Topic: Valve spring install heights

[johno]

Re Power arc, cccccccaaaant taaaalk bbbbbbout it.🤪
Scottly your our resident spark guru😁 what do you think of the new system they are selling at C X;  Sherman coils, wire leads and modified Dyna s to suit the coil / leads etc ? US $1,000.
My thoughts are I much prefer wire leads for obvious reasons and more juiced up coils can only be good but I wonder who does the Dyna S mods ? maybe U No who again, I don't know , love to know. Likely that's what captain power arc should have done ? before reinventing the wheel less effectively.
On this issue of exotic spark versus good ol reliable long proven systems you would have trouble convincing me of it being a race winning deal breaker, bit older and wiser these days. BUT like most rev heads I always like to try something new. ( especially wire leads lol)

[scottly]

Mark, I don't see anything special at all about that "system". Basically, it looks to be a Dyna S with coils of unknown specs and MSD wires, along with a regulator/rectifier, and a rewound field coil and stator, most likely from Rick's. For some reason, Rick's rewinds aren't dipped in varnish like the original parts? The varnish stabilizes the windings, as the rotating magnetic field tries to pull and push on them. (I worked as a "motor winder" 50 years ago, and every stator I wound went straight into the varnish tank for an overnight soak. )

[PeWe]

This thread made me to think about a K head  with  F2 34mm in valves with TI retainers.
I have other 34mm valves K style with TI retainers.
The springs are set by the shop that ported it. By spring pressure.

So measure and note the height and see if the K style with different retainers and keepers will get same heights or if I need other shims.

I found a tool for measure I think will work. Ca $60US on Amazon
Will try with inner springs only first. If too thick find other thin ones.

[willbird]

This thread made me to think about a K head  with  F2 34mm in valves with TI retainers.
I have other 34mm valves K style with TI retainers.
The springs are set by the shop that ported it. By spring pressure.

So measure and note the height and see if the K style with different retainers and keepers will get same heights or if I need other shims.

I found a tool for measure I think will work. Ca $60US on Amazon
Will try with inner springs only first. If too thick find other thin ones.

As a machinist from birth I have thought about this a bit as far as a simple and cheap way to reliably measure the feature we are talking about. But then I look and see there is one on Amazon for $14 :-).

https://a.co/d/9nCdwTT

The micrometer as they are made let you apply some tension to make fairly sure everything is seated. Calipers and other things require a "feel" that the user develops within themselves when they do the job a bit, but for most users the job is not a frequent one. In the industry some do what I have heard called an "GR&R" . They will take a measuring tool and have a group of humans measure a provided thing and then they chart the answers and grade the method of measurement being proposed for use. Gage Repeatability and Reproducibility is what GR&R is an acronym for.

[PeWe]

I saw that design but not sure if it was too wide for the CB750 head.