SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: 2savage4you on December 11, 2007, 09:47:45 AM
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I have a Edelbrock carb 750 cfm that i had on my other boat with a 455 Olds and now im building a BBF 460. Im just wondering if i should use it or go with a 850 Holley DP?
Im kinda leaning to the holley, So my question is what would you guys do?
Im thinking sell it on Ebay and pick up a Holley, or should i just run it and go from there. And what is the difference on car vs Marine carbs. This has probably been asked here before but i dont want to do it twice ;D
People here give out good advice, soooo......... lets get some ;)
2sav
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Well from personal experience Holley will get you more power. The Edelbrock will be smoother and easier to tune and save a little gas. Ive seen 500+HP running off those Edelbrocks with a great powerband and smooth idle etc.
The Edelbrock 800 AVS is a great carb and will run 555ci. and 600+HP all day. Its getting really popular on crate engines.
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The difference between a marine and an automotive carb lies in the vent tubes. Automotive carb bowl vents stick straight up, whereas the marine vents are "J" shaped (hence the name "J tubes") so they point down into the bowl. The purpose of this is so in case the bowl overfills the extra fuel gets dumped back into the motor rather than leaking all over itself, preventing a fire hazard.
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My BBF has an Edlebrock and until it craps out, I'm going to leave it on there. It doesn't have the "J" tubes either so I just hope it never over fills the bowls.
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I've had the question. Right now I've got a q-jet that runs like a charm. Fires up, idles, and purrrrs. I actually like the vaccum secondaries because I can part it at 4200rpm and keep the gas bill down. BUT what would a 750-850 Holley dp do for me? With less than 400hp now, will it give me any bang for the buck? The dp should have a better throttle response -but that isn't needed in my large boat...
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I may be wrong but I think the marine holly also has a special " hard to kill" power valve. On my olds 455 iI had in my k boat, it ran great with the quadra-junk carb, till one season I put it in the water and she was done. then I bought an edelbrock, and never could get it to run as well as the spreadbore qj, not to mention I'd have to tear it apart every spring. then I went to a 780 vac sec holly, it was close but I'd swear the old quadra jet hit hardest. Maybe i had the floats adj wrong or something but with the holly everytime the boat would "land" at wot it felt like the boat would stumble/pause.
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I swear by the demon. The Holley's are great, just a little harder to get support from Holley.... I had the 1050 Dominator on my truck, worked well. Needed to be tweaked constantly. When I called Holley for input they referred me to my nearest auto parts dealer who knew nothing. So on my jet boat I went with the 850 Mighty Demon, tuned it once and never touched it again. The demon was not a marine carb, however I have been told you can buy the "J" tube and install it...
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Well the way its looking so far is Edelbrock, Holley and demon and im sure others all have there problems. So this is still a toss up ;) keep the info coming guy's
2sav
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A few of my friends have had edelbrocks. Easy to work with, not much in the way of tuning options compared to the others. The way I understand it, the edelbrocks are in the "beginner class..." haha. I really liked my Demon. Whatever carbed engine I do next will have another Demon.
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when i had the test motor in the boat, it had an edelbrock on it bought it new put it on and very little tuning needed, never had a problem with it at all. am now using the same 2 holleys i had on my flatbottem, no problems when they were on that boat, tuned them and forgot them, have not had enough time on the new motor to make a verdict, but so far so good, just rebuilt them last week, so time to start over :)
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I've got a Mighty Demon 850dp and love the fukin shit out of it as of late . Holley's and Demons are pretty much the same thing . I think the demon has more adjustability though .
I thought those shiney things Edelbrock made were tire chocks ???
-beerjet-
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I've got a Mighty Demon 850dp and love the fukin shit out of it as of late . Holley's and Demons are pretty much the same thing . I think the demon has more adjustability though .
I thought those shiney things Edelbrock made were tire chocks ???
-beerjet-
Ok then screw it, i dont want no tire chocks on my new engine ;D
Its going to ebay ;) And then i will pick up a Holley 850 DP. I think Jim has one anyways. Yep
Anyone need a carb for their car or truck? thats what this thing looks like, not for a boat. But what do i know
2sav
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fi223.photobucket.com%2Falbums%2Fdd269%2F2savage4you%2F001-3.jpg&hash=e3b982a22fd70b3645e00d6b84a041b1cd3af9dd)
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I just ordered a Holley 800dp (4150, pn 9022?). I was told for my application it should be tuned out of the box from Holley. Are there any pointers I need to follow? I'll have to change the throttle location, install the fuel log, and square bore/spread bore adapter, but I think that's it. I hope it works and doesn't become an expensive paperweight.
As it runs now with the Q-jet: WOT is ~4800-4900rpm. Think I'll see 5k w/the new carb?
Hopefully next weekend I'll make it out for a test run. Any takers for a ride w/some Carb experience? Free beer and ride w/your expertise!
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I would pull the float bowls off and double check the float levels before i'd install it (easy to do on the bench with no fuel in it).
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Go 850 Holley. On my 455, I picked up 500 RPM over the 750 vac (though the 750 did have some problems).
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speedy what did you do with your 455?
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Sitting in my garage. Ran good (recent rebuild - herbert hyd .490 lift 230 duration cam, performer) , it was the boat stringers that got trashed. I had to either fix the stringers, or change to a different engine. Given the fact I have 4 BB mopars in the garage, my entire fleet is Mopar (inc a 12 second 440 van and a 9 second duster), the choice was clear (and a good excuse).
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I have 4 BB mopars in the garage, my entire fleet is Mopar (inc a 12 second 440 van and a 9 second duster).
I'm gonna guess that 12 sec van isn't a mid 80's Caravan. :o How 'bout some pics?
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Here are a few
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and a timeslip to go with it
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My BBF has an Edlebrock and until it craps out, I'm going to leave it on there. It doesn't have the "J" tubes either so I just hope it never over fills the bowls.
You don't have to worry the Edelbrocks don't have J tubes. Just grab the part number off of the base of the front and type it into a web search it will tell you what it is. A lot of the shelf edelbrocks for automotive applications are calibrated for small blocks and generally need their "calibration kit" to work a little better.
A Sea Demon is on my Glastron, and until it shows me an problems it will stay their, but I would not have chose it personally. Our wholesale supplier and Summit Racing chose to drop the whole Demon line due to too many problems, porossity and manufacturing defects. We bought a pair of Demons once that had a porosity problem, just kept flooding over no matter what you did with the needle and seat.
Holleys are great carberators and the HP series are eaven better. But generally the HP series holley cost more than a Proform, Quick Fuels or AED carb and wont flow as much. The Engineer at quick fuel Technologies told me that the 950HP holley only really flows about 860cfm compared to their 950Q which really flows 950+. The difference being the 950 holley = 850 baseplate + 750 based body. 950 QFT = 850 Baseplate + 950 Proform Main body. However the 950 holley does have an awesome Booster signal and throttle responce. That Info finally solved the mystery of why the 950hp Holley works so awesome on my SBF, compared to the 850 dp which never worked worth a crap on the same engine.
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I will say however the Sea Demon DP on my Glaston does kick ass compared to my grandpas Identical boat with the original 4160 style 650 vacuum carb(both 78 CVX20 with same original berkpack-a-jet 460's).