SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: WORD on May 07, 2008, 08:49:00 PM
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I have so many questions...it is amazing. But I think my questions will help out newbie's like myself. I am currently running a Edlebrock 750. I have no issues, runs great. But when it comes to a 454 jet boat....what do most people run and what are the performance differences that are noticible if I changed???
Again, thank you all for your responses and support.
I see where you can donate to the site. Doe sthat money go directly to the development of this site, or an outsde charity?
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Your carb size is based on what mods are done to the engine. I ran a holley 750cfm on basically stock engines and was good to go.
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If you have no issue's with it and it runs great, run it!
From my small amount of experience the Edelbrock is easier to work on and the Holley DP's will give you more power. A 750 is a good sized carb for a stock 454.
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Thanks, as of now, not any mods to my engine and I have been pleased with the edlebrock.. But, I said in another thread, I am almost ready to send my boat to TOm with a $20K check atteched telling him to do whatever he feels!!!!
THanks for the insight, I guess I was just wondering if I switched back to a holley, what would differece be. and with what I am running, i dont think i woujld notice squat>
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Thanks, as of now, not any mods to my engine and I have been pleased with the edlebrock.. But, I said in another thread, I am almost ready to send my boat to TOm with a $20K check atteched telling him to do whatever he feels!!!!
THanks for the insight, I guess I was just wondering if I switched back to a holley, what would differece be. and with what I am running, i dont think i woujld notice squat>
Well just remember this and I think I am quoting Ralph on this but "an engine is an air pump, the more you can get in and out and faster the better." I also know that the more efficient you can get an engine to run the more HP potential it will have.
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I totally concur with you, but the reason I was asking is because of the 3 jet boats I know of out my way....everyone is running alchohal, 1300 hp, so anyhing I have to show them is never enough.
but Edlebrock carbs on a stock 454 is decent, correct?
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... everyone is running alchohal, 1300 hp...
I need to move to Georgia! (again)
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but Edlebrock carbs on a stock 454 is decent, correct?
The carb you have should work well with your engine. Marcsrollin has a dual carb both 600cfm setup on a (if i remember correctly) mostly stock 460. Its somewhat over carbed but runs well.
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Back in 95, we went through the motor in our Advantage. I bought the Edelbrock Performer RPM package, 750 carb, intake, cam, valve springs, timing chain and a few other things. It ran strong, 5200 rpm's. Last year we freshened the motor up and I decided to get an 850 Holley. Way too much carb and we lost rpm's. Jetted it way down but haven't run it yet. My stock 330 hp bbc came with a 650 Holley, so your Edelbrock should be plenty of carb for now. We got 10 trouble free years out of our Edelbrock and I just gave it to my brother-in-law for him to put on his Liberty.
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The carb you have should work well with your engine. Marcsrollin has a dual carb both 600cfm setup on a (if i remember correctly) mostly stock 460. Its somewhat over carbed but runs well.
Marc's engine has dual Holley's and I think it's a stock high output Hardin Marine 460. It runs great!
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I have had great luck with edelbrock carbs on stock to mildly modified engines very easy to set up However I have had problems with them on high compression ,huge cammed motors they seem to be lazy on the bottom I like the holleys in those applications currently I have a 460 stroker ,513 cid in a 1978 nordic and I couldnt get the edelbrocks to work to my liking...got tired of pulling the tops off messin with springs and step up rods,I went to two 450 holleys problem solved,the carbs were almost right on out of the box had to jet up a bit but greatly improved throttle response and mid,I drive a 1974 chevy 3/4 ton 4x4 with a very small cam and basically stock with a performer 2/0 intake and a 750 edelbrock carb have had no problems in four years, I did notice more fuel economy with the edelbrock versus holley carbs to.......hope this helps I am completely new to jetboats also but have built several wicked cars and trucks
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The edelbrocks strengths are also its weakness.
The single acc pump circuit is not strong (uses an air door for the secondaries to slow the air instead of adding fuel). This leads to better mileage and drivability on most vehicles. However on cams and heads that NEED better tip in, they fall short with no real way to improve it much past the "as shipped" state.
Holleys on the other hand, can tune this circuit dramtically, independently on both primaries and secondaries, and is the real reason why Holleys (and clones) continue to dominate.
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Marc's engine has dual Holley's and I think it's a stock high output Hardin Marine 460. It runs great!
The carb you have should work well with your engine. Marcsrollin has a dual carb both 600cfm setup on a (if i remember correctly) mostly stock 460. Its somewhat over carbed but runs well.
To clear the record they are 750 vacuume secondaries. holley 4150's matched.
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To clear the record they are 750 vacuume secondaries. holley 4150's matched.
Which means you basically have a mechanical 750 until you get to 4K, then additional CFM starts flowing. Nothing wrong with that...
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Which means you basically have a mechanical 750 until you get to 4K, then additional CFM starts flowing. Nothing wrong with that...
When i bought my Hondo it had two 750 on a tunnel ram vacuume secondary, could not get them to work for me do to low vacuume, got a smoken deal on two 750 Edelbrock mechanical secondary,ran strong ever since. Holly vs Edelbrock.
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Everyone I've talked to that has a relatively stock motor loves their Edelbrock. I got a smokin deal on a modified 750 Holley DP from a carb shop on ebay. Can't remember their name on ebay but I know they still sell carbs there. Anyway, I also had a little experience with Holleys from bracket racing days (although it seems like I forgot a lot of it) and none what so ever on the Edelbrock, so that's why I got my Holley. If I were you, I'd leave the Edelbrock alone until you do any major mods to the motor.
ps. found the guy I bought my carb from
http://cgi.ebay.com/ebaymotors/HOLLEY-CARBURETOR-830-CFM-HI-PERFORMANCE_W0QQitemZ120259031264QQihZ002QQcategoryZ33550QQssPageNameZWDVWQQrdZ1QQcmdZViewItem