Hughes Engines 1.6 Rocker Geometry/Setup

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Your welcome. I went to Hughes to see if I could quickly scan for the clearance amount and I couldn’t find it. There new site blows.

I did t want to state a clearance of .030 or .060 because I don’t remember it. I don’t want to give a number of .030 and that’s not enough when the engine is hot or .060 and you break through the rocker while grinding on it or worse, break it while running it.

IMO, and this is just that, an opinion, .030 clearance from the spring is enough to clear and be OK. It’s what I would do but I don’t know if that’s a good thing to do. If I tried and winged it at .030 & it broke, well, that’s fine because it’s on me.

Don’t do Jack until you get a good answer!

Do a Google search, find magazine articles and even better yet, find a racer or member here that has done it. I have not been there and done that.

Best of luck with the project!
 
This was a built-in feature of the SB engine & Chrys didn't charge extra for it!
There is simply not enough room for the stiff/big valve springs reqd with bigger cams because of the short rockers.
Yes, grinding the alum rocker is an option but you are grinding the rocker in a very heavily loaded area, where the load has already increased because of the stiffer springs.
Other options:
- use beehive springs or maybe smaller diam springs
- use steel/ductile iron rockers which do not need to be so thick in this area.
 
rumblefish360 said:
Your welcome. I went to Hughes to see if I could quickly scan for the clearance amount and I couldn’t find it. There new site blows.

I did t want to state a clearance of .030 or .060 because I don’t remember it. I don’t want to give a number of .030 and that’s not enough when the engine is hot or .060 and you break through the rocker while grinding on it or worse, break it while running it.

IMO, and this is just that, an opinion, .030 clearance from the spring is enough to clear and be OK. It’s what I would do but I don’t know if that’s a good thing to do. If I tried and winged it at .030 & it broke, well, that’s fine because it’s on me.

Don’t do Jack until you get a good answer!

Do a Google search, find magazine articles and even better yet, find a racer or member here that has done it. I have not been there and done that.

Best of luck with the project!
Click to expand...
Thanks yes I agree, I’m a hot rodder by nature but i also know my limitations when it comes to more precise things of this nature. My plan is to look for member input and also call Mike at B3 he did my correction kit and hooked me up with new adjusters to run ball/ball pushrods so I’m sure he can shed some light. Worst case is I’ll see if he can mill them for me and have the assurance they are exact. Thanks again and ps the new Hughes site is trash haha
 
Bewy said:
This was a built-in feature of the SB engine & Chrys didn't charge extra for it!
There is simply not enough room for the stiff/big valve springs reqd with bigger cams because of the short rockers.
Yes, grinding the alum rocker is an option but you are grinding the rocker in a very heavily loaded area, where the load has already increased because of the stiffer springs.
Other options:
- use beehive springs or maybe smaller diam springs
- use steel/ductile iron rockers which do not need to be so thick in this area.
Click to expand...
Yes I thought about the beehive avenue as an alternate to trimming material on rockers because of structural durability and potential failure
 
Before you go clearancing your rocker arms tripple check your geometry correction shims are in the right way (moving the shaft away from the springs). You should have much more clearance with the B3 kit than you had at your earlier mock up with the straight shims.
What diameter springs are you using? A spring change might be a an option.
 
Can you post of pic from the side showing the clearance from the retainer to the rocker body as well as the shim orientation. I agree that it is very odd that you would have interference with the shims, even with large springs. I guess those rockers are pretty blocky, but still. Mike should have some good input too.
 
Not many times do I get away with not clearancing Harland Sharp rockers. The hardest part is taping them up to keep the shavings out of the bearings. They offer the service but I do it myself. These are all Harland Sharp rockers and look at the difference.

EA5763A4-37E6-4DFE-B927-95CB6B75ECEA.jpeg


6D4B210D-F4F6-4F20-93F7-CFC4E05693CF.jpeg
 
A little grinding will not harm or shorten the rockers life or integrity. The rocker would have to be under great stress to give way at the grinding point.
 
Ted265 said:
Before you go clearancing your rocker arms tripple check your geometry correction shims are in the right way (moving the shaft away from the springs). You should have much more clearance with the B3 kit than you had at your earlier mock up with the straight shims.
What diameter springs are you using? A spring change might be a an option.
Click to expand...
All the shims are right just ended up having to trim some material nothing the carbide and dremel couidnt handle. Evidently common with HS/Hughes rockers cuz they are short
 
If you only need a little retainer clearance, some offset valve locks could get you there. Of course you'll have more seat pressure, less max lift etc. 10 degree SM -0.030 locks were $9 last time I looked. This is if you're using the SM retainers of course
 
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