1984 Bronco build thread

[StraightSix]

There is a tiny amount of vacuum present to draw air through the choke stove.

The carb will be tuned to run with this 'leak' just like it's tuned to run with the PCV.

But you don't want cold air drawn into the choke coil, so you should cap/plug it.

If anyone ever wondered, this part number will plug the o2 holes in the efi exhaust manifolds

- 4936K929, mcmaster carr

And a 3/4 pipe plug from the plumbing section (sorry, no pn) will plug the EGR hole after you remove the bung.

The threaded bolt holes on the manifold flanges are 7/16-14, which ACE doesnt carry. Hopefully I can find some today.

Hoping to get the better part of the exhaust welded up today, and maybe even do some of the installation work inside the engine bay.

[Gary Lewis]

If anyone ever wondered, this part number will plug the o2 holes in the efi exhaust manifolds

- 4936K929, mcmaster carr

And a 3/4 pipe plug from the plumbing section (sorry, no pn) will plug the EGR hole after you remove the bung.

The threaded bolt holes on the manifold flanges are 7/16-14, which ACE doesnt carry. Hopefully I can find some today.

Hoping to get the better part of the exhaust welded up today, and maybe even do some of the installation work inside the engine bay.

Good info. The McMaster Carr catalog says that 4936K929 is a "Compact Extreme-Pressure Steel Pipe Fitting, Plug with Hex Drive, M18 x 1.5 mm Male Thread".

Thanks!

[StraightSix]

Good info. The McMaster Carr catalog says that 4936K929 is a "Compact Extreme-Pressure Steel Pipe Fitting, Plug with Hex Drive, M18 x 1.5 mm Male Thread".

Thanks!

 

Hey everyone,

I haven’t posted in a few days because most of the stuff Ive done has felt pretty mundane. mostly hoses, band clamps, cleaning stuff up here and there, etc. however there may be some useful part numbers or notes for anyone following along in the future.

I tapped all of the manifold bolt holes in my head (3/8-16), applied never seize, and installed my studs.

I attempted to weld the exhaust system with a walker WLK-21910. It’s a rectangular muffler with offset inlet and outlet. It does fit (tightly) between the driveshaft and the frame rail, but I couldn’t get the collector pipe to line up and bolt up with the exhaust manifolds because of the offset in the muffler. Someone with much more welding skill could have probably done it, maybe with some additional fittings. I elected to order a round muffler that is more similar in form to the stock muffler. I ordered a walker 21151. It should be here today. As a matter of interest, Walker also makes extensions with a female end that has a 2.5” ID and a male end with a 2.5” OD. These have been handy for sure. That PN is Walker 53539. With any luck the exhaust will finally be finished up tonight.

I decided to run new wires for the battery->block ground (on my truck the ground lands on one of the bolts that holds the starter into the bell housing) as well as the starter wire. Both were severely fouled by the new collector pipe (which is the walker 45166). I ran both as size 4 with copper crimp on terminals. The block ground needs a 3/8 diameter hole in the ring terminal while the starter wire needs a smaller one (1/4” maybe??).

I am getting rid of the stock steel fuel line that comes up from the pump, over the valve cover and then threads into the carb. Im replacing it with 5/16 fuel hose. The fitting for the fuel pump discharge needs to be a ½-20 inverted flare to a 5/16 hose barb. I ordered this part – edelmann 821550. Summit says this part has 5/16 thread, but that is incorrect. This part does have ½-20 thread.

After a lot of thought (and some work unfortunately) Ive decided to prematurely dump my water heat spacer in favor of a plate under the intake like everyone else uses. I don’t feel confident that the spacer will accomplish the goal of heating the bottom of the intake. With that being said, these are the part numbers Im using to adapt my Offenhauser C to my 2150. These parts fit correctly and seal everything up including the bottom of the carburetor. Fel-Pro 60529, transdapt 2065. The transdapt will not seal the bottom of a 2150, an additional spacer is required. Ill also be using this air cleaner – SUM-G30010B. it’s a 14”x3” air filter. I selected it based on cost, I cant imagine all the chrome would have made it “go faster”. The rod and wing nut it came with are complete garbage though. I went to ace, bought a 6” ¼-20 rod and new wing nut, cur rod to length and that is what Ill be using instead. This whole assembly fits handily under the hood, might have even gotten away with more air filter height.

After reading about others having problems getting the efi exhaust and offy intake to fit together I decided to lay mine on the concrete in my garage and see if interference seemed likely. It did. The front runner on the rear exh manifold seemed to be about a hairs width away from contacting the intake. Keep in mind this is all approximate because I was laying on the floor trying to line everything up until it looked right. I ended up doing some grinding on that exh runner to improve clearance.

!

Finally, the throttle bracket. I mocked up the intake and carb last night to see what I needed to do for a throttle bracket. I didn’t take pictures, but I will take some when I get a chance. Basically, my plan is to butcher the factor throttle bracket and then make an addition bracket that will hold it in place and provide a location for a throttle return spring. My plan is to attach the throttle bracket to the intake manifold using the two thru holes for the water heat plate. From there, it will run forwards to the radiator before bending 90 deg up for an attachment point for a throttle return spring. From the mounting holes, it will run a few inches back and provide a location to bolt in the butchered original throttle bracket.

Im optimistic that it will idle in the drive way by tomorrow night, and may be road worthy early next week. Ill keep you all posted.

[ArdWrknTrk]

 

Hey everyone,

I haven’t posted in a few days because most of the stuff Ive done has felt pretty mundane. mostly hoses, band clamps, cleaning stuff up here and there, etc. however there may be some useful part numbers or notes for anyone following along in the future.

I tapped all of the manifold bolt holes in my head (3/8-16), applied never seize, and installed my studs.

I attempted to weld the exhaust system with a walker WLK-21910. It’s a rectangular muffler with offset inlet and outlet. It does fit (tightly) between the driveshaft and the frame rail, but I couldn’t get the collector pipe to line up and bolt up with the exhaust manifolds because of the offset in the muffler. Someone with much more welding skill could have probably done it, maybe with some additional fittings. I elected to order a round muffler that is more similar in form to the stock muffler. I ordered a walker 21151. It should be here today. As a matter of interest, Walker also makes extensions with a female end that has a 2.5” ID and a male end with a 2.5” OD. These have been handy for sure. That PN is Walker 53539. With any luck the exhaust will finally be finished up tonight.

I decided to run new wires for the battery->block ground (on my truck the ground lands on one of the bolts that holds the starter into the bell housing) as well as the starter wire. Both were severely fouled by the new collector pipe (which is the walker 45166). I ran both as size 4 with copper crimp on terminals. The block ground needs a 3/8 diameter hole in the ring terminal while the starter wire needs a smaller one (1/4” maybe??).

I am getting rid of the stock steel fuel line that comes up from the pump, over the valve cover and then threads into the carb. Im replacing it with 5/16 fuel hose. The fitting for the fuel pump discharge needs to be a ½-20 inverted flare to a 5/16 hose barb. I ordered this part – edelmann 821550. Summit says this part has 5/16 thread, but that is incorrect. This part does have ½-20 thread.

After a lot of thought (and some work unfortunately) Ive decided to prematurely dump my water heat spacer in favor of a plate under the intake like everyone else uses. I don’t feel confident that the spacer will accomplish the goal of heating the bottom of the intake. With that being said, these are the part numbers Im using to adapt my Offenhauser C to my 2150. These parts fit correctly and seal everything up including the bottom of the carburetor. Fel-Pro 60529, transdapt 2065. The transdapt will not seal the bottom of a 2150, an additional spacer is required. Ill also be using this air cleaner – SUM-G30010B. it’s a 14”x3” air filter. I selected it based on cost, I cant imagine all the chrome would have made it “go faster”. The rod and wing nut it came with are complete garbage though. I went to ace, bought a 6” ¼-20 rod and new wing nut, cur rod to length and that is what Ill be using instead. This whole assembly fits handily under the hood, might have even gotten away with more air filter height.

After reading about others having problems getting the efi exhaust and offy intake to fit together I decided to lay mine on the concrete in my garage and see if interference seemed likely. It did. The front runner on the rear exh manifold seemed to be about a hairs width away from contacting the intake. Keep in mind this is all approximate because I was laying on the floor trying to line everything up until it looked right. I ended up doing some grinding on that exh runner to improve clearance.

!

Finally, the throttle bracket. I mocked up the intake and carb last night to see what I needed to do for a throttle bracket. I didn’t take pictures, but I will take some when I get a chance. Basically, my plan is to butcher the factor throttle bracket and then make an addition bracket that will hold it in place and provide a location for a throttle return spring. My plan is to attach the throttle bracket to the intake manifold using the two thru holes for the water heat plate. From there, it will run forwards to the radiator before bending 90 deg up for an attachment point for a throttle return spring. From the mounting holes, it will run a few inches back and provide a location to bolt in the butchered original throttle bracket.

Im optimistic that it will idle in the drive way by tomorrow night, and may be road worthy early next week. Ill keep you all posted.

You've got a fantastic amount accomplished!

Congratulations.

I'm sure you're excited to hear it run.

[Gary Lewis]

You've got a fantastic amount accomplished!

Congratulations.

I'm sure you're excited to hear it run.

Wow! That's a lot of work. Well done!

Here's hoping that it is purring in the driveway tomorrow night.

[StraightSix]

Wow! That's a lot of work. Well done!

Here's hoping that it is purring in the driveway tomorrow night.

Gary and Jim,

Thanks! I cant wait! This whole time Ive been worried about getting done in time for my trip and Ive only recently stopped to consider that this thing is going to drive like a different truck when I get done! Im looking forward to it for sure! Ive owned other ford trucks in the past (put 150k on a 95 f150 w/ the 302 in high school and college, briefly owned a 1990 bronco w/351 Windsor) and have a fair deal of home auto repair experience just keeping those on the road. However this is really the beginning of me making proactive improvements, upgrades, or generally putting things back together in non-stock configuration. Its been an awesome learning experience. Im really looking forward to having a simple, reliable “no nonsense” drive train with better torque, power, and fuel economy to boot. Im eager to see how the fuel economy works out in the end. I know others with similar set ups have achieved 15-16 mpg on the highway or better on occasion. Fingers crossed! Im sure my 3.55 gears and lack of an OD gear wont help.

Buyer beware! Ive lead you astray! The walker 21151 muffler has a 2.5” OD outlet, while the walker tail pipe has a 2.25” OD inlet. And so Mr. Bezos makes another buck. The reducer will be here Saturday. Otherwise the muffler looks like its going to fit great and not cause any heartache.

I went over to my uncles house and did some work last night

Im not sure if the throttle bracket “makes sense” to all of you yet, but Ill be sure to post pictures once it is fully installed. The blue plate is for my intake manifold water heat spacer. I should be able to get the plate drilled and tapped to ½ npt and install my 1/2npt -> 5/8 hosed barb fittings tonight. With any luck, Ill have everything completely ready for the installation of the manifolds and carb tonight. The welds may not even be cool on the exhaust by the time its running!

[Gary Lewis]

Gary and Jim,

Thanks! I cant wait! This whole time Ive been worried about getting done in time for my trip and Ive only recently stopped to consider that this thing is going to drive like a different truck when I get done! Im looking forward to it for sure! Ive owned other ford trucks in the past (put 150k on a 95 f150 w/ the 302 in high school and college, briefly owned a 1990 bronco w/351 Windsor) and have a fair deal of home auto repair experience just keeping those on the road. However this is really the beginning of me making proactive improvements, upgrades, or generally putting things back together in non-stock configuration. Its been an awesome learning experience. Im really looking forward to having a simple, reliable “no nonsense” drive train with better torque, power, and fuel economy to boot. Im eager to see how the fuel economy works out in the end. I know others with similar set ups have achieved 15-16 mpg on the highway or better on occasion. Fingers crossed! Im sure my 3.55 gears and lack of an OD gear wont help.

Buyer beware! Ive lead you astray! The walker 21151 muffler has a 2.5” OD outlet, while the walker tail pipe has a 2.25” OD inlet. And so Mr. Bezos makes another buck. The reducer will be here Saturday. Otherwise the muffler looks like its going to fit great and not cause any heartache.

I went over to my uncles house and did some work last night

Im not sure if the throttle bracket “makes sense” to all of you yet, but Ill be sure to post pictures once it is fully installed. The blue plate is for my intake manifold water heat spacer. I should be able to get the plate drilled and tapped to ½ npt and install my 1/2npt -> 5/8 hosed barb fittings tonight. With any luck, Ill have everything completely ready for the installation of the manifolds and carb tonight. The welds may not even be cool on the exhaust by the time its running!

You are right, I've not "twigged", as the Brit's say, to how the throttle bracket works, but I'll wait on the later pics. You keep on keeping on and soon you'll be truckin'!

[ArdWrknTrk]

Gary and Jim,

Thanks! I cant wait! This whole time Ive been worried about getting done in time for my trip and Ive only recently stopped to consider that this thing is going to drive like a different truck when I get done! Im looking forward to it for sure! Ive owned other ford trucks in the past (put 150k on a 95 f150 w/ the 302 in high school and college, briefly owned a 1990 bronco w/351 Windsor) and have a fair deal of home auto repair experience just keeping those on the road. However this is really the beginning of me making proactive improvements, upgrades, or generally putting things back together in non-stock configuration. Its been an awesome learning experience. Im really looking forward to having a simple, reliable “no nonsense” drive train with better torque, power, and fuel economy to boot. Im eager to see how the fuel economy works out in the end. I know others with similar set ups have achieved 15-16 mpg on the highway or better on occasion. Fingers crossed! Im sure my 3.55 gears and lack of an OD gear wont help.

Buyer beware! Ive lead you astray! The walker 21151 muffler has a 2.5” OD outlet, while the walker tail pipe has a 2.25” OD inlet. And so Mr. Bezos makes another buck. The reducer will be here Saturday. Otherwise the muffler looks like its going to fit great and not cause any heartache.

I went over to my uncles house and did some work last night

Im not sure if the throttle bracket “makes sense” to all of you yet, but Ill be sure to post pictures once it is fully installed. The blue plate is for my intake manifold water heat spacer. I should be able to get the plate drilled and tapped to ½ npt and install my 1/2npt -> 5/8 hosed barb fittings tonight. With any luck, Ill have everything completely ready for the installation of the manifolds and carb tonight. The welds may not even be cool on the exhaust by the time its running!

I understand how it will fit over the studs coming through the carb flange and provide an anchor for the return spring.

Nice to have a relative you can go over and fabricate something like that bracket.

I can't wait to see it all in place!

[StraightSix]

I understand how it will fit over the studs coming through the carb flange and provide an anchor for the return spring.

Nice to have a relative you can go over and fabricate something like that bracket.

I can't wait to see it all in place!

Hey guys!

Sorry for the hiatus, I finally had some luck in the deer stand so I have spent a few days getting the animal cleaned up, butchered and in the freezer. I was finally able to get back to the bronco today. The exhaust is now fully welded and the water heat plate is finished and installed to the intake. Im going to knock off for the night then wake up bright and early to install the manifolds and try to get it all hooked up. Not positive it will run tomorrow, but Im feeling good about the progress for sure.

[ArdWrknTrk]

Hey guys!

Sorry for the hiatus, I finally had some luck in the deer stand so I have spent a few days getting the animal cleaned up, butchered and in the freezer. I was finally able to get back to the bronco today. The exhaust is now fully welded and the water heat plate is finished and installed to the intake. Im going to knock off for the night then wake up bright and early to install the manifolds and try to get it all hooked up. Not positive it will run tomorrow, but Im feeling good about the progress for sure.

Well, it's bright and early!

Congratulations on a successful hunt!

A freezer full of venison is money in the bank, and food on the table.

The water plate looks good, but I'm sure you're going to be looking for a third arm to juggle the manifolds and a ratchet.

So, I hope today goes smoothly for you!

Yes, yes, Progress is GOOD!