Valve Guide Inserts

[billpedalino]

There was an article in the AMCA AMgazine a couple of issues ago describing the use of Goodson's coil-insert valve guide system in lieu of changing valve guides. I've routinely changed guides for many, many years as part of my motor/top end rebuilds. However, the tolerances described in the article seemed too good to be true. To me, it seemes more and more evident that the descructive act of removing and re-installing valve guides in aluminum heads seem like one that we should start to avoid, even when the heads are pre-heated and the task is properly executed.

The ability to remove and replace coil-inserts is intrieging, especially if the stated tight tolerances can be used. But.... the article seemed to be geared to side valve models.

I might consider this system for my own machines, but before spending any money I thought I would reach out with a few questions;

1. Has anyone personally used these inserts on overhead models, specifically Knuckle Hheads, Pan Heads, Shovel Heads and Iron Head Sportsters?

2. If so, was the installation as straight-forward as described?

3. Can you actually use the valve stem-to-guide clearances stated?

4. How did the installation (s) work out? Did the valves perform well over the long-haul or was valve stem galling an issue?

5. Given the tight stem fit-up, was the use of valve seals required?

Thanks

[redfred84]

Hi Bill,
I used a flathead situation in the article because that is perhaps the most torturous enviornment for a valve guide. Flatheads tend to be way hotter in the guide area than OHVs. This, and the fact that I have personally used this appication on many a Chief & Scout, which are both Flatheads, prompted me to expose this product line.
Sorry, but I have no personal experience with these in an OHV application, but that is what they were initially intended for. I happened across them via a some race car guys I knew who used them in very high revving 4 cyl applications. Goodson has expanded greatly since then, and actually offers products for the V-Twin Harley line, I believe, covering all their OHVs! They have an excellent tech system, and are very, VERY helpfull. Be sure an tell them that you learned of them via the AMCA.
All the best, RF.

[T. Cotten]

Bill!

My personal experience with automotive guide inserts occurred while working for a speed shop in the mid 80's.
The proprietor decided it was a good idea to push for Harleys.
Unfortunately, Harley OHV's eccentric rockerarm thrust ate many of them in a season.

Considering the heat barrier that they introduce, I am amazed that they would last in a flatty for a minute.

....Cotten

[redfred84]

Flatheads portray the worst possible scenario for a valve guide. I am on my 3rd lower end (over 20 years) with my original set of Goodson thread-in inserts, set at .001 clearance to the valve stem. This is on my Black & Plaid 80" Chief that was royally punished for 15 of those years (I don't beat her so bad lately).
I also ran these inserts in my Scout Flat tracker, which saw severe track punishment. The clearance was also set .001". These days, my engine guru sets them up at .0015. I have never had a problem with this product.
I would also consider the phospher-bronze material to conduct heat, more than isolate it. This set-up definately works for me, and I have a lot of varying types of mileage with them, a LOT. I'm also into the various internal coating lately, and have been starting to get my valve stems & piston skirts "wet" coated. But I still have never had any issues before I started coating the valve stems either.

RF.

[billpedalino]

Fred/Cotton,

Thanks for the additional input. What I'm wondering is that because the load on the flathead valve is purely axial, there is almost no side thrust against the inside wall of the valve guide, other than that implied by valve rocking. However, rocker arm motors certainly do cause a lateral force (thrust) against the guide, toward the centerline of the cylinder assembly.

This may be hair-splitting - I'm sure it is. We engineers tend to over-analyze everything and its a habit I'm trying to break as I get older. But Cotton certainly has a good point. However, if it works on a Harley with the radial movement of the overhead rocker arm, the benefits are quite substantial. Do you know what this set-up costs? Maybe its worth some 'venture capital'....

[redfred84]

HI Bill,
I have no idea what the costs are these days. I do know that the good people at Goodson were everly helpfull though, and should be able to steer you to a local venue, or guide you to their best product for your application, if you are willing & able to perform the duties.
I'm well aware of the side thrusts cast on a valve guide by incorrect rocker arm geometery. I've suffered the consequences in the past with a '37 4our cylinder Indian which had adjustable rocker supports, that were way out of wack when I received it. I haven't used the Goodson inserts on this application yet. But I don't see a problem. They were originally designed for very high revving sports car racers when I caught wind of them. Try their Tech Line, I have full faith in them. But again, tell them that the AMCA sent you.
All the best, RF.