Wrong recommendation, bigger is not better with most street engines. The bigger carb will hurt low end throttle response and hurt gas mileage as well. The 4180 is an emissons carb and rather than rebuild it a List 1850 Holley 600 CFM as a replacement will improve throttle response and gas mileage. At least that's the way it worked with my 1984 F-250 Super duty with 4.10 gears and a stock 460.

 

Sorry,
I meant no confusion.

What you see plumbed in metal is the PCV inlet. It goes into the front of the EGR spacer plate which sits between the carb and the manifold.

The yellow line next to it goes to the charcoal cannister purge valve (per the diagram)

The "E" port is the one in the first pic with the 'White" line going to it (by the choke housing)

If you look at the picture of my engine with the carburetor removed (in the other thread) you will see the EGR port *to the side* of the 4 venturi inlets in the manifold.

I hope this is clear.

 

Yes, that does make it clear and is how I originally understood it from the pictures. That last picture and comments in the post I guess I misread.

Thanks for bearing with me. This is all rather new to me, and I am just trying to learn.

Joe ...

 

Bear -

Based on your posts and alot of other info I have read, I am sticking with a 600cfm carb. With a 15K lb RV, I do not want to sacrifice any low end power. I know that I at least need to rebuild the carb, as the acc pump is dripping. Since a rebuild kit is $100 or so and then depends on the quality of the rebuilder (me..ouch), and a new carb is $250 and will already be generally setup, I thought it may be worthwhile to just go the new route.

As for the List 1850 Holley, I am assuming it does not have the EGR port, and therefore I will not be able to reconnect the EGR valve. Will there be any long-term issues around the combustion temps wthout it hooked up? The EGR was not working when I bought the RV, so lord only know how long it has been this way. I was just looking at what it would take to get it operational if it was going to make a large temperature difference and keep me from burning up the heads.

I do have a set of Thorley headers to install (passenger side cracked manifold due to the 460 broken bolt syndrome I have read so much about), and have been told this will cool the temps down a bit. I thought that was strange as I would think that the better air flow through the headers might make things hotter, but just goes to show my lack or real-world knowledge. I was also told that the headers could allow me to potentially drive a larger carb if I wanted, but it would definitely suck more fuel and burn hotter. If all of this is accurate, I will just stick with the 600 cfm class carb and know that it will be more than adequate to get this 15K lb RV around in a generally efficient manner... sub-10 mpg I am sure...

Any thoughts around Holley carbs verses Edelbrock? I am not a carb tuning guru at all, so would want something that would maintain a good calibration over time. I have heard the Holleys are a better overall carb if you know how to adjust and re-adjust them, where the Edelbrocks are pretty good too, and once set stay set with no fiddling needed. Not sure what is accurate and what is the Ford verses Chevy type of preferences coming out. Let me know if you have an objective opinion on the topic.

Thanks so much!

Joe ...

 

Bear -

Also, I have now seen Holley List 1850-2, -3 and -4s. What is the difference? Also, there seems to be numerous cfm ratings associated. Is that what the different -x numbers stand for?

Just to be clear, it is the Model 4160, correct?

Thanks again!

Joe ...

 

The Holley 1850 (I would have to look up which version, but it has to be for a Ford with and auto trans, which is a -2, IIRC) but it is a bolt on replacement and the EGR stays if you so desire. Yes, it is a 4160. I don't favor Edelbrock, AKA Carter carbs. My old Hemi had a pair and those things had more carb fires in a year than all my Holleys put together in 50 years. Besides metering rods are a tuners nightmare where tuning a Holley is done with the KISS principle.

 

Bear -

I will try and make this my last draw on your time. I really appreciate all the info.

In looking at new Holleys, I am trying to find the 1850. I am finding the 0-80457-S, which I think is a 4160 with electric choke and the shiny finish. There seems to ne no dichromate finish available in this choke combination. They are also showing an 1850C that is the 4160 but with manual choke, my current 4180 is electric choke. Both of these are listed and square flange square bowl 600cfm carbs.

There is also a square flange V-bowl 650cfm electric choke 4160 model, which I have not seen before. It is 0-80783C in dichromate finish. What is the v-bowl and would this carb be a good consideration for my application?

Thanks again!

Joe ...

 

A 0-80318-1 is the carb you want. It is already calibrated for your engine.
Holley Performance Products 600 CFM Four Barrel Carburetor*0-80318-1

You are not wasting my time, you are learning.

 

Bear -

You do not know how much it is appreciated. I can learn anything with the right tutor...!!

As for the last post, when I hit that link for the Holley you specified, it is a marine carb and it says it should never be used for street applications... This is going on a Winnebago RV... Was that just a typo?

I would think that the 0-80457S is the land version of the 4160, 600cfm with the electric choke... here is the link to the Holley page that references this carb.

Here is the Holley page for this specific carb:

http://www.holley.com/0-80457S.asp

And the links to this class carb. I think that other 650 cfm carb I referenced before with the v-bowl was the 4150.

Holley Performance Street Performance – Traditional Products

Thanks again!

Joe ...

 

Here is an inexpensive option that has run well on my 86 F250 4x4:

Holley 0-1850S - Holley Model 4160 Non-Adjustable Float Carburetors - summitracing.com

It does not have the adjustible float level, but I have not found that a problem on my application which is likely the same as your MH.

 

Holley 0-1850S - Holley Model 4160 Non-Adjustable Float Carburetors - summitracing.com

Budget replacement. Works great on my otherwise stock 86.

ADMIN: Can be removed. I didn't think the 1st POST made the trip.

 

Yes, I am going to go with the electric choke version of the 1850S which is the 0-80457S. Based on what I have seen and been told by the others, this should work well on my RV.

Thanks!

Joe ...

 

the reason you burn up valve seats is because the older engines were designed for leaded fuel, which lubricates the valves and etc. you need hardended valve items because of that- I don't think emissions equipment have anything to do with burning up valves. The original 460 pre 74 or so, non-california, had 0 emissions stuff on it. you need to put the hardened valve seats/stems in there, or put leaded substitute in every tank. if your heads were already shot, and you got them rebuilt, the hardended ones are already in there, and no emissions shaite is going to make a diff. what will make a diff is how their disconnection affects your timing, advance, and the engine temp - if there is too much advance it runs hot, etc.

I am not an expert, but I play one in my 1976 F-250 trailer special with a 460 and AT every year when I have to get it through Arizona emissions inspection.

 

another point. My understanding is that the square flange carbs don't run as well with the adaptor plate on. Something about affecting air flow. Its better to replace the manifold as well so the two work together- and you lose 50lbs of weight- the cast iron vs the aluminium.

A while back, I got stuck in a situation where my truck flunked emissions, and I had 1 day before leaving town for a 2 month project. my 4350 carb was leaking fuel from the accelerator pump bushing and the accelerator pump was shot- it was high on hydrocarbons and CO2 at idle, and high on CO2 at idle. Tried to rebuild it, adjust the mix, and after 2x with nothing but fuel spilling out of the bowl vents, I gave up, bent over and bought a rebuilt 4350 from Oblarneys, ouch, so I could bolt something on quick and get her through. that carb I had was in such better condition overall than the POS I got from them - the quality of rebuilt parts now days is amazingly low- better to go with a new system- which means carb and intake manifold.