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Rocker shaft shimmimg #376765 07/15/09 10:46 PM 07/15/09 10:46 PM
Joined: Oct 2004 Posts: 16,479 Canada CrAzYMoPaRGuY OP I Live Here
CrAzYMoPaRGuY OP I Live Here Joined: Oct 2004 Posts: 16,479 Canada	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... CrAzYMoPaRGuY

Re: Rocker shaft shimmimg [Re: CrAzYMoPaRGuY] #376766 07/15/09 10:53 PM 07/15/09 10:53 PM
Joined: Jan 2003 Posts: 32,930 Grand Prairie,Texas stumpy I Win
stumpy I Win Joined: Jan 2003 Posts: 32,930 Grand Prairie,Texas	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.

Re: Rocker shaft shimmimg [Re: stumpy] #376767 07/15/09 11:14 PM 07/15/09 11:14 PM
Joined: Jan 2003 Posts: 274 Visalia, CA. P poison_ivy enthusiast
poison_ivy enthusiast P Joined: Jan 2003 Posts: 274 Visalia, CA.	Actually shims will correct inproper rocker geometry. I have .090 under my shafts.

Re: Rocker shaft shimmimg [Re: stumpy] #376768 07/15/09 11:21 PM 07/15/09 11:21 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	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 live every 24 hour block of time like it's your last day on earth

Re: Rocker shaft shimmimg [Re: poison_ivy] #376769 07/15/09 11:29 PM 07/15/09 11:29 PM
Joined: Aug 2003 Posts: 8,716 Baltimore/Denver 64Post master
64Post master Joined: Aug 2003 Posts: 8,716 Baltimore/Denver	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.

Re: Rocker shaft shimmimg [Re: CrAzYMoPaRGuY] #376770 07/15/09 11:56 PM 07/15/09 11:56 PM
Joined: Jan 2003 Posts: 75,008 U.S.S.A. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 75,008 U.S.S.A.	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 ?

Re: Rocker shaft shimmimg [Re: JohnRR] #376771 07/16/09 12:29 AM 07/16/09 12:29 AM
Joined: Oct 2004 Posts: 16,479 Canada CrAzYMoPaRGuY OP I Live Here
CrAzYMoPaRGuY OP I Live Here Joined: Oct 2004 Posts: 16,479 Canada	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.... CrAzYMoPaRGuY

Re: Rocker shaft shimmimg [Re: stumpy] #376772 07/16/09 12:31 AM 07/16/09 12:31 AM
Joined: Oct 2004 Posts: 16,479 Canada CrAzYMoPaRGuY OP I Live Here
CrAzYMoPaRGuY OP I Live Here Joined: Oct 2004 Posts: 16,479 Canada	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. CrAzYMoPaRGuY

Re: Rocker shaft shimmimg [Re: 64Post] #376773 07/16/09 12:33 AM 07/16/09 12:33 AM
Joined: Oct 2004 Posts: 16,479 Canada CrAzYMoPaRGuY OP I Live Here
CrAzYMoPaRGuY OP I Live Here Joined: Oct 2004 Posts: 16,479 Canada	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! CrAzYMoPaRGuY

Re: Rocker shaft shimmimg [Re: CrAzYMoPaRGuY] #376774 07/16/09 01:02 AM 07/16/09 01:02 AM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	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. live every 24 hour block of time like it's your last day on earth

Re: Rocker shaft shimmimg [Re: RapidRobert] #376775 07/16/09 01:21 AM 07/16/09 01:21 AM
Joined: Jan 2004 Posts: 27,347 Today? Who Knows? 1_WILD_RT Management Trainee
1_WILD_RT Management Trainee Joined: Jan 2004 Posts: 27,347 Today? Who Knows?	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... 5355659-Rockergeometery.bmp (61 downloads)

Re: Rocker shaft shimmimg [Re: 1_WILD_RT] #376776 07/16/09 01:34 AM 07/16/09 01:34 AM
Joined: Jul 2008 Posts: 403 NE Ohio 7 71 FJ6 Charger mopar
71 FJ6 Charger mopar 7 Joined: Jul 2008 Posts: 403 NE Ohio	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? '71 383HP FJ6 Charger SE

Re: Rocker shaft shimmimg [Re: 71 FJ6 Charger] #376777 07/16/09 01:43 AM 07/16/09 01:43 AM
Joined: Jan 2004 Posts: 27,347 Today? Who Knows? 1_WILD_RT Management Trainee
1_WILD_RT Management Trainee Joined: Jan 2004 Posts: 27,347 Today? Who Knows?	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...

Re: Rocker shaft shimmimg [Re: RapidRobert] #376778 07/16/09 07:05 AM 07/16/09 07:05 AM
Joined: Jan 2003 Posts: 25,200 Upper Midwest M MoparforLife Too Many Posts
MoparforLife Too Many Posts M Joined: Jan 2003 Posts: 25,200 Upper Midwest	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.

Re: Rocker shaft shimmimg [Re: MoparforLife] #376779 07/16/09 08:47 AM 07/16/09 08:47 AM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	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. Fastest 300

Re: Rocker shaft shimmimg [Re: MoparforLife] #376780 07/16/09 10:31 AM 07/16/09 10:31 AM
Joined: Oct 2004 Posts: 16,479 Canada CrAzYMoPaRGuY OP I Live Here
CrAzYMoPaRGuY OP I Live Here Joined: Oct 2004 Posts: 16,479 Canada	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... CrAzYMoPaRGuY

Re: Rocker shaft shimmimg [Re: CrAzYMoPaRGuY] #376781 07/16/09 10:49 AM 07/16/09 10:49 AM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	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??? Fastest 300

Re: Rocker shaft shimmimg [Re: Crizila] #376782 07/16/09 10:54 AM 07/16/09 10:54 AM
Joined: Oct 2004 Posts: 16,479 Canada CrAzYMoPaRGuY OP I Live Here
CrAzYMoPaRGuY OP I Live Here Joined: Oct 2004 Posts: 16,479 Canada	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! CrAzYMoPaRGuY

Re: Rocker shaft shimmimg [Re: CrAzYMoPaRGuY] #376783 07/16/09 11:15 AM 07/16/09 11:15 AM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	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. Fastest 300

Re: Rocker shaft shimmimg [Re: CrAzYMoPaRGuY] #376784 07/16/09 11:28 AM 07/16/09 11:28 AM
Joined: Jan 2003 Posts: 75,008 U.S.S.A. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 75,008 U.S.S.A.	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 ??? Last edited by Johnahah; 07/16/09 11:32 AM.

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