Small block EFI build
 

I have a 22 ft Celebrity bow rider that came with a 350 mag EFI and an alpha. The manufacturers claimed dry weight is 3600 lbs. On GPS it ran 53 mph with 2 people and 50mph with 6 on board. I wanted more performance. Of course spending my evenings surfing OSO doesn't help either.

Starting over with more of a performance hull with a bravo drive probably would have made more sense. We have looked at many newer boats but nothing else caught our eye. The boat that we have is just about the largest hull size that will fit in to my garage and my wife really likes the layout. Got to keep the missus happy so I was stuck working with the boat that I have. We replaced all of the interior 2 years ago and the rest of the hull is in good shape so I had a clean slate to start with. My original plan was to make a 383 out of the original 350 but as I talked with others the plan evolved into starting with a new block. At that point the 406 was pretty much the same cost as a 383. The original 350 has been set aside complete and will be reinstalled when I sell the boat some day.

This process has been rewarding and at times overwhelming. These forums have been a great resource. Thanks to all. This is what I have put together over the last year and a half:

Bottom end: Dart shp block, scat forged crank and 6" h-beam rods, Icon dished forged pistons for a calculated 9.25:1 compression, Champ 7qt pan, Pioneer SFI balancer, Howard's roller cam 112 LSA , 225/[email protected], 578/537 lift at the valves, Howard's (Morel) roller lifters.

Top end: AFR 195's w/inconnel exhaust valves, Comp Ultra Pro Mag XD rockers, Holley HP EFI, ported stealth ram intake, EFI Connection cam sync distributor, Holley DIS waste fire ignition with sequential fuel injection.

EMI exhaust, short ss risers w/custom extended tails, Corsa mufflers and non switchable quick-n-quiet Y pipes. Switched exhaust is not legal in Minnesota and the lengthened risers would probably extend into the valve area anyway.

I used DuPont Jollipop candy blue powder coat for the intake, exhaust, pan, engine brackets and pulleys. It seems to be a close approximation of Mercury Racing blue and really gave the motor more 'wow factor'. I thought it was well worth the $180 the powder coat shop charged me.

I had the engine running on a stand for the first time this past weekend. Alex Haxby emailed me a base tune and after cranking over for a couple of seconds it lit right off. Thank you Alex. This guy knows his sh....stuff. I had hoped to dyno it this spring but now that we are well into boating season I don't think I want to loose another week or two just for the dyno numbers. I'm guessing it would have 480 or so both horsepower and torque with dyno headers. If anyone cares to venture another guess I'd like to hear your thoughts.

I plan to start the installation of the engine into the boat this weekend. For the rest of this year at least I plan to stick with the alpha drive. A bravo and hydraulic steering are most likely in my future. Does any one have thoughts on how to wire the alphas shift interrupter with the Holley ecu?

I plan to add an oil cooler with a thermostat and a higher volume fuel pump but I don't know if I will need to remove or replace the fuel cooler. Again any opinions are appreciated.

Motor pics please.

Here's a cellphone video that shot when it was on the test stand.

https://www.youtube.com/watch?app=de...&v=AdL5gYCsjd8

We dropped the motor in to the boat last weekend. Now I have to sort out all of the wiring and fuel systems. With my busy schedule over the next few weeks I'm doubtful that I will get it on the water before next month.

Pee Wee, just something I noticed. Look at the clearance between the belt and the water hose from the thermostat. Belts move around A LOT and it could come close enough to touch and put a hole in the hose.

Very nice setup. I like your choice on parts. Should make for a sweet running setup. Spent a lot of time behind the wheel of a 23' Celebrity when I was younger.

Phughes- thanks for the observation. Currently there is only about a half inch of clearance between the top of the tensioner pully and the hose. The adjustment range is maxed out with the current belt. I'm going to replace it with the next size shorter serpentine belt which should drop the tensioner down.

What was a total dollar amount on that build? Did you do any of the work yourseld?

Also, are you liking the Holley HP system? Is it pretty easy to use? A lot of opinions in these forums is that aftermarke ECMs don't work well in a marine environment. They recommend sticking with the stock setup and having that reprogrammed

I have the Holley HP EFI on my 548. It is an amazing system. I run closed loop with O2 sensor, distributorless ignition. Starts, idles, runs awesome. Datalogging is incredible.