borrow a carb

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rdb
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borrow a carb

Post by rdb »

Anybody have a 600-750 Holley Double Pumper laying around that I can run on my engine? Need to try a different carb on engine to prove I have a carb issue or not. I will pay shipping and rent for the carb. Any help or suggestions are appreciated.

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Deano
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Re: borrow a carb

Post by Deano »

Rather than endure that expense and then still have a broken carb to fix, IMHO, it would make more sense to have Allen Bills at S & S Performance Carbs fix the one you have. I believe he's around Houston and his number is 281-445-7996. You would get it back from him in absolutely perfect working order.

Many here have used him . . . never heard anything but great reviews. I would expect
A quick [Search] here, would yield about the most creditable referral I could imagine.
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but it is not the path to knowledge; it has no place in the endeavor of science."
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jeepinocala1111
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Re: borrow a carb

Post by jeepinocala1111 »

rdb wrote:Anybody have a 600-750 Holley Double Pumper laying around that I can run on my engine? Need to try a different carb on engine to prove I have a carb issue or not. I will pay shipping and rent for the carb. Any help or suggestions are appreciated.
What's your boat doing?

rdb
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Re: borrow a carb

Post by rdb »

Deano thanks for the referral, I will give him a call.

Jeep, Engine freshly rebuilt and brand new carb. Headers are glowing once I hit the 3000 RPM range. Everything has been checked more than a dozen times and have gotten the usual suggestions. Holley has tested carb and says it works great. People suggest since I have checked everything that it has to be carb and that they have had problems with carbs that were new and had to get them fixed by a professional carb guy. This is it in a nutshell.

I am going to run engine with two barrels and see what happens. If I get same results I am going to put my old worn out carb on that only two barrels work and see if there is a difference. Then I will know if carb problem or not.

Thanks for the suggestion.

loudmouse
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Re: borrow a carb

Post by loudmouse »

Headers glowing red will be either timing to low, carb too rich or too lean or an intake gasket/vacuum leak. Check for vacuum leaks. Check or adjust timing. Pull plugs to determine rich or lean. If lean go up 2 jet sizes on primary side only. Retest at cruz rpm. If still glowing, verify plug still lean and go up 2 more at a time until you get afr right for that engine. Then add 8 jet sizes over the primary side to the secondary side. That will get it close. If its rich and fuel is burning in the header check the power valve in primary side first for being blown then for correct vacuum opening against cruz vacuum reading. PV should be about 4 lbs under cruz vacuum(ie: cruz vacuum reading 10lb then a 6.5 pv be about right) after pv has been fixed/checked, then decrease jet size in primary by 2 and retest. Once correct cruz afr is right then adjust secondary jets 8 sizes over primary. When u have the engine running good, check WOT AFR. Error on the side of a lil rich more so than lean as the valves will live longer. If WOT is lean increase secondary jet by 2 sizes first. If still lean increase primary by 1 size. This method has never failed me but you will have to take time to run the boat and read the plugs after every single change and only make one change at a time b4 testing. Remember to set timing first. Then adjust idle rpm and idle screws, then start tuning cruz afr then wot afr. Good luck tuning....
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jeepinocala1111
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Re: borrow a carb

Post by jeepinocala1111 »

loudmouse wrote:Headers glowing red will be either timing to low, carb too rich or too lean or an intake gasket/vacuum leak. Check for vacuum leaks. Check or adjust timing. Pull plugs to determine rich or lean. If lean go up 2 jet sizes on primary side only. Retest at cruz rpm. If still glowing, verify plug still lean and go up 2 more at a time until you get afr right for that engine. Then add 8 jet sizes over the primary side to the secondary side. That will get it close. If its rich and fuel is burning in the header check the power valve in primary side first for being blown then for correct vacuum opening against cruz vacuum reading. PV should be about 4 lbs under cruz vacuum(ie: cruz vacuum reading 10lb then a 6.5 pv be about right) after pv has been fixed/checked, then decrease jet size in primary by 2 and retest. Once correct cruz afr is right then adjust secondary jets 8 sizes over primary. When u have the engine running good, check WOT AFR. Error on the side of a lil rich more so than lean as the valves will live longer. If WOT is lean increase secondary jet by 2 sizes first. If still lean increase primary by 1 size. This method has never failed me but you will have to take time to run the boat and read the plugs after every single change and only make one change at a time b4 testing. Remember to set timing first. Then adjust idle rpm and idle screws, then start tuning cruz afr then wot afr. Good luck tuning....

RDB listen to this post I would have to say not being a jerk but if Holley themselves tested the carb then it is something else for sure.

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90chevy396
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Re: borrow a carb

Post by 90chevy396 »

carb might have tested out good for the factory settings in the carb but you didn't specify engine size or modifications to engine upon rebuild. different rpms read different fuel output. depending on the amount of airflow of your engine at a given rpm on how big of a cfm carb you need then you have to adjust the fuel metering jets to get the correct afr as mentioned above.

I have taken carbs that work great on 1 engine and put them on my buick in the boat and run really learn so much as within 3 minutes of taking off from the landing and cruising around 2k rpms the exhaust is well over 500 degrees and spun around, got to the hill and looked back to see headers glowing bright as day light.

plugs and/or afr gauge will prove what is causing the glowing headers. assuming the timing is set correctly fro the beginning
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