I used to have a square piece of tempered glass for that. Glue some emery cloth to it and start sanding. Miling the heads will probably take off too much. Clamping them could induce a warp. A small scratch or two remaining won't hurt as long as it's within the gasket area.

Those heads are few and far between and the Indian Flathead doesn't need more compression to run well. The people I knew who used to work on them would port and relieve them and install larger intake valves to improve breathing.

My experience was gained on Harley-Davidson 45" flatheads. With vintage equipment, less is more.


.

Do automotive machine shops still have head resurfacing grinders? Back when I had to depend on others for this sort of thing, they had grinders with a stone set in a table that could be adjusted for the amount of cut and just swished the head across it. It would take less time than has already been spent debating.

Bill

Hell, dont listen to me! Follow the guy that has done ZILLIONS!!!

"My experience was gained on Harley-Davidson 45" flatheads. With vintage equipment, less is more."
You dont know what you are talking about, complete nonsense.

With no margin for error and with it being single job the glass is best option.

Recently repaired old Bobcat 825 aux pump that was horribly slow, the end plate was scoured and allowed the oil beside the gears, poor suction and foamed the oil.

A plate of glass and a series of grits made this a 45 minute task and little risk of a hurrled part.

Get good quality wet/dry paper and keep it WET, will cut faster and cleaner.

Start at 80, work with LIGHT pressure, you up-grit when the scratches from sandpaper same as existing, finer grits then remove the high spots.

Complete nonsense, eh? I think not. It's been done on a flat surface like that many times. You're a rude fellow, however. Apparently, I struck a nerve with you.

Yes newman complete nonsense, you say-


"Milling the heads will probably take off too much. Clamping them could induce a warp"

Can you state how many CCs less head volume will result from removing .005" and the resulting increase of compression from doing that? Of course you cant because you just dont know.
The method I showed induced no noticeable warp. Even though you cant clamp them or even ever tried, you just dont know.
Obviously, the heads are warped now or the fellow wouldnt want them flat, in fact I never seen an old set of heads that were not warped.
You say- "Less is more" I would only take that as you would not correct warped surfaces that occur through out vintage motorcycle engine components or try to rub them on glass such as those that have no machinery and attempt to restore these in their basements.
You say- "The people I knew who used to work on them"
Well where are they now, just dont know, dead, gave it up?
Look, you bet I am to the point, and rude when confronted with nonsense, its the nature of this business.

I have cut a number of Indian heads over the years- never used anything more complicated than three shouldered pins that have a small diameter to fit the bolt holes. All pins are the same length on the larger diameter, and can be shimmed to level the gasket surface, holding the head down through the spark plug hole. Don't worry about taking too much off compression wise. Just make sure that when you are finished you have at least .090" between the squish portion of the head and the top of the piston, including the head gasket. Indian machining was so crappy after about 1928 that this is worth checking even if you don't cut the heads.
There is no way that you are going to get the compression too high- remember that they were built to run on gas of far lower than today's. My last Chief had a homemade set of flywheels with 5 1/4 stroke, and while I did have to cut more piston clearance in the heads to prevent head to piston contact (with Onan pistons) the compression was still low enough to run on regular modern gas.

Herb Kephart

I've also been riding and working on motorcycles most of my life. I've owned many used motorcycles that had this changed here and that changed there by several previous owners. Heads milled down, cases bored out for bigger cylinders, flywheels chopped, frames cut, welded, bondoed and ruined. The result often is that there is nothing left to rebuild. Each successive owner and mechanic leaves his mark, like a dog wetting on a fireplug.

Sure. 005 isn't much. After the tenth owner, each one takes off .005 and there's nothing left.

You didn't lke the method mentioned by Forrest Addy either, but you didn't accuse him of talking complete nonsense. In fact, his method is excellent. Remember, I ddn't criticize your method. I've used Forrest Addy's suggested method using a lathe to surface cylinder heads in the past on my recent Shovelhead. It works very well.

Many of the people whom I knew who worked on motorcycles over the past 50 years are, in fact dead. Unlike you, they shared their knowledge freely. They were decent folk, too. Some used sandpaper, some used milling machines, perhaps even before you were born.

Apparently it's your way, or the highway. I promise you this, the next time I buy a used vintage bike with a set of heads that have been milled, I'll be thinkng of you.

Newman - You appear to be a knowledgeable and experienced man, and reasonable too. Before donie gets too far under your skin, you might want to skim through this thread to see what you are dealing with. We've been down this road more than once before -

OT-Harley sprocket spline

Thanks for reminding me of that great thread. I do recall the "moron" comment. That's word I only use in quotes. It's a hurtful word, especially when used in the context as it was.

I have no interest in arguing with anyone here. This should be a forum for different, even conflicting views offered without personal attacks.

Thank you.

Oh boo hoo, Mud is still whining cause I called his tattoo hippie freak buddy Kendall Johnson a Moron!
Come on Mud, show some more hollow engines " no parts inside" to prove that you are an expert on Korean HD knock offs and how great they are.
Yes, we went down that road Fatso.
The poor poster of this thread was looking for How to Fly Cut a flat head. As the only experienced pro that so far posted, I showed how.
So, the rest should sink their sorry asses in Bees Wax, and surface grind their brain.

So Donie..... are you turning 12 years old this month? lol Even w/o the Moron's posts(Donie) Most experienced machinists could fixture up this head and cut it within tolerance.

From my personal experiences and others I've learned from- turning this head would be the best and most efficient way of completing this job.

So go ahead and raise some more hell because everyone else on this topic is a complete Tard and Donie knows everything lol

I have to point out that Donie suggested a method of fixturing that he would have likely used on his Moore. He would have then used the facing head to get a nice concentric set of grooves to true up the surface.

Forrest suggested the more direct approach, grab it in a 4 jaw and face it with a lathe. Same result, same cutting action, more direct application.

The both require indicating and bringing in. Unless I was doing 5 or more I would probably use a similar approach.

If I was doing a few sets, or doing them regularly, I'd have made a fixture that grabbed the head through the bolt holes with studs, then clamped across. The threads would bite into the material to hold it, and the fixture could be made to repeat reasonably well with adjusting nuts to bear on the spot faced pads on the top of the head. You could even do this with a set of custom soft jaws for a kurt vise and avoid fixture plates.

Neilert: I guess you have your head figured out now. Just thought I would tell you about a guy in Montana that restores Indian motor cycles in case you need a contact for parts. He does some neat tricks like putting electric start on them, you wouldn't know it was there untill he starts it. here it is.

Montana Indian
Vintage Motorcycle Restoration
Tom Benson

Home Phone 406-434-2005
Cell 406-450-0282



Ron

I guess It's good to know I'm not an "experienced pro". I've only been working on motorcycles about 45 years or so and thought I knew what I was doing. thanks for setting me straight......

55 years here--but not the first person that I ran into that thought that he knew everything.

Is this thread moderated?


Herb Kephart

i may be out of my element here as the only flatheads i've ever resurfaced were on BSA bikes but seeing that the name fits i just thought a bit of video would be appropriate: http://www.youtube.com/watch?v=O8MqXXX3jOA&NR=1

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Zagnut wins teh internets for "Most Appropriate Link"



-DU-

Right on Zagnut!!!!!!!!!!