Rocker arm issues.
#3037838
04/28/22 12:16 AM
04/28/22 12:16 AM
|
Joined: Sep 2017
Posts: 344 Red Deer, Alberta
Greenwood
OP
enthusiast
|
OP
enthusiast
Joined: Sep 2017
Posts: 344
Red Deer, Alberta
|
So, as part of my refresh, I decided to replace my ancient Crane Golds. After some consideration, including the premise that they're made in the USA, I purchased a set of PRW rockers. In the end, this also necessitated a switch to new beehive springs. Now the engines all assembled and ready to bolt up to the trans and drop in. Just for the heck of it I put the dial indicator on the head tonight and measured up my actual valve lift. I'm at .513" net valve lift on a .575" roller, at .020" lash. With 1.6 rockers. Wonderful.
Last edited by Greenwood; 04/28/22 12:17 AM.
|
|
|
Re: Rocker arm issues.
[Re: lewtot184]
#3037910
04/28/22 10:13 AM
04/28/22 10:13 AM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
I just recently had a builder verify the net lift at the valve was going to be under .700” for this particular build. He checked two rockers, the theoretical lift would have been .690. One was like .650, the other .665. The lobe lifts were .460” for both. PRW steel 1.5 rockers. This was on a BB. If you’re working with a SB and the stock 59* lifter bank angle, that alone will cost you about .05 worth of effective ratio.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Rocker arm issues.
[Re: Greenwood]
#3037920
04/28/22 10:53 AM
04/28/22 10:53 AM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
The Cranes I have checked were always higher than the advertised ratio.
Also, if you’re using a shaft relocation kit for geometry improvement, I’ve seen instances where they have resulted in a lower effective rocker ratio.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Rocker arm issues.
[Re: B1MAXX]
#3037941
04/28/22 12:12 PM
04/28/22 12:12 PM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
I’m saying that when the lift was checked with and without the relocation kit, there have been instances where the addition of the kit lowered the effective ratio. So, if the OP has one of those kits installed, he could remove it and see if, in his particular situation, it has any impact on the ratio.
The highest departure from the “advertised” ratio I recall seeing was 1.67 from a set of HS 1.6’s on some Indy SR’s using checking springs. With the full spring force(700lbs) at .700” lift, the effective ratio was still 1.63.
Edit- re-read the OP. I didn’t see where it said if the lifters were solid or hyd. You can’t get a good read on the true running lift using a hyd lifter for mock ups(it compresses)......... if that’s what you’re doing.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Rocker arm issues.
[Re: Stanton]
#3038178
04/29/22 10:19 AM
04/29/22 10:19 AM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
Here's the thing with Mopar rockers, the length from the fulcrum to the contact point on the valve should be fairly close on any rocker It should be....... but in reality, there are definitely length differences on the valve side between the different brands. Stealing a pic from Andy’s book:
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Rocker arm issues.
[Re: Greenwood]
#3038181
04/29/22 10:26 AM
04/29/22 10:26 AM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
Solid roller, and no shaft relocation. Sounds like you just have to decide how badly you want that ratio to be closer to “correct”.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Rocker arm issues.
[Re: AndyF]
#3038211
04/29/22 12:18 PM
04/29/22 12:18 PM
|
Joined: Jan 2003
Posts: 75,106 A Banana Republic near you.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 75,106
A Banana Republic near you.
|
Yeah there were all these arguments on the forums years ago so I went and bought one rocker from each mfg and put them all on a shaft. Once I did that I said "okay, now I get it"!
The Mopar rocker arms are all over the map. You don't know what works until you try it. Eventually I created a little cheat sheet that told me which rocker arms worked with which cylinder heads. If a person just randomly selects a rocker arm package then good luck and may the force be with you. Not everything works on everything. Have you shared this cheatsheet ?
running up my post count some more .
|
|
|
Re: Rocker arm issues.
[Re: JohnRR]
#3038239
04/29/22 01:30 PM
04/29/22 01:30 PM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
I’ve used the Crane golds on stock heads, stage 6’s, Indy SR’s, Indy EZ’s, B1/BS, and RPM’s........no problems with the fit that were serious enough for them not to be used.
Plus...... they were pretty affordable too.
My go to replacement for them are the Mancini rockers, but I haven’t had the opportunity to test fit them on all of those applications.
The solid spacers between the rockers that the Mancini rockers use aren’t as universally install friendly as the springs that came with the Cranes.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Rocker arm issues.
[Re: Greenwood]
#3038265
04/29/22 03:38 PM
04/29/22 03:38 PM
|
Joined: Nov 2003
Posts: 1,366 Out of the State of Confusion
blue_stocker
pro stock
|
pro stock
Joined: Nov 2003
Posts: 1,366
Out of the State of Confusion
|
I really hate to sound obtuse but I fail to see how a 'geometry correcction kit' can have a ratio effect (change) on a set of rockerarms. Regardless of the rocker ratio itself, all a 'correction kit' does is move the position of the rocker arm contact to achieve proper scrub angle...does it not? So, how then does THIS change the actual ratio or effective valve lift/ratio?
I predict future happiness for Americans if they can prevent the government from wasting the labors of the people under the pretense of taking care of them. Thomas Jefferson
Freedom must be repurchased by every new generation General Daniel Jones, WW2 Tuskegee Airmen
|
|
|
Re: Rocker arm issues.
[Re: blue_stocker]
#3038270
04/29/22 03:58 PM
04/29/22 03:58 PM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
Brad Haak had some really good examples, actual measurements, and CAD drawings in a detailed post about that very thing.
If you search through his posts you should be able to find it.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Rocker arm issues.
[Re: JohnRR]
#3038272
04/29/22 04:13 PM
04/29/22 04:13 PM
|
Joined: Jan 2003
Posts: 31,096 Oregon
AndyF
I Win
|
I Win
Joined: Jan 2003
Posts: 31,096
Oregon
|
Yeah there were all these arguments on the forums years ago so I went and bought one rocker from each mfg and put them all on a shaft. Once I did that I said "okay, now I get it"!
The Mopar rocker arms are all over the map. You don't know what works until you try it. Eventually I created a little cheat sheet that told me which rocker arms worked with which cylinder heads. If a person just randomly selects a rocker arm package then good luck and may the force be with you. Not everything works on everything. Have you shared this cheatsheet ? I wrote a couple of books
|
|
|
Re: Rocker arm issues.
[Re: AndyF]
#3038276
04/29/22 04:30 PM
04/29/22 04:30 PM
|
Joined: Jan 2003
Posts: 10,772 North Dakota
6PakBee
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 10,772
North Dakota
|
Yeah there were all these arguments on the forums years ago so I went and bought one rocker from each mfg and put them all on a shaft. Once I did that I said "okay, now I get it"!
The Mopar rocker arms are all over the map. You don't know what works until you try it. Eventually I created a little cheat sheet that told me which rocker arms worked with which cylinder heads. If a person just randomly selects a rocker arm package then good luck and may the force be with you. Not everything works on everything. Years ago Racer Brown recommended going through a set of stock rockers and selecting those that had equivalent lifts. I have done this multiple times and yes, the ratio of a stock Mopar rocker is all over the map.
"We live in a time when intelligent people are being silenced so that stupid people won't be offended".
|
|
|
Re: Rocker arm issues.
[Re: Greenwood]
#3038305
04/29/22 06:40 PM
04/29/22 06:40 PM
|
Joined: Nov 2003
Posts: 1,366 Out of the State of Confusion
blue_stocker
pro stock
|
pro stock
Joined: Nov 2003
Posts: 1,366
Out of the State of Confusion
|
Thanks Dwayne, I'll look into it...wb
I predict future happiness for Americans if they can prevent the government from wasting the labors of the people under the pretense of taking care of them. Thomas Jefferson
Freedom must be repurchased by every new generation General Daniel Jones, WW2 Tuskegee Airmen
|
|
|
Re: Rocker arm issues.
[Re: Greenwood]
#3038344
04/29/22 07:54 PM
04/29/22 07:54 PM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
I'm at .513" net valve lift on a .575" roller, at .020" lash. With 1.6 rockers. The rockers aren’t marked for ratio, correct? My guess is....... they’re 1.5’s in a 1.6 box. .575 lift with a 1.5 is .383 lobe lift. You getting .513 with .020 lash, which would put the number at .533 gross lift. 533/383 = 1.39. I find it hard to believe they’d be that far off(1.6 > 1.39). 1.5 > 1.39 would be bad enough.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Rocker arm issues.
[Re: fast68plymouth]
#3038401
04/30/22 01:07 AM
04/30/22 01:07 AM
|
Joined: Sep 2017
Posts: 344 Red Deer, Alberta
Greenwood
OP
enthusiast
|
OP
enthusiast
Joined: Sep 2017
Posts: 344
Red Deer, Alberta
|
I'm at .513" net valve lift on a .575" roller, at .020" lash. With 1.6 rockers. The rockers aren’t marked for ratio, correct? My guess is....... they’re 1.5’s in a 1.6 box. .575 lift with a 1.5 is .383 lobe lift. You getting .513 with .020 lash, which would put the number at .533 gross lift. 533/383 = 1.39. I find it hard to believe they’d be that far off(1.6 > 1.39). 1.5 > 1.39 would be bad enough. The rockers themselves are marked 1.6..
|
|
|
Re: Rocker arm issues.
[Re: Greenwood]
#3038448
04/30/22 11:03 AM
04/30/22 11:03 AM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
The rockers themselves are marked 1.6. Interesting. The ones that were on a motor that was just on the dyno here had no markings. The two that were checked measured in the 1.45 range. This isn’t doing much to make me change my mind about not using Chinese rockers.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Rocker arm issues.
[Re: fast68plymouth]
#3038530
04/30/22 03:57 PM
04/30/22 03:57 PM
|
Joined: Aug 2003
Posts: 43,333 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,333
Bend,OR USA
|
The rockers themselves are marked 1.6. Interesting. The ones that were on a motor that was just on the dyno here had no markings. The two that were checked measured in the 1.45 range. This isn’t doing much to make me change my mind about not using Chinese rockers. I've measure a bunch of different brand BB Mopar adjustable rocker arms, stock Ductile iron Max Wedges, stock Street Hemi ductile iron rockers from many different motors, Isky, Cranes and Erson brand ductile iron rocker arms as well as several different brands of aluminum rocker arms like Harland sharp, both early and later made, and several sets of T&D single shaft sets, none of them were dead nuts on the ratio on the complete sets sent to me from the factories I use to send the ductile iron sets to a company in northern, CA for blue printing and making them accurate, after checking several different sets I had done by them I stopped doing that i have not yet check a complete set of Jesel paired shaft aluminum or steel rocker arms, that is next
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Rocker arm issues.
[Re: fast68plymouth]
#3038673
05/01/22 02:32 AM
05/01/22 02:32 AM
|
Joined: Sep 2017
Posts: 344 Red Deer, Alberta
Greenwood
OP
enthusiast
|
OP
enthusiast
Joined: Sep 2017
Posts: 344
Red Deer, Alberta
|
The rockers themselves are marked 1.6. Interesting. The ones that were on a motor that was just on the dyno here had no markings. The two that were checked measured in the 1.45 range. This isn’t doing much to make me change my mind about not using Chinese rockers. Fair point. I'll probably find out on Monday what the manufacturer has to say.
|
|
|
Re: Rocker arm issues.
[Re: Greenwood]
#3038700
05/01/22 08:46 AM
05/01/22 08:46 AM
|
Joined: Dec 2021
Posts: 1,200 Loudoun County, VA
Brad_Haak
pro stock
|
pro stock
Joined: Dec 2021
Posts: 1,200
Loudoun County, VA
|
Fair point. I'll probably find out on Monday what the manufacturer has to say.
How many of the eight common dialects spoken in China do you know?
2021 Challenger 6.4L Scat Pack 1320 100% stock: 1.680, 11.894 at 113.75 (DA 175 ft) weight reduction, wheels, tires, Hellcat air box: 1.661, 11.686 at 115.97 (DA 710 ft)
1973 Challenger 452 ci street/strip [2008] pump gas, DOT radials: 1.454, 10.523 at 126.44 (DA 514 ft)
|
|
|
Re: Rocker arm issues.
[Re: Stanton]
#3038743
05/01/22 11:33 AM
05/01/22 11:33 AM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
That’s all fine and dandy, but it sounds like the Crane 1.6’s yielded .080” more valve lift than the PRW’s with the same cam(lobe lift).
I know which scenario I’d rather have in my engine.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Rocker arm issues.
[Re: AndyF]
#3038761
05/01/22 12:38 PM
05/01/22 12:38 PM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
The old unbushed will-seize-on-the-shaft CAT stainless rockers were also like that.
There is obviously no testing done on that stuff, or input from builders familiar with the platform for that matter.
I didn’t see where the OP mentioned if this is a BB or SB.
On the SB, there is a definite loss of effective ratio(as measured at the valve) from the 59* lifter bank angle and the pushrod angle.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Rocker arm issues.
[Re: AndyF]
#3038817
05/01/22 04:42 PM
05/01/22 04:42 PM
|
Joined: May 2003
Posts: 6,571 Downtown Roebuck Ont
Twostick
Still wishing...
|
Still wishing...
Joined: May 2003
Posts: 6,571
Downtown Roebuck Ont
|
My guess is that someone at the PRW factory stamped a set of 1.50 rockers with the 1.60 ID and then they got boxed and sold as 1.60 rockers. PRW gave me a set of their steel rocker arms when they first came out for a magazine article, but the rockers were a timebomb so I never used them. The rockers had ribs around the roller tip that were too big. The ribs hit the valve lock before the roller hit the valve stem so the load was all being carried by the valve lock. I never even started the engine when I saw that. Just boxed up the rocker arms and sent them back and never included them in the article. I assume they fixed this design flaw but I haven't looked at a set since. I had the same issue with the ones that 440Source marketed briefly. Put them in the mill and fixed them. Rocker body wasn't spot faced for the jam nut and when you tightened it down, it broke the adjuster. Source replaced them with new and improved but still had to trim the roller end. Then discovered the adjusters were made of glass. Replaced them with Comp adjusters and thought we had beat them into submission... Some time later, I had a valve cover gasket leak that was a big blessing in disguise. Pulled the cover and found one side of the roller end was broken on one rocker and when I took them off the engine discovered the rollers were loose enough on their axles that you could hear them rattle from across the shop when you shook them... Shoulda just bought the Comp Magnums... Kevin
|
|
|
Re: Rocker arm issues.
[Re: AndyF]
#3039049
05/02/22 11:50 AM
05/02/22 11:50 AM
|
Joined: Aug 2019
Posts: 9,581 Super Spudsville
Mr PotatoHead
Half Baked
|
Half Baked
Joined: Aug 2019
Posts: 9,581
Super Spudsville
|
Seen two vids on the new mopar small block trick flo heads, the rockers beating the tops of the retainers and one broke valve. Wonder what the mis match in parts was here? My guess is that someone at the PRW factory stamped a set of 1.50 rockers with the 1.60 ID and then they got boxed and sold as 1.60 rockers. PRW gave me a set of their steel rocker arms when they first came out for a magazine article, but the rockers were a timebomb so I never used them. The rockers had ribs around the roller tip that were too big. The ribs hit the valve lock before the roller hit the valve stem so the load was all being carried by the valve lock. I never even started the engine when I saw that. Just boxed up the rocker arms and sent them back and never included them in the article. I assume they fixed this design flaw but I haven't looked at a set since.
STOP POTATO HATE!
|
|
|
Re: Rocker arm issues.
[Re: Mr PotatoHead]
#3039114
05/02/22 03:06 PM
05/02/22 03:06 PM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
Seen two vids on the new mopar small block trick flo heads, the rockers beating the tops of the retainers and one broke valve.
Wonder what the mis match in parts was here?
The only rockers I would have any real “expectation” about fitting those heads, without needing modifications to something, are the HS part numbers recommended by TF. Anything else should get extra scrutiny(although they should all be checked). If there is evidence of contact between the rocker and the retainer.......IMO, that’s on the one doing the final assembly.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Rocker arm issues.
[Re: Greenwood]
#3040015
05/05/22 04:51 PM
05/05/22 04:51 PM
|
Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
|
If the engine combo is slightly “under-cammed”, then the added ratio(area under the curve) should pay off. Adding ratio is no guarantee of added power. I’ve swapped rockers from 1.5 to 1.6 several times where the result was a reduction of power across the board.
We have 1.2 break in rockers for SBC. Sometimes even when swapping from those to the normal 1.5’s or 1.6’s doesn’t result in huge gains.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Rocker arm issues.
[Re: Greenwood]
#3040055
05/05/22 07:02 PM
05/05/22 07:02 PM
|
Joined: Aug 2003
Posts: 43,333 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,333
Bend,OR USA
|
[ That's an interesting observation. I've just got a set of worked over J-heads. I have a hunch I will be able to do a real world comparison where I find out exactly what the power difference is between 513 lift and 585-590 lift, with no other changes. Are you sure that the cam with more lift doesn't have more duration at .020, .050, .100 and at .200 lift on the lifters? All the BB Mopar V8 I've dealt with at the track and on a engine dyno like more air with more fuel Your on the right path
Last edited by Cab_Burge; 05/05/22 07:03 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
|
|