Carb question. 850 vs 800
#41
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Thread Starter
Thanks. I have an open port on the side of the carb, would this be it? Old carb didnt have this so i know it didnt hook up there
One more question. The old carb had no vacum lines ran to it. It had one port on the base with a small hose that ran over to the choke area.
The quick fuel carb has two ports on the front both of which have a nipple to plug them. It also has a pory coming out the side of the carb. Unplugged. Its on the same side as the choke. Not sure what i should do with that port?
One more question. The old carb had no vacum lines ran to it. It had one port on the base with a small hose that ran over to the choke area.
The quick fuel carb has two ports on the front both of which have a nipple to plug them. It also has a pory coming out the side of the carb. Unplugged. Its on the same side as the choke. Not sure what i should do with that port?
Last edited by cabin fever; 03-01-2017 at 11:25 AM.
#42
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Bumping this thread.
Ordered the 850. QF. Recieved over the weekend. Looks like a nice piece. Installed and about ready to go.
I run an older holley mechanical fuel pump. Where does the vent hose from the pump suppossed to go?
For the life of me i dont recall where it was hooked up to if anything before the engine build.
Ordered the 850. QF. Recieved over the weekend. Looks like a nice piece. Installed and about ready to go.
I run an older holley mechanical fuel pump. Where does the vent hose from the pump suppossed to go?
For the life of me i dont recall where it was hooked up to if anything before the engine build.
#43
Registered
May I interject something here.....the motor will only pull so many cfms. If it pulls 812cfm and you have a 1050cfm carb, great, if you're wide open all the time.
Carbs, particularly Holley, are very touchy about getting good references on it's circuits for proper operations at ALL speeds. In the old days when I was a pup, we would carb down for response, carb up for overall power. Without a dyno velocity hat, it's near impossible to tell exactly how much "flow" you really have at any given rpm on the range.
The calculations given and a vacuum gauge will get you about as close at anything. imho, anything over 1000cfm carb could give you some idle and low end acceleration issues.
Another .02 cents, there's a lot of throttle body injection systems that are the same or slightly above what your looking to spend on a carb, and are infinitely adjustable up to 1200hp. Might be worth looking at.
Carbs, particularly Holley, are very touchy about getting good references on it's circuits for proper operations at ALL speeds. In the old days when I was a pup, we would carb down for response, carb up for overall power. Without a dyno velocity hat, it's near impossible to tell exactly how much "flow" you really have at any given rpm on the range.
The calculations given and a vacuum gauge will get you about as close at anything. imho, anything over 1000cfm carb could give you some idle and low end acceleration issues.
Another .02 cents, there's a lot of throttle body injection systems that are the same or slightly above what your looking to spend on a carb, and are infinitely adjustable up to 1200hp. Might be worth looking at.
#44
Registered
Vacuum gauge and the size of the throttle bores and venturi...cause carb manufacturers and modifiers lie profusely about their carbs cfm ratings.
#45
Registered
Most, if not all, Holley carbs don't have a fitting for the hose from the pump, as it needs to be in an atmospheric position and near enough the throttle bore openings if the pump diaphragm ruptures and pous fuel thru the line. If the arrestor doesn't have a fuel fume fitting, I simply drill a hole in the base plate of the arrestor near carb opening and thread in a pipe threaded brass nipple fitting. Wallah.
#46
Registered
My 80443 Holley 850 marine carbs, had a fuel pump vent tube, on the port side of the carbs.
#47
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Yup. Good call.
#48
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Thread Starter
I have the worst f'n luck! I could fall into a barrell of boobs and come out sucking on my thumb!
Bought the quick fuel 850. Installed
Week later finely got the time to fire it up
Ran like complete dog chit! Black smoke so bad it covered the back of the boat. Wtf?
After a minute or 2 it came out of it and idled fine. While looking through the sight glass, seemed the float was adjusted a little high. While adjusting the float my son was talking to me and withouht paying attention i stripped the threads on the f'n float bowl!
Of course since its the black diamond bullchit a new bowl was the price of a kidney and bj. I ordered 2 new polished bowls for less then 1 black one. Fixed and ready to fire up again
I must say after it came out of the horrible rich condition it idled like a champ.
Probablly be another week or so before i can get back to working on the boat. In the middle of a kitchen remodel, that like the engine rebuild is way over budget and doesnt seem to end. Happy wife/happy life.
I did get my new aluminum swim platform yesterday. Cant wait to get it installed.
Bought the quick fuel 850. Installed
Week later finely got the time to fire it up
Ran like complete dog chit! Black smoke so bad it covered the back of the boat. Wtf?
After a minute or 2 it came out of it and idled fine. While looking through the sight glass, seemed the float was adjusted a little high. While adjusting the float my son was talking to me and withouht paying attention i stripped the threads on the f'n float bowl!
Of course since its the black diamond bullchit a new bowl was the price of a kidney and bj. I ordered 2 new polished bowls for less then 1 black one. Fixed and ready to fire up again
I must say after it came out of the horrible rich condition it idled like a champ.
Probablly be another week or so before i can get back to working on the boat. In the middle of a kitchen remodel, that like the engine rebuild is way over budget and doesnt seem to end. Happy wife/happy life.
I did get my new aluminum swim platform yesterday. Cant wait to get it installed.