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View Full Version : Small block chevy Mill table jigs?? Looks like?



Dawai
02-26-2009, 08:56 AM
Looks like?? I been thinking perhaps to jig off the ends where the acc bolts are.. aren't they mostly in the same places? perhaps some leveling bolts and tie down bolts to the T-slots?

Doing simple regrinds.. I got five sets or more to play with..

Jack F
02-26-2009, 12:59 PM
Hi David,
Sounds like you plan to mill some chev. heads? Do you plan to cut the ends off chev. heads to be used in the jig? I made a jig for my pontiac heads to mill them on the Comet 3KV vert. mill. I would be interested in seeing your set up when done to see where I might improve mine.

Jack.

Jack F
02-26-2009, 04:27 PM
Hi David,
Ignore the sentence in the previous post where I asked you about cutting up the chev. heads. I re read your post and it looks like you just want to use the bolt holes at the end of the heads to mount the jig. Thats what I did on my pontiac heads and it works fine. I did have to shim up one end of my jig to get the head level to the table in the X axis then used leveling bolts to get the head level to the Y axis. I made a practice cut on a cracked head to try it out and it was solid as a rock. I used a 5" face mill with carbide inserts and had to make two passes to cover the full width of the head and I noticed I need to tram my head before I do a real head but I think .0005 thou difference between the two cuts might be acceptable. What do you think?

Jack.

madman
02-26-2009, 07:41 PM
I got a Homemade adjustable to 8 inch diameter flycutter. Man does it cut SWEET. Too bad im too stupid to send pics with my new 10 meg camera. NOW are you going to face these Heads? Make sure they are clamped in a boltted down stressed condition just like on a block cause i did one and it was bowed like a banana BUT being a enthusiastic guy just kept Milling it( LOL Im still laughing) till it was flat. WOW was it ever warped when ubolted from the block. Now when i took it of my aluminumn angle plate i realized i kinda messed it up, Due to the severe bow and machining to clean up i sure took off material ,Anyhow you get the picture. Good Luck Mike

bob308
02-26-2009, 08:37 PM
i used a bar 1 1/4" dia. 6" longer then the head that way 3" sticks out on each end. mill a 1/2" flat. and drill it to bolt to the exhaust side of the head. then you make 2 stands for the bar to set in that hold the head off the table so it can be rotated and calmped. with this set up you can mill them flat or shim up the intake side and angle mill them. also use the same bar to correct the intake side after angle milling.

i would not use the acc. holes in the ends of the heads as they are not the same from head to head. and some heads don't even have them.

Willy
02-26-2009, 11:04 PM
Here's a video showing a setup much like the one bob308 descibed.

http://www.youtube.com/watch?v=m1I_ds3ow5s

Jack F
02-27-2009, 12:37 AM
Bob 308 or Willy,
I like the idea of using the exhaust flange for mounting but how do you adjust in the X axis for those holes maybe not drilled the same from one end to the other. Do you have to shim?

JoeFin
02-27-2009, 01:20 AM
I've done OverHead Cam Heads before using the cam bearing caps mateing surface - worked really well. But then again I used the surface grinder rather then a mill

A.K. Boomer
02-27-2009, 08:13 AM
Iv done a few Subaru heads on my mill and also some in line 4 toyo's and houndawgs, most of my milling has to do with removing enough material to take care of what the steel head gasket ring does to the aluminum head, upon heating and cooling cycles it frets a recess into the head and I end up taking whatever material I need down to clean this up --- Like jack stated I have to take two passes at it but with the proper head tram its well within deviation specs --- I also have the entire head gasket surface done with one swath and just match the other area's to it.

For all these heads either the cam flats or even the valve cover mating surface (both are the same plane) can be utilized for these little OHC engines

asallwey
02-27-2009, 10:06 AM
We have one of these fixtures from Goodson at school, works good.

VM-42 Vertical Mill Roll Over Fixture
http://www.goodson.com/store/template/product_detail.php?IID=2957&SID=773e10113d18f29772064314e88c21f6

You mount the head using clamps, valve cover side down, on a platform. The platform can go up/down on either end, and rotate, allowing you to achieve any angle you need.

Alex