Valve to Retaining Collet Distance

[Ribrickulous]

Does anyone have a head with valves installed that can take a measurement for me?

Looking for the distance between the top of the valve stem, to the top of the retaining collets that hold the spring retainer to the valve.

Looking for someone either with a depth gauge or who’s real confident with their calipers.

Full disclosure - this is very much partially out of laziness. My engine is 90% build up and the cam is orange loc-tited to the sprocket already. Really hoping to not have to pull it off to take this.

Can sketch up what I’m looking for if it’s helpful.


-Ed
1972 CL350

 

[Ribrickulous]

For reference, I’m looking for the dimension in red

-Ed
1972 CL350

 

[LongDistanceRider]

If my parts coming home from Sturgis get here I'll be able to make that measurement for you, just waiting for them to appear one day. Given the speed of which the cam guy was working I might see them by summer.

 

[Ribrickulous]

Lol ok.

I also just realized that I don’t necessarily need them installed. I can work with the extra valves from my last engine and just take the distance from the top of the valve stem to the underside of the channel in the valve.

I know one was ground out and is ruined, but I’m hoping the other one at least has a good surface to work with. Will know on Friday.

To get it right this might be a good job for the mill to keep everything in the correct axis.


-Ed
1972 CL350

 

[Ribrickulous]

And of course I remembered I’m a pack rat, so I still have this garbage valve in my apartment thinking I’ll use it for something crafty eventually.

Looks like about .130” even after being ground off.

That makes me very confident that the .063” lash cap will fit, but I’ll check the good one to be sure:

-Ed
1972 CL350

 

[MrPepper]

I measured 2 intake and 2 exhaust
Straight portion before it starts to curve
Got 0.172" +/- 0.004" for all of them

The tips were shiny silver and also appeared flat

 

[LongDistanceRider]

You want to measure the distance with the spring retainer and collets in place, then reduce that number .020"-.040" so there's a bit of clearance between the cap and collets. If they're in contact there's the chance they could pop one or both collets loose, although unlikely.

 

[MrPepper]

I have at least 1 head I can measure.
OP, if you want any ref photos of valves or head them pm me your email address

 

[MrPepper]

Stem protrudes approx 0.035"-0.040" EX and IN

 

[Ribrickulous]

Damn, that’s a huge shift. I can throw you my email, but can you post some here for everyone’s viewing pleasure?


-Ed
1972 CL350

 

[MrPepper]

It would seem the stem height past the retainer and collet would ensure the cam consistently makes contact with the stem, which is recessed in a concave retainer, and not the retainer.

 

[Ribrickulous]

Well, we can file this under “might’ve just been simpler to take it apart”

Wood blocks as shims and a mallet got me within about .003” coplanar of the ways, measured across the valve tip. Test indicator picked up ~.040” between the valve tip at the lowest it could measure, which is actually being interfered with by the spring retainer:

So there could be a few more thou there.

I’m going to try and find something with .030” of skirt depth for the lash cap, and run from there.


-Ed
1972 CL350

 

[Ribrickulous]

Measured another way - just zerod the indicator in the “gap” gets me .037” to the edge of the valve tip, and when zero’d, I can juuuuuuust slip a .0025” feeler in there without disturbing it.

.003” tips the indicator.

Minimum .039” of clearance, could be slightly more.


-Ed
1972 CL350

 

[Ribrickulous]

https://vimeo.com/655714625


https://vimeo.com/655714938


-Ed
1972 CL350

 

[MrPepper]

Where did your valves come from?
The shape of the tip is different than mine... the taper seems different and tip smaller dia

 

[Ribrickulous]

All but two original to the bike. They all look like that.


-Ed
1972 CL350