Slant 6 Roller Rocker Arm Vendor(s)

[CichliDart]

Just found this while wandering the web.

http://www.rockerarms.com/images/chartimages/PL33R.jpg
Rocker Arms Unlimited

16575 Clear Creek Rd. Redding, CA. 96001
Tel: 530-242-1316 ~ Fax: 530-242-1332 ~ Email: rockerarms@rockerarms.com

I was on Slantsix.org last night and found a 12 year old thread on Cox Brothers in Ohio that were makers of slant six roller rockers. But nothing current about them making them.
Cox Bros mailing address - Slant Six Forum

Cox Brothers Fabrication
1467 Weldon Ave.
Columbus, Ohio
43224


Mike

 

[Killer6]

I believe the Cox Bros. were a machine shop, one of the Brothers passed away IIRC unfortunately, I do not believe The shop is fabricating them any longer. PP&R and another Aussie outfit offer them as well as at least one of the big domestics(T&D?), read big $$$$, usually ~ $1,200 a set or higher. I've not heard any opinion on the Unlimited's......

 

[whit68]

G’day all

Pentastar Parts here in Aus make a set, can choose 1.5 or 1.6 ratio ($1350 Aus). I have not used them myself but I have purschased from PP&R often and have never had any problems with their quality.

Cheers
Anthony

Just found this while wandering the web.

http://www.rockerarms.com/images/chartimages/PL33R.jpg
Rocker Arms Unlimited

16575 Clear Creek Rd. Redding, CA. 96001
Tel: 530-242-1316 ~ Fax: 530-242-1332 ~ Email: rockerarms@rockerarms.com

I was on Slantsix.org last night and found a 12 year old thread on Cox Brothers in Ohio that were makers of slant six roller rockers. But nothing current about them making them.
Cox Bros mailing address - Slant Six Forum

Cox Brothers Fabrication
1467 Weldon Ave.
Columbus, Ohio
43224


Mike

 

[rumblefish360]

http://www.rockerarms.com/pdf/slant6flyer.pdf

 

[Charrlie_S]

If I remember correctly, At one time RAS made roller rockers for the slant six. They did have some problems with the shaft deforming when tightened down. I'm pretty sure RAS has/was sold a couple of times, and is now called Rocker Arms Unlimited. These arms were not available for awhile. It looks like they are making them, again. Hopefully they have fixed the shaft problem.

Disclaimer: As I said, I'm going by memory, and could be wrong, so do your due dillegance.

 

[lilnoah]

Pardon me for being ignorant, but what is the advantage of roller rocker arms?

 

[rumblefish360]

Pardon me for being ignorant, but what is the advantage of roller rocker arms?

Exact dead on ratio, high strength non flexing rocker arm, lighter weight & adjustable for the best sweep pattern across the rocker top.

 

[Hyper_pak]

And if you have ever looked at a stock slant six rocker and wondered what they were smoking, you start thinking about replacement arms. That being said stock rockers have worked well on many higher performing slants. On the Daytona Valiants, they turned well over 7000 rpms. I found some Gotha Rocker Arms years ago and I thought I had found the solution. However, that didn't last long and I went back to stockers for years. I bought some parts from the Cox Bros a few years ago, Jim still has some parts, he might have some rocker arms. If you want his phone number send me a PM.

 

[valiantpatrol]

I agree with Hyper-Pak. If you don't turn your six above 5500-6000 RPM the roller tipped rockers are not a necessity even though they have some advantages over stock. However on a higher revving engine like a 170 CID they are very beneficial for adding durability. I broke many stock rockers on the underside where the load bearing ring was tack welded to the stamped rocker body. I finally fully welded the circumference of the ring on both sides and this stopped most (not all) of my problems with breakage. And while what I did is a workable solution it is not the end all to the broken rocker dilemma like a quality set of billet roller tipped rockers should be. Nothing more frustrating than trying to fix broken rockers between rounds at bracket event !!

 

[rumblefish360]

If you don't turn your six above 5500-6000 RPM the roller tipped rockers are not a necessity even though they have some advantages over stock. However on a higher revving engine like a 170 CID they are very beneficial for adding durability.

Sorry, almost everything in the quote above (not the entire post, just the quote) I disagree with for the following reasons.

Roller rockers are not needed on anything period!
RPM has NO play in determining what style of rocker is needed. Just strength.

Moving away from a stock rocker to an improved design and/or stronger rocker will improve durability over a stock rocker. Though at stock engine specs, anyone would be hard pressed to prove they will out last the OE part.

You could very well produce that same power and most probable, equal the longevity with a mechanical rocker vs a roller rocker at every point.

(Edit)

The draw back of any aftermarket rocker is material used. Durability and overall weight. If the mechanical rocker is heavier than the roller rocker, it will show less power during a dyno pull. An amount you’ll never feel and see at the track.

 

[/6 Matt]

Sorry, almost everything in the quote above (not the entire post, just the quote) I disagree with for the following reasons.

Roller rockers are not needed on anything period!
RPM has NO play in determining what style of rocker is needed. Just strength.

Moving away from a stock rocker to an improved design and/or stronger rocker will improve durability over a stock rocker. Though at stock engine specs, anyone would be hard pressed to prove they will out last the OE part.

You could very well produce that same power and most probable, equal the longevity with a mechanical rocker vs a roller rocker at every point.

(Edit)

The draw back of any aftermarket rocker is material used. Durability and overall weight. If the mechanical rocker is heavier than the roller rocker, it will show less power during a dyno pull. An amount you’ll never feel and see at the track.

But higher rpm necessitates stiffer valve springs which in turn requires stronger rockers yes?

 

[rumblefish360]

Depends on the pressures of the spring and the limitations of the rocker arms.

Aftermarket parts do not equal stronger parts.

 

[CNC-Dude]

Imagine if your cam had a different profile ground for each cylinder. That is basically what you are experiencing by using stock rocker arms that have inconsistent and inaccurate ratios one to the other. If you think that is good enough for you...fine! Then they will probably not benefit you since you don't see the benefit in what they provide. Unless you sit down and graph the mechanical ratio and observed lift on each rocker arm(which you wont), that is exactly what you will end up with. Roller rockers, since they are CNC machined will have an exact true ratio for each rocker on each cylinder, plus the benefit of friction losses through the roller tips and less tugging on the valve tips. There is 50+ years of proof and evidence of the benefits they provide.

Are they expensive for a Slant....yes, but good quality ones are also for any other engine! Does the cost warrant you buying a set for your application.....only you know that! Are they for everyone....of course not! If your breaking stock rockers now, it can be from several issues. Too much valve spring pressure(even the cheap Crane aluminum ones have a maximum spring pressure recommendation before you have to step up to a better one), mechanical interference such as coil binding the springs. Poor rocker arm geometry from excessive head and block milling but not correcting the pushrod length. You can even have piston to valve contact slight enough to break one, but not drop the valve. Being diligent with your builds in checking all these possible issues can help. But more than likely, you've just exceeded the limitation of the rocker for your application.