Dads Sport Scout

[FLFD7]

Paul

Guides come out with a little heat, a little penetrating oil (probably doesn't do anything), a brass punch, a 1/2" bolt and a bfh.

New guide will live in the freezer a couple days, a little heat on the cylinder, a piece of pipe over the guide, and a bfh ought to do it.

Joe

[FLFD7]

Well I cleaned up the intake area and of course where the cast iron broke it was a little rough so I smoothed it out with a dremel.

F454CB71-6F81-4BB1-96BE-8D4B0CA6BC19.jpeg2A6F4204-E7E6-47A0-B4A5-3E721E84E943.jpeg

A little before and after.

4C5A5747-CA5A-4D87-BEDA-AB5323D74CDB.jpeg614850D7-582F-4A15-A8BF-0587604D8162.jpeg

The new and broken guides measure the same.

23DCFF4A-7B57-4343-9C35-0ADFBF6DDC3B.jpeg

Got to clean up the thru hole and do some shade tree knurling.

[FLFD7]

I noticed the guide I was using was a bit shorter then the original broken one

661B3EB9-FE08-46D4-9348-CED577B583CC.jpeg

But it measures even longer then what I assume is the correct size according to Greers catalog.

61EC7422-586B-4E75-B87F-225630C4E58B.jpegD3F83D60-D2B6-436F-819C-27A16DB029B9.jpeg

So I don’t know what it’s from but it’ll work.

DADF4E79-4A67-46BB-8919-461DB7FA8A57.jpeg798F9667-1B19-4AF6-8FDB-20CFF6CA065C.jpeg

As Arlo Guthrie would say my implements of destruction, a high tech guide driver made of black pipe and a bfh.

[FLFD7]

So with a center punch I created my shade tree knurling

97D24FB5-348C-429D-85E8-E743C0E6341F.jpeg

A little heat on the cylinder, the guide was in the freezer for a couple days, some red Loctite and a few whacks with the bfh and the new guide seated home and in.

99903592-F681-4730-B269-4C53586D7CF2.jpegF197C848-3685-429A-A61D-215B4024F4E4.jpeg0DC20A88-A68E-4206-94AB-F90BBD784668.jpeg

So that’s done, now to lap the valves in.

[Jerry Wieland]

Well I hope your knurling works. Oversize guides are not available? I friend of mine on his 40 Scout cad plated the bearing races to get a better press fit. Jerry

[PaulCDF]

Thanks for tutorial, Excellent pictures. I am facing this on my 741 and was wondering.

[T. Cotten]

Sorry I've been biting my tongue so long, Folks,...

But if you chisel the guide off on the outside, you can then easily press the rest into the port without damage to the cylinder.

Ain't that the way it is in the book?

And if you really, really must knurl something (causing a heat barrier where you do not want one), wouldn't it be better to knurl the temporary guide, than torture the cylinder?

Please, please, Joe, look before you leap.

....Cotten

[FLFD7]

Cotten,

As Sgt Hulka would say

F42AD268-2DD6-4B76-98ED-AA646196122E.jpeg

I do look before I leap, and I considered my options.

I could have plated the guide for a bit more interference, so I’d take my one valve guide to the plater, maybe he can throw it in another job if he’s barrel plating some clear cadmium or maybe some electroless nickel, hopefully the worker won’t forget to take my part out of the batch. It isn’t like I do a lot of business with him so I’m sure it’s not free. Since both cad and nickel can vary from .0003 to over .0005 thick hopefully it won’t reduce the id enough to cause a problem. Hmmmm...I don’t think so.

I would love to knurl the guide itself, sure. Except one thing, Indian valve guides are hardened, which is why it shattered the way it did when it broke. So I guess I could take it to a shop and have it annealed, there’s a lot charge. Get it knurled then back to the shop for heat treatment, another lot charge. Hmmmmm....I don’t think so.

Or I can take my friends advice, who has used this technique himself, and put some center punch marks in the cylinder, a little Loctite wouldn’t hurt either, and drive the new guide home. Yeah, there you go.

Fifteen or so punch marks later ( I didn’t count), a frozen guide, some heat on the cylinder, 3 or 4 whacks with a bfh and we done. Winner winner chicken dinner.

I don’t know what book you are referring to, but the Indian Scout operations manual doesn’t say anything about chiseling the valve guide and pushing it in. It says to punch out the old guide. Since there is a shoulder on it, it means punching it from the inside out...which of course makes perfect sense.

And while I don’t remember too much from my heat transfer class at NJIT back in my college days, I’m pretty sure that 15 or so center punch marks, which are now pretty much pushed back flat by the valve guide, will not cause any kind of “heat barrier” problem.

So we good? Explanation makes sense. Excellent, we’ll be moving on now.

[T. Cotten]

Cotten,

As Sgt Hulka would say

F42AD268-2DD6-4B76-98ED-AA646196122E.jpeg

I do look before I leap, and I considered my options.

I could have plated the guide for a bit more interference, so I’d take my one valve guide to the plater, maybe he can throw it in another job if he’s barrel plating some clear cadmium or maybe some electroless nickel, hopefully the worker won’t forget to take my part out of the batch. It isn’t like I do a lot of business with him so I’m sure it’s not free. Since both cad and nickel can vary from .0003 to over .0005 thick hopefully it won’t reduce the id enough to cause a problem. Hmmmm...I don’t think so.

I would love to knurl the guide itself, sure. Except one thing, Indian valve guides are hardened, which is why it shattered the way it did when it broke. So I guess I could take it to a shop and have it annealed, there’s a lot charge. Get it knurled then back to the shop for heat treatment, another lot charge. Hmmmmm....I don’t think so.

Or I can take my friends advice, who has used this technique himself, and put some center punch marks in the cylinder, a little Loctite wouldn’t hurt either, and drive the new guide home. Yeah, there you go.

Fifteen or so punch marks later ( I didn’t count), a frozen guide, some heat on the cylinder, 3 or 4 whacks with a bfh and we done. Winner winner chicken dinner.

I don’t know what book you are referring to, but the Indian Scout operations manual doesn’t say anything about chiseling the valve guide and pushing it in. It says to punch out the old guide. Since there is a shoulder on it, it means punching it from the inside out...which of course makes perfect sense.

And while I don’t remember too much from my heat transfer class at NJIT back in my college days, I’m pretty sure that 15 or so center punch marks, which are now pretty much pushed back flat by the valve guide, will not cause any kind of “heat barrier” problem.

So we good? Explanation makes sense. Excellent, we’ll be moving on now.

If you had looked, Joe,...

Greer's sells guides intended to be machined to size.
DIXIE's were malleable enough to knurl (which I do NOT advocate on any guide).
But if you really had to anneal what you had, just soak it in a bed of hot coals, and let it cool there overnight. Re-hardening would take a web search, but I imagine its just a hot oil quench.

(Some folks cut guides from scratch from old window weights, but I found it pretty hard on the lathe!)

Even a perfect guide installation is still a heat barrier, and if you studied it, you know it.
(That's why "Seal-Lock Fluid-Weld" is used to improve guide and seat transfer.)

So you've got fifteen or so stress risers in your cylinder now, that could have been avoided. Don't worry, nobody can see them.

....Cotten
PS: Speaking of seats, what's the run-out now that the guide bore is boogered?

Herman Munsters opinion.jpg
Hmmmmm....?

[FLFD7]

73AA89C2-55EE-4CC3-BA9A-D237D2493224.jpeg You’re right, nobody can see them....and I ain’t worried....

[T. Cotten]

73AA89C2-55EE-4CC3-BA9A-D237D2493224.jpeg You’re right, nobody can see them....and I ain’t worried....

You haven't cut the seat yet, Joe!

Got spring shims?

....Cotten
PS: And a way to grind the pushrod/adjustor so it all can be assembled if too deep?

(Or a fresh cast iron seat?)

PPS: Ain't that crown a copy of this?.... Or vice versa!

redcrwn2.jpg

[exeric]

Keep up the good work, Joe. I have enjoyed your build thread.

[FLFD7]

Just a quick update finishing up the valve lapping and doing a leak test, cover the valves in lacquer thinner and wait 5 minutes. No leaks and we’re good.

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Now finish painting the cylinders and get them on the engine.

[FLFD7]

Been real busy the last couple of weeks but still putting some time in on this bike.
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got the rear cylinder done, now I got a set!

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now to get them on the engine....

[exeric]

Delighted to see an update, Joe. You certainly have a nice pair of cylinders to work with. I have about 3 broken fins on my SS cylinders but I have repaired many broken fins so that's no big deal. I can't wait to get back to my shop in Florida as we are about done with our Summer stay here in Georgia. . . Then I can get serious about working on my Sport Scout.