Prop selection and/or trim tabs for 350 vortec on 21' bowrider?
07-20-2016, 07:46 PM
#21
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For a close 2nd to DP,you can get a quick change sec spring kit.
Don't listen to others as far as what spring.
As you go softer and softer and sec open sooner and sooner to see what works best, you'll poop yourself even with planing power. Smaller boats with decent power rewrite some rules.That is a fact....the poop yourself part too.
Don't listen to others as far as what spring.
As you go softer and softer and sec open sooner and sooner to see what works best, you'll poop yourself even with planing power. Smaller boats with decent power rewrite some rules.That is a fact....the poop yourself part too.
07-20-2016, 08:14 PM
#22
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had a 21' bowrider with a 350 set up close to what u have.stock alpha outdrive.dont remember the gear ratio.(started out as a stock 2000 250hp 5.7/alpha combo)ran a 21 pitch mercruiser vengeance prop.61 mph on gps(on the rev limiter)stock 4800 rpm thunderbolt ignition.would pull two tubes with 4-5 kids or a wake boarder,water skier no problem.plenty of hole shot to tube good cruise speed.i think it was a 600-650 marine demon.once dialed in never touched it again.might try a dp next time if I did it again.probably wont,big block now.
I'll throw the Vengeance into the mix. Still researching which brand/model to get. Leaning toward the Laser II in 3 blade or the Revolution 4 in 4 blade. Mirage/plus is out. Don't think my boat is big enough for it.
07-20-2016, 08:30 PM
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For a close 2nd to DP,you can get a quick change sec spring kit.
Don't listen to others as far as what spring.
As you go softer and softer and sec open sooner and sooner to see what works best, you'll poop yourself even with planing power. Smaller boats with decent power rewrite some rules.That is a fact....the poop yourself part too.
Don't listen to others as far as what spring.
As you go softer and softer and sec open sooner and sooner to see what works best, you'll poop yourself even with planing power. Smaller boats with decent power rewrite some rules.That is a fact....the poop yourself part too.
I don't think I can do that with an Edelbrock because it doesn't have the kind of secondary that uses a spring? I'm lost when it comes to springs, jets, metering, etc. That's kind of why I went with the Edelbrock to begin with... bolt it on and go.
I see this...
https://www.summitracing.com/parts/edl-1488
And just the springs but I don't think these are the springs you're talking about...
https://www.summitracing.com/parts/e...laoaAvmS8P8HAQ
Last edited by Gannz; 07-20-2016 at 08:59 PM.
07-21-2016, 06:27 AM
#24
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$10 for springs vs $700 for a new carb and I still get to poop my pants? Where do I sign up? LOL
I don't think I can do that with an Edelbrock because it doesn't have the kind of secondary that uses a spring? I'm lost when it comes to springs, jets, metering, etc. That's kind of why I went with the Edelbrock to begin with... bolt it on and go.
I see this...
https://www.summitracing.com/parts/edl-1488
And just the springs but I don't think these are the springs you're talking about...
https://www.summitracing.com/parts/e...laoaAvmS8P8HAQ
I don't think I can do that with an Edelbrock because it doesn't have the kind of secondary that uses a spring? I'm lost when it comes to springs, jets, metering, etc. That's kind of why I went with the Edelbrock to begin with... bolt it on and go.
I see this...
https://www.summitracing.com/parts/edl-1488
And just the springs but I don't think these are the springs you're talking about...
https://www.summitracing.com/parts/e...laoaAvmS8P8HAQ
Additionally...it's been my experience with Vortec Heads and the LT-4 cam that the SBC is craving more CFM. There are several SBC Dyno tests on line that compare different carbs and manifolds with that combination. Seems I remember reading that if you run too lean with smaller CFM carbs under a constant load (Marine Service) cylinder head temps rise quickly and exhaust valves/upper piston rings eventually suffer.
As a suggestion...shop around for a used 750 DP in good shape and try it. Check the swap shop here from time to time for that carb. They are very popular and plentiful and lot's of Chevy guys have them sitting on the shelf. I bought a pair here locally a few years back for $500 with fuel lines !
As always...no rush...enjoy and learn.
07-21-2016, 10:10 AM
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I'll pull a plug and see if she's running lean.
I went for a best bang for buck build. As mentioned, I only paid $1500 for the boat and trailer. When it was all said and done, I think I was around $2500 for the 350. I was able to re use many parts from the 305 which was in great shape. I just forgot to winterize it one year which turned out to be a good thing. I would have never pulled it and put in the 350 if it didn't need it.
I made sure to get the 906 heads.
Went with the most aggressive cam that would work without having to do any extra machine work to the heads. Went with Howards springs and retainers and the only thing I had to do was grind a little off of the bottom of the retainers to keep them from hitting the seals.
The comparison tests/charts I saw didn't have much difference between Edelbrock, Summit, Weiand, etc. intakes. The AFR Titon was the best but I think it was less than 5% over the Summit and the cost was 300% more.
For rockers, I stuck with the stamped 1.5's. Rollers would obviously be better but, for the cost, there wasn't enough performance improvement to make it worth it to me. And the general consensus I found was that 1.6 roller rockers wouldn't have a noticeable difference unless the heads were heavily ported.
Considered GLM manifolds but again, not enough bang for the buck. Also considered a thru hull but the wife probably wouldn't get on the boat if it had a loud exhaust.
A 383 would have been the best bang for the buck but not if I had to buy a new outdrive after I tore up the Alpha.
From my research, everyone agreed that a Holley DP performed better than the Edelbrock but most said that it really wouldn't be a noticeable difference and the Edelbrock was easier to tune (bolt it on and go) and more economical. I never heard of an 8mph increase which is huge IMO. Not doubting anyone, this is just the first I've heard of such a large increase. I'll tinker with the tuning and pay more for gas if I can get that kind of increase. I've already started looking at them. I want the one with electric choke and vacuum secondaries?...
https://www.holley.com/products/fuel...parts/0-9015-1
I went for a best bang for buck build. As mentioned, I only paid $1500 for the boat and trailer. When it was all said and done, I think I was around $2500 for the 350. I was able to re use many parts from the 305 which was in great shape. I just forgot to winterize it one year which turned out to be a good thing. I would have never pulled it and put in the 350 if it didn't need it.
I made sure to get the 906 heads.
Went with the most aggressive cam that would work without having to do any extra machine work to the heads. Went with Howards springs and retainers and the only thing I had to do was grind a little off of the bottom of the retainers to keep them from hitting the seals.
The comparison tests/charts I saw didn't have much difference between Edelbrock, Summit, Weiand, etc. intakes. The AFR Titon was the best but I think it was less than 5% over the Summit and the cost was 300% more.
For rockers, I stuck with the stamped 1.5's. Rollers would obviously be better but, for the cost, there wasn't enough performance improvement to make it worth it to me. And the general consensus I found was that 1.6 roller rockers wouldn't have a noticeable difference unless the heads were heavily ported.
Considered GLM manifolds but again, not enough bang for the buck. Also considered a thru hull but the wife probably wouldn't get on the boat if it had a loud exhaust.
A 383 would have been the best bang for the buck but not if I had to buy a new outdrive after I tore up the Alpha.
From my research, everyone agreed that a Holley DP performed better than the Edelbrock but most said that it really wouldn't be a noticeable difference and the Edelbrock was easier to tune (bolt it on and go) and more economical. I never heard of an 8mph increase which is huge IMO. Not doubting anyone, this is just the first I've heard of such a large increase. I'll tinker with the tuning and pay more for gas if I can get that kind of increase. I've already started looking at them. I want the one with electric choke and vacuum secondaries?...
https://www.holley.com/products/fuel...parts/0-9015-1
07-22-2016, 05:37 AM
#26
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I'll pull a plug and see if she's running lean.
I went for a best bang for buck build. As mentioned, I only paid $1500 for the boat and trailer. When it was all said and done, I think I was around $2500 for the 350. I was able to re use many parts from the 305 which was in great shape. I just forgot to winterize it one year which turned out to be a good thing. I would have never pulled it and put in the 350 if it didn't need it.
I made sure to get the 906 heads.
Went with the most aggressive cam that would work without having to do any extra machine work to the heads. Went with Howards springs and retainers and the only thing I had to do was grind a little off of the bottom of the retainers to keep them from hitting the seals.
The comparison tests/charts I saw didn't have much difference between Edelbrock, Summit, Weiand, etc. intakes. The AFR Titon was the best but I think it was less than 5% over the Summit and the cost was 300% more.
For rockers, I stuck with the stamped 1.5's. Rollers would obviously be better but, for the cost, there wasn't enough performance improvement to make it worth it to me. And the general consensus I found was that 1.6 roller rockers wouldn't have a noticeable difference unless the heads were heavily ported.
Considered GLM manifolds but again, not enough bang for the buck. Also considered a thru hull but the wife probably wouldn't get on the boat if it had a loud exhaust.
A 383 would have been the best bang for the buck but not if I had to buy a new outdrive after I tore up the Alpha.
From my research, everyone agreed that a Holley DP performed better than the Edelbrock but most said that it really wouldn't be a noticeable difference and the Edelbrock was easier to tune (bolt it on and go) and more economical. I never heard of an 8mph increase which is huge IMO. Not doubting anyone, this is just the first I've heard of such a large increase. I'll tinker with the tuning and pay more for gas if I can get that kind of increase. I've already started looking at them. I want the one with electric choke and vacuum secondaries?...
https://www.holley.com/products/fuel...parts/0-9015-1
I went for a best bang for buck build. As mentioned, I only paid $1500 for the boat and trailer. When it was all said and done, I think I was around $2500 for the 350. I was able to re use many parts from the 305 which was in great shape. I just forgot to winterize it one year which turned out to be a good thing. I would have never pulled it and put in the 350 if it didn't need it.
I made sure to get the 906 heads.
Went with the most aggressive cam that would work without having to do any extra machine work to the heads. Went with Howards springs and retainers and the only thing I had to do was grind a little off of the bottom of the retainers to keep them from hitting the seals.
The comparison tests/charts I saw didn't have much difference between Edelbrock, Summit, Weiand, etc. intakes. The AFR Titon was the best but I think it was less than 5% over the Summit and the cost was 300% more.
For rockers, I stuck with the stamped 1.5's. Rollers would obviously be better but, for the cost, there wasn't enough performance improvement to make it worth it to me. And the general consensus I found was that 1.6 roller rockers wouldn't have a noticeable difference unless the heads were heavily ported.
Considered GLM manifolds but again, not enough bang for the buck. Also considered a thru hull but the wife probably wouldn't get on the boat if it had a loud exhaust.
A 383 would have been the best bang for the buck but not if I had to buy a new outdrive after I tore up the Alpha.
From my research, everyone agreed that a Holley DP performed better than the Edelbrock but most said that it really wouldn't be a noticeable difference and the Edelbrock was easier to tune (bolt it on and go) and more economical. I never heard of an 8mph increase which is huge IMO. Not doubting anyone, this is just the first I've heard of such a large increase. I'll tinker with the tuning and pay more for gas if I can get that kind of increase. I've already started looking at them. I want the one with electric choke and vacuum secondaries?...
https://www.holley.com/products/fuel...parts/0-9015-1
[IMG]
[/IMG]You can beat the factory list price by a mile....shop around or better still look for good used one.
The Quick Fuel is a great alternative and is a great choice also with the added bonus of see thru float bowl plugs. http://www.quickfueltechnology.com/c...arburetor.html
[IMG]
[/IMG]Remember...the greatest benefit of these carbs is the Mechanical Secondaries...you control when the secondaries open from the helm...and how much. There are 2: accelerator pumps and 2: separate metering systems. When you want ALL of it like when coming out of the hole...it's there...no waiting on some vacuum system to gradually begin to open the secondaries. Once on plane and cruising...you back off enough where your running economically on the front two barrels of the carb. If you want to quickly accelerate...you open it all up and throttle response is instant !! You experience the benefit of total control over performance and economy.
Don't think you have to break the bank to get into one of these. As said earlier...keep your eyes open for a good used one. Sounds like the motor build is spot on for a strong SBC and what you're doing now is fine tuning what you have and tweaking it for your boat and personal needs. There's some science involved to get it where you want it and once you do it will be sweet !!
Have fun !!
Last edited by sprink58; 07-22-2016 at 06:14 AM.
07-22-2016, 09:24 AM
#27
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Very helpful. Thank you. It's not all about looks but that Quick Fuel is sweet.
Holley had a genuine factory refurb with warranty on fleabay for $430 shipped so I pulled the trigger on that. The 600 CFM and/or 750 CFM with vacuum secondaries are plentiful but not the 80537. I'd probably be looking at $250-350 for a used one and I'd most likely have to rebuild it.
How about the flame arrestor? I don't buy into the K&N hype and avoid them due to the lower filtering capacity but, since it was for a boat, I did buy this one for the Edelbrock...
Ouside Diameter: 9",229 mm
Inside Diameter: 8", 203 mm
Total Height: 2.75", 70 mm
Is this large enough for the Holley? Will it even fit?
Holley had a genuine factory refurb with warranty on fleabay for $430 shipped so I pulled the trigger on that. The 600 CFM and/or 750 CFM with vacuum secondaries are plentiful but not the 80537. I'd probably be looking at $250-350 for a used one and I'd most likely have to rebuild it.
How about the flame arrestor? I don't buy into the K&N hype and avoid them due to the lower filtering capacity but, since it was for a boat, I did buy this one for the Edelbrock...
Ouside Diameter: 9",229 mm
Inside Diameter: 8", 203 mm
Total Height: 2.75", 70 mm
Is this large enough for the Holley? Will it even fit?
07-22-2016, 10:35 AM
#28
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Very helpful. Thank you. It's not all about looks but that Quick Fuel is sweet.
Holley had a genuine factory refurb with warranty on fleabay for $430 shipped so I pulled the trigger on that. The 600 CFM and/or 750 CFM with vacuum secondaries are plentiful but not the 80537. I'd probably be looking at $250-350 for a used one and I'd most likely have to rebuild it.
How about the flame arrestor? I don't buy into the K&N hype and avoid them due to the lower filtering capacity but, since it was for a boat, I did buy this one for the Edelbrock...
Ouside Diameter: 9",229 mm
Inside Diameter: 8", 203 mm
Total Height: 2.75", 70 mm
Is this large enough for the Holley? Will it even fit?
Holley had a genuine factory refurb with warranty on fleabay for $430 shipped so I pulled the trigger on that. The 600 CFM and/or 750 CFM with vacuum secondaries are plentiful but not the 80537. I'd probably be looking at $250-350 for a used one and I'd most likely have to rebuild it.
How about the flame arrestor? I don't buy into the K&N hype and avoid them due to the lower filtering capacity but, since it was for a boat, I did buy this one for the Edelbrock...
Ouside Diameter: 9",229 mm
Inside Diameter: 8", 203 mm
Total Height: 2.75", 70 mm
Is this large enough for the Holley? Will it even fit?
07-22-2016, 11:17 AM
#29
Jonseyfxr here on OSO has a nice set of Bennett trim tabs for sale in swap shop at a very reasonable price and he is a good guy to deal with. I could not imagine not having tabs on a boat.
07-23-2016, 11:00 AM
#30
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PM sent.
As for carbs, I'm also a big proponent of Holley or QF. If you're thinking about taking the plunge and buy a new carb, don't forget about Allstate Carbs. He remans all sorts of carbs and if you call him, he will guide you in the right direction for your application.
Best of luck!
As for carbs, I'm also a big proponent of Holley or QF. If you're thinking about taking the plunge and buy a new carb, don't forget about Allstate Carbs. He remans all sorts of carbs and if you call him, he will guide you in the right direction for your application.
Best of luck!
