454 upgrades

[Dwayne]

Hey guys!
Well been slowly getting my off season upgrades and maintnence done.

I have gotten my new headers and risers on went with the stainless marine headers and risers and I am very glad I did they look great and made the boat sound entirely different hooked it up to the hose and run it and I could even tell it had more throttle response also made it run cooler.Also have installed my trim tab indicators and went ahead and replaced all trim tab lines <span class="ev_code_RED">NOTE</span>When installing new lines come to find at the factory they did not seal the exposed wood in transom with resin and could tell it had recieved a little moisture in the holes one hole even had a little rot and could have become severe so I sealed all holes with resin also pulled my exhaust tips no resin there either exposed wood to transom sealed that also just couldnt sleep well thinking some water may be able to get to my transom wood....

But overall everything is going great Was just wanting some input on the intake and carb upgrades.I'm planning on putting the edelbrock performer rpm intake and 750 edelbrock carb any input on the setup if anyones using it or has etc. would be greatly appec.That is all I have left expect for clear coating the boat and paintng some grapics on it and I will be posting some more pics soon so stay tuned.Ohh also should be getting my Garmin chartplotter/sounder any day now(x-mas present from Dad thanks Dad)have to install it also them ill have all them gps speed readings yall always askin for

Cant wait to run this baby see how much speed I gained..

96 convincor 454 carbed

 

[Dwayne]

Hey guys!
Well been slowly getting my off season upgrades and maintnence done.

I have gotten my new headers and risers on went with the stainless marine headers and risers and I am very glad I did they look great and made the boat sound entirely different hooked it up to the hose and run it and I could even tell it had more throttle response also made it run cooler.Also have installed my trim tab indicators and went ahead and replaced all trim tab lines <span class="ev_code_RED">NOTE</span>When installing new lines come to find at the factory they did not seal the exposed wood in transom with resin and could tell it had recieved a little moisture in the holes one hole even had a little rot and could have become severe so I sealed all holes with resin also pulled my exhaust tips no resin there either exposed wood to transom sealed that also just couldnt sleep well thinking some water may be able to get to my transom wood....

But overall everything is going great Was just wanting some input on the intake and carb upgrades.I'm planning on putting the edelbrock performer rpm intake and 750 edelbrock carb any input on the setup if anyones using it or has etc. would be greatly appec.That is all I have left expect for clear coating the boat and paintng some grapics on it and I will be posting some more pics soon so stay tuned.Ohh also should be getting my Garmin chartplotter/sounder any day now(x-mas present from Dad thanks Dad)have to install it also them ill have all them gps speed readings yall always askin for

Cant wait to run this baby see how much speed I gained..

96 convincor 454 carbed

 

[vinny p.]

You didn't mention anything about changing the cam or heads, so I will assume they are staying stock. I don't think that you will see a big difference in changing the intake and carb. The stock Merc pieces will work fine. But, if you wanted to, the Edelbrock air gap would be a good choice for that motor. However, I am not so sure about the Edelbrock carb. Edelbrocks' marine 750 carb is actually a modified Thermo Quad. It is difficult to fine tune that carb to your engine. I would recommend either a Holley or Demon. They are much more adjustable to meet your specific needs.

 

[Dwayne]

Thanks Vinny!! I will do the heads and cam next year maybe even pull the whole thing just depends on this season. So you dont think it would be of any advantage at all? I know Ill get a little more weight out of the engine room by removing the stock manifold.so what kinda manaifold do you recomend? thanks for the held.Dwayne

 

[jrumon]

I agree with Vinny P.

Go with the Holley or Demon marine carb!!!

Also, use the Performer RPM "Air-Gap" intake... I dyno'd one on a 454 Mag with Gil headers... By just changing manifolds (headers were already on it), it made 15-18hp over stock Merc and better torque while still using the factory Merc carb!

 

[vinny p.]

Dwayne,

If your intensions are to wait until next year to upgrade the heads and cam, I would suggest leaving the stock manifold and carb on for this season. The reason I say this is because your new heads and cam will require a different manifold and carb than your stock ones. You would be waisting money on good parts that wont work right with your new combination. As far as any weight savings, the weight is not enough to make any difference in performance. You did the right thing by getting a good exhaust system, now just wait it out until you are ready to go the rest of the way.

 

[Dwayne]

Vinny I had decided exactly what you suggested early today when it hit me I have the oval port heads and will want to invest in some rectangle port heads when I do the head work and cam to get the full performance out of it.So that confirms It will I need to make any changes to the stock carb since adding the new exhaust? And any informantion you could give on the timing would be greatful if I should set It to factory specs. or if there is something else I could do for performance.I really appericate the info guys.I dont know alot about engines in general as to build performance I have no problem making the upgrades myself if I know the right combination so cant help you guys there but if you have any paint, body, fiberglass, etc. type questions let me know that is my full time trade. I work with all the new adhesives and chemicals and things of such so have good knowledge and alot of tricks so maybe ill be able to be of some help sometime. Thanks again guys...ohh Vinny do you run a 4-blade or 3-blade prop on your convincor?

 

[vinny p.]

Dwayne,
You are making the right choice by waiting until you can do the entire motor. Things have to match to work properly or you will be waisting money. As long as your stock carb ran good last year, and there is no dirt in it, it will be fine with the addition of the new exhaust. I would set the timing up a bit on the conservative side to about 32-34* total advance. After you run it and do a few plug checks, you can possibly advance it to 34-36*, but you have to check first. Forget about what Merc says about base timing, that is all B.S. We all should be soley concerned with total advance, who cares where the base is, as long as it can crank over when hot without blowing off the nose of the starter. I am not sure how much advance your distributor has built into it, hopefully it has enough to get to the target total advance without having too much base.
Up until last year, when I had my stock powered 454 Magnum, I was running a labbed 26" Bravo 1 4 blade. This year with the new 540, I will be running a labbed 27" P-5X Hydromotive 5 blade. At least that is where I am starting out with. Who knows for sure what it will end up with.

 

[Dwayne]

Thanks for all the help guys.The stock carb is working great no probs at all.I'll set the timing like you said and run it check the plugs and go from there.Hope to get to run it soon it was beautiful had some days last week close to 70 sunshine was great but wouldn't you know finally get my tab work done and my headers on and since then it hasn't gotten over 40 the river is also running strong and it is to risky to run it and take a chance of hitting something floating in the water so ill wait it out but as soon as it breaks ill run it and let everyone know the results.Ohh Vinny you lookin to sell that 4 blade? Well thanks again guys.

 

[vinny p.]

Not just yet. I may need it as a back up so I can at least get around while my new prop is being worked. I am sure it wont be right the first time around. I am expecting to ship it back and forth a few times.

 

[Dwayne]

well if you do want to sell it let me know.Good luck with the new power.Callin for the 60's here sunday and all next week so hopefully i'll get to launch my mate

yhanks again for all the info..

 

[Dwayne]

hey well it was nice yesterday and had to go run the mate...Boy it was geat picked up 6mph with the new exhaust..

Did find out I dont have enough air getting to the carb because I can pick up 2 more mph buy opening the hatch 6 in which may be causing some drag also guess in gonna have to put some more vents and boxes in just dont know were yet or how because of limited space on the side were the vents are now. So if any one has had this prob before any info would be great...well thanks for all the help guys..

 

[DONCONVINCER]

What flame arrestor do you have, if it's the stock one you need to upgrade to a high flow item. Opening the hatch is giving you a ram-air effect and presurizing your engine compartment. To get that much volume without opening the hatch you'll need some pretty big scoups. I'd be unconfortable with the hatch open at 60 for fear something might break and I'd lose that thing

 

[Taz]

Wow! 6-8 mph gain with upgraded headers!

What are the specifics on your boat, model, size, engine?

What make headers did you use?

 

[jrumon]

CAREFUL!!! I wouldn't run with a hatch open!!! Lossing a hatch is NOT the plan... I had one open under way (latch pulled through rotted wood) on a "Blaa-Haa"...Tore it right off!

At least I saved it before it sank!!!

Turns out the plywood it was made out of was just regular ply (non-marine, non-treated junk)...FIGURES!!! Sounds like you need some better vents!!!

 

[jrumon]

I've seen more than that on a 454 Mag merc that had stock manifolds running through the prop... Changes to headers and 4" thru-hulls and saw 500+rpm increase with the same prop!!!

 

[boatn70]

my brother runs his eliminator with the hatch open about 3", he has lost it at 93 mph before.......now hes got retainers that he puts on after the hatch is open, cables or small chains i cant remember.

id do something like that if you run with it open!!! i cant believe you picked 6-8 out of exhaust!!!

 

[jrumon]

Maybe that's why so many of those "breathin' hard" motors use a fiberglass ram-air scoop on the hatch over the carb or blower!!!

Seems to me you could put one on and have your hatch upholstry modified to go around the scoop...???

 

[Dwayne]

dont worry guys im not gonna run with my hatch open it was just a little test to see if I needed more air.Im going to add 4 more vent boxes and fab a box around the carb and get it some more air if that isn't enough well im happy with my speed and I have about 500 or 600 rpm more than I need and the water was really cold so I can spin some more prop.As for the air scoop not looking to modify my hatch at all want to keep the boat like it is I like laying on the engine hatch to catch some rays and so do the ladies and I have to keep them happy.... on that hatch.Taz its a 96 220 convincor 454 carbed.Put the stainless marine headers on with the stainless risers them suckers are so much lighter than the stock ones and the flow is so much better stock has a lot of restrictions.It was well worth the investment.Thanks again Jrumon If you remember you told me back in the summer last year to make the headers my first upgrade and went with what you said and am very pleased thanks alot.Now I just have to let it warm up a little then I can work on getting the right prop. Thanks again Guys.

 

[jrumon]

Hey Dwayne...
See...every now and then, my advise comes in handy! Now all you need is the motor mods and your going to be screamin'...

Jim