1050 Carbs for marine use
 

We've been trying a 1050 cfm Holley Dominator carb my buddys boat. It seem's to run very rich, particularly at mid-range. We've been going down in jet sizes very carfully and it has helped clean up the plugs but I'm concerned about leaning out the mixture at different RPM's. I was hoping that someone has some tricks or has established some baseline set-up on Dominator carbs that we could begin with (primary to secondary linkage set-up, power valve set-up, etc). The motor is a Merlin Big M tall deck 588 cu in 9.5:1 (naturally asperated), Merlin 2.25 intake oval port heads, 615/615 roller cam.

I would suggest playing with the air bleeds. I had so many problems with the 1050 Dominator on my previous boat I sent it to Nickerson 3 times to help get it right and it still was never quite there. The only place you really need to be concerned about being lean is the upper mid to top end, being naturally aspirated you can't really hurt anything below that. What exactly do the plugs look like? are they a light brown or ??.

The first run they were SOAKED!!!! We've gone down 4 jet sizes to 85's That has helped. Holley suggests (in their literature) to remove the power valves (and plug) and step up 4 jet sizes. I'm sure we'll be back were we started at lower RPM and maybe too lean at the upper end if we remove the power valves. This motor is occasionally pushed to 5600-5800 RPM so leaning would be disasterous!!!

which carb is it? Is it new? I need the list # to help you. I just hung up 10 minutes ago with Holley tech support. I'm running 2 boats with similar setups and one carb is coming off tonight. I can give you my jet setups. I run both power valves. Last time I had a pv problem, it was stuck shut and there was no 1/4 to 1/2 throttle, just a big surge after that. If its a 3 circuit metering vs a 2, you're already behind the 8 ball.

DanL, It is Holley 8896-1 which is the 3-circuit carb. He did have one back-fire when we first bolted this carb on that could have blew-out the power valve. This is a brand new out of the box carb. I am interested in your jetting and if your power valves are 6.5's. Thanks for the reply.

thats the newest w/ the power valve protection. My f/r mains are 90's, but I'll have it apart tonight. Thats also got the soft linkage. the marine carb has a harder transition than this lnkage and you're probably fighting the linkage opening the secondary too early. Tthats more of a drag carb. They use that 3rd circuit for trans brake tuning. You may want to go down one size in the rear. Whats the intake? You may have too much carb. What came off? Dan

I would suggest getting the carb dialed in as close as possible with the power valves plugged. I've always been told the PV is for fine tuning...especially naturally aspirated. You might start with 92's to be safe and no PV as a baseline. My 1050 dominatored 502 had 78 / 82. (I had another post that said 82/88, but I just checked to be sure) Anyway, significantly below the 88 square as it came new...NO POWER VALVES. What kind of power does your motor make?? That 502 made around 625hp and was over carbed.;) what intake are you running???

The intake on this engine is a single plane Brodix for the Dominator carb.

You guys are SCARING me! My 1050 Dom, 3 circuit, has 124 jets at all 4 corners and 5.5 PV in pri. only. Maybe this explains where my gas goes. ;)

the pv # is the inches of mercury, or vacuum, that the valve opens at and starts to just dump raw fuel from the bowl. The lower the number, the wider the throttle plates are open, or just more throttle, high load, lower r's. If you have a bog down low, put in the next higher pv until the bog starts to clear out or goes away. Big engines need big fuel, but only when the engine is ready for it. AZ, on my one pair of 600's, the 8082 Dominators, 1050's, have 88's, f/r and 6.0 pv. Idle is great, no lag, dumb,flat tappet cams, lift,no duration. The other motor has 90's front, 88 rears, and the power valve says 12. I hope my eyesight is failing. That means its open all the time. I have a decently jetted 1050 for a natural, if you want, I'll loan it to you. BTW, Holley lists your carb as the HP, which is jetted 88/88 and no pv. Did you add the vavle? The hp's were listed in the marine catalog as blower carbs. Dan