I've got some good info from this board on how to beef up my 350 mag. into the 450 hp 420 lb tq range. Before I start on this project I would like to know what is needed to swap out the sb for a 502. Do I need to move the engine mounts, will I need new brackets for alt, steering, ect. The alpha is going and being replaced with a bravo.
Thanks

In my humble opinion, you are headed down a road of expense at the end of which you will be disappointed. I would maximize your 350 and be happy. You can go into moving mounts and probably exhaust and converting to a BB. At the end of the day, even if you make over 600HP (at which point you'll need an XR drive) you'll be lucky to see upper 60's or 70MPH. The 242 is a nice looking entry level boat that will never be that fast.

That is basically what i thought but wanted to make sure. I think beefing up the 350 is the best call. I have no desire to start moving mounts. Thanks

I had a 27 Pachanga that did 58 mph some couple of years ago and wanted to swap out the 350s for big blocks to go faster.Thinking about the the work and what it would be worth I sold it and purchased a 292 Formula with Big 502s bored to 509 for a few $ more and it will hit 80 mph gps.That is the best thing I did.My .02 Good luck...

I got this boat so cheap I could dump $8000 into it and I would still be able to sell it and make a profit. So I'm not afraid to spend some money to make it faster. I'd say now its just under 50 mph, speedo' says 54 mph. So I'm just trying figure the best way to get it up to around 60 or so. I really think putting a set of AFR Heads, lunati cam, and my stealth intake on it should make it move out quite a bit better. Total cost should be under $2100.00. A blower is another option that has been suggested but there I'm looking at about $4000.00 and really not gaining that much over the head, cam intake combo, maybe another 20 hp and a little more torque. But added weight for the supercharger.

I have an '86 242-LS that came with a small block/Alpha also. Mine was a 260 horse, not a magnum though. I went through the exact same thing you are about to go through.

When I bought the boat, it had the original 260 horse motor, and the best it would do is 42-43 mph. It came out of the water like crap, and had no balls. I purchased a new 325 horse small block, and added an Edelbrock intake, Holley carb, EMI exhaust (4" through hull), etc etc. It ran better, but not even close to good enough. It did 46-47 mph at it's best. The small block just dosen't have enough torque to get our heavy ass boats moving. I sold that motor complete, and found a killer deal on a big block/ Bravo set-up. I re-powered it over the winter. It's like a different boat now. It pulls out of the water like a bear, and it does about 55 mph now. All I had to do to convert was drill a few holes and move the motor mount brackets up a inch or so. Very easy, only took about an hour or so.

And the best part is, the motor is 100% stock Mercruiser power. It should run for many years without issues. Not to mention the fact that the boat has got to be worth a lot more money with a big block / Bravo package in it now. Our boats should have never been offered with the small block Alpha if you ask me.

Good luck with whatever you decide to do. Let us know how you make out!

Randy,
I like the though of a big block over a small block. Did all the brackets from the small block bolt up to the BB? I know I can find a BB for a good deal if I look. The other concern I have is the thu-hull. The BB is a little wider, did you have an issue with that? I too really scratch my head as to why Formula ever offered a SB in this boat? Mine does ok for what it is, its only got 300 hours on it, but it definitely needs something extra.

I think the big block is the way to go, without a doubt. I think most of the brackets are different. I sold my motor as a complete, running, drop-in package. I sold it on Ebay, and got real good money for it. I think a lot of people look to convert to Mercruiser, so the complete motor brings real good money. Then I bought a complete, running, drop in big block for a great deal...also on Ebay. So, the brackets didn't matter at all to me.

All I did was move the motor mounts up 1 inch by drilling a few holes in the stringers. As for the exhaust, you are right, the big block is a little wider, but the 4" hose has more than enough play in it to work. I thought that was going to be an issue, but it bolted right up, and looks fine.

I'll try and get you some pics, if it stops raining here...lol. I stripped everything out of my bildge, and re-painted it with Awlgrip paint, and everything got re-wired and replaced. All new battery cables, bildge pump, hoses, etc. I must say, it looks awesome now. And the cool thing is, mine is an '86, and the Bravo drive wasn't around yet, it would have been a big block/ TRS. So it's a pretty cool package now. Any questions, let me know.

I found a 496 (vortec 8100) for $300. This is a truck engine with around 50,000 miles on it. From what I have read its pretty easy to change out the cam and injectors and I now have a marine version. I will then need a wiring harness and the ECM but again those can be had used as well. I know Raylar has most of the parts I need. This will be a winter project so I have lots of time to find everything. I would like to see some pictures of your project.

I had an ‘88 242 SS that I purchased new with a 330 HP 454 and a bravo drive. I added a blower to it, MSD ignition and Stainless Marine exhausts, modified the Silent Thunder Exhaust and a few little things that got me to upper 60’s.

After about 8 years instead of freshening up the engine I purchased a new 450 HP 502 crate motor. My wife thought I was nuts! I guess she still thinks that. I put into the new motor J&E blower pistons, new cam, roller rockers, pushrods, timing chain, new valves and valve job, replaced all of the lower end bolts, replaced the head bolts with studs had the blower rebuilt, put my Stainless Marine exhaust on and SCHAZAM!! I had a 630 HP upper 70’s MPH GPS boat. I also upgraded to the later model Bravo and IMCO hydraulic steering (you need this above 70 MPH). An old friend once told me there is no replacement for displacement, more is always better.

This was a great boat in the late 80’s and 90’s that used to kick a lot of but. There were not a lot of boats that went 70+ MPH. This boat was a real sleeper, it is a SUN and Sport and it all fit under that rear bench seat (1/2 inch to spare over the Holly carburetor float adjusting nut).

Always remember Eagles do not hunt flies!