Holley Gurus.... a question
 

I have a Holley 850 on a 540 with AFR 315 and gill manifolds i and thinking about the proform center carb body. has any one had experience with these? a friend of mine dynoed his 540 dart motor and he was showing over 1050 cfm on a proform 950. I have 89 primary jet and 95 secondary and we are about 1000 ft above sea level. I am having a Little trouble getting above 80 with more than three people in the boat. with two and no fuel i can reach over 90 easy . Any suggestions? what about staggered jetting?

Re: Holley Gurus.... a question
 

two people and fuel knock 10 mph off, what kind of a boat do you have?

Re: Holley Gurus.... a question
 

Hello, I have used proform bodys, and they are a very nice peice. Do I think you will see a big difference in performance? not really, I don't think you have maxed out the 850, but yes I would put one on yours. They look great, and are reasonably cheap. 850's should be square jetted as they are the same size front and rear, unless you don't have a power valve in the rear. The old saying is 10 bigger on the jet size without one, but I have found it to be more like 6, 10 on a dominator carb. Just keep jetting bigger until it slows down, and then back off to the last jet size. Be aware that you will lose the choke provision, so you will have to pump the throttle a few times to get it started. P.S. tell the wife, they make great xmas presents! :chimp:

Re: Holley Gurus.... a question
 

I ahve had great success with my Nickerson prepped HP 1050 Dominator. I would highly recommend them.

Re: Holley Gurus.... a question
 

After finding our best dyno setup, we switched out the main throttle body and throttle plates for the proform ones and picked up 18hp from 563 to 581. Still were pulling pretty good vacuum. But didn't have the bucks to go dominator manifold and carb. Well worth the bucks, but not USCG legal of course.

Re: Holley Gurus.... a question
 

dominator manifold and carb. Well worth the bucks, but not USCG legal of course.


that not true dominator comes uscg aproved

Re: Holley Gurus.... a question
 

My Nickerson dominator is a marine approved.

Re: Holley Gurus.... a question
 

I have a 23.5 ft eliminator twin step eagle. a relatively light boat. it chines a Little up to like 83 with two people but then settles down. Yes i need the steering. But motor work is more fun.

OK so i noticed that you can get a center proform section for a 850 and it is 189 but not as many places carry the 850 section as the 950. is there a difference in the throttle plates? can i use the 950 center or should i just get new plates and the 950 center body? when i look at the throttle plates it says 850 -950 . are these the same size? I have talked to 69cstaub and he seems to think i have too much cam and i need more carb. well i am going to go for the MORE IS BETTER TOO MUCH IS JUST RIGHT theory and just add carb and intake this year.

Re: Holley Gurus.... a question
 

Too much can also be a waste :(
I had a 540 with too much carb and everything happened in the first 3/4 throttle. The last 1/4 did nothing as to speed , it just made more noise. Quickfuel replaced my primary boosters with more restrictive ones and cut the airflow down. The result was the same speed but it varied throughout the entire throttle range. The only other alternative is use less prop and turn the engine harder , then you can use the extra airflow if the cam and heads can support it :rolleyes:

Re: Holley Gurus.... a question
 

What list number holley is it? and is it an HP series? Are you running any power valves? RPM engine spins light on fuel? get me a little more specs and I can place you right where you need to be. Thanks,

Dean Gellner

Re: Holley Gurus.... a question
 

The proform main body and billet throttle plates are not USCG approved

Re: Holley Gurus.... a question
 

6.5 PV on front and back 89 front jets and 95 back

carb number 80330

i was spinning 5600 with no fuel and it was still pulling but slowly (94 mph gps w 2mph downstream current) i am running a 1.36 drive and a 27 pitch mirage that has been shaved quite a bit but never dialed to the boat i have to rering this spring and i am making a few changes. I was running 5400 with 7 people in the boat only doing 80 and it was topped out. it had no more. This is the time i melted the three pistons..... I had a distributor go bad. I have since replaced the dist. I know the proform body is not USCG approved. the main difference is the vent tubes and the pilots and a small plastic/uhm piece around the choke rod on the top of the carb. And sealed throttle shafts to prevent fumes from escaping in the bilge area. So for the sake of argument i am not running a hatch cover......

I am thinking about at least cutting the choke horn off.....

Roller hyd cam and 629 lift with 236 and 244 dur i cant remeber the Lsa right now.

Re: Holley Gurus.... a question
 

I would put the body on the carb, it's cheap enough, and is a hell of alot easier than cutting the old one. You should definately square jet that carb with the power valve in the rear. I would go to 92 square and start going fatter 2 jet sizes at a time. We ended up with 93 square with power valves on our drag cars. They were 650 hp 468's on 93 octane. Don't waste your money on a Dominator. We put one on those motors and gained nothing on the track, and they spun 7500 rpm.

Re: Holley Gurus.... a question
 

Ok so what about the differnce in throttle plates? And can a person use the 950 proform body with the rest of my carb parts?

Re: Holley Gurus.... a question
 

I checked out proforms website, and heres what I see. The 67108C main body is the same one used for 850 and 950 carbs. The throttle plate assembly is what makes the 950. The fact that is has the thinned shafts and button head screws make the 850 body flow 950. You will only have to use the 67108C body on your baseplate. I usually take the baseplate apart and thin the old shafts myself with a die grinder and put them back in with locktight on the threads. But once again, the thinned shaft kit is so cheap and simple to install, why not spend another 100 and have a real nice trick looking carb that flows great cfm? Heck a nice looking boat like that DESERVES a great looking carb. :chimp:

Re: Holley Gurus.... a question
 

Be sure and tiewrap or glue on all the vacuum port boots and it is also a good idea to locktite any screws that can drop into the intake.

The last post in this thread shows the proform base plate http://www.offshoreonly.com/forums/s...75#post1315475