[bowtie468]

Hey Guys a couple weeks ago I switched the intake manifold on my 468BBC. And while it was off I did my annual valvetrain inspection of the roller lifters,springs,rockers etc. Well this engine has 2700 miles on it and the roller lifters looked and felt good, the cam looked good but when I checked out the rockers I found five of them to be cracked see pics, and one was split in half where the rocker stud goes thru these are 7/16 ARP studs. I then took five rockers off my Vega also has a 468BBC these are thre same Scoripion 1.7's and I found one of them was also split where it goes thru the rocker stud also an ARP 7/16. I e-mailed Scorpions tech people and they got back to me the same day, and said to send both sets back and they would replace them. So I did and exactly one week later I received two brand new sets of the Scorpion rockers see pics. This is good customer service that needs to be saluted. Also I called the tech guys number on the e-mail that I got and we chatted awhile about my rockers and possiable causes for the cracks and breakage and he told me that he was down in Daytona beach that Scorpion had hired several of the tech guys from Crane Cams and set them up in an office in Daytona beach so they would not have to move, Scorpion is in Ft. Lauderdale. I thought this also was pretty good, the tech guy that I spoke to Gordon had 25years of tech experiance and really did seem to know his stuff, all in all I really am happy with the service that Scorpion gave me and I will now buy their products with no reservations at all. Please don't treat this as a an ad for their products, this is just plain old good service from a company that still makes parts in the USA

 

[wildman926]

I have those same rockers, AND couches!! LOL!!!

 

[Stokerboats]

OK but what did they say caused the cracks?

 

[M.Maner]

Did you check the valvetrain for proper clearance and geometry when you assembled the engine? Did the rockers show any signs of interference.
Mike

 

[68chevelle533]

It looks like you are lucky that it didn't fail. Smart to look you stuff over, good lesson for us all.

 

[andrew T]

OK but what did they say caused the cracks?

yes, what caused them cracks to happen?

 

[steveracer33]

you are doing better than me! i am still waiting after 2-3 weeks for my replacment on one Jesel rocker arm and i had to pay for it since they claimend it was due to installation

 

[Lionel-n-Chevelles]

Scorpion sounds like a stand up company. Made In The U.S.A. is another plus. I will definitely use their ptoducts in the future.

 

[StevenS]

I would check the springs for coil bind. Like to know if the tech had any suggestion on why 5 cracked. That seems like a lot at one time.

 

[novaderrik]

how happy is the ending going to be when you have a rocker actually break in half under power?

 

[kettbo]

These things should not crack. One would be a fluke of production, or bad luck.
I'd be looking at my spring set-up very closely, check for coil bind as mentioned above.
Got a rev limiter that works? Rev it to the moon a few times?
5 bad units just is not random....something is wrong.

 

[bowtie468]

I had had an issue with the Comp guide plates, Mike Lewis had pointed out that one of the pics that I sent him he did not like the way the rockers were lineing up with the valvestem, see pic. I overlooked this when I assembled the engine I took for granted that they would line up correctly, I won't make that mistake again.I also have Comp quideplates on the Vega engine and they are aligned with the valvestem as best as I can see. I installed another set of comp guideplates along with this intake swap, the rockers look to be aligned much better. I run K-Motion K-1000's for valvesprings they are pretty beefie and maybe the rocker misalignment along with the high spring pressure had something to do with this, The rocker pattern looks good on the valve tip see pic, and I know that there is no coil bind also see pic. They (Scorpion) did not say what they thought was the problem, I didn't ask them either. The rev limiter on this engine is set to 6800 RPM, this should not be high enough to get valve float with those springs. Im going to but the new rockers on Fri. and we will see how it goes.
Rocker pattern does not look to bad in this pic

Rocker misalgnment can be seen in this pic with old guideplates.

This is valve at max lift I don't see any problem with coilbind!

 

[MadmanMark]

It looks like you might need adjustable guide plates, since both rockers look a little too far to the outside of the valvestem.

 

[mkube396]

what adjustable guide plates would you guys recomnend? think i need them 2

 

[GRN69CHV]

Had to use the adjustables to line up on my Dart heads. Dart has them, Comp, probably all the same - repackaged.

 

[kettbo]

I sure do like that dual carb set-up!

 

[Camaro_fever68]

Scorpion will stand behind their products but their stuff does fail. I've had two rockers fail and they replaced the whole set... but on my other car I've had Harland Sharp rockers for just as long with the same spring pressures/cam and never had a failure...

 

[Wolfplace]

For info I have seen brand new Scorpion rockers with those cracks,, actually they were a private label brand made by Scorpion but same rocker

My opinion is it is something about the interference fit they are using
The bad part was it was a set I sent to Sweden :sad:
Damn shipping was almost as much as the rockers,,,,,

 

[427L88]

I'm going steel next time.

 

[bowtie468]

I put the new rockers on yesterday, no problems. I think what Wolfeplace said about the press fit of the pin on the roller has alot of merit, That was my thought along with many of my friends. I don't klnow how I missed seeing the cracks earlier as these rockers are a few years old now.I worked as a machinist for the better part of 30 yrs, and most of my friends either were or still work in the metals trade and they said the same thing.Took new pics and the new guideplates do seem to have the new rockers aligned much better with the tip see pics.I think that a stud girdle is in my future along with a new cam, these will be over the winter projects.Thanks for all the posts guys There is alot of knowledge on this site!!
New rockers and guideplates

Again new rockers and guideplates