The Ford Barn

blk tudor · 04-04-2012, 10:44 AM

I know NGK BL-6 or B4-L plugs are what are used with aluminum heads, but there both 7/16 reach. Has anyone tried NGK B6HS their the same heat range as BL-6 and are 1/2 reach. I'm useing new Offy. 400 heads that I really don't want to fire spot. I saw just one ref. to this plug for this application. Thanks for any help! I don't have a high lift cam.

BillM · 04-04-2012, 01:43 PM

I made several measurements of my Offy heads and various plugs. The attachment shows the details. Its important to measure carefully as the exhaust valve is right under the plug; and there are different thicknesses in Offy heads.

blk tudor · 04-04-2012, 11:10 PM

Thanks for the info BillM. If I have these heads opened around the plugs does anyone know a machine shop in the s.e. Mich. area that knows flatheads? I know of several good auto engine machine shops that say they can do flatheads but they all specialize in other types of engines, GM LS etc,.

flathead4rd · 04-05-2012, 08:53 AM

Check out motorcityspeedequipment.com I know they aren't in Dundee anymore but may be able to refer you to who is doing their flatheads now. Mark kirby did my heads when he was still working and did what he called pocketing the spark plug holes. Maybe you can get some info there.

GOSFAST · 04-05-2012, 09:06 AM

Any decent machine shop with a Bridgeport and a "ball" mill should be able to handle that chore with ease!

We've been doing that procedure for decades now, really, it's simple!

You need to supply the plug you intend to use and nothing more.

Thanks Gary in N.Y.

P.S. Here's a shot of one setup in the mill being done by my son!

flathead4rd · 04-05-2012, 09:07 AM

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Quote:

Originally Posted by flathead4rd

Check out motorcityspeedequipment.com I know they aren't in Dundee anymore but may be able to refer you to who is doing their flatheads now. Mark kirby did my heads when he was still working and did what he called pocketing the spark plug holes. Maybe you can get some info there.

Update: Check out gollershotrods.com Evidently they have taken over the Motorcity Flathead business. They are in Defiance, Ohio

Ol' Ron · 04-05-2012, 10:50 AM

I countersink the threads with a 45 degree tool I do this from the combustion chamber side. I leave enough threads to use a 1/2 reach power tip plug. Have several of these running in customer engines.

blk tudor · 04-06-2012, 04:57 PM

Still can't find a shop! No one seems to know flathead Fords in Mich. Any Help! Rich.

russcc · 04-06-2012, 07:47 PM

Hi

Suggest taking the heads to a machine shop and tell them what you want, show them the photo, and give them the plugs. It a real simple operation, once it is setup.
You may have to call around to find a shop with a Bridgeport, instead of all the new CNC machines. There is plenty of those vertical milling machines around. Actually call WT Tool in Warren Michigan. They are a machine shop supplier, and can tell you who has what, and who to call.

quickchange34 · 04-06-2012, 10:31 PM

To unsroud the plugs it needs to be done with a mill,if you want to do it right. Find a shop with one and take them the plugs.

JWL · 04-07-2012, 06:36 AM

Aw bull----. Buy yourself a countersink cutter, turn the heads upside down, turn on your hand-held 1/2" drill and start cutting from the combustion chamber side. Frequently screw a plug in to the hole, you are working on, to gauge your cutting depth. You do not want any threads on the plug body exposed, in the chamber, nor do you want excess threads showing in the head. Keep playing with your depths until you get them perfect.

Vergil · 04-07-2012, 08:15 PM

I knocked the porcelain from a spark plug of the brand I was going to use, drilled out the hole to fit a cutter I had and used to center the cutter while removing the threads in Off 400 heads. Screwed the modified plug into the head and used cutter to cut the exposed threads down to the spark plug, then rounded of the sharp edges. Other ways to do it but used what I had.

Vergil

Capn John · 04-08-2012, 01:14 AM

Vergil,
What did you use to polish the combustion chamber???
Thanks,
John

Ol' Ron · 04-08-2012, 09:23 AM

It's nice to see how complicated we can make a simple job. Good job Vergil

blk tudor · 04-08-2012, 03:21 PM

I like that idea. Thanks Vergil!

Vergil · 04-08-2012, 04:41 PM

Quote:

Originally Posted by Capn John

Vergil,

Quote:

Originally Posted by Capn John

What did you use to polish the combustion chamber???
Thanks,
John

I used the small flat sanding disks and scotch brite type flat disks ..

Thanks Ron and blk tudor

Vergil

JWL · 04-09-2012, 05:52 AM

If you use a chamfering cutter there is no need for a pilot. It will be self-centering and make the job doable by the least experienced enthusiast.

04-04-2012, 10:44 AM	#1
blk tudor Junior Member Join Date: Aug 2011 Location: Brighton Michigan Posts: 14	Offy. head spark plugs I know NGK BL-6 or B4-L plugs are what are used with aluminum heads, but there both 7/16 reach. Has anyone tried NGK B6HS their the same heat range as BL-6 and are 1/2 reach. I'm useing new Offy. 400 heads that I really don't want to fire spot. I saw just one ref. to this plug for this application. Thanks for any help! I don't have a high lift cam.

04-04-2012, 11:10 PM	#3
blk tudor Junior Member Join Date: Aug 2011 Location: Brighton Michigan Posts: 14	Re: Offy. head spark plugs Thanks for the info BillM. If I have these heads opened around the plugs does anyone know a machine shop in the s.e. Mich. area that knows flatheads? I know of several good auto engine machine shops that say they can do flatheads but they all specialize in other types of engines, GM LS etc,.

04-05-2012, 08:53 AM	#4
flathead4rd Senior Member Join Date: May 2010 Location: Michigan Posts: 512	Re: Offy. head spark plugs Check out motorcityspeedequipment.com I know they aren't in Dundee anymore but may be able to refer you to who is doing their flatheads now. Mark kirby did my heads when he was still working and did what he called pocketing the spark plug holes. Maybe you can get some info there.

04-05-2012, 09:06 AM	#5
GOSFAST Senior Member Join Date: May 2010 Location: Long Island, NY Posts: 1,052	Re: Offy. head spark plugs Any decent machine shop with a Bridgeport and a "ball" mill should be able to handle that chore with ease! We've been doing that procedure for decades now, really, it's simple! You need to supply the plug you intend to use and nothing more. Thanks Gary in N.Y. P.S. Here's a shot of one setup in the mill being done by my son!

04-05-2012, 10:50 AM	#7
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,919	Re: Offy. head spark plugs I countersink the threads with a 45 degree tool I do this from the combustion chamber side. I leave enough threads to use a 1/2 reach power tip plug. Have several of these running in customer engines.

04-06-2012, 04:57 PM	#8
blk tudor Junior Member Join Date: Aug 2011 Location: Brighton Michigan Posts: 14	Re: Offy. head spark plugs Still can't find a shop! No one seems to know flathead Fords in Mich. Any Help! Rich.

04-06-2012, 07:47 PM	#9
russcc Senior Member Join Date: May 2010 Posts: 2,871	Re: Offy. head spark plugs Hi Suggest taking the heads to a machine shop and tell them what you want, show them the photo, and give them the plugs. It a real simple operation, once it is setup. You may have to call around to find a shop with a Bridgeport, instead of all the new CNC machines. There is plenty of those vertical milling machines around. Actually call WT Tool in Warren Michigan. They are a machine shop supplier, and can tell you who has what, and who to call.

04-06-2012, 10:31 PM	#10
quickchange34 Senior Member Join Date: May 2010 Location: charlottesville, Va. Posts: 589	Re: Offy. head spark plugs To unsroud the plugs it needs to be done with a mill,if you want to do it right. Find a shop with one and take them the plugs.

04-07-2012, 06:36 AM	#11
JWL Member Emeritus Join Date: May 2010 Location: Fitzgerald, Georgia Posts: 2,204	Re: Offy. head spark plugs Aw bull----. Buy yourself a countersink cutter, turn the heads upside down, turn on your hand-held 1/2" drill and start cutting from the combustion chamber side. Frequently screw a plug in to the hole, you are working on, to gauge your cutting depth. You do not want any threads on the plug body exposed, in the chamber, nor do you want excess threads showing in the head. Keep playing with your depths until you get them perfect.

04-07-2012, 08:15 PM	#12
Vergil Senior Member Join Date: May 2010 Location: Tehachapi, CA Posts: 361	Re: Offy. head spark plugs I knocked the porcelain from a spark plug of the brand I was going to use, drilled out the hole to fit a cutter I had and used to center the cutter while removing the threads in Off 400 heads. Screwed the modified plug into the head and used cutter to cut the exposed threads down to the spark plug, then rounded of the sharp edges. Other ways to do it but used what I had. Vergil __________________ Bigger fonts to aid in reading

04-08-2012, 01:14 AM	#13
Capn John Senior Member Join Date: May 2010 Location: BIRTHPLACE OF SPEED, FLORIDA Posts: 531	Re: Offy. head spark plugs Vergil, What did you use to polish the combustion chamber??? Thanks, John

04-08-2012, 09:23 AM	#14
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,919	Re: Offy. head spark plugs It's nice to see how complicated we can make a simple job. Good job Vergil

04-08-2012, 03:21 PM	#15
blk tudor Junior Member Join Date: Aug 2011 Location: Brighton Michigan Posts: 14	Re: Offy. head spark plugs I like that idea. Thanks Vergil!

04-09-2012, 05:52 AM	#17
JWL Member Emeritus Join Date: May 2010 Location: Fitzgerald, Georgia Posts: 2,204	Re: Offy. head spark plugs If you use a chamfering cutter there is no need for a pilot. It will be self-centering and make the job doable by the least experienced enthusiast.