HBF comes out of retirement

[ArdWrknTrk]

I suspect you're right! The extra vibrations likely shook the mirror loose from the glue pads!

Another thing hanging by just a thread... My exhaust/heat shield thingy. One bolt was still holding it on. Where the other bolt was, the shield had rusted away around it! And, of course, when I tried to remove the bolt, I broke the bolt and the thread is lodged in the intake manifold. So....

Ideas on how to fix this or to find a replacement?!? How critical is it?!?

Today, I bought a small roll of roof flashing and have tin snips. I also bought some aluminum foil tape while I was at the hardware store.

I didnt know these warm inlet air shrouds bolted to the intake on 4.9's

On V-8's they are held by a double sided stepped stud, so even if the shroud nut breaks off the stud holds the exhaust manifold tight.

I'm sure heated air in winter helps a 4.9 especially.

But it's absence isn't going to hurt anything.

I had to weld some stainless fender washers into mine because it had completely disappeared around the studs.

[HBF84]

I didnt know these warm inlet air shrouds bolted to the intake on 4.9's

On V-8's they are held by a double sided stepped stud, so even if the shroud nut breaks off the stud holds the exhaust manifold tight.

I'm sure heated air in winter helps a 4.9 especially.

But it's absence isn't going to hurt anything.

I had to weld some stainless fender washers into mine because it had completely disappeared around the studs.

Well, it got a bit colder this week so I figured I would try to see if the lack of the exhaust shield feeding warm air to the carburetor was the cause of the persistent high idle. And, after a quick trip to the hardware store for some aluminum tape and flashing, I fashioned this:

It seemed to work with the temperatures in the 40's but not last night when it was about 25 or so.

 

[ArdWrknTrk]

Well, it got a bit colder this week so I figured I would try to see if the lack of the exhaust shield feeding warm air to the carburetor was the cause of the persistent high idle. And, after a quick trip to the hardware store for some aluminum tape and flashing, I fashioned this:

It seemed to work with the temperatures in the 40's but not last night when it was about 25 or so.

It's got to be helping!

Poor atomization and carb icing are very real.

Any warmth the inlet air sees is better than none.

[Gary Lewis]

It's got to be helping!

Poor atomization and carb icing are very real.

Any warmth the inlet air sees is better than none.

It will help with atomization, but not the high idle. The choke heater should be bringing the choke off, with or without heat through the air cleaner, and as the choke comes off the fast idle should drop down. If it isn't dropping down and eventually coming completely off you need to make sure that the choke heater is working and bringing the choke off. And if that's the case then figure out why the fast idle linkage may be stuck.

[ArdWrknTrk]

It will help with atomization, but not the high idle. The choke heater should be bringing the choke off, with or without heat through the air cleaner, and as the choke comes off the fast idle should drop down. If it isn't dropping down and eventually coming completely off you need to make sure that the choke heater is working and bringing the choke off. And if that's the case then figure out why the fast idle linkage may be stuck.

Don't all the YF's have that red silicone hose coming from the choke stove?

Are only some of them electric assist?

I'm not too fluent in 4.9.

[Gary Lewis]

Don't all the YF's have that red silicone hose coming from the choke stove?

Are only some of them electric assist?

I'm not too fluent in 4.9.

I don't know the answer to that question. I don't speak YF/A very well. Which is why I was careful to say "choke heater" as I didn't know what form it might take.

But, to me, a high idle in cold weather implies the choke isn't coming off.

[FuzzFace2]

I don't know the answer to that question. I don't speak YF/A very well. Which is why I was careful to say "choke heater" as I didn't know what form it might take.

But, to me, a high idle in cold weather implies the choke isn't coming off.

I also don't know the answer to that question

I know my 81 is the asst. type but I also had to "mod" the choke hot pipe.

I am using EFI manifolds and they don't have a way to pass the tube through the manifold so I got copper tubing and made a few wraps around 1 of the manifolds.

A few weeks back I adjusted the choke as the fast idle was not coming on, think the choke was not closing enough. I now think I went to much as I stays on a little longer than I think it should.

Or did I not make enough wraps of the tubing?

I am heating the intake with a hot water plate but I don't have the hot air inlet part as there is no way to have one on the EFI manifolds. As said this hot air intake will not have anything to do with the fast idle coming off, that is a choke thing.

As for the icing of the carb.

I don't think I have had any issues with that but it is only 2 miles to the high way with 1 (1/4mile from house) maybe 2 (2 mile mark) lights and only the fist I have to stop at 99% of the time.

Other wise on the high way for 37 miles, and then 2 miles, no lights to work.

So not a lot of idle time where I think the icing would show up most of the time?

I am running the factory tear drop air filter assy. with the vacuum hose / flapper hooked up and think it works as I have not checked.

Just what I found with my set up.

Dave ----

[ArdWrknTrk]

I don't know the answer to that question. I don't speak YF/A very well. Which is why I was careful to say "choke heater" as I didn't know what form it might take.

But, to me, a high idle in cold weather implies the choke isn't coming off.

I also don't know the answer to that question

I know my 81 is the asst. type but I also had to "mod" the choke hot pipe.

I am using EFI manifolds and they don't have a way to pass the tube through the manifold so I got copper tubing and made a few wraps around 1 of the manifolds.

A few weeks back I adjusted the choke as the fast idle was not coming on, think the choke was not closing enough. I now think I went to much as I stays on a little longer than I think it should.

Or did I not make enough wraps of the tubing?

I am heating the intake with a hot water plate but I don't have the hot air inlet part as there is no way to have one on the EFI manifolds. As said this hot air intake will not have anything to do with the fast idle coming off, that is a choke thing.

As for the icing of the carb.

I don't think I have had any issues with that but it is only 2 miles to the high way with 1 (1/4mile from house) maybe 2 (2 mile mark) lights and only the fist I have to stop at 99% of the time.

Other wise on the high way for 37 miles, and then 2 miles, no lights to work.

So not a lot of idle time where I think the icing would show up most of the time?

I am running the factory tear drop air filter assy. with the vacuum hose / flapper hooked up and think it works as I have not checked.

Just what I found with my set up.

Dave ----

The point I was trying to make is that the carb is out there in the middle of an intake hanging off the side and getting no heat from the block (and in the case of EFI manifolds no heat to the floor of the plenum!)

The carb is a restriction and as the intake charge expands it uses heat. As the fuel atomizes and vaporizes it consumes heat too.

There is a large cooling effect which means condensation and puddles of fuel.

Even in Dave's case, that plate isn't warming up until the truck warms up.

It isn't helping when it's needed most.

With the factory carb setup hot exhaust gases are licking at the plenum floor from the first moment the engine fires.

Flames, as hot as it gets, are swirling around directly under the carb.

Yes, none of that affects how fast the choke warms up and comes off.

Maybe Dave needs a few more turns of the worm?

Maybe there would be better heat transfer if he brazed it directly to the E manifold casting?

Maybe it's better to ditch the choke stove and go with a full electric option from Mike's Carburetor Parts?

Like I said I'm no 4.9 expert. But cold affects all carburetor enriching circuits pretty much the same, and the faster you can get the engine up to temp and the choke off, the better.

[HBF84]

The point I was trying to make is that the carb is out there in the middle of an intake hanging off the side and getting no heat from the block (and in the case of EFI manifolds no heat to the floor of the plenum!)

The carb is a restriction and as the intake charge expands it uses heat. As the fuel atomizes and vaporizes it consumes heat too.

There is a large cooling effect which means condensation and puddles of fuel.

Even in Dave's case, that plate isn't warming up until the truck warms up.

It isn't helping when it's needed most.

With the factory carb setup hot exhaust gases are licking at the plenum floor from the first moment the engine fires.

Flames, as hot as it gets, are swirling around directly under the carb.

Yes, none of that affects how fast the choke warms up and comes off.

Maybe Dave needs a few more turns of the worm?

Maybe there would be better heat transfer if he brazed it directly to the E manifold casting?

Maybe it's better to ditch the choke stove and go with a full electric option from Mike's Carburetor Parts?

Like I said I'm no 4.9 expert. But cold affects all carburetor enriching circuits pretty much the same, and the faster you can get the engine up to temp and the choke off, the better.

Thank you for the informative dialogue! I will certainly lubricate the choke linkage before I start tearing into the carburetor! And, it ran much better today but of course, it was a bit warmer today. Which brings me to this...

HBF was enjoying retirement in California and is a bit perturbed that he is working here in Maryland. So, this morning, in the garage, I started up his engine and took a look at the mixing valve. It isn't a heated garage so the air was probably about 40 degrees. And, I took this picture:

So, the air entering the carburetor is normal air. I reached inside and flipped the valve so that heated air entered the carburetor. Nothing changed and it ran well this morning. HOWEVER, is this air diversion valve controlled by a bimetallic mechanism or is it vacuum controlled? Does that influence the conversation above?

[HBF84]

Thank you for the informative dialogue! I will certainly lubricate the choke linkage before I start tearing into the carburetor! And, it ran much better today but of course, it was a bit warmer today. Which brings me to this...

HBF was enjoying retirement in California and is a bit perturbed that he is working here in Maryland. So, this morning, in the garage, I started up his engine and took a look at the mixing valve. It isn't a heated garage so the air was probably about 40 degrees. And, I took this picture:

So, the air entering the carburetor is normal air. I reached inside and flipped the valve so that heated air entered the carburetor. Nothing changed and it ran well this morning. HOWEVER, is this air diversion valve controlled by a bimetallic mechanism or is it vacuum controlled? Does that influence the conversation above?

And, one more thing while we're talking about air...

The vermin had made a little racetrack around the air cleaner but they never were able to break through the fence and run around on the infield!