Going from "small log" to "large log" intake head issue

67drewstang

67drewstang

Well-known member
So, as I've posted in my build thread, I have purchased a 1980 head that has been milled, ported and a new valvetrain installed to put on my 1967 small log engine.

viewtopic.php?f=1&t=71441

I am going from an Autolite 1100 to a 1200 with a manual choke, and am wondering what to do with all the additional holes in the new manifold. My old manifold has one small hole on the side next to the carb, with a pipe leading up into the carb. The new manifold has a hole atop the manifold and a milled bit next to the carb mounting pad on the side which has two threaded holes and an unthreaded hole.

What I'd like to know is a) is it necessary to mount something there, and b) if not, what's the best way to plug it off?

Drew
 
Howdy Drew:

I don't recognise a 1200 carb? Did you mean an 1101?

As far as the taps on the log just plug them and seal the pipe threads of the threaded hole and make a cover for the rectangular one under the carb. You can make a gasket to seal that one, or just swab the mating surface with gasket sealant.

I don't recall your carb plans, but most likely you'll need a ported vacuum source for it.

Keep it coming.

Adios, David
 
CZLN6":39ayxvw7 said:
Howdy Drew:

I don't recognise a 1200 carb? Did you mean an 1101?

As far as the taps on the log just plug them and seal the pipe threads of the threaded hole and make a cover for the rectangular one under the carb. You can make a gasket to seal that one, or just swab the mating surface with gasket sealant.

I don't recall your carb plans, but most likely you'll need a ported vacuum source for it.

Keep it coming.

Adios, David
Click to expand...
It might be a 1250. They came on the 223/240 series of sixes, I am told. It's also identical to an 1100 with a slightly larger venturi/barrel. I've found one schematic on it, in the appendix of an an omnibus 1100/1101/1250 manual and it looks exactly like the 1100.

Thank you for the advice. I also assumed I'd need to port vacuum to it, so will plug the other holes as you advise.

Drew
 
2100?
Does it have 4 "holes" or 'Barrels", throats?
Does it have 2? The venturis for the atomozation of the fuel?
 
That would be a 1101, but with an early one like you have you need to watch for SCV/distributor mismatch. I think you said you are running a DSII which will not match well with the SCV on the early carburetor. If your carb has a SCV you will need to use manifold vacuum, or get a later carburetor (the 1101 off a 69 Mustang with 250 doesn't have a SCV and works well).
 
Dont worry about hooking up a Vacuum advance its a MPG thing and worth 1-3 mpg tops The Duraspark is a Great Dist , get the advance curve redone , worry about a more modern carb later if you want the most for money spent
 
CZLN6":1yy71ktm said:
Howdy Drew:

I don't recognise a 1200 carb? Did you mean an 1101?

As far as the taps on the log just plug them and seal the pipe threads of the threaded hole and make a cover for the rectangular one under the carb. You can make a gasket to seal that one, or just swab the mating surface with gasket sealant.

I don't recall your carb plans, but most likely you'll need a ported vacuum source for it.

Keep it coming.

Adios, David
Click to expand...

he is probably referring to the autolite 1250 which came on 71-73 pintos, bobcats, and capris with the 1.6 liter kent engine.
 
Econoline":1x6o1p2d said:
Hope not, that sounds small.
Click to expand...

actually i believe they are basically the same carb, just with some updates. remember that the 1.6 kent engine was fords early performance four cylinder engine in europe, and was used in many spec racing series, like formula ford.
 
I don't know anything about the 1250, I'm not a fan of the 1100. If it's a 1 barrel made for a 98 ci motor, how big is the venturi and throttle bore?
 
Econoline":3me63nfe said:
I don't know anything about the 1250, I'm not a fan of the 1100. If it's a 1 barrel made for a 98 ci motor, how big is the venturi and throttle bore?
Click to expand...

as near as i can tell the 1250 is just another evolution of the original 1100 autolite. venturi sizes are likely the same, just tuning differences for jetting, accelerator pumps, etc for the smaller engine. and remember that the one barrel carb used on the 144 didnt change much until the advent of the large log head. dont judge a carb based on what engine it is put on.
 
I'm not. I have one in my econoline ;) If it was used only in the 1.6 engine wouldn't it be the smaller venturi model?
 
Econoline":hsde8dyn said:
I'm not. I have one in my econoline ;) If it was used only in the 1.6 engine wouldn't it be the smaller venturi model?
Click to expand...

not necessarily.
 
mustang6":21l88tqn said:
That would be a 1101, but with an early one like you have you need to watch for SCV/distributor mismatch. I think you said you are running a DSII which will not match well with the SCV on the early carburetor. If your carb has a SCV you will need to use manifold vacuum, or get a later carburetor (the 1101 off a 69 Mustang with 250 doesn't have a SCV and works well).
Click to expand...

I'm currently running an 1100 with a DSII right now, and I cannot understand why the mismatch matters.

The car makes excellent power and good economy, mismatch or no.

Drew
 
67drewstang":3akqfnol said:
One more issue:

My head gasket doesn't appear to match the head. Here is a picture of the head gasket on the head:

https://fbcdn-sphotos-g-a.akamaihd.net/ ... 6349_n.jpg

Here is a picture of the head:

https://fbcdn-sphotos-h-a.akamaihd.net/ ... 9316_n.jpg

Note that the triangular shaped galleries in the head are not all reproduced on the head gasket. Is this important?
Click to expand...

they match up fine. remember that these days gasket manufacturers are making gaskets as close to universal as possible. also some holes in the gasket are made smaller on purpose for use as steam holes rather than full on coolant passages, but the hole in the block and head are made larger to make it easier to eliminate casting sand.
 
rbohm":extevu0m said:
they match up fine. remember that these days gasket manufacturers are making gaskets as close to universal as possible. also some holes in the gasket are made smaller on purpose for use as steam holes rather than full on coolant passages, but the hole in the block and head are made larger to make it easier to eliminate casting sand.
Click to expand...

Thanks for that. I feel better, now.

I had ordered a Felpro kit, when I stumbled on a Victor-Reinz locally for $20. I seemed to recall it is closer to the original .025 than the Felpro so I snapped it up.

Drew
 
67drewstang":3jn08y24 said:
rbohm":3jn08y24 said:
they match up fine. remember that these days gasket manufacturers are making gaskets as close to universal as possible. also some holes in the gasket are made smaller on purpose for use as steam holes rather than full on coolant passages, but the hole in the block and head are made larger to make it easier to eliminate casting sand.
Click to expand...

Thanks for that. I feel better, now.

I had ordered a Felpro kit, when I stumbled on a Victor-Reinz locally for $20. I seemed to recall it is closer to the original .025 than the Felpro so I snapped it up.

Drew
Click to expand...

good choice. as much as i like the felpro gaskets, i think the victor is a little bit better. (y)
 
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