Posted By: lahatte
Cutters for porting cast iron heads? - 11/02/11 04:58 AM
Any good/bad experiences with cutting tools and sanding tools for porting on cast iron heads? What cutters have you found work weel? What styles? Thanks.
Cutters for porting cast iron heads?
Posted By: Cab_Burge
Re: Cutters for porting cast iron heads? - 11/02/11 05:05 AM
Quote:Carbide steel burrs, not regular steel
Any good/bad experiences with cutting tools and sanding tools for porting on cast iron heads? What cutters have you found work weel? What styles? Thanks.
Not cheap but they do last a long, long time compared to the standard steel buurs 
Posted By: BeEtLeJuIcE !
Re: Cutters for porting cast iron heads? - 11/02/11 05:10 AM
x2 on a carbide burr ... a carbide CUTTER will walk-around too EZ ..
Posted By: Twin Turbo Mower
Re: Cutters for porting cast iron heads? - 11/02/11 05:23 AM
Mondello sells good cutters. Many different shapes and sizes.
http://www.mondello.com/pages/toc_1.htm
http://www.mondello.com/pages/toc_1.htm
Posted By: dodgeboy11
Re: Cutters for porting cast iron heads? - 11/02/11 05:33 AM
http://www.ruffstuff.com/pages/carbide.html
I like the oval, shape E burrs. Double cut, 6" long in a variety of sizes. You can get by with just a 3/8", but a 1/2" speeds things up in the long straight stuff, and a 1/4" can make the fine tuning around the guide boss much easier. Those are the three sizes I recommend. Obviously do not start the burr unless it's against some material, do not free spin it (in other words, not have it against material when you're spinning it at speed). You'll want the walls to look straight and as smooth as the burr will get it before you ever touch it with a sanding roll. For cast iron I like 40 grit sanding rolls, but if you spin them too fast they tend to come unraveled. 60 grits hold up better but they don't remove material as fast. I like a combination of 40, 60 and 80 grit. When they start to leave black smears across the port, put a new one on. Trying to use up the whole roll makes for a frustrating port job.
Also, having a good grinder makes the job so much easier. The Suhner grinder (the expensive one) on the website I pasted in is pretty much the Mercedes of all porting grinders. Milwaukee makes one, but your forearms will feel it and they tend to be burr benders as they spin up immediately and only have one speed. Air grinders work, but you don't have as much control unless you get one of those long air grinders, which I have had no experience with.
Grind away!
One more thing! Have a spray bottle of light oil on hand. It'll make the burr last a lot longer. And have your shop vac ready to vacuum out the cuttings. A fan set to the side of the head blowing across it works pretty good to keep the dust out of your lungs and eyes.
I like the oval, shape E burrs. Double cut, 6" long in a variety of sizes. You can get by with just a 3/8", but a 1/2" speeds things up in the long straight stuff, and a 1/4" can make the fine tuning around the guide boss much easier. Those are the three sizes I recommend. Obviously do not start the burr unless it's against some material, do not free spin it (in other words, not have it against material when you're spinning it at speed). You'll want the walls to look straight and as smooth as the burr will get it before you ever touch it with a sanding roll. For cast iron I like 40 grit sanding rolls, but if you spin them too fast they tend to come unraveled. 60 grits hold up better but they don't remove material as fast. I like a combination of 40, 60 and 80 grit. When they start to leave black smears across the port, put a new one on. Trying to use up the whole roll makes for a frustrating port job.
Also, having a good grinder makes the job so much easier. The Suhner grinder (the expensive one) on the website I pasted in is pretty much the Mercedes of all porting grinders. Milwaukee makes one, but your forearms will feel it and they tend to be burr benders as they spin up immediately and only have one speed. Air grinders work, but you don't have as much control unless you get one of those long air grinders, which I have had no experience with.
Grind away!
One more thing! Have a spray bottle of light oil on hand. It'll make the burr last a lot longer. And have your shop vac ready to vacuum out the cuttings. A fan set to the side of the head blowing across it works pretty good to keep the dust out of your lungs and eyes.
Posted By: lahatte
Re: Cutters for porting cast iron heads? - 11/02/11 05:55 AM
Indeed. That metal dust is some tough stuff to breathe.
I'm curious, why do you not want to spin up the cutter before touching the surface?
Thanks.
I'm curious, why do you not want to spin up the cutter before touching the surface?
Thanks.
Posted By: tubtar
Re: Cutters for porting cast iron heads? - 11/02/11 02:26 PM
Quote:
Indeed. That metal dust is some tough stuff to breathe.
I'm curious, why do you not want to spin up the cutter before touching the surface?
Thanks.
Mask = a good idea. especially on exhaust ports of used heads.
You'll probably still have black snot with a mask , but your lungs will thank you.
I've always done cast iron dry.
Carbide likes coolant , but lubrication , not so much.
A spray bottle of water based machining coolant / lube would be my choice if I used anything.
On aluminum , a shot of silicone ( W.D. 40 or similar ) on the burr periodically really helps cut down on the aluminum in the flutes of your cutter...........they will load up quick even with the more open cutters designed for aluminum. W.D. really helps here.
Posted By: WILD BILL
Re: Cutters for porting cast iron heads? - 11/02/11 03:17 PM
Quote:
Indeed. That metal dust is some tough stuff to breathe.
I'm curious, why do you not want to spin up the cutter before touching the surface?
Thanks.
On a small shank cutter it's really not that big of a deal but when you get to a long shank to get down into the runners if you let it free spin it can and will bend over and "helicopter" right at the collet.
To much unsupported mass spinning at those speeds gets out of balance real quick. DAMHIK
Posted By: JohnRR
Re: Cutters for porting cast iron heads? - 11/02/11 04:15 PM
Quote:
On a small shank cutter it's really not that big of a deal but when you get to a long shank to get down into the runners if you let it free spin it can and will bend over and "helicopter" right at the collet.
To much unsupported mass spinning at those speeds gets out of balance real quick. DAMHIK
Done it myself ... doooh ...
Posted By: MR_P_BODY
Re: Cutters for porting cast iron heads? - 11/02/11 04:37 PM
Quote:Quote:
On a small shank cutter it's really not that big of a deal but when you get to a long shank to get down into the runners if you let it free spin it can and will bend over and "helicopter" right at the collet.
To much unsupported mass spinning at those speeds gets out of balance real quick. DAMHIK
Done it myself ... doooh ...
I have 2 12" long burrs and I made up a holder with
a bearing in it to hold the burr near the end... takes
2 hands to use the 12" cutters... I use to use a leather
glove to hold on to the shaft as close as possible
but it would get warm/hot on the glove
Posted By: mr_340
Re: Cutters for porting cast iron heads? - 11/02/11 06:22 PM
I don't like porting heads, but I put a piece of 3/8" fuel hose over the shank of my long carbide burr. I found it useful for using it as a guide to control the cutting end. 
If I port another set of heads, I'll try using my mill to do most of the work. I don't know how that will work out, but if I can figure out how to program a port, I wouldn't be doing the hand work as much.
If I port another set of heads, I'll try using my mill to do most of the work. I don't know how that will work out, but if I can figure out how to program a port, I wouldn't be doing the hand work as much.
Posted By: lahatte
Re: Cutters for porting cast iron heads? - 11/03/11 01:19 AM
I wouldn't have thought a cutter on a mere 6" shaft would bend like that, but I can believe it could happen.
Posted By: SteveA
Re: Cutters for porting cast iron heads? - 11/04/11 03:02 PM
Can anyone recommend a decent electric die grinder ? I won't use it much, just occasionally to clean up the ports, gasket match, or debur a block or two.
Posted By: Stanton
Re: Cutters for porting cast iron heads? - 11/04/11 05:21 PM
I used to use the Craftsman die grinder - back then it was the only reasonably priced one out there. Problem was it got too hot to handle after short use. Also, get one with variable speed ... you don't want to be doing everything at 25,000 rpm !! For minimal use maybe check out Harbor Freight !!
Posted By: Cab_Burge
Re: Cutters for porting cast iron heads? - 11/05/11 05:00 AM
Quote:Don't buy the newer electric Craftsman or Makita
Can anyone recommend a decent electric die grinder ? I won't use it much, just occasionally to clean up the ports, gasket match, or debur a block or two.
, the chuck sucks, they will hurt you. I like and use the little Harbor Frieght brand Central Pnumatic die grinders with the 1/4 chucks
Posted By: GTXX
Re: Cutters for porting cast iron heads? - 11/05/11 05:28 AM
Posted By: GTXX
Re: Cutters for porting cast iron heads? - 11/05/11 05:46 AM
Quote:
http://www.ruffstuff.com/pages/carbide.html
one of the best things on that site is one of the cheapest, a split mandrel. get a roll of 60 grit cloth and it will save you a ton of cash from all of the cartridge rolls that you won't need.
Posted By: lahatte
Re: Cutters for porting cast iron heads? - 11/05/11 06:16 AM
I suppose that if I have to spend $100 on cutters, I might as well send the heads to Muscle Motors and let them port and rebuild them?
Posted By: tubtar
Re: Cutters for porting cast iron heads? - 11/05/11 05:34 PM
Paying a pro is well worth the $$$ in my opinion.
I have done my own and had decent results by not going overboard.
It is hard to quantify because I also did some suspension changes.....it was an over the winter project that netted .15 on the E.T. , but what helped most is hard to say.
It picked up 3-4 m.p.h. in the eighth though , and that indicated motor over suspension I think.
I have an old Makita electric ( Japan ) and it is a war horse , but as production went over to the Red Menace , quality went south.
Same for Milwaukee , and probably every other tool maker.
If you are going to use it , buy quality.
If it is a one shot , buy junk.
I have done my own and had decent results by not going overboard.
It is hard to quantify because I also did some suspension changes.....it was an over the winter project that netted .15 on the E.T. , but what helped most is hard to say.
It picked up 3-4 m.p.h. in the eighth though , and that indicated motor over suspension I think.
I have an old Makita electric ( Japan ) and it is a war horse , but as production went over to the Red Menace , quality went south.
Same for Milwaukee , and probably every other tool maker.
If you are going to use it , buy quality.
If it is a one shot , buy junk.
Posted By: dodgeboy11
Re: Cutters for porting cast iron heads? - 11/06/11 06:15 AM
Quote:
I wouldn't have thought a cutter on a mere 6" shaft would bend like that, but I can believe it could happen.
Typically it's the sanding roll mandrel that'll bend. The rolls aren't exactly balanced well and if it comes out of the port at speed that puppy will go at a 90 degree angle right away. And if your face is anywhere near the port at the time...
Posted By: wildcargo
Re: Cutters for porting cast iron heads? - 11/06/11 03:28 PM
A simple foot switch that you plug the grinder in will make it a lot easyer. I allso use a variac to slow the grinder downbut don't slow it to much it might hurt the grinder
Posted By: GTXX
Re: Cutters for porting cast iron heads? - 11/06/11 05:34 PM
In the past I've bought a lot of 15-20 new assorted shape carbide burrs off of ebay for $20 or so. A couple were not straight but still usuable at low speed, overall it was a bargain.