Perf 440 build - Pushrod Question(s)

[beanhead]

Hughes engines insructions:

Total sideclearance between a pair of rockers should be 0.005”/0.015”.

Did I mention I wouldn't run .005"..nor would I ever suggest anyone else run at that spacing. It's probably fine for Hughes though, when your parts weld themselves together Dave will simply blame you for not using the right oil, or not using their parts somewhere else on your build, or not using the right air filter.....

I may fatten those to .015 to be safe.

That's what I would shoot for as well. I actually set mine closer to .018"...I prefer to run things a tad looser than the average bear

 

[RBCharger]

I am certainly not arguing the point here, but there is no mention of using shims between all of the aluminum pieces. Says shim as necessary. I'm at least going to make a call to Huges tomorrow (that's if I can get anyone on the phone) and go from there. All of the Spacers are aluminum (.125" / .825") the shims are metal.

 

[beanhead]

Thanks for the picture, I saw that earlier too. I just don't think aluminum on aluminum is a good idea, but see what they say.

 

[RBCharger]

Thanks for the picture, I saw that earlier too. I just don't think aluminum on aluminum is a good idea, but see what they say.

BTW yourpoint about Hughes is well taken. I do no tlike number of things they do and this might be another of those. Really not too hard to get shims between the alumiun pieces so that's likely where I'll go. I appreaciate your input.

 

[not so famous bob]

You’re probably okay, but IMO, 0.010” clearance per pair of aluminum rockers is getting a little on the tight side

I have run .010 clearance per pair of rocker arms for 12ish yrs., I do leave the .010 feeler in between each pair as I tighten the rocker shaft bolts tho,,,

 

[BSB67]

I have run .010 clearance per pair of rocker arms for 12ish yrs., I do leave the .010 feeler in between each pair as I tighten the rocker shaft bolts tho,,,

Good to know. That’s with aluminum rockers and hold downs?

 

[RBCharger]

I have run .010 clearance per pair of rocker arms for 12ish yrs., I do leave the .010 feeler in between each pair as I tighten the rocker shaft bolts tho,,,

That's exactly what I did! Thank you!

 

[not so famous bob]

Good to know. That’s with aluminum rockers and hold downs?

yes sir...

 

[not so famous bob]

Thanks for the picture, I saw that earlier too. I just don't think aluminum on aluminum is a good idea, but see what they say.

steel shims on each side of alum. spacer