Need help combating Vapor lock... 65 Ply SF 383

James Romano

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Most of my motor is original, still have the Carter AFB and I plan to (well... hope to) keep it. The intake manifold has some kind of insulation tucked under the carb, not sure what it's for. I just had the carb rebuilt and properly tuned. I 'm good to 180, then once I get any hotter... it starts loping in traffic and is hard to start once it's shut down.

My plan....

- I bought and will install the Felpro intake manifold pan that has the blockers for the heat riser.
- I already saftey wired the heat riser in the open position.
- I will replace the water pump with a high-flow unit and add in wetter water, also running a 50/50 mix. I think I have all anti-freeze from what it looks like.
- I'd like to get a 1/8" insulator carb gasket, but I can't seem to find one for a Carter AFB
- I am running a 22" electric fan, which works good, however, there is little air movement in the engine bay at idle, so I plan on removing the flat metal plate at the front of the intake manifold pan and expose the underside of the intake manifold to as much air flow as possible.
- If that doesn't work... put the original mechanical fan back in, with the new high-flow pump, I should be ok not having a fan shroud, as my car did not come with one.
- Possibly re-route the fuel line from the production break to the back of the carb from behind the engine, and install an electric fuel pump... this is LAST ditch. I don't want to alter the originality visibly. I based the whole look of the car on being discreet.

Any thoughts/advice on these ideas... maybe something I am missing?

Thanks as always!
 
Check the length of your fuel pump pushrod.
 
Most of my motor is original, still have the Carter AFB and I plan to (well... hope to) keep it. The intake manifold has some kind of insulation tucked under the carb, not sure what it's for. I just had the carb rebuilt and properly tuned. I 'm good to 180, then once I get any hotter... it starts loping in traffic and is hard to start once it's shut down.

My plan....

- I bought and will install the Felpro intake manifold pan that has the blockers for the heat riser.
- I already saftey wired the heat riser in the open position.
- I will replace the water pump with a high-flow unit and add in wetter water, also running a 50/50 mix. I think I have all anti-freeze from what it looks like.
- I'd like to get a 1/8" insulator carb gasket, but I can't seem to find one for a Carter AFB
- I am running a 22" electric fan, which works good, however, there is little air movement in the engine bay at idle, so I plan on removing the flat metal plate at the front of the intake manifold pan and expose the underside of the intake manifold to as much air flow as possible.
- If that doesn't work... put the original mechanical fan back in, with the new high-flow pump, I should be ok not having a fan shroud, as my car did not come with one.
- Possibly re-route the fuel line from the production break to the back of the carb from behind the engine, and install an electric fuel pump... this is LAST ditch. I don't want to alter the originality visibly. I based the whole look of the car on being discreet.

Any thoughts/advice on these ideas... maybe something I am missing?

Thanks as always!

I know we joke a lot about thermostats around here, but make sure you have one and that it is a 180 degree stat. Sometimes, people remove the thermostat thinking that will help with an overheating problem. It doesn't, because the coolant flows too fast through the radiator and never has enough time to cool down. Also, the engine doesn't run well, when its not up to temperature. Except for wiring the heat riser open, I would not do any of the tasks you've listed until you do the following:

A lot of over heating issues are due to a radiator that is full of junk in the bottom and / or lower half. A good radiator shop can check that out and do a refurb for you - or you could replace the radiator with a new one. Depending on how the car was maintained during it's fifty year-plus life, there may also be a lot of buildup in the coolant passages of the block. If it is really bad, I don't know of any way to clear it except by having a machine shop boil the block prior to a rebuild. You may get lucky by running several cycles of a heavy duty cleaner in the cooling system / radiator and flushing the system after each. You can also remove the coolant gallery plugs and the freeze plugs from the side of the block when performing the flushing / cleaning to get a lot of that grundge out of the system. Good luck to you.
 
they made a insulation blanket that go's under the intake manifold to help insulate the carb you can see it under the intake. works great they use to come from the factory with them but they were rapped in aluminium and there ugly when they got oil on them so people throw them out but they worked to stop the heat getting to the carb
waxed 2017 9.jpg
 
The fan shroud will make a huge difference.
Ditto rad yoke to hood seal.
Anything to direct the air flow THROUGH the rad and nowhere else.
Fabricate a "chin" spoiler and attach to the bottom of the rad core support to direct air to the rad,just an idea.
Blocking the heat crossover and adding a carb spacer drops the temps unde the carb 100 degrees F all by itself.
Sliding heat sheathing over the fuel line is good for another 25 degrees.
Hope this helps
 
they made a insulation blanket that go's under the intake manifold to help insulate the carb you can see it under the intake. works great they use to come from the factory with them but they were rapped in aluminium and there ugly when they got oil on them so people throw them out but they worked to stop the heat getting to the carb View attachment 383949
The insulation pad is also there to help quiet engine noise. The valley pan amplifies the lifter noise, so the pad helps.
 
Main purpose of the pad was to reduce noise. Heat riser passage is above the insulation pad so it's value for controlling heat is questionable.

Dave
 
Most of my motor is original, still have the Carter AFB and I plan to (well... hope to) keep it. The intake manifold has some kind of insulation tucked under the carb, not sure what it's for. I just had the carb rebuilt and properly tuned. I 'm good to 180, then once I get any hotter... it starts loping in traffic and is hard to start once it's shut down.

My plan....

- I bought and will install the Felpro intake manifold pan that has the blockers for the heat riser.
- I already saftey wired the heat riser in the open position.
- I will replace the water pump with a high-flow unit and add in wetter water, also running a 50/50 mix. I think I have all anti-freeze from what it looks like.
- I'd like to get a 1/8" insulator carb gasket, but I can't seem to find one for a Carter AFB
- I am running a 22" electric fan, which works good, however, there is little air movement in the engine bay at idle, so I plan on removing the flat metal plate at the front of the intake manifold pan and expose the underside of the intake manifold to as much air flow as possible.
- If that doesn't work... put the original mechanical fan back in, with the new high-flow pump, I should be ok not having a fan shroud, as my car did not come with one.
- Possibly re-route the fuel line from the production break to the back of the carb from behind the engine, and install an electric fuel pump... this is LAST ditch. I don't want to alter the originality visibly. I based the whole look of the car on being discreet.

Any thoughts/advice on these ideas... maybe something I am missing?

Thanks as always!
180° is a very healthy operating temp. Your vapor lock issue is a fuel problem related to engine temp. I would be tempted to installing a carb insulator between your carb and intake which may help or a return style fuel filter and a return line back to your fill tube. Today's gas evaporates at pretty low temps. AFB's and AVS's seem to be more prone. Even my 2 barrel is hard to restart hot. Some have installed a small electric charge pump near the tank with a momentary switch to prime the system.
 
180° is a very healthy operating temp. Your vapor lock issue is a fuel problem related to engine temp. I would be tempted to installing a carb insulator between your carb and intake which may help or a return style fuel filter and a return line back to your fill tube. Today's gas evaporates at pretty low temps. AFB's and AVS's seem to be more prone. Even my 2 barrel is hard to restart hot. Some have installed a small electric charge pump near the tank with a momentary switch to prime the system.
I'm definitely over 180 running temp. Going to address that next week with a high flow 180 thermostat. My gauge is reading around 190-195 when the fan kicks in. The engine bay is crazy warm but I kinda expect that with only an electric fan. The electric fan works very good to cool the radiator, but nothing close to providing the airflow to the engine bay as a mechanical does

Where can I get the carb insulator gasket for a Carter. I see them for Holley, Street Demon and others. Can I use an Edlebrock?

I had a Coolcarb plate under my carb, but I looked terrible and did nothing.
 
I've got all new hoses, and bought a spring for the lower hose as mine is missing.

I have a miliodon high flow 180 waiting to go in, plus the new high flow water pump. It's the amount of heat and no where for it to go until I get on a parkway or out of traffic.

I'm also going to swap out my dual snorkel for my smaller unsilenced air cleaner which should get some of the hot air out from under the air cleaner.

I'm just wondering which is better the electric or mechanical for keeping the hot air moving when idling.
 
Check the length of your fuel pump pushrod.
Brand new from Mancini Racing. I saw your post with the guy and the idling issues. Never thought that would be an issue till you mentioned it. But everything in my whole system is up to snuff. New lines, pump, pushrod, filter...etc. That's why this is driving me nuts.
 
Old school trick is make your own carb spacer/insulator out of 1/2 inch plywood.
With your Carter carburetor, that may be the best way to go.
So,put down the Snap-on tools and pick up the Black n Decker,LOL!!
 
180° is a very healthy operating temp. Your vapor lock issue is a fuel problem related to engine temp. I would be tempted to installing a carb insulator between your carb and intake which may help or a return style fuel filter and a return line back to your fill tube. Today's gas evaporates at pretty low temps. AFB's and AVS's seem to be more prone. Even my 2 barrel is hard to restart hot. Some have installed a small electric charge pump near the tank with a momentary switch to prime the system.
This sound like a good idea. The carb was adjusted, modded and jetted for ethanol based fuel, as well as me adding 2 stroke oil to the fuel I thought would help. But it hasn't.

I've seen the filters you mention on eBay, has a little 5/16 port on it as well as the 3/8. So what else do I have to do? Run a ridged line back to the tank filler?
 
This sound like a good idea. The carb was adjusted, modded and jetted for ethanol based fuel, as well as me adding 2 stroke oil to the fuel I thought would help. But it hasn't.

I've seen the filters you mention on eBay, has a little 5/16 port on it as well as the 3/8. So what else do I have to do? Run a ridged line back to the tank filler?

I think yer making this whole thing too complicated. I have a '66 300 with a 440 engine running a 22" stock refurbed radiator, stock manual fan, no shroud and a new thermostat. It runs great and does not overheat. In the past, I had stalling problems and overheating, etc. with another '66 300 - but with a 383. I tried an insulator under the AFB and it did not help. The problems did not go away until I had the radiator redone and the carb competently rebuilt. I think all these other suggestions are going to create a lot of extra work for you and in the end, won't fix the problem.
 
Old school trick is make your own carb spacer/insulator out of 1/2 inch plywood.
With your Carter carburetor, that may be the best way to go.
So,put down the Snap-on tools and pick up the Black n Decker,LOL!!
If I were to make a spacer out of wood, I would used a dense hardwood that is more homogeneous (consistent) and not laminated, something like black walnut, teak or the like...
 
they made a insulation blanket that go's under the intake manifold to help insulate the carb you can see it under the intake. works great they use to come from the factory with them but they were rapped in aluminium and there ugly when they got oil on them so people throw them out but they worked to stop the heat getting to the carb View attachment 383949

good comment.
I remember gingerly removing these, cleaning them then re-installing since they weren't available from the dealerships even back in the 80's when I could still pull wrenches full time.
 
I did have vaporlock last year and i made a carb insulator from teflon...……. ( 3/8 ).
Works great!!
 
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