To Boost Reference or not to Boost Reference?
12-29-2002, 10:21 PM
#21
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You definately want your powervalve boost referenced if your setup is a drawthru system. You self doer's need to look in the HOLLY book under ...Carb mods for Turbo draw thru systems.It requires drilling a hole in the carb body and pluging another hole in the powervalve chamber. I did both carbs of my carbs 18 yrs ago epoxy still holding. Hope this helps.. HAPPY NEWYEAR OSOERs.
01-05-2003, 01:29 PM
#22
Ginger or Mary Ann?
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The pic is of my 1050 Dom that was also originally a Nickerson carb, that shows the now boost reference port. It appears that it was originally set up the same as RLW's. Boat would not idle more than a couple of minutes and the transom was always pitch black. I sent it to Bruce Dudley to have it boost referenced. He replaced the metering blocks as the originals were modified too much for use. (This was appearent to me from the grinding of some of the passages) The response and idle characteristics from the change over was unbelievable. AND, the transom has always been white. I could not believe the change. The statement "runs like a fuel injected" came from me. By no means knocking Nickersons work, it just did not work for me.
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Last edited by US1 Fountain; 12-02-2011 at 11:17 AM.
01-05-2003, 08:08 PM
#23
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How about this. I found out the carbs I got from Teague are wrong. There was a communication problem about my setup and they are going to trade the 750’s for 1050 Dominators. I’ll pay the difference of course. I think this time I will send them for referencing.
RumRunner
If Teague does there normal modification will it cause a problem to have the 1050's boost referenced. I do have problem with backfires now if the boat isn't started for a week or more.
Roger
RumRunner
If Teague does there normal modification will it cause a problem to have the 1050's boost referenced. I do have problem with backfires now if the boat isn't started for a week or more.
Roger
01-05-2003, 08:17 PM
#24
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Roger
If they boost ref. the carbs it shouldn't have any affect on having problems.
The only reason you should be backfiring through the carb is being too lean or your timing being off. Since this only happens when you let the boat sit for more than a week you're most likely looking at either fuel leaking out of your 750's into the motor, or evaporating. Try to crank your engine over until you have oil pressure (so the carburetor is sure to have some fuel) before you try to start it. That should eliminate that problem.
Doug
If they boost ref. the carbs it shouldn't have any affect on having problems.
The only reason you should be backfiring through the carb is being too lean or your timing being off. Since this only happens when you let the boat sit for more than a week you're most likely looking at either fuel leaking out of your 750's into the motor, or evaporating. Try to crank your engine over until you have oil pressure (so the carburetor is sure to have some fuel) before you try to start it. That should eliminate that problem.
Doug
01-06-2003, 08:17 AM
#25
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Hello Guys!
I just remembered something
Remember when Detroit built carbureted draw through turbo sustems? True, this is not exactly the same as roots or Whipple, but it is the same principle.
GM indexed the power valve on their Q-Jet on the turbo Buick V-6 and Ford did it on the turbo 2.3. The Q-Jet was a pain to do, but they spent the money and did it anyway! Boats are different than cars, but there is NO fuel curve that can account for every situation without INDEXING THE POWER VALVE!!!
I just remembered something
Remember when Detroit built carbureted draw through turbo sustems? True, this is not exactly the same as roots or Whipple, but it is the same principle.GM indexed the power valve on their Q-Jet on the turbo Buick V-6 and Ford did it on the turbo 2.3. The Q-Jet was a pain to do, but they spent the money and did it anyway! Boats are different than cars, but there is NO fuel curve that can account for every situation without INDEXING THE POWER VALVE!!!
01-06-2003, 11:07 AM
#26
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blown1500
Interesting they boost referenced a Qjet. I've seen cars set up with a blower and Carter AFB/Edelbrock carbs. Has anyone seen one of these carbs boost referenced?
Gary
Interesting they boost referenced a Qjet. I've seen cars set up with a blower and Carter AFB/Edelbrock carbs. Has anyone seen one of these carbs boost referenced?
Gary
01-06-2003, 07:59 PM
#27
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Mr. Anderson,
I have boost referenced almost every carburetor there is and a Carter or Edelbrock is a pain to do, but it can be done. It is like doing 2 Q-Jets. The carb body must be drilled below the power valve to connect a vacuum hose and the hole in the cavity now must be plugged. The other thing you must do is use a valve that will close off the boost reference hose when no vacuum is present. I used to have a NAPA part number for one, but I don't remember it and can't find my note. It was a Ford part for evaporative emissions I think. If you will pm I'll try to help.
I can boost reference for you if you need it.
I have boost referenced almost every carburetor there is and a Carter or Edelbrock is a pain to do, but it can be done. It is like doing 2 Q-Jets. The carb body must be drilled below the power valve to connect a vacuum hose and the hole in the cavity now must be plugged. The other thing you must do is use a valve that will close off the boost reference hose when no vacuum is present. I used to have a NAPA part number for one, but I don't remember it and can't find my note. It was a Ford part for evaporative emissions I think. If you will pm I'll try to help.
I can boost reference for you if you need it.
01-07-2003, 09:12 AM
#28
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blown1500
Thanks, I was just curious. From your description the port at the bottom of the piston needs to be plugged. I wasn't sure if there was room to drill a new port below the piston though. That's the hard part, right?
Is the function of the valve you were talking about to prevent the positive blower pressure from leaking around the piston or blowing it out? That piston does not seem to have an air tight seal around it.
Gary
Thanks, I was just curious. From your description the port at the bottom of the piston needs to be plugged. I wasn't sure if there was room to drill a new port below the piston though. That's the hard part, right?
Is the function of the valve you were talking about to prevent the positive blower pressure from leaking around the piston or blowing it out? That piston does not seem to have an air tight seal around it.
Gary
01-07-2003, 11:18 AM
#29
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Mr. Anderson,
The power piston can be plugged in the bottom and a hole drilled
CAREFULLY from the front of the main body very near the bottom of the piston bore. I generally drill the hole and insert a 3/16" piece of steel tubing on each side.
The piston is not a perfect seal on this carb or a Q-Jet and any boost will leak past the piston and wreak havoc in the float chamber!! That is the function of the valve. The NAPA part number for a compatable valve is 207449. I believe these are good carbs, just annoying to tune or boost reference-but worth it.
If I can further assist, I will give it my best effort. pm if you want my number and we can talk
The power piston can be plugged in the bottom and a hole drilled
CAREFULLY from the front of the main body very near the bottom of the piston bore. I generally drill the hole and insert a 3/16" piece of steel tubing on each side.
The piston is not a perfect seal on this carb or a Q-Jet and any boost will leak past the piston and wreak havoc in the float chamber!! That is the function of the valve. The NAPA part number for a compatable valve is 207449. I believe these are good carbs, just annoying to tune or boost reference-but worth it.
If I can further assist, I will give it my best effort. pm if you want my number and we can talk
Last edited by blown1500; 01-07-2003 at 11:35 AM.
01-07-2003, 11:37 AM
#30
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blown1500
Thanks for the info. I know where to send it now if I want to try this. I dont think I would want to try to drill it myself. There doesn't seem to be much clearance for that hole.
What is used for a check valve. Is it a specialty, custom made piece or is something like a small PCV valve available?
Gary
BTW, This board is great for learning some of this stuff that's almost impossible to find out elsewhere!
Thanks for the info. I know where to send it now if I want to try this. I dont think I would want to try to drill it myself. There doesn't seem to be much clearance for that hole.
What is used for a check valve. Is it a specialty, custom made piece or is something like a small PCV valve available?
Gary
BTW, This board is great for learning some of this stuff that's almost impossible to find out elsewhere!
