Special parts to avoid retainer hitting valve cover?

[Hop Up]

OK, the reason for the valve collars hitting valve covers is too many valve jobs and valves sunken too deep in the heads.
I want to avoid putting in new valve seats as long as possible. I wonder if there is some special parts to avoid the problem with valve covers.
For example:
1. smaller diameter valve springs and retainers.
2. shorter valves to correct the valve spring installed height.
Of course those parts can be custom made, but it would be easier if they were readily available. Bigger diameter valves help too and expensive aluminium valve covers could be modified to make more room.
I think the solutions number 1 or 2 would be fine. So are there ready parts to do it or maybe something wiser?

[Robert Luland]

Thicker gaskets?

[Panhead Ed]

once upon a time HD made oversize valves , dont know who might have some .

[steinauge]

Oversize head valves are available from Rowe and kibblewhite and are the correct repair. Anything other than an oversize head valve or new seat does not address the actual problem.

[Hop Up]

Thicker valve cover gaskets don't help because they move the cover up and the contact happens at the side of the cover.

[nmaineron]

There are collars available for this issue from V - Twin Pt #11-9619. I think they are made by Sifton and they are gold colored.

[Bosheff]

"The contact happens at the side of the cover" ? ....bosheff

[Hop Up]

This picture isn't very goog but I don't have pics of the inside of the covers right now. The touch marks are inside of front and rear vertical "walls" of the covers (tried to draw it on the picture) shaped like smiley face. Quite close to the corner where the gasket surface begins. I'll post an inside pic when I have one. That Sifton part looks great, I'll have to investigate it closer.

[RUBONE]

Be aware that the higher the valve sits, the more out of line the rocker arms become. As the height of the valve stem increases the arm pushes at more of an angle to the detriment of stems and guides.It also starts to sit off center in the pushrod upper. There is a reason H-D tried to keep the valves down and it wasn't about the clearance as much as about the rocker geometry!
Robbie

[kitabel]

Unfortunate as the clearance problem is, more valve stem height is needed to correct the geometry if cams with more lift are used.
Assuming that the heads are in excellent condition and all parts are correct dimension, stock cam is close to .400" (EL, FL are less, FLH is more), a .500" cam would need the valve stem 50% of the lift difference (.500 - .400 = .100, ÷ 2 = .050") or .050" taller. The other 50% just moves the valve farther down at full lift.
Anything that raises the stem (seat wear, lash caps, or longer valves) also moves the rocker tip's contact point on the stem tip inboard and closer the the rocker shaft.

However, if the extra stem height is due to the valve sinking back into the seat, the opposite correction should be applied to fix the geo: raise the rocker blocks (this doesn't cure the seats, but the rocker operation will be correct). Same idea for the distance: if the stem is too tall by .100", the blocks can be shimmed up. Since the blocks are parallel to the cylinder axis, but the stems are at a 39.25° angle from the cylinder (and 78.5° to each other). The shim thickness must be more than the stem correction because it's moving the blocks on an angle and part of the motion is lost as the block also moves away from the stem. The correction for shim thickness is the stem error (extra length over standard) ÷ the cosine of the 39.25° stem angle, or .774 (or multiply by 1 ÷ cosine, or 1.291). If the stem change is .100", the block shim is .129" - close enough that an 1/8" shim will do.
The shim can be brass, steel or aluminum stock, 1 piece of 1/8" or 2 pieces each 1/16" etc. Cut with a punch or shears, to exactly match the bottom surface of the lower (cast iron) block 1/2 including studs, oil holes and locating pins. Check the stud lengths, you must still have enough threads for the nuts.

[Hop Up]

Thanks for all the information. Attached is a picture of the touch marks. As you can see they are not on the top of the cover. As far as I can see shorter valves would correct both the geometry and the clearance issues underside the valve cover (leaving the breathing and seat problems). Bigger valves would correct everything if there is still enough seat left.

[kitabel]

There's no reason why smaller diameter springs and upper collars can't be fitted, except that the locks must match the existing valves, or you need new valves.
The obvious smaller spring is the iron Sportster, but the locks are for 11/32" stems (not 3/8"), and the big twin's lower collars are also not a good fit - the inner spring will fit but the outer will sit on the outer ring. I've never tried to re-machine a valve stem to suit a smaller lock, but I'm sure it can be done if your lathe work is up to it.
The stock XL spring set is pretty close to the OHV set as to pressure, but it won't take more than about .400" lift before coil bind, so you need (example) a Manley set etc. for your cam lift.

[pan620]

Be careful of the gold or any other color upper collars, coil bind may result!

[Panhead Ed]

Find some oversize valves and stop pissen up the rope , you start fittin and missmatchen springs and collars n keepers and youll be posting a new problem evry day, and if by some chance you take it to somebody that really works on pans youll have to explain evry dumm thing you did........... of corse this is ny opinion and we all know what they are like. Ed

[Cotten]

Folks,

It would be a shame to do a second valve job just because of a mm or so of interference.

A piece of modelling clay (and a steady hand) tells you if indeed you have decent clearance.

I've shaved many a top collar in the lathe, and ground many a chamfer upon springs.

The springpack will have to be shimmed as well, of course.

But that's one more 'lifetime' before the leap to oversized valves.
Although valves are available in 1/8" and 1/16" oversizes, many machinists will grind them down precisely to match a freshly re-cut seat, rather than to cut more meat to suit the enormous valve.

....Cotten