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440 Rocker shaft shims

Posted By: bobs66440

440 Rocker shaft shims - 03/10/12 08:28 PM

I'm putting my 440 together and I have a question regarding rocker shaft shims for stock hydraulic lifters/rocker arms.

The stock pushrods were too long so I calculated the new length I needed to get approx .030-.045" preload. Well, I got the new pushrods, bolted it all together and I'm coming up with .055-.075 with most around the .060 mark. Somehow I miscalculated and I don't want to order new pushrods.

Mancini has .015 shims which would put me right in the ballpark. I have heard stories not to use them for various reasons. Comp tech said it would be ok and so did Mancini because it was so little.

What do you guys think?


Thanks
Posted By: lewtot184

Re: 440 Rocker shaft shims - 03/10/12 09:02 PM

the mancini shims are ok because they are soft aluminum and made on an eccentric. personally, i wouldn't get my panties in a knot on .050-.070 preload. i usually run between .060-.090. you need to check the plunger travel in the tappet to make a more precise decision on preload.
Posted By: DusterMan

Re: 440 Rocker shaft shims - 03/10/12 10:32 PM

I bought some thin copper sheets and made mine. But I always
set mine around .040 to .060 preload. I would put it together and run it like it is. If you want to shim the
rockers, go for it. I have run them for years with no problems. But i never had more then about .015 to .020 shim.
Just make sure if you make them the ones that go on the oiling hole has a larger hole in it then the bolt so you don't block off the oil going to the rockers.
Posted By: 1964superstock

Re: 440 Rocker shaft shims - 03/10/12 10:41 PM

I would recommend against using shims of any kind under the rocker arm shafts ever. This can cause the rocker arm pedistals on the heads to crack, and kill your heads. The shims cause the rocker arms shafts to be effectively larger in diameter, which loads the corners of the rocker arm pedistals of the heads. In effect it acts like a log splitter. Call Ray Barton if you don't believe me. Do it right, and order the right length pushrods instead. New heads cost a lot more than new pushrods.
Posted By: lewtot184

Re: 440 Rocker shaft shims - 03/11/12 01:26 AM

Quote:

I would recommend against using shims of any kind under the rocker arm shafts ever. This can cause the rocker arm pedistals on the heads to crack, and kill your heads. The shims cause the rocker arms shafts to be effectively larger in diameter, which loads the corners of the rocker arm pedistals of the heads. In effect it acts like a log splitter. Call Ray Barton if you don't believe me. Do it right, and order the right length pushrods instead. New heads cost a lot more than new pushrods.

this is why the shims need to be eccentric. just sticking anything under the shaft can crack the rocker stand. i've never had a problem but i use aluminum eccentric shims and don't over torque.
Posted By: RapidRobert

Re: 440 Rocker shaft shims - 03/11/12 01:41 AM

aluminum or soft copper & proper hole dia on the one that feeds it & correct torque. I'd add some shims & run it
Posted By: Anonymous

Re: 440 Rocker shaft shims - 03/11/12 02:32 AM

I have made my shims for years --I have used them on about 100 big block mopars and have never cracked a head because of shims--can it happen? Yes. Have I ever seen it ? NO and if you read Hughes website about preload--( and no matter what some think he knows) you can run anywhere between zero and two turns and more --if you want RPM out of a hyd cam use zero and put up with the noise--if you want them quiet--put 1 1/2 turns and its like a mouse peeing on a ball of cotton kinda quiet-You will be FINE with what you have unless you expect to turn it hard--like over 5500 hard. A .015 shim will not hurt one darn thing even if it is made out of a beer can IMO. PM me and I will send you a set for FREE ( not made from beer cans) and two will have the bigger hole to make you sleep better. Glad to help. One more thing the Cresent moon shaped shims ARE the best choice for thicker applications but not needed for a .015 or .030.
Posted By: MoparforLife

Re: 440 Rocker shaft shims - 03/11/12 02:36 AM

I wouldn't worry about the preload you have. There is a lot of forgiveness built into the hydraulic lifter. You will be fine. Besides rocker shaft shims are not meant to be used for that purpose. Run it as is - don't loose sleep over it you will be fine.
Posted By: bobs66440

Re: 440 Rocker shaft shims - 03/11/12 03:19 AM

Thanks for all the replies!

Which of the pedestals provide the oiling? I'm using Stealth heads if that matters.
Posted By: 383man

Re: 440 Rocker shaft shims - 03/11/12 03:42 AM

I used the Mancini shims on a 383 I drove in my old Dart. Drove it for 7 years like that and raced it also. Never a problem. I like my lifter preload about .020. Ron
Posted By: JohnRR

Re: 440 Rocker shaft shims - 03/11/12 08:30 AM

Rocker shaft shims are for correcting incorrect rocker arm to valve tip geometry not for setting lifter preload.
Posted By: MoparforLife

Re: 440 Rocker shaft shims - 03/11/12 01:48 PM

Quote:

Rocker shaft shims are for correcting incorrect rocker arm to valve tip geometry not for setting lifter preload.

Posted By: bobs66440

Re: 440 Rocker shaft shims - 03/11/12 01:56 PM

Quote:

Quote:

Rocker shaft shims are for correcting incorrect rocker arm to valve tip geometry not for setting lifter preload.



I understand and agree. But is there any harm in using it for adjusting preload as long as it doesn't adversely effect valve tip geometry?
Posted By: 383man

Re: 440 Rocker shaft shims - 03/11/12 03:12 PM

Quote:

Rocker shaft shims are for correcting incorrect rocker arm to valve tip geometry not for setting lifter preload.



But they do the trick when you have block and heads milled. As long as the rocker tip hits correct you can get by with them on a mild build. I proved it in my old 383 Dart with stock non adjustable rockers. It was done on a very tight budget and thats why I did that instead of buying adjustable rockers. It was a mild .484 cammed 383. Like I said I drove it for 7 years and ran 12.30's @ 110 with it. I only had .025 of shims under the shft as there is a limit on how much you can go without messing up rocker geometry. Ron
Posted By: MLR426

Re: 440 Rocker shaft shims - 03/11/12 03:13 PM

Quote:

Quote:

Quote:

Rocker shaft shims are for correcting incorrect rocker arm to valve tip geometry not for setting lifter preload.



I understand and agree. But is there any harm in using it for adjusting preload as long as it doesn't adversely effect valve tip geometry?



They will effect geometry even if a small shim is used, watch what your doing. If you use to much you could put extreme side load on the guides and wear them out.

logan426
Posted By: 6PakBee

Re: 440 Rocker shaft shims - 03/11/12 03:31 PM

Back in the day, rocker shims were used frequently to decrease the stock preload on hydraulic lifters with the stock valve gear. I have an old Motion Performance handbook from the 70's that goes through the procedure for that very reason. But I agree with everyone else, like many things in life don't overdo it.
Posted By: MoparforLife

Re: 440 Rocker shaft shims - 03/11/12 03:55 PM

Repeat- run as is - won't hurt a thing. Spend the $$$ for something that is more cost effective.
Posted By: bobs66440

Re: 440 Rocker shaft shims - 03/11/12 11:57 PM

Thanks for all the input!!
Posted By: Colin Frolick

Re: 440 Rocker shaft shims - 03/12/12 01:19 AM

Quote:

- its like a mouse peeing on a ball of cotton kinda quiet-



Posted By: MLR426

Re: 440 Rocker shaft shims - 03/12/12 02:04 PM

Quote:

Back in the day, rocker shims were used frequently to decrease the stock preload on hydraulic lifters with the stock valve gear. I have an old Motion Performance handbook from the 70's that goes through the procedure for that very reason. But I agree with everyone else, like many things in life don't overdo it.



I agree and I have done that with a hydraulic cam.

logan426
Posted By: PJSIXPACK

Re: 440 Rocker shaft shims - 03/26/12 08:00 PM

I have a Bob K. stock cam for the Pure Stock races, which I am not running with this block, stock 69 Six Pack heads, but a decked block. I plan on using the shims, if I can figure out a simple way to check the pre-load.

Attached picture 7136623-68DARTINDPLS(WinCE)(2)(Custom).jpg
Posted By: MoparforLife

Re: 440 Rocker shaft shims - 03/26/12 08:04 PM

Quote:

I have a Bob K. stock cam for the Pure Stock races, which I am not running with this block, stock 69 Six Pack heads, but a decked block. I plan on using the shims, if I can figure out a simple way to check the pre-load.

Take off the intake and check how deep the lifter plunger is. Still not what shims are for.
Posted By: PJSIXPACK

Re: 440 Rocker shaft shims - 03/26/12 08:15 PM

Thank you. I don't have the rocker arms, shafts or intake on it yet. I don't plan on using shims if I don't have to. I am using Rhoads anti-pump up lifters and .039 009 head gaskets. I am trying to slow this thing down from a 6.74 @ 103 mph to a 7.50 in the 1/8th to fit into the bottom of my class.
Posted By: JohnRR

Re: 440 Rocker shaft shims - 03/26/12 09:37 PM

Quote:

I am trying to slow this thing down from a 6.74 @ 103 mph to a 7.50 in the 1/8th to fit into the bottom of my class.



Hey PJ , long time ...

Just run it on the center carb, that should slow it down .
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