OK,
im a machinist and i have access to all equipment that i would ever need CNC and manual machines (i work for john deere).

my problem is i've never done machinework on engines before and was wondering if anyone knows where i could get info on this subject.

i would realy like to do my own work to save $$$ and the pride of doing it myself. any help would be greatly app.

im planning on building a 350 to drop into my 89 305 (LB9)formula.

thanks

 

CEDOE,

Engine machining is generally very crude compared to the kind of things you are doing. The key is going to be experimentation. There are several means to achieve the same end result in most cases. Most automotive machine shops use manual (or sometimes crude NC) equipment and specialized (form) tooling. Measurement is not done with the machine encoder or part sensor, but manual instruments. A CMM would be extremely rare in a common automotive machine shop.

It really should be easy, and a guy with a larger (table) four-axis CNC horizontal could kick butt on most machine shops for porting, valve work, decking, align boring, bore/sleeve work, etc. Intakes and heads are easy, too. Part of this is that, personally, I think ceramic tooling provides a better surface finish than even the grinding done in most auto machine shops. (As a hint, you won't see any 15,000 RPM through-tool cooled spindles in an automotive machine shop.) Many shops don't even pay much attention to surface finish, and don't even have finish gauges. This is a cardinal sin on bi-metal engines (iron block, aluminum heads), where finish is critical in good sealing and gasket retention. Some shops are catching on, but only after warranty complaints and rework.

The trig and geometry are no different than what you would use to fab up a fixture or jig, or a special one-time piece. There are no good web sites that I could find that outline what is typically done, but if you understand the purpose and philosophy behind machining engine parts for performance, the things you would change become fairly obvious.

I hope someone has better, more specific examples, otherwise you may find yourself hanging out at the auto machine shop for a couple of Saturday mornings just to see what is going on. It isn't "rocket-science" compared to common manufacturing machining, for sure. More like "slingshot-science". No flames intended to any automotive machinists here, but it certainly is a lot different game when you start making precision parts in manucfacturing. You can't often get away with much more than +/- 0.00015" and still make an acceptable part in many places. Forget about thousandths altogether, and start thinking microns.

 

you amaze me with the knowledge you have . i see your responces all over the bords and respect you opinion.

and actually my specific job the last 11 months has been setting up and programing an OKUMA MA60 4 AXIS HOR. MILL . thats what got me thinking about all this. i do all our prototype work and fixture design for this new mill so i will take your advice and keep reading all post to gain more knowledge about proform. upgrades and go from there. maybe a little practice on a head or block that isnt any good will get me on the ball .

i see all these post from people about porting and siameasing ,etc
and think to myself how fast and accurate i could do these things with the tools i have access to all i need is the knowhow i have the determination. i will learn!!

thanks again !!

 

 

CEDOE,

Okumas are a nice piece of equipment. Mori Seikis are very nice as well. Even some of the Mazaks, as lightweight as they are, can be made to do decent work if not pushed too hard.

Since you've been setting up prep work, you probably know exactly what I'm saying. If you had a jig to mount heads, indicate them in or touch-probe them in a couple of axes, you could kick butt. After all, they're only iron or aluminum. Automotive machining is a piece of cake compared to Zed-F axles, injection pump parts, transaxle housings, ext. Even cheap hydraulic pumps have tighter tolerances than most engines (at least engines that don't have turbines).

Scrap heads would be a really good place to start, so you can get a feel for how far you can go. You might even want to take one to a bandsaw or stone saw and through-cut it in about four different directions around the valves and ports to see what kind of material you have to work with. The stone saw or a DoAll skip-tooth blade will eat through the "hardened" valve seats without a problem, but a regular saw blade may have some trouble and need a little coolant.

HINT: Save your programs!

 

I'm a machinist too (18 years) and have full access to several CNC lathes and mills plus lots of conventional machines, I've done lots of automotive work for myself but I usually end up doing it on conventional mills to get away from having to build special jigs and fixtures to hold the part in the CNC mills because I'm only doing a couple parts at a time and it takes too long to set up and program the CNC's for such a low number, it might take all day to set them up for a job I could do in a conventional machine in a couple hours. The area where they are best is doing lot's of parts. I'm currently working on a program to build myself a super short throw 5-speed shifter for my Camaro. The owner and I have been wanting to build some fixtures to be able to BluePrint engine blocks using the 4th axis but we just haven't gotten around to it yet. I don't know any good books on the subject, most of what I know I picked up reading magazines over the past 25 years.

 

vader :hail: as always very imformative!!

and dart i know exactly what you are saying about setup time .

heads will probably be done on the bridgport vet. milling machine.
but not enough z clearance for block work. hence the 4 axis hor.

and hey my new okuma can run circles around my old and gone (1989)mazak ajv(vert) but look you cant underestamate mazak good machines.and believe me it was abused regularly.

thanks again guys will let you all know what happens over the next few months