302 Clevo 2V Heads with undersized valve guides

[Rimmo]

I have a set of 302 Cleveland closed chamber 2V heads that look like they came out of an XD model year falcon.

They've had the chambers opened up to 63cc and a port job to run on a 351C. Intake port is now ~2.3 sq in at the pinch.
They have hardened exhaust seats installed and when they were reco'd they installed 0.500" iron valve guides and bronze liners.
They have S.F. stamped on the end so I'm guessing they were done by the old Super Flow shop in Brisbane. they've been closed
for a while now. This is how I received them and I've had them on the shelf for 20 odd years so they were done before that.

Here's the catch. They have the standard ford valves with the multi groove keepers which I want to replace. When I measure the
valve stems and and guides they are .005"under? The valve stems measure at .336" instead of the standard .343"or 11/16th. I'd heard
of some shops just turning down the stems on worn valves and installing under sized guides to save some bucks on a head reco
so this is probably what was done to these.

Am I going to be able to get new valves with single groove keepers in this stem size or will I need to get the
guides opened up to standard size when I get the seats re-cut?

[PRH]

Just boil it down to the basics, and you’ll likely find the correct answer.

Do you think you can find performance build quality single groove valve locks that will provide adequate clamping pressure on some .336 stem valves(if you could even find .336 valves)?

The easiest path forward(although, probably not the “best” path) is to ream/hone the current guides out to fit the commonly available valves.

[Ericnova]

I'd sleeve the guide to take a smaller 5/16" or 8mm stem valve, just for availability of part reasons combined with the benefit of lighter valve weights .

If you have to keep cost down, ream to 11/32"/.343" for parts availability, that cuts of the cost of replacing or sleeving the guide.

if you've got to replace the valves, option #1 is the way to go.

[Rimmo]

Pretty much what I was thinking as well. Just get the guides reamed to 11/32" and use some left over valve gear I already have from another project. The heads may need a larger valve installed to sort out what was done with the seat / throat by the previous porter though, they're pretty rough in this area. If that's the case I'll go with a 5/16" stem valve and buy new gear.

But yes. This is just a fun motor so I'm keeping a lid on costs while still wanting / aiming for a clean flowing set of heads.

[benno318]

just a comment - the cleveland valves seem to be some of the worst wearing valves on the stems that i have ever seen. just about every standard set i have stripped - maybe just the valves used here in australia? but its common to see a 3-4 thou ridge worn into the stems. they obviously ground the stems undersize on your heads.

[ProPower engines]

Reman'ing valves is a popular deal even today. THey will grind the stem to an undersize then flash chrome them and polish to a close size.
The fact that they wear is the guides may be harder them the allowable compatibility between the stem and guide material to promote even wear.
All it means is they are junk at this point for a HP build and new valves are in the plan to move forward.
Replace the guides with some stepped bronze guides to suits what will fit your heads and redo the valve job to suit.

[BCjohnny]

Almost thirty years ago I went to the liquidation auction of a cylinder head rebuilding company ..... one of the items was the 'machine' that reduced valve stem diameter so the valves could be re-used in undersized guides

It resembled a glorified horizontal belt sander, even in my callow youthfulness I was quite amazed that it could be considered a serious device

There are ways to maybe do it, but that didn't seem one of them ...... and in my mind went some way to explaining the auction

[BCjohnny]

...... just a comment - the cleveland valves seem to be some of the worst wearing valves on the stems that i have ever seen ......

Function of the compound valve angles and inline follower location ?

[benno318]

...... just a comment - the cleveland valves seem to be some of the worst wearing valves on the stems that i have ever seen ......

Function of the compound valve angles and inline follower location ?

personally i think more to do with the quality of the standard valve stems.

[Rimmo]

I didn't like what had been done to these heads either. Turned down OEM clevo valves in a set of ported heads seemed like a ticking bomb.

I managed to find a set of new stainless 2V valves in 11/32" with 10 deg locks and retainers and springs in a box of parts I didn't know I had. They're a tad heavy but that's what I'll use for this build if the seat will take a decent valve job with the 2.04" head. I love finding parts.

[dannobee]

Back when super stock required stock valves, we couldn't reliably keep the stock 4V cleveland valves from popping the head off of the stem. There's no way in hell that I'd trust grinding the stem diameter down on one. Especially now that cheaper, better quality valves are available. That whole thing falls into the "you can polish a turd until it shines, but it's still a turd" category.