Edelbrock Performer RPM question

[filafella]

Anyone have any experience with the Edelbrock kits? I have a 1997 7.4L rebuilt merc motor in my SeaRay 230. I had the engine rebuilt to stock specs thinking that 330ish HP would be enough for me, but of course now I'm wanting more power and performance. I already have a Edelbrock 750 carb and Performer intake and would like to get new Edelbrock heads and cam. The marine kits I see are all Performer RPM which gives power from 1500-6500 RPM, but this seems high for a marine application. Is this OK for a boat? I would think it would be better to have power from idle to 5500 (which the Performer cams and intakes supposedly provides) since that's more in the range that a boat operates in. I want a good and efficient all around towing and cruising boat, not just some speed machine, and I don't want to exceed the capabilities of my Bravo 1 outdrive. Any inputs?

 

[Bob_VT]

Re: Edelbrock Performer RPM question

Bravo 1 are good to 600 HP. I doubt your build is going to hurt it

The truest statement is what will the net gain be. I am afraid to say the most reliable is stock form. With the improvements since you are not building a go-fast I am afraid to say all you will do is actually burn a bit more fuel even at cruising speeds.

I am partial to the edelbrock products and if you use all of the suggested then you get the best performance. The cam. intake and since you are in that far...... I would have the heads re-done. Yes the range is wider then normal and will allow you to rev higher. That is the primary reason big blocks blow up since people want them to rev like a small block. Just because tha capability is there....you do not have to use it.

Have you looked in fuel injection?

If I was in your position...... I would call a few of the High Performance marine engine builders and ask for advice

 

[Scott Danforth]

Re: Edelbrock Performer RPM question

are you running a closed cooling system, or raw water cooling? Salt or Fresh water? This will determine your intake manifold direction

what type of exhaust? Thru-hull or thru-drive. this will determine the limits of your cam.

since your motor has been rebuilt, I wouldnt throw money towards a set of heads. I would invest in a good cam to go with your intake.

 

[filafella]

Re: Edelbrock Performer RPM question

I've looked into fuel injection, but the cost seems too high with not alot of benefit. I have a closed cooling system that I run in both salt and fresh water. I have also considered a thru-transom exhaust since I hear you can get a decent boost without a lot of cost. As it stands now I think I'll just go with the Performer Plus cam and give my wallet a breather before doing the heads. Thanks

 

[Scott Danforth]

Re: Edelbrock Performer RPM question

make sure you stick with marine grinds.

with a thru-leg exhaust, your limited to about 268 to 270 degrees of duration to prevent reversion.

stock GM marine cams are made by Crane for a long time, not sure if they still are.

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=595&sb=2

the stock cam specs can be found here:
http://www.perfprotech.com/store/articles/mercruiser-bigv8-mechanical-specifications.aspx

I did not see anything on the edlebrock site that is marine compliant or thru-leg exhaust friendly

 

[filafella]

Re: Edelbrock Performer RPM question

"Thru-leg"? Is that the thru-transom? Thanks for the info.

 

[Scott Danforth]

Re: Edelbrock Performer RPM question

thru-leg or thru-drive exhaust is where the exhaust goes thru the outdrive. thru-transom exhaust is free flowing, and much louder.

 

[Tail_Gunner]

Re: Edelbrock Performer RPM question

7.4 are pure tourqe monster's and what it takes to build them up like a 350 is a differnt world...Supercharge it that should be enough and there should be a great selection of SC's