b71vette

Check out my latest Mod - Scorpion 1.6 Ratio Roller Rockers, Jomar Stud Girdles, and Comp Cams Hi-Tech Pushrods, Sweet

Guru_4_hire

How is the scorpion quality?

b71vette

I purchased these from AED perfromance here in Richmond, Va. They are a performance shop and make custom built holley race carbs. AED highly recommended and employess their used them on their personal cars, one which turns 8400 RPM and had been using for several years. I did research on the net and could not find any negatives. Scorpion claims to be the largest manufacturer of aluminum roller rockers and I believe they make rockers for Isky.
They claim and appear to be stronger than the Crane Gold and were aout a $100 less, quality appears excellent.
http://www.scorpionperformance.com/

Guru_4_hire

I actually live in the brandermill, I have a bunch of AED stuff, and Just got my heads flowbenched by wallys down 1 past the lowes.

BB72

That looks great. Just a note for the guys wanting to do this mod. I ran into a problem with the scorpion rockers and the Jomar girdle on my BB. The shoulder on the locking studs wasn't high enough. The shoulder would hit the top side of the rocker when installed. I just traded the scorpions for Crowers and now there's lots of clearance.

b71vette

One other thing I forgot to mention, AFR head Manufacturer list the Scorpions on their website too, which tells me they must be decent quality for a head manufacturer to sell with their heads.

75 Hot One

Scorpion workmanship looks excellent. I've just put about 30 easy km on the engine since installation so I can't really comment on their strength but they definitely look good.

b71vette

75 - what length pushrods did you use ?, I had to go with 8.125" to get the proper "centered witness" mark on the top of the valve stem. It did have 7.94" with the previous set of 1.6 ratio Chinese rockers , but they were too short for the Scorpions. the geometry was different.

I did the witness mark test on 4 different valves (2 intake and 2 exhaust #2 and #8 cylinders and both produced the same results with a 8.125" Comp Cam Hi-Tech pushrods. I spoke to Scorpion and AFR tech support and they both said that seemed long, both said I should go with what ever the test produced.

kdf1986

Hello,
That looks like a nice setup.
Thats something that I want to try on my 73 BB and my 75 L82
Thanks for posting the photos. It helps keep me going with my
mods seeing others working on the same issue.

Nice looking engine you have too.

kdf

75 Hot One

My pushrods are 8.000" long. The engine is a Bill Mitchell small block but the info should still apply to a GM engine since the Bill Mitchell engine is made with the same dimensions and use standard small block parts. For kdf1986, here's another shot of the rockers:

b71vette

75 - do you know if Bill Mitchell verified that the pushrod length is correct so that the roller tip is centered across the valve stem. here is a link
http://www.compcams.com/Technical/FA...inGeometry.asp
to Comp Cams write up on this. There is also a procedure to follow to verify this, in lieu of just looking at it with naked eye. Basically this is the procedure done on a solid lifter cam which is what I have:
Bring an intake valve to the base circle on the cam
remove the roller rocker
wipe oil off of valve stem and roller tip
using a permanent black marker cover the entire top of the valve stem
place the rocker back on and screw lock nut down to zero lash
crank the engine over serveral times, don't start though
bring the valve rocker up to base circle
remove roller rocker
inspect top of valve stem there will be a witness mark where the roller tip traveled and removed the permanent marker
if it isn't in the center you should purchase Comp Cams pushrod length checker about $17, and perform this same test until you have centered, then purchase new pushrods the same length of the length checker pushrod.
I checked 2 cylinders on my engine #2 and #7. Glad I did otherwise I would have worn out my valve guides prematurely.

75 Hot One

I'm aware that there are procedures to set the rocker arm geometry but I don't know if Bill Mitchell used them. I assume he did the engine assembly right since he/World Products is a fair size operation and they sell quite a range of engines. I'd be surprised if they screwed up on pushrod length, but anything's possible.