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Summit 600 CFM Carb

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Machspeed

Summit 600 CFM Carb

Administrator

Hey gang, I've been running an Edelbrock 600 CFM carb for some time now and it has proven itself to be a good reliable easy to rebuild carb. It is a hard start though after sitting for a week or so, which I've read is quite common for this carb. Also, it's pretty picky about fuel pressure.

That said, I've read raving reviews on this Summit 600 CFM carb. It is made by Holley but designed around the Ford 4100 series carbs, which were great.

Anybody running one of these?

John

"Blackie" - 1986 F150 4x4 - Mildly warmed over 351W HO - Original owner

Gary Lewis

Re: Summit 600 CFM Carb

Administrator

I think Rick/Lariat 85 is running that carb. Let's see what he has to say.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

LARIAT 85

Re: Summit 600 CFM Carb

In reply to this post by Machspeed

Machspeed wrote

Hey gang, I've been running an Edelbrock 600 CFM carb for some time now and it has proven itself to be a good reliable easy to rebuild carb. It is a hard start though after sitting for a week or so, which I've read is quite common for this carb. Also, it's pretty picky about fuel pressure.

That said, I've read raving reviews on this Summit 600 CFM carb. It is made by Holley but designed around the Ford 4100 series carbs, which were great.

Anybody running one of these?

I am running a Ford/Autolite 4100 (480cfm) carburetor on Lucille - the grandfather to the Summit carburetor.

Can you describe in better detail on what you mean by a "hard start after sitting a week or so?"

What is happening exactly, and what is your starting procedure?

Lucille: 1985 Ford F150 XLT Lariat

*Colors: Dark Canyon Red exterior, Canyon Red interior
*Engine: 5.0, CompCams 31-230-3, "Thumper" E7 heads, Edelbrock Performer intake, Autolite 4100 carburetor, DuraSpark II ignition, Thorley Tri-Y headers, Flowmaster dual exhaust, H-pipe.
*Drivetrain: AOD transmission, 3.55 gears, 2wd.

Machspeed

Re: Summit 600 CFM Carb

Administrator

Common problem with Edlebrock carb, as fuel evaporates in the bowl. I don't drive my truck much, but if I park it and let a week go by, it takes a few attempts to fill the bowls and fire up the truck. Once started, fires up first time every time. Much conversation on this at a Mustang forum I'm part of.

Supposedly, this is not a problem with the Summit carb I'm inquiring about. Also, this particular carb has annular discharge and my particular Edlebrock does not. Entertaining the idea of going with it.

John

"Blackie" - 1986 F150 4x4 - Mildly warmed over 351W HO - Original owner

Gary Lewis

Re: Summit 600 CFM Carb

Administrator

I can't see why this is a problem specific to one brand of carb vs another. If the gas evaporates from a carb, any carb, the engine won't start until it is replenished.

It would seem to be more an issue with the gas vs the carb.

Gary, AKA "Gary fellow": Profile

Machspeed

Re: Summit 600 CFM Carb

Administrator

This post was updated on .

Here's some discussion on the topic:

https://www.vintage-mustang.com/threads/fighting-fuel-evaporation-after-sitting-for-multiple-days.1209617/

John

"Blackie" - 1986 F150 4x4 - Mildly warmed over 351W HO - Original owner

Gary Lewis

Re: Summit 600 CFM Carb

Administrator

John - I get:

Gary, AKA "Gary fellow": Profile

Machspeed

Re: Summit 600 CFM Carb

Administrator

Should work now, Gary.

John

"Blackie" - 1986 F150 4x4 - Mildly warmed over 351W HO - Original owner

Gary Lewis

Re: Summit 600 CFM Carb

Administrator

Yep. I'll do some reading...

Gary, AKA "Gary fellow": Profile

Gary Lewis

Re: Summit 600 CFM Carb

Administrator

John - I've now read all the posts on that thread and I see 3 guys that say it is an Edelbrock issue. But they don't say why they believe that, nor any facts to support that belief. (Then there's you, and you are having the problem but don't know if it is due to having an Eddy.)

If a carb is dry after a period of time then there are only two explanations - leakage and evaporation. So let's break this down and think logically about what the issue might be:

Leakage: It is unlikely that the Eddy is leaking because it is the only one of the traditional carbs (Eddy, Holley, Autolite) being discussed that have no gaskets or fabric holding the fuel in. The Eddy is all metal where the fuel is.

Evaporation: This is probably the area where an Eddy comes in last, or first depending on how you think, as the Eddy has a wide fuel bowl so the gas has more surface area than that in a Holley or similar design carb which has taller bowls. But I think the Autolite might be closer to the Eddy than the Holley due to the shape of the carb.

Reducing heat, which contributes to the evaporation, is obviously a good approach. But you said you already have the Eddy heat spacer, so there's not much left to do there.

What gas are you running? Straight gas or ethanol? The latter evaporates faster than gas does. And, you could add a fuel stabilizer to the fuel.

Bottom Line: I can see why gas in an Eddy might evaporate faster than gas in a Holley - surface area. But I don't know that going to an Autolite will be that much better since I don't really know how much surface area their bowls have.

Gary, AKA "Gary fellow": Profile

85lebaront2

Re: Summit 600 CFM Carb

Administrator

Gary, last time I looked, Autolite/Motorcraft 2100/2150 carbs along with the 4100 do not have a gasket sealing gas in, they, like a Carter have a top cover with a gasket.

The Carter AFB and AVS, and even the Thermoquad have long narrow bowls on the sides, where Holley and Autolite have end bowls, that depending on actual design and float size/shape, may or may not hold more gas than a Carter. The old Holley cork bowl gaskets were terrible if they dried out, next time the bowl(s) filled up, they would leak like a sieve.

Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413

Gary Lewis

Re: Summit 600 CFM Carb

Administrator

Bill - What are power valves made of? FABRIC. Which is why I said "because it is the only one of the traditional carbs (Eddy, Holley, Autolite) being discussed that have no gaskets or fabric holding the fuel in."

I'm not saying that leakage is a problem with the others. I'm just saying it isn't likely to be with an Eddy. So that can't be why an Eddy may be losing gas.

Anyway, do you think the Eddy has more surface area than a Holley or Autolite?

Gary, AKA "Gary fellow": Profile

Rembrant

Re: Summit 600 CFM Carb

In reply to this post by Machspeed

Machspeed wrote

That said, I've read raving reviews on this Summit 600 CFM carb. It is made by Holley but designed around the Ford 4100 series carbs, which were great.

Anybody running one of these?

I have the 500CFM version on my newly built 302, but it's not running yet.

https://www.summitracing.com/parts/sum-m08500vs

I've been intrigued with this carb based on some of the stuff I've read about Rick's comments over the years. My 302 is very mild, and it'll just be a cruiser so I thought the little 500CFM carb would be a nice fit. I can't wait to get it fired up and running...hopefully in another month or so.

I just installed a Holley TPS on it recently to signal my Quick4 transmission controller.

Here it is with the hard supply line removed and TPS installed.

1994 F150 4x2 Flareside. 5.0 w/MAF, 4R70W, stock.
1984 F150 4X2 Flareside. Mild 302 w/ 5spd. Sold.
1980 F150 4X4 Flareside. 300i6 w/ 5spd. Sold in 2021.
1980 F100 4X2 Flareside. 351w/2bbl w/NP435. Sold in 1995

Machspeed

Re: Summit 600 CFM Carb

Administrator

Gary, I think there are more than three guys on there saying that or at least confirming that this is "typical" with the Edlebrock. Curious, you have one on your truck. If you go more than a week, does it fire right up or do you have to crank on it for a bit? The longer I wait between starts, the longer it takes me to start my truck too, so I know there is no fuel in that carb. It's really not that big of a deal for me as the truck runs fine. Once started, it will fire right up easily and repeatedly. It idles nicely too! I brought my hard starts up because it is something that was said does not happen with the Summit Carb??? Also, it has the annular discharge and I've read all kinds of raving reviews on it. Not sure I'm going to get one, but am very curious about it. A rebuild kit for it is $85 though.....ouch!

John

"Blackie" - 1986 F150 4x4 - Mildly warmed over 351W HO - Original owner

Gary Lewis

Re: Summit 600 CFM Carb

Administrator

I have EFI on Big Blue, and it starts right up every time, regardless of how long it has been sitting, how cold or hot it is. But I ran an Eddy on it, as well as on Dad's truck and Rusty, for a few years. And yes, after they sat for a few weeks they had to crank to start. But that's not unusual in my experience, regardless of what carb I've been running.

Gary, AKA "Gary fellow": Profile

Machspeed

Re: Summit 600 CFM Carb

Administrator

LOL....how could I forget that you went to fuel injection. Sorry, Gary!

John

"Blackie" - 1986 F150 4x4 - Mildly warmed over 351W HO - Original owner

Gary Lewis

Re: Summit 600 CFM Carb

Administrator

No problem, John. You can't remember everything.

Gary, AKA "Gary fellow": Profile

85lebaront2

Re: Summit 600 CFM Carb

Administrator

In reply to this post by Gary Lewis

True on the fabric (rubberized) power valves. As for losing gas, I had a very nice little AFB on a 312 Thunderbird special in my 1958 F100. It was from a 1964 or 65 Buick 300 ci V8 and was a great match for the 312. I had two issues with it, first I was getting gas showing up on the right side around the throttle shafts and on a cold start it acted like it was only running on 4 cyls. I finally decided to carefully remove it and sit it on a large can. Gas would very slowly drip out of the right side due to a hairline crack in the bottom of the right float bowl.

I wound up putting a 292 2 barrel intake and a non-feedback VV carb on. 25 mpg using the OD on a 312 with the truck's 3.70 gear.

Bill AKA "LOBO" Profile

Gary Lewis

Re: Summit 600 CFM Carb

Administrator

Bill - The Buick 300 came out in '64. We had one with the Super Turbine 300 with the switch-the-pitch feature. Man, that thing would RUN! Right up until the water Dad was using as coolant ate the aluminum heads. Took it into the dealership and they wouldn't stand behind it - seems I'd beaten the shop foreman's son in a drag a couple of days before.

Anyway, yes a crack in the casting will cause them to leak. But that's about all that will do it. (Unlike others that have gaskets or fabric, and some that had plugs in the drilled passages that leaked.

) But I've not had a Carterbrock leak due to that, and I've run a few.

Gary, AKA "Gary fellow": Profile

FordFETruck

Re: Summit 600 CFM Carb

Just some feedback with the summit carbs. I own two of them. The 600 CFM variant (I would have bought the 500 CFM if they offered it back then) I bought for my truck 10 years ago. Never had a problem with it, and it had the original power valve in it for like 8 years before I swapped it out for the correct HG rating for the engine and it was still like new. I have done some tuning to it with the help of a wideband o2 AFR gauge and got it all spot on and put a Motorcraft 7 volt choke cap on it. Starts right up and runs fantastic in cold or hot weather.

I like it so much I replaced my extensively tuned 600 CFM Holley on my 64 galaxie 390 with a 500, yes 500 CFM Summit carb on that big engine. I tuned it to the application with the help of a wideband o2 AFR gauge and put a 7 volt Motorcraft choke cap on it also and I'll be darned if it didn't pick up torque and throttle response below 2000 RPM and scream just as hard to 5500-6000 as the 600 CFM Holley did. Both can sit for over a week and fire right up with just a few squirts of the accelerator. I really like both of mine.

1986 F250 351W, C6, 10.25 Semi float 3.55 gear, 250K Miles