Bought a set of J2K shaft mount roller rockers to top off my stroker build. I got the idea from an article in the November '06 issue of GM High-Tech. Anyway, I called Jesel, told 'em I had an LS-1 with AFR 225 Mongoose heads, and I filled out the form they fax you before you buy.

Man, these things are beautifully made! I spent an evening reading the install instructions, the GM High-Tech article, and a few other tech articles. The next night, I bolted the rocker stand on, made sure #1 intake was closed, and that the lifter was on the cam's base circle, and bolted the intake/exhaust shaft/rocker assembly to the rocker stand. The pushrod end of the rocker moves MAYBE .015" before it hits the valve cover rail. I thought I either ordered the wrong kit, or maybe the wrong kit, was sent by mistake. I have kit K2A-2004409T, J2K Corvette LS-1, 1.500 Pivot 2nd Design, 1.7 intake/1.7 exhaust. A call to Jesel confirmed I had the right kit for AFR 225 heads.

Before you ask, yes, I am using a hydraulic roller cam set-up, and this kit is for solid lifter cam set-ups. I don't see what difference this should make, though. If I were using a solid lifter cam set-up, what the heck could possibly change, dimension-wise, that would prevent the rocker arm from contacting the head's valve cover rail? Before I got the die grinder out and started clearancing, I e-mailed AFR. I didn't want to start blasting away on a $2,300.00 set of heads if I didn't have to. One of there tech reps answered, and said, before I start grinding, am I using a solid, or hydraulic roller cam?

Unless I'm missing something stupid obvious, I still don't understand what the heck difference it makes whether I'm using a solid lifter cam, or a hydraulic roller cam. The distance from the center of the valve stem, to the center of the pushrod wouldn't change, so why/how could the length of the rocker arm?

I'm not afraid to go after the valve cover rail to clearance the rocker arm; what I AM afraid of, is that I won't be able to remove enough material without compromising the ability of the valve cover gasket to seat/seal correctly.

Anybody experience this problem?

 

You need to call me tomorrow at AFR....

I will get you squared away on this situation and others you aren't even taking into consideration (but ought to be).

(661)257-8124 Ext. 109

Leave me a message with a return phone in the event I don't pick-up.

Thanks,
Tony

 

That's right. You will have to clearance the rails. You will also need a 1/2" spacer and clearance it also along with gutting the valve covers. You can avoid gutting the valve covers if you go with a 3/4" or 1" spacer.

I just put these rockers (1.8 ratio) on my ETP heads. If you zoom in on this pic you can see it's not really that much material removed. I only try to get .060-.080" clearance. These rockers are worth the hassel. They will add RPM range and horsepower to your motor and are bullet proof. I have been running them on my 408 over 2 years (7000+rpm's).

 

"I will get you squared away on this situation and others you aren't even taking into consideration (but ought to be)."

Tony: Not 5 minutes ago, I got another e-mail from one of your tech reps RE: the rocker arm clearance problem. While I can't say I was overjoyed with the answer, I can't argue, either. Let's just say I am shocked, and leave it at that. Just as long as it's known that my post was not an AFR bash; I'd buy another set of your heads without thinking twice. My head is spinning after learning about dyno thrash test results, though. I don't know if I should be disappointed, or ticked off.....

 

67SS509....I relocated my coils, and am using a set of Nasty Performance valve covers.....Nate does some really bichin' work...they're gorgeous....

 

Then all you willl need is 1/2" spacers to keep from having to clearance the covers. Got any pics of the covers?

 

Care to share the info?

 

i think the answer might be is to get the rocker shaft to a higher position.spacers maybe?if somebody makes a kit for this i would get one.

 

Here is a link to the Jesel instructions for the rocker kit.


http://www.jeselonline.com/docs/inst.../INS-24021.pdf

The kit for a HR has a pressed in cup for the pushrod which isn't adjustable. The K2A-2004409T for the SR has the typical screw adjuster. I have a set of the adjustables at my desk, but I haven't seen the non-adjustables in person. I, too would choose the adjustables even for an HR.

Note that the instructions mention clearancing may be needed even on stock GM heads, as well as rocker arm cover modifications and spacers or aftermarket covers. I think they covered it well in the instructions.

I wouldn't advise trying to move the centerline of the rocker shaft unless the AFR heads have a different shaft location from the LS1/6 heads, which I doubt very much.

If you compare the size and shape of the stock, non-adjustable steel rocker arm to the J2K in the pushrod area you'll see why there could be an interference problem. I guess GM didn't consult with the aftermarket rocker guys during the LS1/6 head design phase.

 

Another thing to consider is the adjustable rockers will require a shorter pushrod. This is due to the lash adjuster hanging down below the rocker while the cup is pressed inside of it.

 

"Care to share the info?"

It's not that I don't want to share information, but doing so would force me to mention specific brands, and test results. I've seen that kind of stuff create hard feelings, and that's the last thing I want to do on this site.

The Nasty Performance valve covers won't be an issue. The clearancing I have to do is on the head itself, directly behind the pushrod end of the rocker arm. The Jesel J2k rocker arms make the OEM rocker arms look microscopic. And what a difference between the billet Jesel rocker arm stand, and the OEM rocker arm stand. The Jesel stuff is pricey, but the quality of workmanship (machining, finish, materials) is top-shelf. You gets what you pays for. That's why I didn't bat an eye when pricing the heads, crank, rods, cam, pistons, intake, headers, clutch/pressure plate/flywheel, blah, blah, blah. Once you start, there's no sense cheaping out on ANYTHING. That doesn't necessarily mean you have to buy the most expensive parts out there, but, by and large, manufacturers with a known reputation for quality, and no-nonsense customer service, are not going to sell cheap parts.

Once I start removing material from the heads, I'm sure I'll find out that it looks worse than it really is; i.e., I won't have to remove much for adequate clearance.