150. Should I try 8.200 to get it perfect. I was worried it seems too long already.

http://i48.tinypic.com/34gklg9.jpg

http://i49.tinypic.com/qr0wle.jpg




Also note the cheap Pro Comp 7.900" push rods I have do not match up to the Comp Cams checker. When both are set for 7.900 the Pro Comp is much shorter than the checker. Since it uses gauge length I would have thought it would be a tad longer. Guessing the Chinese crap is like playing the lottery?

http://i49.tinypic.com/jhshtx.jpg

Here are the push rods I am thinking of ordering:
COMP Cams Hi-Tech Pushrods 8478-16 - SummitRacing.com

8.100"- 3/8" 0.135 wall
or
8.280"- 3/8" 0.135 wall

So before I order, am I missing something? Seems like my Lunati lifters may be standard flat tappet height and not stock roller lifter height?

The 8.150 looks good to me, try to get push rods as close to that as you can, if not have a custom length made for you, nothing stock about your engine so expect the unexpected.

Bogie

engineczar 02-04-2013 10:49 AM

Putting a dial indicator on the retainer which pushrod length gives you the most lift?

ap72 02-04-2013 12:12 PM

B I N G O and bingo was his name-o!

engineczar gave you a foolproof way of checking, the one that gives you the most lift should also give you the smallest pattern and be the correct one- BUT the pattern may not be quite centered, to fix that you'll need to move the rocker stud which can be a pain in the *** and usually not worth it.

Landshark928 02-04-2013 08:57 PM

Thanks guys! I will get a dial indicator this weekend and see which length gives the most lift.

496CHEVY3100 02-07-2013 08:08 PM

I had to throw out my pro comp puchrods POS .replaced with trick flow mine is BBC had to go .250 longer becacse of aluminum heads TF. .Did not save any money as i had to buy 2 sets,buy a good set first time save money i did have to clearance bottom of comp cam rollere rocker to clear my springs.

Landshark928 02-09-2013 11:16 AM

Got the dial indicator on this morning. Seems like 8.150 is the ticket. Going to order .120 wall 5/16th rods instead of 3/8ths so I don't have to change my guide plates. Any issue with thicker walls as far as oiling? Can they be too thick?

Looking at these Manley rods.
Manley Pushrods 25242-16 - SummitRacing.com

engineczar 02-09-2013 01:26 PM

No problems as the oil hole at each end is still smaller than it is in the center. The stiffer the pushrods the better. .120 wall will work well. One thing to clarify is that the description on the Summit site says .080 wall. I'm not near my Manley catalog to check.

Richiehd 02-09-2013 01:47 PM

I ordered my pushrods from Scorpion, they have any length you want. Also with a 1.65 rocker you will have a wider pattern, centered is good

Landshark928 02-09-2013 03:32 PM

Thanks guys! I wanted scorpion but they only have .083 thickness in the 5/16th.

I double checked the Manley with their catalog and other sites. Good to go at .120"


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