Rocker stand spacer

[allrightmike]

I am machining up a set of rocker stand spacers. The question is, do spacers tend to stay put or do they need to be doweled or attached to the stand in any way. Aluminum stands, steel spacers .090 thick.

Mike.

[chris_r]

yes pin or dowel

[GerryP]

yes pin or dowel

Why?

[Joe-JDC]

The torque from the stand bolts/studs will hold the spacers in place.  Pinning will only make them harder to remove or harder to position.  Joe-JDC

[blykins]

They do not need to be doweled or pinned. 

If you want them to stay put while assembling, just put some heavy grease on the bottoms of them. 

[allrightmike]

   Once again I appreciate the response. The engine is a 427 that has no windows or sleeves and I am being very cautious in the build so that it stays that way! Not a side oiler but still a for real 427.


Mike.

[chris_r]

Mike it's like this do what you feel comfortable doing. Now this is a fact fe rocker stands walk the way i stop that is pin the stand and shim to the head. Now it is a pain to do. A lot of fe builders do the same. I also know of  couple engine master engines over years that was pinned or doweled,or some thing like.

[blykins]

If the rocker stands are moving, then you have the wrong rocker system. 

It is possible, I've had it happen with solid rollers and T&D streets, but the correct rocker system would have been a T&D race rocker, and there would have been no movement. 

For 99% of builds out there, you don't have to pin anything. 

[Joe-JDC]

I've been around FEs and driven, owned, raced them since 1964, and I have never heard of anyone pinning a rocker stand on the FE.  Not to say it hasn't been done, but I have never seen the need for it, and I raced a 427 for many years with it turning 7400 rpm through the lights nearly every run, and I had a mechanical tach drive unit, not electronic.  Joe-JDC

[blykins]

I've been around FEs and driven, owned, raced them since 1964, and I have never heard of anyone pinning a rocker stand on the FE.  Not to say it hasn't been done, but I have never seen the need for it, and I raced a 427 for many years with it turning 7400 rpm through the lights nearly every run, and I had a mechanical tach drive unit, not electronic.  Joe-JDC

I have seen the need for it, with a 7500 rpm 700 hp 465 inch Tunnel Port.  Running a solid roller with 650-660 spring pressures and T&D streets but that was not the right rocker system for that application. 

We switched to a solid flat tappet just because it was a hot street application and there was no reason to modify the heads and take the chances with going to a paired rocker system.

With all that being said, that was the only time I’ve seen fretting on the bottoms of the stands and I don’t see the need to pin stands or spacers in the majority of applications.

[CaptCobrajet]

I use dowels sometimes.  In some cases, sliding the stand "up" towards the carb(s) can solve a geometry issue.  I slot the bolt holes a little, so I use the dowels to repeat the desired location.  It does nothing to aid clamping strength, only a means of locating the stand repeatably.  Unlike a dowel in a rotating bore, such as a main bore, the rocker is just reciprocating, so the dowel is only a locator, rather than a dual purpose item for location and stability.   Doweled or not, if you overcome the clamp force of the four 3/8 fasteners, you will see evidence of metal transfer.  It can come from harmonics, detonation, valve springs/camshaft too aggressive for the bolts, valve-to-piston contact, and even piston-to-head contact.......but the dowel is a locator, and would not cure any of that.

[fe468stroker]

Instead of individual spacers under the stands, what about using the desired thickness of plate steel/aluminum drilled for the stand bolts and oiling hole in the heads.  I would think that a one piece spacer would be more secure than 4 individual ones.

[blykins]

I like doing that just for one reason, it makes it simpler to deal with supporting end stands.

Nothing wrong though with individual spacers, even Jesel rockers for BBFs with 1200 lbs of spring pressure use individual washers under the common bar.

[Nightmist66]

Instead of individual spacers under the stands, what about using the desired thickness of plate steel/aluminum drilled for the stand bolts and oiling hole in the heads.  I would think that a one piece spacer would be more secure than 4 individual ones.

That's what I did for one of mine. I just used some steel flat stock.

[My427stang]

Instead of individual spacers under the stands, what about using the desired thickness of plate steel/aluminum drilled for the stand bolts and oiling hole in the heads.  I would think that a one piece spacer would be more secure than 4 individual ones.

That's what I did for one of mine. I just used some steel flat stock.

That's what I did on the recent Trick Flow build, on my iron head truck motor I used individual spacers.  I don't really like individual spacers, but in some cases, that is all that will work cleanly. Of course if you oil through pushrods, you can keep all 4 located tight to the bolt, then I can live with them a bit easier.