Lash caps for SOHC non-adjustable rockers, factory vs. aftermarket SOHC rockers

[jayb]

One of our forum members has taken the SOHC plunge, and purchased what sounds like an early engine with the non-adjustable rocker arms.  He sent me an email asking about availability of lash caps of various thicknesses, in order to be able to set the lash.  Since I've never used adjustable rockers I'm not much help on this.  I've been told that people buy standard lash caps and grind them to fit on a valve stem tip grinding setup, but depending on the valve stem height, cam base circle, valve seat depth in the head, etc. there is a wide variation in thicknesses that could be required.  In fact, a few years ago at the PRI show, Barry R and I bumped into Ohio George Montgomery, and he told us that he had to use lash caps as thick as 0.280"!  I don't even know where you'd get a lash cap that thick as a starting point.  Can anybody shed some light on this issue of acquiring lash caps in various thicknesses?  Barry, I know you've had to do this before...

Another potential issue is the factory rockers, which use a roller wheel that is crowned in the middle; as I understand it, this was done to work properly with the cast iron cams used in the original SOHC engines.  Again I have never used the factory SOHC rockers, so I wonder how these crowned roller wheels would hold up on a new billet cam, like the ones available from Comp.  The T&D rockers that I use don't have a crowned roller wheel, so that is not an issue with the aftermarket parts.

Any information on this is appreciated - Jay

[Barry_R]

There are a few sources for caps.
The normal stuff comes from Comp, Manley or Crane
Less normal comes from CV products
Really odd comes from Esslinger - outfit specializing in 2.3 four cyl race engines
Beyond that you make them
Willy - my in house machining guru - uses a ceramic bit in the lathe and can do really nice stuff that only needs hand detailing when taking a few thou away from an existing cap - damn things are hard all the way through

[cammerfe]

Somewhere around here I have a set of 16 of the original SOHC lash caps. I got them from Carl Holbrook VERY long ago. It doesn't surprise me to hear that they're through-hardened.

I'd believe it would take a bit of pre-planning in regard to valve seat placement, etc. so as to not have to have a dozen or more different thicknesses.

An alternative would be to acquire a set of the same sort of 'spring buckets' such as are used in my AJ Jaguar engine. They have a recess in the top into which you place small circles of shim stock. In the case of the Jag engine, the cams are arranged in such a way that the lobes ride directly on the shims.

KS

[nhsohc]

Jim Barillo maybe?  Had a lot of cammer stuff.

[thatdarncat]

Back in 1980 I became friends with a couple local Minnesotans who campaigned a 427 SOHC powered 4x4 Pulling Truck, and had tons of Cammer stuff. I'm still friends with them today ( Cammer parts are long gone ). The engine builder told me he preferred using the lash caps and non-adjustable rockers since there was no adjuster to come loose and back off, or break. It was more work initially setting up, but less chance of a failure and gave you the ability to use either the early or late valve covers. The lash caps were available in various select sizes, but he said he often just used the thicker caps and ground as needed to set clearance. He also told me that lash caps were available from most cam companies ( as Barry stated ). About 15 years later I bought out some NOS 427 SOHC parts from a person I met in the southern U.S. He threw in a couple boxes of assorted lash caps that he thought might be original Cammer, but I have no way of knowing their source for sure, and Ford may have just sourced the originals from the aftermarket as well. Only a couple thick ones, most are thin. Here's a picture:

[ToddK]

So has anyone actually used factory rockers on a billet steel cam?

[WConley]

Yes - A few years ago I did a top-end rebuild on a guy's factory aluminum-head SOHC with non-adjustable rockers.  I swapped out the old regrind Crane Nitro660 cams for new Comp billet cams that Jay helped develop the profile for.

John Vermeersch helped me out with an assortment of lash caps that I touch-ground to the right thicknesses.  The engine is running just fine and seems to be holding steady clearances.

I see no reason why you can't run the factory crowned rollers with a billet cam.  The billet material is way better than the old cast iron cam material, and the crown was put in place to reduce peak compressive (hertz) stress on the iron.  The old cams were in fact starting to flake, which necessitated the rebuild in the first place.  Billet steel won't flake under this type of stress.

[jayb]

Bill, how about the roller itself on the rocker arm?  Any issues there?  I would think it would be more like a point contact rather than a line contact, and maybe cause a wear issue on the roller, but I don't know.  If the engine you put together is having no issues, that pretty much answers the question...

[WConley]

Jay -  So far no issues.  There aren't a lot of hours on the engine, but it runs just like when I put it together.

The billet steel is no harder or stiffer than the old flame-hardened iron, so the roller really sees the same thing on the contact patch.  I've seen no witness marks or any sign of distress so far.

The big difference with the new steel billets is that they will not fatigue and flake like the original iron cams.  Of course you've got more choice of base circles and profiles too.

- Bill

[Leny Mason]

Jim Barillo has the caps, and the guy that got Wayne Jeffers stuff got an assortment of them, Wayne thought that was the way to go he had a lot of them, John V has the most miles on a Cammer and he would know to. Leny Mason

[cammerfe]

I believe the name is 'Barillaro'. This should help if you are trying to google it.

KS

[Leny Mason]

You are right Sorry. Leny Mason