Blayze

70s carburetor questions

Recommended Posts

So I have an international scout 2. But when I picked it up, there was no carb. I spent a few hours at a junkyard and pulled one off of a 70s ford pickup (small v8 2wd auto, dont remember much else). The only markings on the carb are the "motorcraft" logo and the raised number "10".

In short, 15 year-old me grabbed the first carb that bolted up, and now 22 year-old me needs help with some vacuum port connections and the choke's temp tube. Here's what I got

 

Open vac port above the fuel intake (pic 1)

Open vac port below aircleaner housing (bypasses filter, pic 2)

 

And a large pledged vac port near the manifold (also pic 2. Although, if it's for the power booster, then mine comes directly from the manifold)

 

Choke temp tube (I think?, pic 3 screwdriver pointed to it)

 

Any help is appreciated. Thanks guys.

15448848157767633188542115123728.jpg

15448849718422393553199326853435.jpg

1544885078389601813427832258200.jpg

Share this post


Link to post
Share on other sites

Is the Scout currently running good with this carb?  You have a 2V version (2Bbl).  Are there any stampings/markings on the base of it where it bolts to the intake?

 

The fitting in Pic 3 (screwdriver pointing to) is your threaded choke tube connection for the tube coming off of the exhaust manifold.  That tube connected into the top of the exhaust manifold and had a brass female fitting that screwed into this port which fed hot air into the automatic choke housing which contains a wound spring that expands and compresses.  You don't necessarily need this hooked up for it to run.  The automatic choke assembly had a second tube that connected to the bottom of the exhaust manifold and ran parallel to the first tube and connected to the port that points down on the airhorn via a small vacuum hose.  The port is pictured in pic 2 and 3.  I'm not sure what the port next to the Motorcraft stamping is for.  The zinc colored port to the left of your screwdriver is probably the anti-stall dashpot.  Not sure where that would have gotten its vacuum from either.  Being that its not a Ford engine you could probably fabricate some choke tubes to work or you could install an electric choke on it.

 

Good luck and let us know how it goes.

 

Matt

 

Share this post


Link to post
Share on other sites
On 12/15/2018 at 6:51 AM, Blayze said:

Open vac port above the fuel intake (pic 1)

 

That's the bowl vent. On the Ford it would have been hooked into the evaporative emission controls (charcoal canister). Earlier setups just vented this to the atmosphere and had no hose fitting. Unless you have a similar place to hook it, leave it open.

 

On 12/15/2018 at 6:51 AM, Blayze said:

Open vac port below aircleaner housing (bypasses filter, pic 2)

 

This supplied filtered air to the choke stove. On the Ford, filtered air flowed out from here, through the choke stove, and then the heated air flowed back up to the choke housing. On some cars, the choke stove does not use filtered air like the Ford did. Either use this fitting the way it was intended, or plug it to avoid dirt getting around the air filter.

 

On 12/15/2018 at 6:51 AM, Blayze said:

 

And a large pledged vac port near the manifold (also pic 2. Although, if it's for the power booster, then mine comes directly from the manifold)

 

This might be PCV. If so, the passages inside and under the carb will distribute the incoming air evenly between the two barrels, in such a way that it mixes evenly with the fuel. WIth the carb removed, you should be able to see if this is what it is. Some (maybe most) Fords used a separate plate underneath the carb for a PCV port. Either way, the PCV valve should be connected to a port designed to mix the air evenly, not some random manifold port. Power brakes can connect anywhere.

 

On 12/15/2018 at 6:51 AM, Blayze said:

Choke temp tube (I think?, pic 3 screwdriver pointed to it) 

 

Yes, thats what it is. Hot air from a choke stove connects here. On Fords the choke stove was typically inside the right exhaust manifold, with two steel tubes. One (noted above) sent filtered cold air to the stove, the other one fed the heated air up to this port.

Edited by Bloo (see edit history)

Share this post


Link to post
Share on other sites

Thanks for your help guys. I'm going to try to fab up a choke stove and see if that'll work better (otherwise, I found an adapter kit to make it into a manual choke). I'll sum up what happened up to this moment for you (you might cringe).

 

Grabbed a carb from a junkyard on the sole reasoning that it was the only one I found that was a 2bbl that fit the bolt measurements to-a-tee. It fit, however, the gooseneck pushed the accelerator lever (the Holley 2210 has the lever on the side so this wouldn't happen) causing the truck to go full tilt. I ground down the lever arm so it would fit better and moved the hook to the back side of the set arm (on the butterfly mechanism by the throttle cable). Now you might've found a couple sins, but trust me... it gets worse.

 

Now, it's a good thing (is it though?) that jeep was the bastard child of ford and chevy, because the pressure valve (from the driver-side valve cover) plumbs directly into the jeep aircleaner housing (like the 80s impalas).

 

In short, it runs, but not well. It'll idle fine but it backfires on warmup, and starves itself on startup. If I drop it into gear, the slight drop of rpms stalls it without a little coaxing. I'll get more pics and a diagram soon.

Share this post


Link to post
Share on other sites

Kinda made a choke stove (I think) by running some steel line into the pre-heater shroud (pre-heater dosen't work anyway)

15452355921412035921302287981362.jpg

15452356239546783623226887724649.jpg

Share this post


Link to post
Share on other sites

I'm not sure. It's probably ported vacuum for the distributor. if it is, it will connect to a tiny pinhole next to a throttle plate. The port will be above the throttle at idle, and below the throttle as soon as you open it slightly.

 

If its already on the car you can check it with a vacuum gage. The distributor port will have noting at idle, and full vacuum as soon as you crack the throttle.

Share this post


Link to post
Share on other sites

Nice job fabricating those tube sets!  You can adjust the tension of the choke spring by turning the black dial to your desired liking.  How is it running?

 

Matt

Share this post


Link to post
Share on other sites

Thanks Matt. Still runs a little rough though. I think the springs on the jet screws are stopping them from closing just enough (back fires when I tap the throttle to I'm assuming it's running rich from that or has a major vacuum leak stopping the air from getting in properly). I'm gonna try and take them out to see if setting them in closer is gonna be better. It seems to idle pretty low as well but I need a temporary tac to see how fast it spins at idle.

Share this post


Link to post
Share on other sites

Well I feel dumb. I tried to move the vac advance to the hiding port (under the fuel pot) and plugged the other one up. Fired right up without the slightest of hesitation. No back fires, no stalls, and no rough idle. Thanks is for all the help though guys!

  • Like 2

Share this post


Link to post
Share on other sites

Thanks to all of you who have helped Blayze with this problem. If you have not done so, I would invite you to go to the International Harvester forums and look at the work this young man had put in to his Scout. He has worked very hard for a long time to bring his project back to life. It is wonderful to see a young person with his passion fulfilling his dream. Way to go, Blayze

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...