milling flathead heads (How?)

OK...I see now he wanted bolt holes from the sides, not boltholes at right angles to deck like all of them are...but isnt this still done with pegs and jacks?? the idea of milling a surface that is not directly supported beneath seems worrisome. Could he have been discussing the modern belt-sander kind of surfacing machine??

 

Just about any head I've seen re-surfaced was blanchard ground. Just too many variables to cut a head on a standard milling machine for my liking, I'm sure it can be done though.

Bob

 

Really pretty simple when you think about it. I just put 4 machine jacks under the head on each corner. Dial in the head from each corner with the jacks. Place a long all-thread through the sparkplug hole to hold the head in the machine. This method gives you full adjustablity so you can dial the head to the cutter for the least amount of stock removal >>>>.

 

Haha! That's awesome, I feel the same way, joking or not.

 

FINALLY!

Why must every question receive a lecture accompanied by no answer?

BTW, if the place is a modern race engine shop, they've never had to machine a flat head before.

Modern heads are hung from angle plates using the intake manifold bolts, and then screw jacks on the outboard side under the head bolt bosses for support and to aid leveling. You can see said angle plate behind the head in this picture, along with various and sundry screw jacks.

If the shop in question has never worked on flat heads before, they won't know what the fixtures are supposed to look like. A general machine shop would figure it out, but a race shop that only works on modern overhead valve stuff might not. Some places have a box they're good inside, and they don't venture out of it very often.

Now, maybe you don't want them working on your flat heads without decades of experience, but just because they're not familiar with age old obsolete technology does not automatically make them bad engine builders. It just makes them modern engine builders with little imagination.

Also, I don't remember who said it, but the guy who would surface a head with no hold downs at all is nuts. I marvel at the luck some people have. If I tried that, even once, I'd be patching a big hole in the wall and rebuilding a machine spindle.

There will never be a machining operation undertaken on my machine tools which relies strictly on gravity to secure the work to the table. No way, no how. Hell, if for no other reason than you cannot use the mass of the machine to damp vibration if the work is not securely coupled to said machine. I'm just not that lucky.

 

We use a Van Norman 570 Broach and machine heads and blocks all the time. I can post some pictures of a model A head being planed later. We also do the blocks this way also. I agree with the others, if the shop has to ask you better run as fast as your little legs will take you to another more competent shop!

 

I'm wondering why mill the heads in the first place. How about piston/valve clearance etc.

I agree with the RUN crowd. Not that the machinist can't learn flatheads but the fact that he can't figure it out on his own. These are the guys that deck blocks without knowing that the valve angles are different side to side.

 

I think what the issue here is the shop he took the heads to has a new fangled machine like a straight cutting CBN style machine that doesn't have a platform table to bolt the heads down to. The travel on the machine doesn't sweep as the older ones like mine so the heads have to be bolted at right angles. I guess you need a Vintage machine from back in the day to adapt to all needs !!! >>>>.

 

So basically, you know better than the OP when it comes to having his engine built.

Some folk's arrogance knows no bounds, I guess.

The guy asked a simple question, and got forty seven "Trust me, I know best, leave it to the adults" type suggestions (with zero actual information in them), and two useful and straightforward answers.

You don't know him or his engine guy from Adam, but you assume a multitude of things about them both.

Maybe the engine guy just asked a question, maybe he doesn't really want to do the job, maybe he's the only guy with an engine shop for three hundred miles. None of us know any of that, but a lot of you guys are giving him advice like you're right there.

Maybe there are thirty other machinists local to him, and one of them specializes in flat head motors. Or, maybe this guy is it, and he's gotta make it work.

I dunno, it just irks me to see so many people basically tell this guy that he's too stupid to make his own decisions. He didn't ask if he should find a special flat head machinist, he asked for pictures of a head being surfaced.

I think I've just had enough of nannyism in general. I trust my fellow man to decide what's best for him, and I expect him to trust me to decide what is best for me. Full stop.

Call it the Responsibility Corollary to the Golden Rule.

 

I agree with you about the many opinions here. But mine is based on known facts and experience. That I mite ad im trying to pass on so others don’t have to suffer threw what I and others have gone threw (golden…..?)
Most recent for instance.
A friend of mine 100 miles form me had his work done buy a local to him guy.
First time. The crank wasn’t cleaned correctly.
Second time. The guy didn’t see the cam needed over size bearings.
Third time. The guy didn’t check piston to head clearance.

Were talking over a year of dickin around now. Finally (after building it 3 times) he made the 100 mile drive over to my guy to get his heads domed and now can run his flathead (hopefully).

 

Yup, even though I am pretty well set up at home to do most metal machining and fabricating jobs myself, there are some jobs that I will gladly pay someone else to do.
That is usually because they will have some special equipment I don't have, and the knowledge and experience to do the job right.

But I always like to know exactly what is to be done, how it is to be done, any points to be careful about, and why.

So I might get onto an internet forum and start asking some serious questions about the finer points of maybe, engine balancing (for example).
If six different dorks all suddenly pop up out of nowhere and say "just take it to an engine place" that just shows total ignorance, and is of zero help.

 

The 36 heads have a water pump mount at the front of each head, When flipped over,they take up some space. A machinist can make a simple mounting fixture utilizing 4 stanchions at the furthest corners off the stud bosses welded on a flat 3/4" plate/remnant, Drill and tap the plate in order to provide a mounting for a 7/16" NC stud (of the desired length) at the 1st and 4th plug boss,then bolt through the spark hole with a shallow nut, It will need stabilization though on the corners as well as the mid section or a vibration will/may occur.

I can't post a pic, but you're welcome to shoot me a email and I'll try to get you a pic of how we @ Cyclone Racing Equipment/Cook's Machine Works did/do it since back late 30's.

 

Whats a nannyism?

 

My thinking exactly.

 

OK, I'll bite.

Well, you live in NY, and the mayor of NYC recently moved through the city house an ordinance banning (or severely curtailing) the use of salt in restaraunt food and all packaged foods sold in NYC.

I believe a companion bill is working its way through your state houses as well.

THAT is a nannyism.

The thinking is something along the lines of: You're too stupid to regulate your own salt intake via the choices you make when buying and cooking your own food, therefore the government must force you to "do the right thing" "for your own good".

Now, eating right is a laudable goal, but it is absolutely and entirely outside the purview of government, local or otherwise.

It is the government enforced version of the robot utopia that the villain of "I Robot" tried to create, by protecting humans from themselves, as they were too frail and too weak willed to be entrusted with their own survival.

I don't know about you all, but I would much rather die as a consequence of my own choices than live a long and peaceful life under the total control of another.

YMMV

 

and run it does, boy howdy i tell you what.

 

COOL HAND; You nailed it with the nannyism...........I think I'll use that word every day for the rest of the week..........Pipes

 

anyways, not to disctact from all the bs drama, heres another set up that i use on my blockmaster for doing flat head type heads.

basically its some short peices of angle iron with a peg and a set screw, they go in the headbolt holes and the set screw presses agains the head holding the head tight to the pegs if that makes sense, then it can bolt to the adaptor plate on my mill, ill let the pics do the explaining.

jeff

 

Coolhand thanks for doing what I had asked for( showing me a picture). You were correct in all your assumptions, the shop that I had the heads at do all my balancing of assemblys for my flatheads currently I am doing 5 engines at this time. They do all the race motors for all the circle track cars here in the midwest. Yes all the motors they do are overheads and made the comment how do I hold it and I said I will try to find out. Well you can see what happend. I just happened to go to another shop that had done work for me before today and I posed the question to him. He reached under a bench and pulled out a kit from Goodson Machine tools and showed it to me and it looks just like the stands and bolts in your pictures. Warp Speed thanks for your comments. Yes I do all my own work. Welding, fabricating, painting and figuring out all my own chassis problems, but could not answer the question how to hold the head. Thanks again guys

 

Piston to valve clearance? In a flat head?
<O
Milled heads in a Blanchard grinder. Did lots of them. <O
<O
Regarding the valve clearance on a flathead, we used to ‘flycut’ the heads for valve clearance. Anyone that has milled flathead heads should know how to do the flycuts. Then ‘clay’ the head to check for valve clearance, and the pistons too.
<O<O
Most of the guys I knew back in the early 50’s milled their stock heads instead of buying aluminum aftermarket heads which cost $$$$.

 

You're welcome, but that wasn't me that posted the pic, I just quoted the guy that did.

EnginePro always has his shit wired straight, and this time the always excellent information came with a very well chosen photo. He's the one you should thank.

 

guys i have some Edmunds 24 stud heads that have been milled and how much i don't know so how big should the combustion chambers be and i mean when measured in CC'S. is their a certain amount of clearance with valves and pistons when checking with clay for clearance. i do believe the engine is a 8BA thanks.

 

Cool Hand( I can anderstand how someone gave you that name) Giving credit where credit is due. I screwed up, my appoligies to Engine-Pro who did a great post. Titus who is also from Minnesota offered a neat, well thought out solution to the problem. Thanks. The reason for the surfacing is I welded a few spots on the face of a head. Yes I have measured how much I can take off. Thanks to all.

 

I'll throw some more chips on the table guys while we are on the flat-head subject. The experts that tell you never to mill the deck surface of the block aren't always guiding you in the right direction !! Let's say if I can put the block in the mill and remove 0.007 to 0.010 off of the deck to get it back flat and true that's going to ruin the block?? In the modern day flat head craze that I'm caught up in I see the head bolt threads trying to pull up at the deck surface so this requires milling and a counter sink at deck surface. In my mind this is a process that needs to be done to these blocks to get them to quit having head gasket trouble and to add to the life of the rebuild >>>>.

 

Thanks Engine-Pro for your added information on the decks. Makes sense about the stud or bolt holes(like the chamfering idea). Do you have a preferrence on helicoils or? Thanks again

 

Maybe not on a NA motor, but on a blown motor or one with high compression and heavy race use, it can make a heck of a difference. When I decked my block the second time I built my blown motor, I never had gasket sealing problems again -- before that it was the original surface, didn't look back, but it was not perfectly flat after 50+ years. Also, you can use the opportunity to set the deck height the same on both sides and perfectly square to the bore.

For a street engine, may not be a big deal . . . but if I had an engine all apart and was building up a hot flathead, I'd sure do it.

 

I guess I just like to get things as perfect as I can get them and the race engine builder in me makes me look for the problem areas in engines. I have always tried to take an engine apart and make it Faster and Live Longer so when I ran across the stress riser at the head bolt holes I had to address it in the best way I knew how. I just want to start out with an engine that is as near perfect as I can get. Now I have read posts on here that say "Never Mill The Deck On A Flat-Head Block" and another is "Never Run a Tap Through the Head Bolt Holes". Now I'm not saying everything I do is perfect but I think the things I'm doing are helping these engines in performance and to live longer and I hope some of my information can help others !!! After all that's what the H.A.M.B. is all about !!!! >>>>.