what size carberator do you run?

[Donzi_Dude]

looking for an idea what is common or not.

[silverghost]

I like the Edelbrock (built by Webber) version of the old Carter AFB/AVS.
You don't have any rubber pump, & power valve, rubber rot & dry-out problems, or the leaky bowl gasket issues season to season that you have with the Holley carbs.
For me this carb has been totally trouble free.
I swapped my stock marine float needle valves & seats with the spring loaded "Off-Road" units.
I find they control float level much better in a pounding & bouncing boat.
My CFM depends on horse-power & engine dispacement.

[Jraysray]

Barry/Grant Demon.

[JimG]

Out of the box Edelbrock. I've run them on everything from 318 Chryslers to 454 Chevys. Never had one fail yet...

[MOP]

I resemble that statement of Quardrajunk a very good carb misunderstood by many, IMO better than a Holley less trouble and easier on fuel!

[pipnit]

Pro-Systems 830cfm 4bbl

http://www.pro-system.com/

[Fishermanjm]

mpi here,,, no help at all,,, i know

[MOP]

One thing most of us old timers that know something see is way to may use carbs too big for the RPM's we run, 90% of the small blocks need nothing bigger than a 650. I run a 750 on a 383 stroker and it is a bit overboard, Griz and I have both posted on this. In most all cases your engine will run better all the way around with a proper sized carb, big bore carbs come into play at HIGH RPM's meaning 7-8,000 but do not do a great job at 5,000.

Phil

[pipnit]

One thing most of us old timers that know something see is way to may use carbs too big for the RPM's we run, 90% of the small blocks need nothing bigger than a 650. I run a 750 on a 383 stroker and it is a bit overboard, Griz and I have both posted on this. In most all cases your engine will run better all the way around with a proper sized carb, big bore carbs come into play at HIGH RPM's meaning 7-8,000 but do not do a great job at 5,000.

Phil

Interesting post. What makes you say the 750 is too big for your 383? I had a 750 on my 350 and it seemed to do a good job. Bob Madera at Marine Kinetics designed my motor and between Bob and the people at pro-systems, they decided on 830 for my 383 so I'm not even questioning that move.
I had a friend with a hot rod 350 who kept playing with carbs and got the best results (both seat of the pants and GPS) with an 850cfm. He started out with a 600 I believe. He did have to increase the accelerator pump size because there wasn't enough vaccum off the line to get the gas to dump quickly enough.

[BUIZILLA]

only the ignorant would use the word quadrajunk...

[bzsmarina]

mighty demon 750

[Donzi_Dude]

only the ignorant would use the word quadrajunk...



its a good carb for up to 400HP. if i was looking to make over 500 ponies i would look elseware.

not saying it cant be done but another carb is likely to make more power @ these levels with less work.

maybe im not so ingnorant?

:confused:

[pipnit]

maybe im not so ingnorant?
:confused:

For your sake, I hope that spelling is just a joke. It is, right? :bonk:

[MOP]

Interesting post. What makes you say the 750 is too big for your 383? I had a 750 on my 350 and it seemed to do a good job. Bob Madera at Marine Kinetics designed my motor and between Bob and the people at pro-systems, they decided on 830 for my 383 so I'm not even questioning that move.
I had a friend with a hot rod 350 who kept playing with carbs and got the best results (both seat of the pants and GPS) with an 850cfm. He started out with a 600 I believe. He did have to increase the accelerator pump size because there wasn't enough vaccum off the line to get the gas to dump quickly enough.

You are talking road engines! Wet engines need a different way of thinking, some figure it out some don't.

[pipnit]

You are talking road engines! Wet engines need a different way of thinking, some figure it out some don't.

Sorry that word HotRod probably threw you a curve ball. I meant to say hotrodded engine. These are all boats I'm talking about. In the case of my friend with the 350, he wound up getting much, much better performance from the 850 over the 750 and other carbs.
The man who reccomended the 830 for the motor that I've built I think has it figured out, being that he makes his living building marine race motors.
I don't fully understand all this and you obviously understand it all or have "figured it out." A little emperical information would be helpful rather than some shrouded snide comments.

[BUIZILLA]

For your sake, I hope that spelling is just a joke. It is, right? :bonk: he also spelled carburetor wrong... :wink:

[Donziweasel]

What size carb does Critter SS #13 have?

[Donzi_Dude]

i might not be ables to spells carberator but i sure as hell can tune one.

:wink:

[f_inscreenname]

Out of the box Edelbrock. I've run them on everything from 318 Chryslers to 454 Chevys. Never had one fail yet...

+1

My 318 = 650
454's = 750
496 = 800

[Donzi_Dude]

What size carb does Critter SS #13 have?


why ask me.

the internet guru's dont know-all?

:frown:

[JimG]

+1

My 318 = 650
454's = 750
496 = 800


Nope, I ran the same 650 cfm Edelbrock 1409's out of the box on:

1979 Chrysler 318 (Trojan 26' Flybridge)
1970 351W (Donzi 18)
1976 Chevy 454 (24' Blackfin)

That 650 CFM carb performed great on all three. Never had a carb problem, never adjusted anything.

[pipnit]

why ask me.
the internet guru's dont know-all?
:frown:

Don't go sour grapes on us, lol. I was just funning about the spelling.

What motor and what carb do you run?

[Just Say N20]

1987 SBC, Volvo 310 hp, GM dual plane intake, Holley 715 cfm single pump.

[realbold]

Nope, I ran the same 650 cfm Edelbrock 1409's out of the box on:

1979 Chrysler 318 (Trojan 26' Flybridge)
1970 351W (Donzi 18)
1976 Chevy 454 (24' Blackfin)

That 650 CFM carb performed great on all three. Never had a carb problem, never adjusted anything.
The 1409 is actually 600 cfm. Thats what's on my sbc.

[JimG]

Ok 600cfm. Its a good carb, plug and play.

[pipnit]

You are talking road engines! Wet engines need a different way of thinking, some figure it out some don't.

Maybe it's a good thing that I haven't "figured it out.". I have finally broken in my motor, made one prop swap and took some readings with my gps. Yesterday went out in my 2+3 with a full tank and two big boys and hit 75.2 mph.
I still need to do a little more tuning and then some more prop swaps to see if there is any low hanging fruit there for me.
In the mean time, I'll be looking for the answer on how to figure it out. ::jestera::drive:

Oh yeah, forgot to mention this was with a small block and pro systems 830cfm carb.

[pipnit]

MOP, you there? :popcorn:

[pipnit]

I wonder if I take off my 830cfm custom built pro-systems carb and slap a 600 cfm carb on my 18 footer if it'll run faster?!
MOP?

http://gnarld.com/wp-content/uploads/2011/07/Micheal-Jackson-Thriller-Popcorn-Animated.gif

[BUIZILLA]

I wonder if I take off my 830cfm custom built pro-systems carb and slap a 600 cfm carb on my 18 footer if it'll run faster?!
MOP?

http://gnarld.com/wp-content/uploads/2011/07/Micheal-Jackson-Thriller-Popcorn-Animated.gif leave Patrick's carb alone... :popcorn: :)

[pipnit]

leave Patrick's carb alone... :popcorn: :)

Well hell, if my boat does 75 with this junky 830 cfm pro systems, I'd love to see what it can do with the "correct" carb. Maybe I just don't get it...

I do have an old Carter I took off a Studebaker 259, maybe that's the ticket!?!?!

[joseph m. hahnl]

I wonder if I take off my 830cfm custom built pro-systems carb and slap a 600 cfm carb on my 18 footer if it'll run faster?!
MOP?

http://gnarld.com/wp-content/uploads/2011/07/Micheal-Jackson-Thriller-Popcorn-Animated.gif

I think you may have mis under stood what Phil said. I didn't mis under stand at all . What he said is for the RPM that most of us drive ,Meaning driving in moderation, There is no need for a large CFM carbs. But obviously you plan on Driving a push rod V8 balls to the wall all the time like a 2 stroke outboard. Let me know the name of your sponsor I would like to be able to rebuild my motor every time out too.

http://www.blogcdn.com/www.dailyfinance.com/media/2010/11/wrench240.jpg

Oh yah! Stock Webber/Edelbrock, Not sure of the CFM but it gets me back to the dock ahead of most:yes:

[pipnit]

I'm no where NO the RPM's he was talking about which was 7,000-8,000. The motor will turn 6,400 pretty safely but I'm doing 75 at 5400 rpm.

[Walt. H.]

Most people choose carburetors like they pick camshafts, and that is usually two sizes bigger then what would perform best for their application, it's a good thing they don't buy their shoes like that otherwise they'll be looking like they have Clown Feet.

If you check any of the carburetor manufacturer tech selection chart or speak with someone in the business, you'll find that any mildly modified naturally aspirated small block marine engine up to 400 cu. in. running under 5500 rpm will perform best with a 600 to 650 cfm carb, remember an engine is nothing more then a air pump and CFM stands for Cubic Feet per Minute of air and the volume flowing thru that engine will not even need a carb any larger then that.
Too large of a cfm carb will hurt the low and mid range performance regardless of how it's jetted and other fuel mods made to it, every good engine tuner knows and will tell you that you're capable to make a small carb flow more fuel with jet and nozzle changes as needed with great atomization but down jetting a too big a carb is a losing battle competing against poor atomization from a big cfm carb flowing into a too small cubic inch engine.

One advantage of having a too big of a carburetor is that you won't have to worry about hammering your sterndrive or eng coupler when you thump the throttle hard from an idle. :jestera:

[pipnit]

I'm just funning and running! lol

All I know is that the boat is screamin' and I haven't even tuned the motor up yet, still running at 31 degrees advance and have only done one prop swap.
I also know from my seat of the pants that this motor pulls SO much harder than my old 350, .030 over and I'm not talking about just the top end.
I don't claim to be an expert in ANY of this but I did hire some experts to help build the motor.

[Walt. H.]

Well then from your description it sounds like it's kickass spot on.

[pipnit]

Well then from your description it sounds like it's kickass spot on.

Well it met my requirements, I wanted to build a motor that would run very safely on 87 octane and go over 70. I got there right away. This week I'm putting in an MSD with the adjustable rev limiter (cheap insurance) once we set the curve in it and then I'll get to tuning the motor up a little and then maybe some prop work but this 23" quad four is doing a nice job. Tomorrow I'm testing a 22" Bravo just for kicks but I think the 23" might be the ticket because I'm cruising around 50 mph right near three grand which is pretty nice. It'll be interesting to see what the 22 is like.

[Walt. H.]

I'm going to venture a guess and say that 22-P 4blade Bravo is going to give you unwanted excess sternlift and cause a mega loss of mph, like 4 to 7-mph?
A good 3-blade 25" pitch should bring you down to 5100/5000 rpm's and your MPH closer to 80 if you're already doing 75.2 @ 5400-rpm's.

[pipnit]

I'm going to venture a guess and say that 22-P 4blade Bravo is going to give you unwanted excess sternlift and cause a mega loss of mph, like 4 to 7-mph?
A good 3-blade 25" pitch should bring you down to 5100/5000 rpm's and your MPH closer to 80 if you're already doing 75.2 @ 5400-rpm's.

Thanks,

I know this is the wrong thread but it's what we're talking about. My wife and I are going out tonight (date night!) on the boat and I'm testing the stock 22 bravo which I rented from BBlades. I'll let you know what happens perfomance wise.
One thing that I've noticed with the stock 23" quad four is that my steering doesn't seem quite as good as it used to. The boat tends to lean more and carve less if that makes sense. The sensation I get and this is just seat of the pants is that the stern of the boat doesn't dig in and carve in the turn.
I've made a lot of changes to my boat this year though and one of them was to fix the damaged skeg so maybe that has something to do with it.
Maybe the next prop to try is a 24 or 25" quad for as you suggest. Before I rent anymore props though, I'm going to tune the motor back up after installing the MSD. Thanks for your thoughts and advice!

[Walt. H.]

I'll suggest a 4-blade when you're after the best mid-range cruise speed to obtain good fuel mileage, but for squeezing the most mph for your 18-C i'd say work with a 3-blade so you can swing a bigger pitch then a four in your rpm hp curve.
For your size boat you want more bow lift then stern.

[Ghost]

My wife and I are going out tonight (date night!) on the boat and I'm testing the stock 22 bravo which I rented from BBlades...

Sorry about the hijack, but for juvenile people like me, this is crying out for a link to:
http://www.sportfishermen.com/board/f17/his-hers-diarys-1145769.html


End of hijack, back to our regularly scheduled thread.

[pipnit]

haha, Ghost, I got that in an email the otherday. Good one! lolzzz

[Donzi_Dude]

Don't go sour grapes on us, lol. I was just funning about the spelling.
What motor and what carb do you run?


hee,hee,

glad to hear your boat is running like it should.


i run a BBC and Barry Grant 850.

[mrfixxall]

this audda confuse some of ya!

[Walt. H.]

this audda confuse some of ya!
1969 thru early 71' 950 cfm Holley three barrel, when less barrels gave more.:wink:

[Donzi_Dude]

so what happened with the 22 Bravo?

ya, the cruise on a 23" quad-4 is awsome.