Best rocker arm for 906 heads. Mild roller
#1821438
05/07/15 10:40 PM
05/07/15 10:40 PM
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Joined: Jun 2010
Posts: 1,144
wellington ohio
68-scatpack-rt
OP
In thin ice
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OP
In thin ice
Joined: Jun 2010
Posts: 1,144
wellington ohio
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Hello all.
I had a pair of 906 heads done up recently for a 440 for my coronet.
I'm thinking of having a mild roller cam ground at cam motion and I'm wondering what roller rocker gives the best geometry on a 906 head.
I don't want to buy Chinese junk, but I don't want (or need) jesel or T&D either.
The heads are done except for the spring selection, so I don't want to get into machining the shaft bosses.
Considering Harland sharpe, comp cams or the new scorpion.
Thoughts?
unions....the folks who brought you the weekend!
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Re: Best rocker arm for 906 heads. Mild roller
[Re: 68-scatpack-rt]
#1821472
05/07/15 11:10 PM
05/07/15 11:10 PM
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Joined: Jul 2013
Posts: 561
USA
B3RE
mopar
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mopar
Joined: Jul 2013
Posts: 561
USA
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Hello all.
I had a pair of 906 heads done up recently for a 440 for my coronet.
I'm thinking of having a mild roller cam ground at cam motion and I'm wondering what roller rocker gives the best geometry on a 906 head.
I don't want to buy Chinese junk, but I don't want (or need) jesel or T&D either.
The heads are done except for the spring selection, so I don't want to get into machining the shaft bosses.
Considering Harland sharpe, comp cams or the new scorpion.
Thoughts? Geometry is way more than just the rocker arm design. In fact, I have yet to see a properly designed single shaft rocker for Mopar wedge engines. Almost all big block rockers are too long, and a lot of the small block ones as well. If you want good geometry with a roller rocker, you have no choice but to relocate the shafts. It can be done without milling off the stands. Having the roller tip is the same as running a longer valve, as far as geometry is concerned, so unless you move the shaft/fulcrum, it will be off considerably. For rockers, I'd go with Crane, and use full time oiling to the shafts. Set them up with spacers (no springs), and .015" side clearance per pair. They will need the shafts relocated as well, but will require less correction than most big block rockers.
Mike Beachel
I didn't write the rules of math nor create the laws of physics, I am just bound by them.
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Re: Best rocker arm for 906 heads. Mild roller
[Re: 68-scatpack-rt]
#1821591
05/08/15 12:59 AM
05/08/15 12:59 AM
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Joined: Jan 2003
Posts: 5,485
So Cal
Sinitro
master
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master
Joined: Jan 2003
Posts: 5,485
So Cal
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Harland Sharps are excellent.. I tossed a set of the Crane ductile iron rockers into the dumpster, that were not hardened properly around the time they went through their bankruptcy a few years back.... I complained to Crane even talking to their engineers @ SEMA, they blew me off and gave me the sunshine treatment.. I have installed several sets of Harland Sharps, when one considers the importance and stress on the valve train it is not the place to cut $$... Regarding the shimming process, we use a spare head to mock up the shafts/rockers and we add/modify the shims as required. Then we transfer the shaft to the engine, torque it down and recheck the clearances and alignment. Sometimes they change slightly.. Just my $0.02... 
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Re: Best rocker arm for 906 heads. Mild roller
[Re: 68-scatpack-rt]
#1822890
05/09/15 06:41 PM
05/09/15 06:41 PM
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Joined: Dec 2004
Posts: 10,682
Rittman Ohio
fourgearsavoy
I Live Here
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I Live Here
Joined: Dec 2004
Posts: 10,682
Rittman Ohio
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Rob do you deal with Nick over at Compu-flow? I would give Nick a call and get his recommendation on some rockers as he has probably built a ton of 906 headed street/strip engines. He probably has them on the shelf in Comp, HS,or Crane and he's only about a half hour from your house  Gus  I would use these on a small roller 
64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60
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Re: Best rocker arm for 906 heads. Mild roller
[Re: 68-scatpack-rt]
#1822934
05/09/15 07:46 PM
05/09/15 07:46 PM
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Joined: Jun 2010
Posts: 1,144
wellington ohio
68-scatpack-rt
OP
In thin ice
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OP
In thin ice
Joined: Jun 2010
Posts: 1,144
wellington ohio
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Thanks for the replies.
I've never dealt with nick gus. Maybe, I'll give him a shout. I bet you're right about the number of combos he's seen.
Andy F. I'm aware of the variances in aftermarket roller rocker length. That was the main point of the thread....to see if there was one that was "good" with a stock height valve in a 906 head.
How does one go about shimming the bosses?
unions....the folks who brought you the weekend!
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Re: Best rocker arm for 906 heads. Mild roller
[Re: 68-scatpack-rt]
#1822967
05/09/15 08:41 PM
05/09/15 08:41 PM
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Joined: Feb 2006
Posts: 1,057
The Great White North
RAMM
super stock
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super stock
Joined: Feb 2006
Posts: 1,057
The Great White North
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The Crane irons or the Crane golds seem to be about the best IME. I would prefer the irons over the aluminum if street bound. J.Rob
2009 PHR\EMC Competitor
2010 PHR\EMC Competitor
2011 PHR\EMC Competitor
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2013 PHR\EMC Competitor
2014 HotRod/EMC Competitor
2015 HotRod/EMC NoShow
2016 HotRod/EMC 3rd place SPEC Bigblock
2018 HotRod/EMC 7th place G3
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Re: Best rocker arm for 906 heads. Mild roller
[Re: 68-scatpack-rt]
#1823018
05/09/15 09:40 PM
05/09/15 09:40 PM
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Joined: Dec 2004
Posts: 10,682
Rittman Ohio
fourgearsavoy
I Live Here
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I Live Here
Joined: Dec 2004
Posts: 10,682
Rittman Ohio
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Rob you mentioned Scorpion rockers.They have a very good reputation in the racing world but I haven't seen the Mopar rockers for a while. The shaft placement deal that has been discussed til feelings got hurt is a very interesting procedure. I can really see the point of doing it if your going to lose sleep over your rocker geometry being off a few thousands of an inch. I've read the procedure for calculating your ratio and it requires some measurements that need to be VERY precise or why bother. Next step is send the measurements to the rocker shim guru and he will use his engineering skills to machine some spacers based on your measurements. Now when you get your spacers buy some checking pushrods and send your measurements to Smith Brothers and get some pushrods to match your new correctly re-engineered cylinder head rocker stands. Seems like a lot of work for a mild street/strip engine but when you look at the number of cycles your valve train endures on a 50 mile cruise a drag engine only runs a fraction of cycles that a street engine does  Gus
64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60
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Re: Best rocker arm for 906 heads. Mild roller
[Re: 68-scatpack-rt]
#1823035
05/09/15 09:59 PM
05/09/15 09:59 PM
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Joined: Jun 2010
Posts: 1,144
wellington ohio
68-scatpack-rt
OP
In thin ice
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OP
In thin ice
Joined: Jun 2010
Posts: 1,144
wellington ohio
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Thanks Gus.
I was hoping one of the offerings would be close for correct geometry without shims.
I'm not going for a 100% effort build, just a warmed up 440.
That said, I'd like to maximize the parts I'm using by setting it up correctly.
I'll have to do some calling around this week.
Ps....i heard scorpion was making B/RB rocker arms now. Lots of the marine guys are running scorpion on their BBC stuff with good results.
unions....the folks who brought you the weekend!
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Re: Best rocker arm for 906 heads. Mild roller
[Re: fourgearsavoy]
#1823386
05/10/15 12:16 PM
05/10/15 12:16 PM
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Joined: Jul 2013
Posts: 561
USA
B3RE
mopar
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mopar
Joined: Jul 2013
Posts: 561
USA
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Rob you mentioned Scorpion rockers.They have a very good reputation in the racing world but I haven't seen the Mopar rockers for a while. The shaft placement deal that has been discussed til feelings got hurt is a very interesting procedure. I can really see the point of doing it if your going to lose sleep over your rocker geometry being off a few thousands of an inch. I've read the procedure for calculating your ratio and it requires some measurements that need to be VERY precise or why bother. Next step is send the measurements to the rocker shim guru and he will use his engineering skills to machine some spacers based on your measurements. Now when you get your spacers buy some checking pushrods and send your measurements to Smith Brothers and get some pushrods to match your new correctly re-engineered cylinder head rocker stands. Seems like a lot of work for a mild street/strip engine but when you look at the number of cycles your valve train endures on a 50 mile cruise a drag engine only runs a fraction of cycles that a street engine does Gus Gus, you bring up a great point about the number of cycles a street engine makes, but a race engine is usually under much greater stress than a street engine. Either way, with a roller rocker, it is more than a few thousandths to lose sleep over. It is physically impossible, with the roller rockers currently on the market, to have correct geometry with the shafts bolted directly to the factory stands. Rob, As far as something that will be close just bolted on, put a set of irons on it. If the valve lift is less than .550", leave it alone. If over .550", put a lash cap on it. That will get you close, since that's all you're shooting for. If you want a roller rocker, getting it close ain't happening without moving the shafts. And, shims aren't doing it. Offset spacers and hold downs will.
Mike Beachel
I didn't write the rules of math nor create the laws of physics, I am just bound by them.
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Re: Best rocker arm for 906 heads. Mild roller
[Re: 68-scatpack-rt]
#1823404
05/10/15 12:38 PM
05/10/15 12:38 PM
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Joined: Jun 2010
Posts: 1,144
wellington ohio
68-scatpack-rt
OP
In thin ice
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OP
In thin ice
Joined: Jun 2010
Posts: 1,144
wellington ohio
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Hey mike.
Thanks for taking the time to reply.
The lift will be in the low 500 range. (Heads were flow tested and peaked just north of .500)
A friend has a set of irons. Probably the hot ticket for what I'm doing.
Thanks guys!
unions....the folks who brought you the weekend!
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