engine overhauling

Is it always necessary to have the engine head resurfaced prior to new gaskets...putting things back together? If so, where do you take a 1950's-1940's head to be properly resurfaced? Whats a fee range thats fair for the shop and yet fair to the tractor owner for the head cleaning/resurface work? Is there a "unique" tool to get the springs back in? Or is it best to have the shop work out the springs (gaps) etc..?
any other thoughts on the engine rebuild a person might overlook that you guys have picked up on???
thanks for the help

EVERY head should be checked for 1)cracks 2)warpage 3)guide wear 4)valve seat recession 5)and of course valve and spring wear. You may not have all of these problems but it is very foolish not to have them checked. If you aren't gong to check things why take the head off in the first place?

a good machine shop will check the head to see if it needs surfacing. if you put a warped head back on, more than likely it will leak. you do need a valve spring compressor to get the valves back together. with out the proper knowledge, skill and equipment, it is real easy to ruin a head. generally heads will run from 100 on up and over 500 depending on whats wrong. i have a hot rod machine shop that does work for me, they do a great job, and get a kick out of the old motors.

Charley,
If you are truly overhauling, it's a good idea to take the head (complete) to a machine shop and have them check for cracks and flatness, put in hard seats for unleaded gas, check valves and guides for proper clearances

Usually a place that sells parts will have a machine shop that they send heads to for valve grinds and cleaning and surface grinding as well as blocks,Usually an auto parts place,but tractor parts places too.Lots of towns have a machine shop like that,depending on where you are.The auto parts place that does it here has a truck that comes and picks up the head and brings it back in a week or 2,but there is a machine shop in the next town about 14 miles away.I have taken a head to the machine shop and got it back 2 days later.Machine shop was cheaper and did a better job as far as I could tell.Auto parts place put in all new stuff,machine shop put in what was wore out.

I noticed that you were asking what it cost,the best thing is to find a machine shop and ask what their rates are,if you are close to a big city there could be several machine shops,so ask a few of them,and if you find one that you like,take the head to them and see what they say.A head thats got a lot of burned valves can get up to 400 dollars maybe more.If it just needs a few valve guides,and they are replaceable,which a lot of old tractors are,and not many burned valves that can be reground might even get it done under a hundred.You are better off leaving it to a machine shop unless you have a valve grinder and know about how to repair a head and check it for cracks and warpage.
If you are thinking about rebuilding your motor,and have not done a motor,or even seen somebody do a rebuild,you need to ask lots of questions,and watch someone if you can.A tractor can get expensive just for the parts,and while its not real hard to do,it is kind of a particular job.It has to be clean,and you need to torque all the bolts which means the bolts need to be clean,threads wire brushed and lightly oiled.Bearing shells have to have tangs lined up on the same side and rods have to go back in turned the same way as before,arrows point to the front on pistons,things like that.You need a manual.Then set down and read the whole thing about rebuilding a motor before you even start.Try and find somebody that has rebuilt motors and ask them,and ask on here because you will most likely have questions.Take pictures if you can before you take it apart just in case you dont remember how it was put together.

Since you don't know what a spring compressor is you had better take the engine and have a shop do the disassembly and rebuild. Hal

At first glance, to a child's eye, tying a shoe string looks undaughnting and as if magic has taken place, in fact at one time the world was thought/believed to be flat....
Maybe if I had no thumbs your statement might have some weight to it but thumbs are attached.
Thanks for your positive input.

Great information! I have seen it done and am aware of many of the finer points. But like you said, I need to learn alot and ask many questions before I begin. Mainly the steps once the engine is taken down into its components. What small nuiances I need to be able to detect that indicates further problems or needs...hope I'm making sense? Anyway, thanks for your imput...I liked hearing the comparison between the machine shop and an autoparts store...I like the Machine Shop approach I think.

Great point! A service manual can only tell a person so much. You guys on this web-site are the key.
Thanks for the knowledge.

Yes, but when a child attempts to tie his own shoes without even knowing what function the laces serve, he ends up flat on his face on the floor, in tears, with his shoes tied together with knots even his parents can't undo.

Take a lot of pictures and a lot of notes. Hal

Hal,
Be careful I think you hurt someones feelings. Don't you love it when someone asks for advice and experience says they're in over their head. You try to tell them so and they get insulted.

Everybody has to start somewhere. People that won't tackle something new because they're not "experts" at it will never get anything done.

People that warn folks away from trying something new give me a giant pain.

I'll try my hand at anything because I guess I'm just too stupid to know I'm not supposed to be able to do it without some sort of license or degree.

Do I screw things up? Sure. But not twice. Anybody that never made a mistake never did anything.

I just fixed up my first tractor last year, a '42 H. Hal was rough on me too with a few of my less insightful questions to the forum. Seems like a nice guy, I don't understand why he does that. I knew a very limited amount when I started, now I can't wait to dig into another one.

But I just called around to different machine shops. You'll be able to tell who wants your business and who doesn't. Ask around at your auto parts stores and break open the yellow pages. After you talk to a few you'll know more what to ask. I even stopped in to a few and talked to the guys until I found one I was comfortable with. Ended up being a great guy/shop, charged me a very fair price.

Most shops will want to do it right, so be ready for a little more work than just resurfacing. They'll want to mag and pressure test for any cracks, check valves and guides, etc., etc.. I wanted all new parts in mine, and although he wasn't overjoyed at it, he let me supply the parts. They have to make money on parts they sell, understandably, and I saved quite a bit buying them myself. Most everything I got from this site. Basically bought a whole engine overhaul kit. You don't have to. I would expect to check and surface your head you'll need to be ready to spend about $120. If you just tell them to surface it you could get away with a little less. But then, like the knowledgeable old-times here will tell you, it stinks if you get it all back together and then find that you do have a crack or other problem and have to go through it all again. And the thing about the head is that it can't be straight and smooth, but the top of the block, (deck), needs to be just as straight or you still have a problem. So that was part of what I had done. Also, if you want to, when they surafce your head tell them to mill a little off, about .030. Gives you a little extra compression/power, but not so much you can't still work it.

It's very common to spend more on fixing an old tractor up than it will be worth when you get done, especially these very common old red tractors.

Best of luck, and don't forget to have fun.

Brian

Typo... The head CAN be straight but the deck could be warped.

I've got to differ.

I'm old enough that I started in wrenchin' helpin' my grandfather as a kid. Learned some there. Got older and had to try and keep whatever wreck I had for a car goin'. Biggest project back then was rebuildin' the motor in a '64 Beetle. No web boards like this. What's a manual? By buddy didn't know or understand as much then about these things as I do now, but he knew more than I did at the time, I learned from him, too, and we got 'er done.

Point is that there's lots of folks with sufficient mechanical skills to work on the older machines who may never have heard of the need to plane a head, and who may never have had occasion to pull a valve, but they have the ability to learn and to do it.

Folks have been walked through a lot more technical stuff on these boards.

I, for one am willin' to help where I can. If it seems like it's boring others, I'll move it off to email.

Scott,
No need to differ, I won't tell you what my tool box contains;6'x4'x8' full of tools for my hobby. I'm almost smart enough to know that I don't need a Bridgeport mill and wouldn't know how to use it. I can't cut new valve seats, but I can stake in hardened ones. There are jobs best left to pros is the point. I can/have hand lapped valves that should have been thrown away. I'm more than willing to help, but there are just things that should be pro done.

I think the difference between finding out about some 'new' tool, tip, trick or technique and being in over your head is your attitude.

It is one thing to ask a straight forward 'how does this work' question and another to start in complaining about how you have been taken advantage of when you might not actually know what you are looking at or talking about.

Greg

(quoted from post at 15:13:17 05/29/08) I just fixed up my first tractor last year, a '42 H. Hal was rough on me too with a few of my less insightful questions to the forum. Seems like a nice guy, I don't understand why he does that.
Brian

Click to expand...

He does it so that you "have both feet on the floor" and will know what you are up against - and will recognize how easy it is to mess something up. mike

In simple terms, just take the head to a machine shop, tell the guy what it is off of and have him recondition it. He has the proper equipment and can get all the parts. The one I take mine to is fairly priced.

I've been a builder for 40 years. Done lawnmowers, tractors, aircraft, boats, you name it, even did a Merlin 60 series in a Mustang.

There is no engine anyone can't rebuild with a manual (need the numbers) and some time, time is the "KEY" word here, take plenty of it and inspect everything before and while it goes together. This is how we learn, an engine is an engine is an engine. Last project was a Porsche 911 engine that dyno'd at 576 hp, on gas, good fun. The sticker in the back window reads "I just had a V8"

Just remember this; Any part that raises a shadow of doubt, goes in the trash. You will never be able to expect an engine with marginal, internal components to perform like it should, much less last. Want to run them hard? They better be right.

Right now I'm in a 3 cylinder Jap diesel engine where one cylinder liner cost close to $200.00. The old liners have .005 to go, they are being replaced along with everything else. The worst thing you can do is skimp on a rebuild. If you do, eventually the hot oily pieces will be all yours my friend.

scott#2

Sorry, gary, I was a little vague in my post on the distinction between learning and having the eqipment to plane a head versus the question of how to remove a valve.

To be more clear . . .

I don't think that a board where I have seen fifty+ posts over the last several years explaining to a fellow (usually going back into his first motor rebuild when he fired it up and had oil pressure problems) how to reface an obscure but important part in the guts of an oil pump on a pane of glass should be a place where somebody doesn't get shut down by being told that, if he has to ask how, he shouldn't be trying to remove a valve.

A lot depends on three factors. How ambitious you are, what kind of shape your head is in, and how much you're willing or able (okay make that four factors) to spend.

Valve removal is not a big deal. A valve spring compressor is basically a big C-clamp. It's wide enough to bridge the head so that one side of the clamp fits over the round (inside-the-head) end of the valve. The other side of the clamp has a fork that fits over the cup that holds the top of the spring. The tool has a mechanism for pressing the cup down onto the valve stem so that you can remove the wedges that hold the cup in place. When the wedges are out and you take the pressure off the tool, the valve is free to slide out of the guide. A smart fellow will have put numbers on the faces of his valves, like 1E and 1I, 2I and 2E (I for intake, E for exhaust) or number them numerically from front to back, and put the springs, cups and keepers from each one in separate envelopes or whatever numbered the same way.

If you want the experience and choose to do it that way, the head should still be taken to a shop for evaluation. (And take your valves, springs, etc. with you.) They can magnaflux it to check for cracks and can plane it if it needs it. There's also something to be said for their experience in evaluating the condition of the valve seats. If the seats are bad enough to need machining, the valves will probably also need grinding. This will involve equipment that it wouldn't be worth your while to acquire for a hobby piece. But a good shop will also tell you if you're head is in relatively good shape and that all the valves need is lapping, and that's an easy and actually quite rewarding project you could do yourself for very little expense.

So one point is that the value of their experience in evaluating the condition of your head will guide how much you want to do yourself, BUT you won't know what that value is until they have a look at it.

That and the cost of the tools you'd need to measure up things like valve stem and guide wear. A good micrometer and a set of small-hole gauges will set you back a good bit more than what they'll charge you for what is a routine part of what they do working on engine heads.

I've been down both roads. I had one head that had been full of water. The shop got that job -- baked it, shot blasted, magnafluxed, planed, milled for new valve seats, and new valves, guides and springs. On another (pet) project, things were relatively clean and I had the tools to determne that the valves, guides and springs were okay, but I still took the head in for magnafluxing and truing.

The bigger point is that these old motors aren't hard to work on. A good set of manuals, a basic set of tools and a torque wrench, and there isn't too much you can't do yourself.

Oh yes, and don't forget the advice. Your thread kind of got hijacked, but there are plenty of folks here willin' to help.

Let us know how you're makin' out and if we can help.

Brian ---

That is no different than going into "Bob Evans" with 3 eggs, sausage, hash browns,bag of coffee and bread and ask them to cook your breakfast.......

Don, I'm not sure I understand what you meant. Did you mean me getting the parts instead of the shop?

To actually answer your question, no it is not necessary to have the head resurfaced every time you take it off. If you have a good straightedge and a set of feeler guages, its pretty easy to tell if it's warped beyond spec.

How much effort you put into it kind of depends on what you're doing with the tractor. If you're actually rebuilding the engine, then its worth investing in having a machine shop check the head and do the valves. Haven't had a head rebuilt in several years, but seem to think it was in the $100 range for surfacing, magnaflux, & a valve grind. Parts if needed would be extra.

If your objective is just to get it running, you can generally get by with a lot less. Clean the head, check it as best you can for flatness, assume if you can't see any cracks that there aren't any serious ones, and lap the valves. Obviously, if the head is warped, has burnt or bent valves, the valve seats are worn enough the valves won't seat properly, or you see a crack, it needs to go to a machine shop anyway.

Valve clearance is set by adjusting the rocker arms, and you don't need any special tools beyond a set of feeler guages for that.

I've always had the best luck with a family owned & run machine shop. I haven't needed one since we moved to Colorado a couple years ago, but when we lived in California I found one that a couple of brothers ran. They did good work, had reasonable prices, were free with advice, and were very knowledgeable. They knew where to find parts for just about anything, and one time actually gave me a replacement valve for one I bent. Hard to find that kind of service any more.

Keith

I wish I was as smart as you, I bet you are the smartest person in north alabama, maybe in all of alabama!!

What are you talking about?

I have never done a complete engine rebuild on anything bigger than a 22 HP, 2 cylinder Onan. But when I can I negociate what labor will cost first then mention that I would like to provide parts if I know I can get them right. Some shops will accept, some will not. If they will not I weigh the value of them vs. me doing the job and go from there. I am speeking of automotive service here and I HATE working on vehicles of all kinds. Most of the time I say "go ahead an fix it right, pay for it later."

Though I do enjoy tractors and equipment. Maybe it has something to do with not having to lay underneath or crawling into an engine compartment under the hood (usually ends in OUCH!) Do not be embarassed to ask if you can provide parts if you intend on buying quality parts. I know some mechanics do not like customer parts because if a customer provides cheap parts and they fail, guess who the customer blames??? The mechanic, they have to cover their butt.

Gas On It!

Charles Todd

(quoted from post at 21:10:02 05/29/08) To actually answer your question, no it is not necessary to have the head resurfaced every time you take it off. If you have a good straightedge and a set of feeler guages, its pretty easy to tell if it's warped beyond spec. ....
Keith

Click to expand...

This becomes more important when you start working on diesels. Some of them have a maximum allowed to be removed in the .010 inch range.