Thread: 302 cyl head print (needed!)

Tweet

I have no clue what c4 rebuild kit i should get. I'v never done a trans before.

Ya im a seinor in hs. I took independent study with my english teacher (only teacher available) and i just pick my project, design it, build it, and write about what i do each day.
I also had to write a ten page paper on manifolds vs. headers if you wanna look that over too... it was a real pain, and the teacher gave me a d+ on it, but a chance to rewrite it. So that is a big grade, so im adding stuff in as i go.

Originally Posted by Henderlong

I have no clue what c4 rebuild kit i should get. I'v never done a trans before.

Ya im a seinor in hs. I took independent study with my english teacher (only teacher available) and i just pick my project, design it, build it, and write about what i do each day.

So how do you have access to a 3 axis CNC machine?? Your High School has that type of equipment??

i think your`e being over precise with measurements that can be quite loose .. a 3/8ths bolt will easily go thru a 7/16ths hole

Originally Posted by rspears

So how do you have access to a 3 axis CNC machine?? Your High School has that type of equipment??

We have a small cnc router (wood), a bridgeport (havnt used yet), a small leathe, jigsaw, bandsaw, mig welder, and other basic tools.
But i duel enroll in a tech center, so i spend three hours at hs (ap calc, american lit, and indepent study), then i go over to the tech center for another 2.5 hours or so. - which we have a small machine shop, multiple welders, plazma cutter, torches, and other cool tools including car lifts.

Don't worry im not one of those spoiled rich kids

Originally Posted by HOSS429

i think your`e being over precise with measurements that can be quite loose .. a 3/8ths bolt will easily go thru a 7/16ths hole

haha over precise? I have to do both sides, 8 ports. all holes must lines up pretty dang close. If i plan to ever sell these- how would i douplicate my messurements and procedures if im not as acurate as possible? Plus the overall aperaence must look good, and i plan on showing my boss this when im done, and hopfuly working a better position.

Originally Posted by Henderlong

Don't worry im not one of those spoiled rich kids

i was actually thinking you were a friend of MR wizzards .. he`s from your area also

Originally Posted by Henderlong

haha over precise? I have to do both sides, 8 ports. all holes must lines up pretty dang close. If i plan to ever sell these- how would i douplicate my messurements and procedures if im not as acurate as possible? Plus the overall aperaence must look good, and i plan on showing my boss this when im done, and hopfuly working a better position.

That's all well and good, precision is a much overlooked facet of building... But if you're doing this for production heads (and some of the offshore aftermarket knockoff junk) you'll need your bolt holes to be much less then precise to allow for casting shift, poor quality control, and other boo-boo's that make it necessary to adjust the flange to align with the ports, sometimes to the point of having to cut the flange between ports, move the tube around to "find" the port, then reconnect!!!!! Precision is good, but adjustability has got to be a consideration, too!

Have any of you heared of transfer screws. Transfer screws are hardened set screws with a point. Thread them into the tapped hole with a special tool place the header flange stock over the bolt pattern. Hit the flange with a hammer. You now have the desired bolt pattern. Drill a starter hole for the port then die grind to to match the cylinder head. The problem with this type of precision is that the dimensions change with temperature. Headers can get cherry red and the cylinder head doesen't get nearly that hot. The cylinder head has greater mass than the headers so they change temperature at different rates. The holes in the exhaust manifold or header flange are large to allow for this. If you are in school and have access to fancy tools ask your instructor about an inspection machine or ask how to take measurements using your milling machine.

herlong must of never used a set of header flange s from any u weld kits ? well most are junk .. i made my own up out of 3/8 cold roll and used the header gasket for lay out i made many as i did build headers for some time. lay them up on the mill stack two sets up at i time use a hole saw and ruffing mill to do the job . i buy them now for the sbc as a guy i know cuts them on a cnc .there are now many that sell just flanges so not a money maker

Any more just the cost of metal to do one set will be more $ than purchasing a set from Stainless Headers in MN. Now if a person was going to do 500 sets-----

Originally Posted by Louey

The name they go by is Transfer punch set. They vary in cost from 10 bucks up to almost 200. Depending on what you plan to use them on. I've used these for years in many things.
Most of the time, on header flanges, they only have one hole that is to the right size, called a locator hole. The rest are bigger to allow for mis-aligned holes, and heat expansion.
Example of transfer punch set.
http://www.harborfreight.com/28-piec...-set-3577.html

i still lay out two holes.then i have used long body pointed set screws for threaded transfer . laying out the hole and finding center some times work s better then just a transfer punch what bears on this is how thick the pattern is

I use the 3/8" flanges that Speedway and many other companies sell with their header kits.... Never had to do more then elongate a hole or two. Building headers is labor intensive enough without wasting a bunch of time building flanges!!!! I'm with Jerry, maybe if I needed 500 sets, but for only a 1 time deal???? On any unique engines or unusual tube requirement, I just get the appropriate header gasket and take it out to my pal Brian at Laser Cut.... Times gotta be worth something, or at least better spent on the rest of the car???

Of course you could do 8 individual ports--I always cut them anyway

Louey--the transfer screws are sort of like set screws with a hardened point that points out and is installed with the tool holder--they come 5 or 6 to a size inside the holder, I will try to find an example

Check McMaster
part number 3385a19

Originally Posted by jerry clayton

Of course you could do 8 individual ports--I always cut them anyway

Louey--the transfer screws are sort of like set screws with a hardened point that points out and is installed with the tool holder--they come 5 or 6 to a size inside the holder, I will try to find an example

Check McMaster
part number 3385a19

Transfer screws have threads to go in a threaded hole. Transfer punches are not threaded. Transfer punches would be used if you were using the exhaust manifold to get the header flange bolt pattern.

yep and all the big tube stuff can be slip fit so the flanges sometimes needs to be cut .when i made the flanges up i could cut them only were i needed keep getting things mixed up. if for a slip fit tube. if a 2.1/4 or 2.3/8 tube and all needed to be slip fit the i cut up the flange more .i try not to make any headers with to may slip fits and welded header collectors tig weld a L and R on them and welded the tabs on the collector on only one way things get mixed up after there all apart. learn that the hard way after a guy beat the hell out of a set i did a long time ago chevy ll with a bbc in it with 2 1/8 he called me after beating the $hit out of them to make them fit after i bent tabs back they fit