Rocker shaft shimmimg

Rocker shaft shimmimg - 07/16/09 02:46 AM

Is there different rocker shaft shims available, and if so- are there ones to stay away from and certain ones to stick with?
I see some look like a simple washer, I would have thought Mopar rocker shaft shims would be rectangular with a hole in the middle, but since I've never even seen them in person what do I know...?

It's for a big block if that matters, I am pretty sure I will need some so I want to have some on hand, I shaved my heads .030 and I'm using a .040 head gasket...

Posted By: stumpy

Re: Rocker shaft shimmimg - 07/16/09 02:53 AM

If you are running stock rockers you shouldn't need shims. If your push rods are too long buy shorter. Shims mess up the geometery of the rocker system. Shims should be beveled not even or you will have an oil pressure problem.

Posted By: poison_ivy

Re: Rocker shaft shimmimg - 07/16/09 03:14 AM

Actually shims will correct inproper rocker geometry. I have .090 under my shafts.

Posted By: RapidRobert

Re: Rocker shaft shimmimg - 07/16/09 03:21 AM

According to Dave Hughes at 50% of gross lift(BB)& 60% if SB) the pushrod and the adj screw should be in a straight line and may need different length pushrods and or shims to accomplish this using a lifter of the same type as you are running & if hyd take a junk lifter & epoxy the cup all the way up. then w light springs mark the valve tips & check the wipe pattern. You moved the heads down .030" by milling but back up .040 minus what the orig shim head gaskets were so you might be pretty close to where you originally were but with tolerances possibly being anywhere you cant assume anything, check everything

Posted By: 64Post

Re: Rocker shaft shimmimg - 07/16/09 03:29 AM

Quote:

Actually shims will correct inproper rocker geometry. I have .090 under my shafts.

Rocker geometry doesn't change with head milling. Pushrod geometry does. Valve contact pattern will not change with head milling. If you have to shim the shafts there are other issues at work, i.e. long valves or sunken seats.

Posted By: JohnRR

Re: Rocker shaft shimmimg - 07/16/09 03:56 AM

Quote:

Is there different rocker shaft shims available, and if so- are there ones to stay away from and certain ones to stick with?
I see some look like a simple washer, I would have thought Mopar rocker shaft shims would be rectangular with a hole in the middle, but since I've never even seen them in person what do I know...?

It's for a big block if that matters, I am pretty sure I will need some so I want to have some on hand, I shaved my heads .030 and I'm using a .040 head gasket...

Do you have a rocker to valve tip contact problem ?

Posted By: CrAzYMoPaRGuY

Re: Rocker shaft shimmimg - 07/16/09 04:29 AM

Quote:

Quote:

Is there different rocker shaft shims available, and if so- are there ones to stay away from and certain ones to stick with?
I see some look like a simple washer, I would have thought Mopar rocker shaft shims would be rectangular with a hole in the middle, but since I've never even seen them in person what do I know...?

It's for a big block if that matters, I am pretty sure I will need some so I want to have some on hand, I shaved my heads .030 and I'm using a .040 head gasket...

Do you have a rocker to valve tip contact problem ?

Nope.
My pushrods are probably down into the lifter about .010" more than they should be, the steel shim gaskets were .020"ish, the Felpro gaskets are .040"ish, and the heads were cut .030", which makes me think my heads are down .010" from stock. I would figure a .010" shim would restore what I had, but when I check I want to have an assortment of shims to correct the lifter preload to where it SHOULD be....

Posted By: CrAzYMoPaRGuY

Re: Rocker shaft shimmimg - 07/16/09 04:31 AM

Quote:

If you are running stock rockers you shouldn't need shims. If your push rods are too long buy shorter. Shims mess up the geometery of the rocker system. Shims should be beveled not even or you will have an oil pressure problem.

I'm not sure I agree with most of this....
I'm running stock rockers BUT I have altered where the head sits in relation to the cam. Buying pushrods .010" shorter doesn't make much sense to me compared to shimming the shafts to be honest. I would RATHER raise the shaft back up to where it should be.

Posted By: CrAzYMoPaRGuY

Re: Rocker shaft shimmimg - 07/16/09 04:33 AM

Quote:

If you have to shim the shafts there are other issues at work, i.e. long valves or sunken seats.

Or milled heads and non-stock gasket thicknesses...
Which is ME!

Posted By: RapidRobert

Re: Rocker shaft shimmimg - 07/16/09 05:02 AM

I'm learning on this also & from what I gather(so far)you want to have the correct length pushrods(for milling/thick/thin gaskets or a factory stack of heck height tolerances) then check the wipe pattern & adj w shims(or deepening the rocker stand saddles in rare cases and guys have used soft copper washers as shims(just check/bevel the ones(s)on the oiling pedestal so they dont impede flow & have had zero problems.

Posted By: 1_WILD_RT

Re: Rocker shaft shimmimg - 07/16/09 05:21 AM

FWIW the amount your shimming shouldn't be a problem...Mancini sells them...

http://chucker54.stores.yahoo.net/rocshafshim1.html

One of the reasons shimming can be a problem is it effects rocker geometry the picture attached will do more to explain that than I can...
Another problem with shimming is people have split rocker stands by using them wrong...

Attached File

5355659-Rockergeometery.bmp (61 downloads)

Posted By: 71 FJ6 Charger

Re: Rocker shaft shimmimg - 07/16/09 05:34 AM

Dont mean to high-jack,got the same deal goin on with a 383.My 346 heads are cut .030 and have a .020 steel gaskets. I have a set of adjustable rockers sitting around,can I use those to correct things and make lifter pre-load right?

Posted By: 1_WILD_RT

Re: Rocker shaft shimmimg - 07/16/09 05:43 AM

Quote:

Dont mean to high-jack,got the same deal goin on with a 383.My 346 heads are cut .050 and have a .021 steel gaskets. I have a set of adjustable rockers sitting around,can I use those to correct things and make lifter pre-load right?

You need to consider custom length pushrods... Typically you want to wind up with two threads showing on the bottom of the adjuster screws... How is the contact between the rockers & valve tips? They should be shimmed side to side to center them on the rocker tips & the rocker pad should be centered to slightly outside of center on the valve stem with the valves closed...

Posted By: MoparforLife

Re: Rocker shaft shimmimg - 07/16/09 11:05 AM

Do your math and you will see that you gained .010 didn't loose it. Using a shim will actually make things worse.
You milled .030 and used a .040 gasket. Therefore you increased the distance not decreased. By milling .030 and using a .040 you actually lost ground.
Put it together and forget the shims they will make things worse.

Posted By: Crizila

Re: Rocker shaft shimmimg - 07/16/09 12:47 PM

Quote:

Do your math and you will see that you gained .010 didn't loose it. Using a shim will actually make things worse.
You milled .030 and used a .040 gasket. Therefore you increased the distance not decreased. By milling .030 and using a .040 you actually lost ground.
Put it together and forget the shims they will make things worse.

and your hyd lifters will easily take up .010 with out a problem. Quite often factory tolerances were off more than that.

Posted By: CrAzYMoPaRGuY

Re: Rocker shaft shimmimg - 07/16/09 02:31 PM

Quote:

Do your math and you will see that you gained .010 didn't loose it. Using a shim will actually make things worse.
You milled .030 and used a .040 gasket. Therefore you increased the distance not decreased. By milling .030 and using a .040 you actually lost ground.
Put it together and forget the shims they will make things worse.

I'm doing the math trust me!

I cut the head .030 = .030" LESS distance
I increased the head gasket from .020"ish to .040"ish = .020 MORE distance

.030 less distance from the cut and .020" more distance from the DIFFERENCE in head gasket thickness makes a total of .010" LESS DISTANCE. Not more.
My heads are .010" closer to the cam centerline than before.

I think you forgot to factor in the original .020"ish steel shim factory head gasket in your equation.... that was REPLACED by a .040" Felpro...

Posted By: Crizila

Re: Rocker shaft shimmimg - 07/16/09 02:49 PM

Quote:

Quote:

Do your math and you will see that you gained .010 didn't loose it. Using a shim will actually make things worse.
You milled .030 and used a .040 gasket. Therefore you increased the distance not decreased. By milling .030 and using a .040 you actually lost ground.
Put it together and forget the shims they will make things worse.

I'm doing the math trust me!

I cut the head .030 = .030" LESS distance
I increased the head gasket from .020"ish to .040"ish = .020 MORE distance

.030 less distance from the cut and .020" more distance from the DIFFERENCE in head gasket thickness makes a total of .010" LESS DISTANCE. Not more.
My heads are .010" closer to the cam centerline than before.

I think you forgot to factor in the original .020"ish steel shim factory head gasket in your equation.... that was REPLACED by a .040" Felpro...

Ether way,your good to go without shims. BTW, why would you want to cut the heads .030 and then add .020 back with a thicker head gasket???

Posted By: CrAzYMoPaRGuY

Re: Rocker shaft shimmimg - 07/16/09 02:54 PM

Quote:

Quote:

Quote:

Do your math and you will see that you gained .010 didn't loose it. Using a shim will actually make things worse.
You milled .030 and used a .040 gasket. Therefore you increased the distance not decreased. By milling .030 and using a .040 you actually lost ground.
Put it together and forget the shims they will make things worse.

I'm hoping I'm OK with the .010 difference...

I'm doing the math trust me!

I cut the head .030 = .030" LESS distance
I increased the head gasket from .020"ish to .040"ish = .020 MORE distance

.030 less distance from the cut and .020" more distance from the DIFFERENCE in head gasket thickness makes a total of .010" LESS DISTANCE. Not more.
My heads are .010" closer to the cam centerline than before.

I think you forgot to factor in the original .020"ish steel shim factory head gasket in your equation.... that was REPLACED by a .040" Felpro...

Ether way,your good to go without shims. BTW, why would you want to cut the heads .030 and then add .020 back with a thicker head gasket???

I wanted to run the FelPro composite gaskets and increase my compression as opposed to REDUCE the compression. I also didn't want to affect my intake mating, and I've done the .030" cut with Felpro gaskets many times before....

I coulda just cut the heads .020", but I would STILL be checking my lifter preload, the heads have been redone by others and I'm not sure I trust the work!

It's a 9:1 engine, I can't afford to drop compression!

Posted By: Crizila

Re: Rocker shaft shimmimg - 07/16/09 03:15 PM

If the heads have been redone by others you might wabnt to CC them, just to verify what you got. I am not a proponent of shims, although it is a much cheaper way to go verses push rods and adjustable rockers and a lot of guys do it with no problems. As long as you are within your lifter plunger travel you are ok. If you are running over .5 lift, I'd also be checking the valve stem scrub pattern per what R.R. said.

Posted By: JohnRR

Re: Rocker shaft shimmimg - 07/16/09 03:28 PM

Quote:

Quote:

If you have to shim the shafts there are other issues at work, i.e. long valves or sunken seats.

Or milled heads and non-stock gasket thicknesses...
Which is ME!

Then you have not been paying attention , shims are for correcting VALVE TO ROCKER GEOMETRY , NOT making up for head/block machining .

Quote:

I wanted to run the FelPro composite gaskets and increase my compression as opposed to REDUCE the compression. I also didn't want to affect my intake mating, and I've done the .030" cut with Felpro gaskets many times before....

I coulda just cut the heads .020", but I would STILL be checking my lifter preload, the heads have been redone by others and I'm not sure I trust the work!

It's a 9:1 engine, I can't afford to drop compression!

Then why are you running a thicker composite gasket ??? the .010 more you gained might have raised your compression what .1 ???

Posted By: MoparforLife

Re: Rocker shaft shimmimg - 07/16/09 03:42 PM

Quote:

Quote:

Quote:

Quote:

Do your math and you will see that you gained .010 didn't loose it. Using a shim will actually make things worse.
You milled .030 and used a .040 gasket. Therefore you increased the distance not decreased. By milling .030 and using a .040 you actually lost ground.
Put it together and forget the shims they will make things worse.

I'm hoping I'm OK with the .010 difference...

I'm doing the math trust me!

I cut the head .030 = .030" LESS distance
I increased the head gasket from .020"ish to .040"ish = .020 MORE distance

.030 less distance from the cut and .020" more distance from the DIFFERENCE in head gasket thickness makes a total of .010" LESS DISTANCE. Not more.
My heads are .010" closer to the cam centerline than before.

I think you forgot to factor in the original .020"ish steel shim factory head gasket in your equation.... that was REPLACED by a .040" Felpro...

Ether way,your good to go without shims. BTW, why would you want to cut the heads .030 and then add .020 back with a thicker head gasket???

I wanted to run the FelPro composite gaskets and increase my compression as opposed to REDUCE the compression. I also didn't want to affect my intake mating, and I've done the .030" cut with Felpro gaskets many times before....

I coulda just cut the heads .020", but I would STILL be checking my lifter preload, the heads have been redone by others and I'm not sure I trust the work!

It's a 9:1 engine, I can't afford to drop compression!

Even compensating for the .020 gasket difference (which I admit miscalculated) a .010 gain isn't a noticable cut no matter how you look at it. It is really no more than a truing trim. You won't even notice a difference. Many thousands of .010 or even up to .040 gains in cutting have been made with no problems or shimming.

Posted By: Dadrules

Re: Rocker shaft shimmimg - 07/16/09 06:16 PM

I thought I had a similar issue with a small block, the blocked was decked so pistons sat at .000 and used cometics .038 gaskets. bought shims, dykemed (sp?) the top of the valve stem to watch how the pattern changed with different thicknesses of shims and learned I didn't need shims, the pattern from the roller on the rocker was closest to right over the valve stem without shims. I'd bought a set of custom length pushrods from Smith Bros in Bend Oregon and everything lined up right, two threads showing from the bottom. I had added Hughes 1.6 roller rockers so I learned I needed to be paying attention to how the bottom of the adjuster and the cup on the pushrod got oiled and that's what led me to custom pushrods. they turned around my order in 48 hours.

Posted By: CrAzYMoPaRGuY

Re: Rocker shaft shimmimg - 07/16/09 08:56 PM

Quote:

Then you have not been paying attention , shims are for correcting VALVE TO ROCKER GEOMETRY , NOT making up for head/block machining .

LOL

Quote:

Then why are you running a thicker composite gasket ??? the .010 more you gained might have raised your compression what .1 ???

I prefer the Felpro composiute gasket to a steel shim gasket, and my heads had a terrible surface on them to boot. Looks like somebody sanded them with a rock before the engine was last put together....

Now...
Can we get back on topic, it's ROCKER SHIMS I want to know about, not different ideas, different theories, how I can use shims for this, not for that...

ROCKER SHIMS.

Is there a difference between types, vendors,... or?

Posted By: JohnRR

Re: Rocker shaft shimmimg - 07/16/09 09:04 PM

Quote:

Quote:

Then you have not been paying attention , shims are for correcting VALVE TO ROCKER GEOMETRY , NOT making up for head/block machining .

LOL

Quote:

Then why are you running a thicker composite gasket ??? the .010 more you gained might have raised your compression what .1 ???

I prefer the Felpro composiute gasket to a steel shim gasket, and my heads had a terrible surface on them to boot. Looks like somebody sanded them with a rock before the engine was last put together....

Now...
Can we get back on topic, it's ROCKER SHIMS I want to know about, not different ideas, different theories, how I can use shims for this, not for that...

ROCKER SHIMS.

Is there a difference between types, vendors,... or?

nce again , get your pencil ready ...

Something must be being lost in the translation from English to Canadian ????

If it ain't broke don't break it ...

Posted By: CrAzYMoPaRGuY

Re: Rocker shaft shimmimg - 07/16/09 09:50 PM

Quote:

Quote:

Quote:

Then you have not been paying attention , shims are for correcting VALVE TO ROCKER GEOMETRY , NOT making up for head/block machining .

LOL

Quote:

Then why are you running a thicker composite gasket ??? the .010 more you gained might have raised your compression what .1 ???

I prefer the Felpro composiute gasket to a steel shim gasket, and my heads had a terrible surface on them to boot. Looks like somebody sanded them with a rock before the engine was last put together....

Now...
Can we get back on topic, it's ROCKER SHIMS I want to know about, not different ideas, different theories, how I can use shims for this, not for that...

ROCKER SHIMS.

Is there a difference between types, vendors,... or?

nce again , get your pencil ready ...

Something must be being lost in the translation from English to Canadian ????

If it ain't broke don't break it ...

NEXT!!!!!

Can it get any more painful?

Either reply about certain types of shims or continue and

AHHH, the beauty of MoParts.....

Posted By: buildanother

Re: Rocker shaft shimmimg - 07/17/09 01:45 AM

Wow. all this back and forth, are you understanding that shimming the shaft up will be changing the rocker tip to valve stem geometry like mentioned?

Posted By: n_bogie1984

Re: Rocker shaft shimmimg - 07/17/09 02:10 AM

ok i have no clue on rocker shims but as the guy said he don't care about every ones ideas on what is doing, he just wants to know the products, and what to look for.

best of luck getting your info cause i dont see this going anywhere fast

Posted By: stumpy

Re: Rocker shaft shimmimg - 07/17/09 02:14 AM

Mancinni sells the tapered shims.

Posted By: MoparforLife

Re: Rocker shaft shimmimg - 07/17/09 02:27 AM

I really don't see why poster thinks that shims or special length push rods would be nessessary with the little bit (.010) gained in the milling & gasket usage which like said before is nothing more than a minor truing trim and done everyday and put back together. It very likly would button back up even with the original gasket thickness with no problem.

Posted By: 1_WILD_RT

Re: Rocker shaft shimmimg - 07/17/09 02:36 AM

Quote:

FWIW the amount your shimming shouldn't be a problem...Mancini sells them...

http://chucker54.stores.yahoo.net/rocshafshim1.html

As I posted yesterday...

Posted By: MoparforLife

Re: Rocker shaft shimmimg - 07/17/09 02:40 AM

Quote:

Quote:

FWIW the amount your shimming shouldn't be a problem...Mancini sells them...

http://chucker54.stores.yahoo.net/rocshafshim1.html

As I posted yesterday...

Why??? No Need. One more un-needed potential problem.

Posted By: CrAzYMoPaRGuY

Re: Rocker shaft shimmimg - 07/17/09 02:59 AM

Quote:

Wow. all this back and forth, are you understanding that shimming the shaft up will be changing the rocker tip to valve stem geometry like mentioned?

Yup. That's pretty simple.
I don't find anybody reading what I REQUESTED except for a very few....

Thanks for the link 1 WILD RT

This sums it up guys... I was just looking for opinions on ACTUAL PRODUCT. That's all.

From n bogie1984...

Quote:

ok i have no clue on rocker shims but as the guy said he don't care about every ones ideas on what is doing, he just wants to know the products, and what to look for.

Posted By: CrAzYMoPaRGuY

Re: Rocker shaft shimmimg - 07/17/09 03:01 AM

Quote:

Mancinni sells the tapered shims.

Thanks Stumpy.

I saw the above link, I'm gonna buy some and see what they look like...

Posted By: CrAzYMoPaRGuY

Re: Rocker shaft shimmimg - 07/17/09 03:02 AM

Quote:

I really don't see why poster thinks that shims or special length push rods would be nessessary with the little bit (.010) gained in the milling & gasket usage which like said before is nothing more than a minor truing trim and done everyday and put back together. It very likly would button back up even with the original gasket thickness with no problem.

I just want them on hand in case, and I want to buy some out of curiosity. That's it!

Posted By: 71 FJ6 Charger

Re: Rocker shaft shimmimg - 07/17/09 03:14 AM

Posted By: CrAzYMoPaRGuY

Re: Rocker shaft shimmimg - 07/17/09 04:04 AM

Quote:

THAT'S IT!!!!!!!
I'm gonna go cause trouble in the General Forum!!!!!!!!!

Posted By: MoparforLife

Re: Rocker shaft shimmimg - 07/17/09 11:39 AM

http://www.hughesengines.com/Index/produ...word&page=3

Posted By: JohnRR

Re: Rocker shaft shimmimg - 07/17/09 01:43 PM

Quote:

Wow. all this back and forth, are you understanding that shimming the shaft up will be changing the rocker tip to valve stem geometry like mentioned?

He OBVIOUSLY does not CARE that he's fixing ... fixing ???

... his NON ISSUE incorrectly.