The Ford Barn

gearheadbill · 04-05-2019, 12:54 PM

Looking at the pics you'll see a nipple fitting (one has a cover over it) on each side of the intake. What were/are these used for? Also notice that the paint is discolored. This area gets really hot.

51 MERC-CT · 04-05-2019, 01:00 PM

That is the heat source for the automatic choke. (when it had one)

gearheadbill · 04-05-2019, 01:27 PM

That hot, huh. OK, so capping them off is the way for me to go. I'm not going to take the intake off just to remove the fittings. Thank you!

tubman · 04-05-2019, 01:29 PM

I don't know if those are factory, since I have never had a later Mercury (post '51) engine for comparison. I notice the engine has a Rochester 2G carburetor which is obviously not stock. Whoever swapped the carb probably added them in an attempt to get the automatic choke (which most 2G's had) to work. Though it seems counter-intuitive, 2G's work best on these old Fords when mounted backwards. It looked like someone tried it the regular way first, then decided it would work best backwards and turned the carb around, thus the fittings on both sides. If you're lucky, they are probably tapped 1/8" NPT and can just be plugged, as they serve no purpose since the carburetor seems to have a manual choke on it now.

I run 2G's on a couple of engines and I think I can add a little to your knowledge base. The engine seems to be a '52 or '53 Merc ("EAC" heads). Even though the Merc manifold has larger throttle bores than a Ford manifold, they are still smaller than those on the carburetor. When I use a 2G on a Merc manifold, I have a fixture that allows me to bore the manifold to match the 2G throttle bore all the way down. I have seen them where the manifold was "bell-mouthed", which while not the ideal way to do it, is better than doing nothing. I have only done these conversions on the earlier Merc manifolds, and on those, the automatic choke linkage is easy as pie, both with the integral and "divorced" choke versions. I have no experience with the later manifolds so all I can say is that the manifold does not have the provisions for the choke stove like the earlier ones. If the choke works, you can probably use it. Normally, a manual choke pulls the wrong way, but it looks like whoever put it on made a new lever on the choke that works properly.

tubman · 04-05-2019, 01:32 PM

Quote:

Originally Posted by gearheadbill

That hot, huh. OK, so capping them off is the way for me to go. I'm not going to take the intake off just to remove the fittings. Thank you!

If you do cap them off with rubber caps like the onje that is already on there, keep an eye on them, as they are exposed to the exhaust gasses and may deteriorate quickly. Some thing metal would be better.

51 MERC-CT · 04-05-2019, 01:35 PM

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Quote:

Originally Posted by gearheadbill

That hot, huh. OK, so capping them off is the way for me to go. I'm not going to take the intake off just to remove the fittings. Thank you!

You don't have to remove the manifold to remove the fittings.
They are pressed in and with a little twisting and pulling they should come out.
Also suspect that the manifold is earlier than '53.
The rubber caps will not see exhaust gasses but will see heat.
( So long as the internal cross tube is intact and not leaking, the fittings do not have to be capped)

gearheadbill · 04-05-2019, 03:40 PM

Thanks for all this info. So...there is no need to cap these fitting off? If so, I'll just leave 'em. The heat has deteriorated the rubber plugs/caps already. I'll check for any leaking from the cross tube.

As to the intake/carb throttle bore mismatch, this particular engine has a manifold vacuum riser installed in which the ports are matching size to the carb. No interference or sticking open at WOT.

04-05-2019, 01:00 PM	#2
51 MERC-CT Senior Member Join Date: May 2010 Location: East Hartford, Ct Posts: 5,898	Re: 1953 intake manifold question That is the heat source for the automatic choke. (when it had one) __________________ DON'T RECALL DOING SOMETHING FOR MYSELF BASED ON SOMEONE ELSE'S LIKES OR DISLIKES Last edited by 51 MERC-CT; 04-05-2019 at 01:22 PM.

04-05-2019, 01:27 PM	#3
gearheadbill Senior Member Join Date: May 2010 Location: Snohomish, WA Posts: 401	Re: 1953 intake manifold question That hot, huh. OK, so capping them off is the way for me to go. I'm not going to take the intake off just to remove the fittings. Thank you!

04-05-2019, 01:29 PM	#4
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,303	Re: 1953 intake manifold question I don't know if those are factory, since I have never had a later Mercury (post '51) engine for comparison. I notice the engine has a Rochester 2G carburetor which is obviously not stock. Whoever swapped the carb probably added them in an attempt to get the automatic choke (which most 2G's had) to work. Though it seems counter-intuitive, 2G's work best on these old Fords when mounted backwards. It looked like someone tried it the regular way first, then decided it would work best backwards and turned the carb around, thus the fittings on both sides. If you're lucky, they are probably tapped 1/8" NPT and can just be plugged, as they serve no purpose since the carburetor seems to have a manual choke on it now. I run 2G's on a couple of engines and I think I can add a little to your knowledge base. The engine seems to be a '52 or '53 Merc ("EAC" heads). Even though the Merc manifold has larger throttle bores than a Ford manifold, they are still smaller than those on the carburetor. When I use a 2G on a Merc manifold, I have a fixture that allows me to bore the manifold to match the 2G throttle bore all the way down. I have seen them where the manifold was "bell-mouthed", which while not the ideal way to do it, is better than doing nothing. I have only done these conversions on the earlier Merc manifolds, and on those, the automatic choke linkage is easy as pie, both with the integral and "divorced" choke versions. I have no experience with the later manifolds so all I can say is that the manifold does not have the provisions for the choke stove like the earlier ones. If the choke works, you can probably use it. Normally, a manual choke pulls the wrong way, but it looks like whoever put it on made a new lever on the choke that works properly.

04-05-2019, 03:40 PM	#7
gearheadbill Senior Member Join Date: May 2010 Location: Snohomish, WA Posts: 401	Re: 1953 intake manifold question Thanks for all this info. So...there is no need to cap these fitting off? If so, I'll just leave 'em. The heat has deteriorated the rubber plugs/caps already. I'll check for any leaking from the cross tube. As to the intake/carb throttle bore mismatch, this particular engine has a manifold vacuum riser installed in which the ports are matching size to the carb. No interference or sticking open at WOT.