Another Omc thread
 

Hello folks! As you can see I am new here. I have read tons of threads on this site and figured I would sign up. So now that is said I have some questions.
I have an 88 fw 241 liberator. Yes I have the dreaded 460 king cobra with the dog outdrive. No need to bash as I know the story. I would like to stroke my 460 and doing so would like to see 65mph. What kind of hp is needed to see 65? Ive read lots who have ran big hp through this drive as long as you are not stupid with it. Currently have 800hrs on this set up. Ran 45mph loaded with a full tank. Any help is greatly appreciated

It would probably be a lot cheaper to buy a 65mph boat.

I kinda figured I would get a reply like that....Thanks

Have you done a compression test,it should run 60 now i would think

well the compression was 105 average .... with low fuel and just me it did 48 on gps. Which from what Ive read that is somewhat normal speed for this setup. I am looking at a 532 stroker kit and making around 600 hp.

Have you looked into exhaust? This is going to be one expensive four winns.

There is a guy that has one with the same set up as you near me. His has very low hours as it gets out maybe 2-3 times yearly but anyway it does 55 mph with a few people on board. Maybe 58 unloaded. So it sounds like your 460 is getting tired.

I would be willing to stick my neck out and say your going to need about 600 hp to meet your goal. I think you'll be ok with the King Cobra drive if you don't hole shot it really hard. But between heads and exhaust for that for dI agree with Lil red, get ready to open your wallet!

As a matter of fact I have a set of hitek headers....so that is covered. As for heads was going to use a set of procomps

Uh oh. Pro Comps are not a friendly word in these here parts. Expect 3 pages of Pro Comp hate, lol.

well as i havent bought em it was just an idea....and i liked the price

Be careful with your cam selection. hitek are better than stockers but unless you have the "standard one piece" system from them with the long pipes you will be quite limited with your cam selection.

Before you dig deep in this, do you have a planned budget in mind?

I bought a boat with Pro Comps on it and just got rid of the whole motor after some discussions here. For a street rod car they may work fine, but for the high intensity of wide open throttle in boats along with raw water they just don't hold up. Valve seats coming loose, incorrect valve angles, bad metallurgy, the list goes on forever.

Well i am hoping to be under 6g..

If you insist on el-cheapo heads see if liberty offers a set of big ford heads they are way better than projunk and builder price is cheaper as far as Chevy stuff goes. Not sure if they offer a Ford head yet. Keep in mind if you change the horsepower of the motor you are going to make the necessary adjustments to the oil and fuel systems as well. If you sit down and add it all up I think you would be way ahead buying another boat.

Double that figure and you should be close.

Just to save you the headache here's what another member did with those heads...
http://www.offshoreonly.com/forums/g...recipes-3.html

Yes, definitely a larger oil cooler so figure on about $600 there, new oil lines as a larger cooler most likely won't fit in the stock location (depending on whether you make them or buy them this can get pricey), new fuel tank pick up and lines so probably minimum of $100 there.

I wouldn't get discouraged, there are just alot of things to consider. Take a look at the whole picture and then make a decision. Is it worth going through all of it or just sell the boat and use your money for something that does 65 already?

Some people get overwhelmed and then never finish what they started. It definitely pays to know what your getting into from the start.

I did a 509 this summer that is about 600. With the purchase of exhaust the total came to just over $12,000. So I would say forget $6,000 when you ad in machine work and assembly.

Hmmm 12g...well im not new to engine building just new to fords. Roataing assembly is 1700...machine work is 600...heads 2g...intake ...pump...w pump...cam..chain.. etc another 2g...where ya get 12g from? As 12 is outta my budget.

$300 intake, $700 carb, $300 fuel pump, $600 ignition, Roller cam and roller lifters $1000, oil cooler and brackets $600, good quality roller rockers $500, $2000 in work on heads I had (new valves, seats, springs, porting, milling), $3000 in the short block (bought a used block as mine was trashed, decent forged crank, new rods, new pistons, machine work and balancing) and exhaust was about $3000.

It adds up really quick! If you don't have to buy exhaust after picking your cam you will obviously knock a good bit off.

Machine work for $600? Run away, my shop charges me $200 just to clean the block.

Alrighty....thanks for all the help

Add in atleast 1500 for misc hoses and fittings.

Ok how's this. Yes! Absolutely! Buy the pro comp heads, drop it off to your local nickle and dime machine shop and never enjoy boating again while owning a $8,000 boat your now have $18000 into and can't sell because it doesn't run.

I'm doing a 355 build and I just paid $300 for cleaning, magnafluxing and shot peening.

Man I'm glad I get my machine work done for free.

You are forgetting something. It's a Ford so the nickel and dime is now translated to dime and quarter��

Just asked a simple question....and you reply everytime with a smart ass answer. Its all good ....hope you have a great christmas.

I think what you're seeing here is that a number of us have been down the exact same path. Pick up a quasi-high performance boat for a song, then find out that it really doesn't go fast enough. (That's probably why it was so cheap.) Try building it up bit by bit to make it go fast enough - and it still doesn't go fast enough. Or worse yet, discover that we now have one evil handling beast and / or it starts falling apart around us due to poor construction. So we try to sell it for what we now have into it. Then we find out why we should have just bought a better / faster boat to begin with because nobody will pay us what we need.

So don't take most of the advice personally. We just don't want to see somebody else make the same mistakes some of us did.

Hope that helps. Happy Thanksgiving!

Too stroked.....very well said! That's kind of whee I was going but without your skills as a word smith!

If you want a novelty, go for it. The caveat is just as others have said, it will be expensive, it won't go as fast as a better hull with less power, and you won't get your money back if you don't like how it handles and the fact that the bass fisherman still pass you. If you get it 65+, time to get at least a single ram steering setup, do they even make those for the Cobra? Not to be a jerk, but everyone I know avoids two names with boats at all costs. Bayliner and OMC.

As someone that tried to make a semi fast boat fast, I would tell you to enjoy it for what it is. Get the motor in perfect running order and enjoy. Move up to a faster boat.

One phone call to Bob Madera @ Marine Kinetics should answer any questions on making usable hp for your boat. Good luck with your project.

I too would say you're going to be in well over $6k to do this even close to right. Even if you could get 600 reliable hp out of that thing for $6k, how well will your drive hold up? I'm assuming it too is an OMC...

Honestly, you're best bet is to enjoy the boat as it sits, or sell it and buy a faster boat.

1st something is wrong if that only runs 45, I had a brand new one of those boats in 86, small block/alpha changed the intake, flame arrester, prop, and tuned on it a bit, ran 52 with 1/4 tank fuel light load, so look into what you have, some of those 460 had a large port intake(like a 429CJ) on very small port heads..idiot move, also cams go away...and the cobra drive is not a bad drive..although a bit slower than a bravo I think due to size/shape...but to run 65 with a freshened/tuned 460 should be no real big deal..

Went through same thing last year with similar set up ,what the people say is true .one thing that is to your advantage if the omc king cobra 460 should have trw forged flat tops .get a modern cam intake real carb $150 unilite some kind of headers use adapters if necessary. Then have Kane or somebody uncobble the heads and it will make some suprising power .the king cobra was a decent drive but if you blow it up your prob going to be doing the bravo swap so save your stroker block fund for that .

Before doing anything, the 80.and 90's Four Winns boats are very well known for transom rot. The transom for OMC / Cobra set up was thinner than it was for Mercruiser installments, this did not help because the OMC transoms being thinner stressed more easily and caused the transom seal to lose its sealing. Hence the process of the transom getting wet at that starting point and on forming the rot afterwards. Also Four Winns and many builders at that timeframe used low grade wood on top of.

before doing any mods to your boat and engine I would check out very closely for rot. The Four Winns hull is not a speed demon either. You will hit a brick wall at some point throwing horsepower at it. Just saying. Also not many around will work on OMC products and even less with King Cobra app as far as 99.9 % boat repair shops.

Also a lot of parts for the King Cobra are no longer available NLA. Years ago my shop held OMC certification in the past and for the last 7 years will not touch a King Cobra. Parts availability and transom rot are the main 2 factors for touching them anymore. Also high cost for the stuff that is still around can not be justified by us nor the end user. I would move on to something else to hot rod. This is very solid advice as others mentioned as well.