Thanks for the info so far. I bought this boat and it has been kinda a nightmare so far but I like to work on things. Blew the lower first time I drove it. Rebuilt it and blew the motor second time I drove it LOL and I was taking it easy. Block had a hole in it the size of my fist but I was able to limp it back to the dock it was crazy seeing the engine run with a piston laying in the bilige. So I was thinking I have a 4 bolt bare block laying around. I was givin a set off Eddie marine small block exhaust. I also have edlebrok rpm manifold and Carb not sure what size Carb tho. Don't know how to identify. Also have a Mallory marine distributed and box. So that's where I am at. I figured since I need to build a motor might as well stroke it and the biggest kit I found all forged h beams and stuff 409. For 1399.00 it may be over kill but that's ok. Previous 48 MPH with a stainless 19 would be overjoyed to hit 60 can I do it with this build and more pitch. I got lots of nitrous laying around too if temptation persists

You will need about 400+HP to hit 60. Your budget is way too low for what you want to do. You will need Exhaust (2K) and a Roller cam (2K for the complete setup), then you still need the internals. After you do this your drive will most likly go shortly after. For your budget, put it back close stock specs and be happy with 50. Just keeping it real....

I'm all about more hp, thats a lot of boat for an alpha drive though. You start throwing more power to it and it won't last long. Rebuild it with what you have and leave it alone.

dart 200cc, vic jr, 750, 480- 230 cam hydrualic flat

You dont need forged stuff with the beans you will be putting out. Trust me just do a good balance on some good cast stuff.

If you block is useable, you should have the dough for a mellow 400HP set up at least high 3's.

You have the exhaust, all the marine stuff from your old setup

The merc stock ignition is fine.

you have a manifold

You may want a real carb, or to just tube up the one you have, Id go with a real carb here.

you are proposing a lot of work for a marginal platform and I understand why the guys are telling you to just stand down and fix what youve got- I get it, but there are times when you just cant and I get that as well.


UD

Do a search for "Reversion" you will need performance exhaust. To get 1HP per CI you will need a roller cam, a flat tappet just will not get it in the marine world. Here is what I would do. Sell the Alpha drive in the swap shop and buy a Bravo setup. Build a 502 or a 489/496 stroker engine. Or sell the boat and buy one with a 454 or 502 that already runs 60MPH. My boat came with a stock 330 454CI and ran 55MPH on GPS. After thousands of dollars worth of upgrades and hundreds of my labor hours I have the boat running 74GPS. All of the upgrades were done over a period of years and I broke many parts until I figured out what I was doing. Good luck with your project!!

Agreed on reversion, Ive built many of these combos as well

The reversion problem is why I said "use great caution" in selecting a camshaft 8 posts ago.

The poster has an EMI exhaust, these are not too bad.

Reversion is a big problem trying to get to high HP using an automotive formula of high lift and valve overlap.

Heres my latest marine small block build.
Its a 500/500 engine.

http://www.offshoreonly.com/forums/d...ent-years.html

This is my 5th small block config in 20 years. The last one lasted 10, and the 4 before that 10 combined years. I think im on a pretty good formula after all this time and money.

I finished this one a week ago and its going into the boat either next week or the week after.

I agree its a pain to get a small block to high HP levels, and if I were him Id start over with a different project.

-but he seems pretty determined.


Uncle Dave

And leave the nitrous on the shelf
-or puff it in with the boys next friday night.

DONT use it in your rig.

UD

Sorry, I missed the part where he mentioned he had aquired the EMI's. I use the EMI's with long risers and have worked very well. If he has he short risers he may want to swap them out.
I used RMbuilder for my cam and I am sure he could easily get him 400HP.

Fixx
 

i have the emi's on my donzi with the regular cast aluminum risers,the cam is choppy and haven't had any reversion problems :drink: my morot performer better (more torque) over the ss risers..
http://www.youtube.com/watch?v=dLdeNiyk0Ew