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Old 03-01-2021, 11:33 PM   #26
geezer#99
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Re: inline 6 carb. question

That works.
The water flow is from the thermo housing to the pump.
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Old 03-01-2021, 11:48 PM   #27
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Re: inline 6 carb. question

I was thinking about running a Rochester 2G carb on the stock intake with an adapter plate. According to this website, the 2G flows from 225-435 cfm.

You guys think the Rochester 2G is worth a shot?
https://www.ebay.com/itm/Carburetor-...53.m1438.l2649


Carb Sizes and CFM
Even though the 2G ended major production in 1979, it still lived on a little further in boats, heavy equipment, and even school buses. In the heavy-equipment applications, some of the carburetors had governors on them even so those can actually be more desirable because they are the biggest ones.

The cfm (cubic feet per minute-a measure of how much air the carburetor can flow) on the Rochester 2G ranges from about 225 cfm in the smallest applications up to what Rochester calls a 435 cfm. But the 435 is actually commonly referred to as a 500-cfm carb in circle track racing because it has the same diameter venturi bore and throttle bore sizes as the Holley 4412, which is a 500-cfm carb. Rochester just ran a different test on the flow bench to rate its carbs than Holley did, but generally, if you flow them both on the same bench, each will flow right around 500 cfm.


https://www.hotrod.com/articles/ctrp...0a%20435%20cfm.
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Old 03-02-2021, 12:42 AM   #28
'68OrangeSunshine
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Re: inline 6 carb. question

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Originally Posted by jaxncurtis View Post
I do not have a heater core? No AC or Heater (at the moment). I did find a picture of a guy running from the Water pump to the Heater Plate, then from Heater plate to the bottom thermo housing.

Would that sound right?
Jax, I live in Tucson. I've never felt the need for carb heat anyway.
If I lived in Michigan or Minnesota or Maine, I might need it, but in AZ, why bother?
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Old 03-02-2021, 10:23 AM   #29
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Re: inline 6 carb. question

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Jax, I live in Tucson. I've never felt the need for carb heat anyway.
If I lived in Michigan or Minnesota or Maine, I might need it, but in AZ, why bother?
Ok!! So that is exactly what I was thinking! I live in AZ (Gilbert) and if the heater plate is meant to give added heat, I feel we have plenty of that radiating through this state. I guess if for some reason its meant to cool the intake, but everything I have seen is it is meant to heat it?

So you are saying you have no heater plate and nothing running to it... correct?
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Old 03-02-2021, 03:25 PM   #30
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Re: inline 6 carb. question

The heat plate is needed at temps below 45 degrees.
When first started the intake is cold. The fuel vapor needs to be kept at higher temp so it stays a vapor. If the vapor cools too much it reverts back to a liquid state and collects on the floor of the intake under the carb. The vapor will be too lean to fire and you’ll get stumbling and misfiring.
Your overnight and early morning temps are high enough that you likely don’t need a heat plate.
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Old 03-02-2021, 07:09 PM   #31
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Re: inline 6 carb. question

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Ok!! So that is exactly what I was thinking! I live in AZ (Gilbert) and if the heater plate is meant to give added heat, I feel we have plenty of that radiating through this state. I guess if for some reason its meant to cool the intake, but everything I have seen is it is meant to heat it?

So you are saying you have no heater plate and nothing running to it... correct?
Exactly. No carb heat. And I've been running the same truck with a 292* Clifford headers, Offy intake and 4 barrel carb since 1978.
The intake and headers are the same, but I changed out the 390 Holley for a 500 CFM Edelbrock 1404 after the first 25 years. * Block is engine #3, or original OEM 292 rebored to .030 over and rebuilt after a 25 year ''rest'' in packing crates.
As for cooling, you can't do better than the air cooling an L6 gets in the generous engine bay of a 67/72. Would a plate below the carb, to keep it at 180-195 *F help? I don't think so.
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Old 03-17-2021, 08:14 PM   #32
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Re: inline 6 carb. question

I'm thinking about this carb: https://www.ebay.com/itm/Carburetor-...53.m1438.l2649

What do you guys think? It looks rebuilt and all I need is this adapter, right?
https://www.ebay.com/itm/Carb-Carbur...53.m1438.l2649
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Old 03-17-2021, 08:48 PM   #33
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Re: inline 6 carb. question

The fun part will be getting linkages set up and adjusted. Don't know why it shouldn't work. Keep us posted.
Going 4 barrel is expensive.
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Old 03-17-2021, 10:55 PM   #34
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Re: inline 6 carb. question

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Originally Posted by '68OrangeSunshine View Post
The fun part will be getting linkages set up and adjusted. Don't know why it shouldn't work. Keep us posted.
Going 4 barrel is expensive.
It depends on which four-barrel you buy, right?
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Old 03-18-2021, 05:55 AM   #35
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Re: inline 6 carb. question

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It depends on which four-barrel you buy, right?
Unfortunately, they're all running about $400 bucks nowdays. Shocking for me as I remember Late '70s [$90], and 1999 [$199] prices. Choices are Holley and Edelbrock. GM of Brazil made a cast iron L6 Quadrajet intake, but you can't get them in North America.
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Old 08-19-2021, 02:54 PM   #36
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Re: inline 6 carb. question

I saw no difference in how it ran with or without the heater plate so I got rid of it.
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