Stamped lifter clearance

[m300b]

Rebuilding a stock 68 383 motor. I bought a new stamped rocker arm package from 440 Source. At first the rockers were too hard to move. After some minor grinding on the spacers I got them to move freely but there is less than .001 clearance between them. Is that enough?
Thanks

 

[1STMP]

Too hard to move?
Please explain further. The rockers
shouldn't move at all once the lifters
are pumped up.
If you're rebuilding a stock engine
there should be no reason to grind
anything.

 

[GTX JOHN]

I would like to see more clearance between them than that for me.
Maybe .005 on stamped rockers I would guess. There should be a spec
somewhere that would give you a definitive answer.

 

[1STMP]

The designed in clearance is in the
lifters with stamped steel rockers
and stock pushrods for a 383.
You shouldn't need to be grinding
on anything.
There again, please elaborate.

 

[Geoff 2]

0.001" is a bit tight. Rub the side of the hold down clamps for a little more clearance.

 

[m300b]

Just test fitting the rockers. Lifters and pushrods are not in yet.
I can not find a spec anywhere.
Thanks

 

[pnora]

Rebuilding a stock 68 383 motor. I bought a new stamped rocker arm package from 440 Source. At first the rockers were too hard to move. After some minor grinding on the spacers I got them to move freely but there is less than .001 clearance between them. Is that enough?
Thanks

What are you using to mount the shafts to the heads?

 

[gkent]

What are you using to mount the shafts to the heads?

Stock rockers had plenty of clearance - probably in the .030 per set range. And that certainly doesn't hurt anything on a stock setup. Given the manufacturing process of both the rockers and the hold downs, I doubt if there's a spec that's anything more than "they should move freely". I'd be grinding or filing the hold down tabs if it were me - a lot easier than trying to grind the spacers.

 

[pnora]

Stock rockers had plenty of clearance - probably in the .030 per set range. And that certainly doesn't hurt anything on a stock setup. Given the manufacturing process of both the rockers and the hold downs, I doubt if there's a spec that's anything more than "they should move freely". I'd be grinding or filing the hold down tabs if it were me - a lot easier than trying to grind the spacers.

The only reason I asked about the hold downs is if he was using any thing other than the factory style stamped hold downs there could be issues. I agree if anything with all stock there should be plenty of clearance. I would be calling 440 source if I had to start grinding.

 

[Don Frelier]

Do you assemble it correctly?
Wide and narrow spacers in the correct locations?

 

[1STMP]

Do you assemble it correctly?
Wide and narrow spacers in the correct locations?
View attachment 1820907
View attachment 1820908

My point exactly. There's no reason at
all to be grinding anything on a stock
engine setup.
Just did this on a 440. All new rocker
arm assemblies, stock pushrods, and
lifters.

 

[m300b]

I believe they are correct.
440 Source had no answer for me. (They are usually very helpful)

 

[1968rt]

Are you talking side clearance? You can clearance them to center them on the valves, but Im not aware of any spec for side to side

 

[m300b]

Yes, side clearance.

 

[gkent]

My point exactly. There's no reason at
all to be grinding anything on a stock
engine setup.
Just did this on a 440. All new rocker
arm assemblies, stock pushrods, and
lifters.

What makes you guys think that the 440Source rockers have the same stamped specs as 50 year-old stockers ?!?!? The stamping dies are probably all new and material thickness that varies a couple thou would make a big difference.

The simple fact remains: the OP has clearance issues. He can talk all he wants withh 440Source but talk is cheap. Its obvious the rockers are the right ones, just a little wider than originals. Its obvious he's assembled them correctly. Now they need a bit of clearance. Help him solve his problem.

 

[1STMP]

What makes you guys think that the 440Source rockers have the same stamped specs as 50 year-old stockers ?!?!? The stamping dies are probably all new and material thickness that varies a couple thou would make a big difference.

The simple fact remains: the OP has clearance issues. He can talk all he wants withh 440Source but talk is cheap. Its obvious the rockers are the right ones, just a little wider than originals. Its obvious he's assembled them correctly. Now they need a bit of clearance. Help him solve his problem.

The simple fact remains that 440
source is held to certain standards
or they wouldn't be selling parts.
The OP is not disclosing his true
issues. There's no reason why a stock
rocker arm assembly for a 383 is
the root cause of any rebuild issues.
If he is having to grind something to
get it to work....there's something
else wrong.
What's the history of the engine?
are the pushrods the correct length
for a 383? ,

 

[m300b]

1968 383. I did not have the original rocker assembly so I decided to buy new.
No pushrods installed. The new rockers rub tightly to the spacers.
Thanks

 

[PRHeads]

How I would deal with it……..
Grind a little off the tabs on the hold downs until I had .010”-ish clearance for each pair.

 

[Don selleck]

did you oil them a bit before installing them? I'd rather have them a little tight than loose to start with, IMO. if so check your spacer's orientation, then clearance the side a bit as stated above.

 

[m300b]

Thanks guys