Isky Rocker Problem

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FomocoReformed

FomocoReformed

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Having a problem with a set of Isky ductile rockers on a 383. I've got them on but they're giving me a real hard time lining up with the valve stems. It looks like the hold downs are offsetting the rockers and I'm not entirely sure if the springs even belong here. They look like they're trying to coil over themselves. I also have spacers and I think I will use those instead but the pressing issue is the offset.

082420121563.jpg
 
Might send the picture,in an email to Isky.Hopefully,someone else will offer their .02.
 
Im not positive from the pics but it looks like you need to swap em from one valve to the other, they look off set at the shaft end. Yes you need the springs in there, Im thinking the rockers are intake/exhaust specific is what they look like.
 
OK I looked at the pic on a bigger screen and yes you just have to swap em around, its no biggie, those are loads of fun to mess with and you really need 6 hands LOL. If I remember right there should be a thin shim/washer on each side of the rocker arm and if theres some left over they go in the middle where the hold downs are to keep them from eating into the rocker.
 
I've seen a bunch of ruined Isky/Crane rockers from running them up against the factory hold downs without the hardened washers at the ends. Running them on stock factory shafts doesn't seem to work so well either, they like to gall. I think a hardened shaft with some oiling grooves would be best.
 
in addition to the above, use shims instead of the springs. the springs eat up hp and the rockers. go pilfer the wider ones from "B" motors in the junkyard. get yourself a die grinder if you don't already have one and some 1/4" or so grinding stones. banana groove on each side of the oiling holes on the shafts about 3/8". this will stop the galling. use moly paste on the shafts for first start up.
 
I just read on another site that Isky used to recommend that you grind down the tabs on the hold downs. That would put them in the correct spot. I did just notice while playing around with them that the springs create quite a bit of drag on the rockers, I will ditch them and go with the spacers I have which consist of rubber O rings and metal shims.

These rockers are already galled, but not terribly. I picked the best out of a box of 32 and some of them are perfectly fine. Do you mean a 3/8" long banana groove or 3/8" from the oiling holes ?
 
Just wanted to update and say that the problem has been solved!

I did some work on the bench grinder and removed the tabs from the sides of the hold downs. That did the trick! The rockers are exactly where they need to be. I went a bit further and used a stone on the hold downs to polish the edges smooth. I chucked the springs that obviously didn't belong there and reused the spacer setup that I found in the bottom of the big pile-o-rocker arms. Metal spacers with rubber O rings between them. They work like a charm! Everything fits nice and snug and the rockers are able to rotate freely with no drag.

I also cut the banana grooves into the rocker shaft with a file, they came out great.

082820121571.jpg


082720121568.jpg
 
Nice work , when you get the iskys new the instruction sheets tells you to grind off the tabs , that is the only way to get them centered , it's not a problem with the crane versions as they are the proper width , I don't know why isky made them wider.

On the galled rockers if they aren't bad I would just run a brake cylinder hone thru them , the galled grooves hold oil , and run them. Adding the banana grooves is good , keep and eye on them though and change to hardened shafts if it looks like your stock shafts are getting beat up.

nice idea on your spacer setup , I'd run shims though between the rockers and the spacers though just for insurance on the parts getting eaten up , same with the holddown side .
 
Well I'm in luck, I actually already ran a brake cylinder hone down the rockers just as insurance. On the shims, I plan to switch over to them when I can find some that will fit with the iskys, so far nothing has.
 
FomocoReformed said:
Well I'm in luck, I actually already ran a brake cylinder hone down the rockers just as insurance. On the shims, I plan to switch over to them when I can find some that will fit with the iskys, so far nothing has.
Click to expand...

How thick a shim do you need ? I'm talking something like .010 between the rockers and the holddowns and your makeshift spacers . If you mean spacers RAS has spacers or you could make some yourself from some tube stock that fits over the shaft and put a thin shim between it and the rockers .
 
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