More power? Of course I want more power!

[burtonrider11]

First, I want to thank all those that have been such a great help on some of my previous posts! Now here is the situation. Just winterized and put the baby away for the winter. By next spring I want to take on a small project to add a little more zip to our boat.<br /><br />The details: 1989 Rinker 186 Captiva, 4.3L V6. MerCruiser has 175HP on carb cover, am unsure if this is Prop HP or Crank HP. When I remove flame arrestor, I swear I only see two holes. It really looks like a 2 barrel carb to me.<br /><br />Right now, according to speedo (I know should use GPS), with wife and I, half tank of gas (42 gallon tank) I am running 47-48 WOT while swinging a 21" stainless prop. (Make unknown)Tach reads 4900 at WOT. I think tach may be a bit inaccurate. I am able to cruise at around 30mph around 2500-3000RPM. <br /><br />I have done a bit of research and I think what I would like to do is install a new intake and carb set. I don't want to invest in new Vortec heads, so I am sticking with a non Vortec Edelbrock performer manifold. I will also most likely be using a 500 CFM EB Performer carb as well. I would really like to hear from anyone who has done this type of set-up and any suggestions to make this happen smoothly. Also roughly, what kind of power gain might I expect. I am hoping for 25-30HP. Top end is not the most important for me, I would prefer to setup for good hole shot and good mid range response...I am planning for about $500 total costs. Any input would be greatly appreciated!

 

[Bondo]

Re: More power? Of course I want more power!

This Exact Subject has been Really Well Covered here in the last week of so,.........<br />Look back a page,.. Maybe 2,+ You'll find the thread...............<br />That guys going with a Rottenchester,......... I Wouldn't,.......<br /><br />Put the 600/650cfm Edlebrock Carb. on their manifold that fits your heads...........<br /><br />You'll get Pretty Much Everything you're Dreaming of................<br /><br />Horsepower,+ Reasonable Economy,..........<br /><br />Good Luck..............

 

[rbezdon]

Re: More power? Of course I want more power!

search for sunbird's postings. He is getting more than 260HP from his, better than a 5.7 4BBL

 

[burtonrider11]

Re: More power? Of course I want more power!

Thanks guys, I did find the "wake up" postings, very informative....<br /><br />I don't think that 260HP+ is realistic for what I am looking to do. My hope is to be in 225 range, which I think is a bit realistic....

 

[Chris1956]

Re: More power? Of course I want more power!

Burton, 205HP is standard for a production 4bbl carb on a 4.3. Will your manifold raise the HP by 20? Also, you better look for carbs on eBay, if you want to stay within budget.

 

[burtonrider11]

Re: More power? Of course I want more power!

Thanks Chris. I am figuring it this way. I will stick with crankshaft HP since I believe in 1989, they were still calculating it at the crank and not at the prop.....<br /><br />My '89 is rated at 175 at the crank with 2bbl. Going with a factory 4bbl/intake would raise it to 205 like you said.....Going with Edelbrock Carb/Intake combo, should give additional 20 HP, I am hoping. Edelbrock claims intake gives 18HP gain, I will be going with 600CFM EB carb which is quite a bit more than the stock, which I believe is in the neighborhood of 480? So from there, I am hoping to hit my target of 225. Which at the prop would equate to roughly 185-195. <br /><br />I have found the "marine" 600CFm EB performer at Summit Racing for about $290. Intake is about $189, should keep me at around $500, probably a little more when figuring gaskets etc....

 

[Bondo]

Re: More power? Of course I want more power!

I don't care Which HP#s you want to use,......<br /><br />But,... Using Your method of figuring your HP,...<br />You're counting the 18/20HP Increase Twice,.....<br />You're only going to get it Once,.......<br /><br />But,.......Don't Worry,......<br />You'll Feel the Added HP in the seat of Your Pants,......... It's Worth It.........

 

[burtonrider11]

Re: More power? Of course I want more power!

At the risk of sounding argumentative, Edelbrock claims an 18HP gain over the stock 4BBL manifold in marine applications. Either way, it will be great to add a little zip to our rig. A lot cheaper than repowering for sure....

 

[Bondo]

Re: More power? Of course I want more power!

Well,........<br /><br />Like I said,....... Use Any #s you'd Like,.......<br /><br />The Edlebrock Carb. is a Carbon Copy of the Merc./Weber Carb.,...... Even the pieces Interchange,.......<br />And,...<br />The Edlebrock manifold is a reasonably close copy of the Cast Iron version of the Merc. manifold..........<br /><br />The only Dyno I have access to is the 1 that's filling My blue jeans,........<br />It tells me that No Matter what #s you want to Brag at the dock,........ <br />Your Dyno,.. Will be Happy with your projects Results,..................

 

[burtonrider11]

Re: More power? Of course I want more power!

Got it, I wasn't trying to argue the point and I agree, any increase in power will be a substantial step up for me. <br /><br />Am I correct in assuming that the EB manifold is aluminum and not cast iron? That would nice in the fact, that it will be double edged, adding HP while losing a few LB's along the way <br /><br />I am still exploring all my options, but I think that I will be sticking with the Edelbrock combo and just be happy. <br /><br />Is the carb going to fairly closely calibrated upon delivery or do these require a substantial ammount of tweaking to get them running right? I have zero to little carb experience....I saw the Edelbrock manual it seems pretty comprehensive.....

 

[rbezdon]

Re: More power? Of course I want more power!

burton, I see you are from Michigan so I guess you are boating mostly fresh water but if you get near salt be careful with the aluminum manifold. It is typically NOT recommended for marine applications and can prove to be a corrosion problem.

 

[burtonrider11]

Re: More power? Of course I want more power!

Thanks Vatter,<br />No plans to be anywhere near anything salty. Also boat is stored out of water and kept pretty dry for the most part. That was a small concern of mine, but since there will be no salt water boating, I think I should be okay.

 

[rbezdon]

Re: More power? Of course I want more power!

I mention it because I got this same advice before I put my aluminum Edelbrock on from some here at the forum. I made the same decision and if I ever (not likely) run salty I'll just have to flush it immediately when I shut it down.