The Ford Barn

cmbrucew · 06-07-2018, 09:46 PM

Clearance for larger secondary throttle plates?
Bruce

Ol' Ron · 06-07-2018, 10:41 PM

The 4 bolt Merc intake throttle bores do not match the 2GC carb throttle bores. So I have an old 2GC base and I just bore the intake to match. This lets the engine get the full benefit of the carb. Besides the mis match would prevent the carb from operating right?? Some guys jur blend the bores in with a grinder. But???

gearheadbill · 06-08-2018, 12:52 AM

Thank you. That is what I figured you were referring to. Its another detail that will need my attention. The fellow I recently got the truck from complained that the throttle would 'stick open'.

tubman · 06-08-2018, 02:51 AM

I have done the same thing. Unless you have the proper equipment it is not a trivial task. I used something called a "Rotabroach" I got from an outfit called "Blair Equipment". I mounted it in my benchtop drill press and used an old 2G base bolted to the manifold as a guide. It worked pretty slick; I was able to enlarge the throttle bores all the way to the base of the plenum. I have done both aluminum (Canadian) and cast iron manifolds this way.

https://shop.blairequipment.com/Rota...SAAEgKIgfD_BwE

gearheadbill · 06-08-2018, 01:55 PM

Are these late 4 bolt 8BA intakes fairly available? Obviously I have the one that's on the truck now but swapping manifolds, having another manifold all ready to go before the tear down, would certainly speed up the process.

tubman · 06-08-2018, 02:06 PM

Sponsored Links (Register now to hide all advertisements)

They're really 8CM or 1CM, not 8BA. All Mercury's from '49-53 had them, so they're still around. I have seen iron ones on eBay in the $50 range. I think swap meets and wanted ads on the H.A.M.B. or here might get one cheaper. I'm always got an eye open for the aluminum version, but haven't seen one in years (I'm not looking real hard though as the weight difference is a little over 10 pounds). I think I paid $120 for the last one I bought. I did the aluminum one with my benchtop drill press and it wasn't bad. I did the last cast iron one on my new floor model drill press and it wasn't too difficult either. Just make sure you get it aligned correctly and clamped down real good. If you need the 2G base to use as a guide, let me know.

Ross F-1 · 06-08-2018, 04:26 PM

I was searching for a Merc manifold for a friend, getting tough to find one in either aluminum or c.i. that isn't roached at the gen mount, rusted to hell, or butchered.

I run my 2G without any grinding of the Merc manifold, no problems. I use two gaskets for heat isolation (aluminum manifold) and being a truck, I'm not winding it out to 5,000 RPM, so any flow benefit would be hard to find.

Kahuna · 06-08-2018, 06:33 PM

Thanks, 40 Deluxe.
Hard to convert/convince some people

Mfirth: You had a matched set

Barn Junk · 06-09-2018, 12:54 AM

Didn't some of the later aftermarket Stromberg 97s have a blended vacuum signal port designed for use with the Load-a-matic dist ?

Has anyone determined if they work effectively?

06-07-2018, 09:46 PM	#21
cmbrucew Senior Member Join Date: Dec 2010 Location: North of sandy ago, CA. Posts: 2,064	Re: 8BA loadamatic dist. with 2GC carb question Clearance for larger secondary throttle plates? Bruce __________________ Works good Lasts long time

06-07-2018, 10:41 PM	#22
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,860	Re: 8BA loadamatic dist. with 2GC carb question The 4 bolt Merc intake throttle bores do not match the 2GC carb throttle bores. So I have an old 2GC base and I just bore the intake to match. This lets the engine get the full benefit of the carb. Besides the mis match would prevent the carb from operating right?? Some guys jur blend the bores in with a grinder. But???

06-08-2018, 12:52 AM	#23
gearheadbill Senior Member Join Date: May 2010 Location: Snohomish, WA Posts: 401	Re: 8BA loadamatic dist. with 2GC carb question Thank you. That is what I figured you were referring to. Its another detail that will need my attention. The fellow I recently got the truck from complained that the throttle would 'stick open'.

06-08-2018, 02:51 AM	#24
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,316	Re: 8BA loadamatic dist. with 2GC carb question I have done the same thing. Unless you have the proper equipment it is not a trivial task. I used something called a "Rotabroach" I got from an outfit called "Blair Equipment". I mounted it in my benchtop drill press and used an old 2G base bolted to the manifold as a guide. It worked pretty slick; I was able to enlarge the throttle bores all the way to the base of the plenum. I have done both aluminum (Canadian) and cast iron manifolds this way. https://shop.blairequipment.com/Rota...SAAEgKIgfD_BwE

06-08-2018, 01:55 PM	#25
gearheadbill Senior Member Join Date: May 2010 Location: Snohomish, WA Posts: 401	Re: 8BA loadamatic dist. with 2GC carb question Are these late 4 bolt 8BA intakes fairly available? Obviously I have the one that's on the truck now but swapping manifolds, having another manifold all ready to go before the tear down, would certainly speed up the process.

06-08-2018, 02:06 PM	#26
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,316	Re: 8BA loadamatic dist. with 2GC carb question Sponsored Links (Register now to hide all advertisements) They're really 8CM or 1CM, not 8BA. All Mercury's from '49-53 had them, so they're still around. I have seen iron ones on eBay in the $50 range. I think swap meets and wanted ads on the H.A.M.B. or here might get one cheaper. I'm always got an eye open for the aluminum version, but haven't seen one in years (I'm not looking real hard though as the weight difference is a little over 10 pounds). I think I paid $120 for the last one I bought. I did the aluminum one with my benchtop drill press and it wasn't bad. I did the last cast iron one on my new floor model drill press and it wasn't too difficult either. Just make sure you get it aligned correctly and clamped down real good. If you need the 2G base to use as a guide, let me know.

06-08-2018, 04:26 PM	#27
Ross F-1 Senior Member Join Date: Nov 2010 Location: NM Posts: 2,438	Re: 8BA loadamatic dist. with 2GC carb question I was searching for a Merc manifold for a friend, getting tough to find one in either aluminum or c.i. that isn't roached at the gen mount, rusted to hell, or butchered. I run my 2G without any grinding of the Merc manifold, no problems. I use two gaskets for heat isolation (aluminum manifold) and being a truck, I'm not winding it out to 5,000 RPM, so any flow benefit would be hard to find. __________________ '52 F-1, EAB flathead

06-08-2018, 06:33 PM	#28
Kahuna Senior Member Join Date: May 2010 Location: NorCal Posts: 2,617	Re: 8BA loadamatic dist. with 2GC carb question Thanks, 40 Deluxe. Hard to convert/convince some people Mfirth: You had a matched set

06-09-2018, 12:54 AM	#29
Barn Junk Senior Member Join Date: May 2010 Location: WA state Posts: 771	Re: 8BA loadamatic dist. with 2GC carb question Didn't some of the later aftermarket Stromberg 97s have a blended vacuum signal port designed for use with the Load-a-matic dist ? Has anyone determined if they work effectively?