245 limited build
 

I have used my 245 the last couple years stock. This year it has a 521 with aluminum SCJ heads and airgap intake in it. It has a MSD billet dizzy, ss coil, and spark box with rev limmiter. Custom cam with 234/244 and a shade over 550 lift with 113 lca. I have not had it dynoed, but a desktop dyno shows it nosing over after 5000.

I have been struggling getting the tach lined out, and now it is so I am finaly ready to get to work dialing it in. I have fattened up the secondary, but last time out it was very hot and I got the feeling it may be to fat.

With the stock 460 I ran a 20 pitch raker (original) to 52-53 mph. A 24 raker (another original) ran 51 but low in the rrrs

I have been running a 24 pitch raker on it, and it seems to do pretty well---without a tach. I also have a 25 Baja Mirage Plus a freind loaned me to try. I think has had a little back yard work done it but we will see how it does. I'll get back when I have some hard data. The next trip out the GPS will be on board.

What prop would you all suggest? Of course I am looking for better cruise without loosing top speed. I am looking at a Rev 4, Bravo 1, or one of hill marine's models.


So far I know it has ran in the mid to upper 60s. I am shooting for 70 and feel I will get it with tunning and a wise prop selection.

Well what I found was that the carb is to fat. Blubbering! One of the hottest days of the year too. Not the best for this sort of thing.

With the 25P mirage
3000rpms got 42.5mph with 15%slip
3500rpms got 50.5mph with 13% slip
4100rpms got 58mph with 15% slip and was maxed out
The boat began to porpous and I could not eleminate it with trim or flaps. The flaps pushed the boat up and made the prop slip.

With the 24 Raker (old OMC)
3000rpms got 42.5mph with 11 slip
3500rpms got 49.3mph with 12% slip
4600rpms got 62.5mph with 16% slip this was with spray from the prop, but when I trimmed down to stop it the boat slowwed down. The boat felt like it may get a little squirly (it never did chine walk, but it felt like it was on the lowest chine), but I had good positive steering feedback and felt it was good.

Any suggestions on props I should try. I want to stay away from the porpousing.

I can get my hands on a 28 bravo. I know it is way to big, but will I get a true feel for the characteristics of a four blade bravo or is it to big for that?

I had an '89 245 Limited. It had a warmed up 502 in it. We figured it made about 500 hp. It had an air gap intake, and a 800 holley on it. We ran a labbed 25 Mirage Plus....and the boat went 67.2 mph on the GPS. It would go 65 mph anytime.

Newest update is with a Bravo One 24.
3000 is right at 41
4400 is just above 60. If you use 23 for the Bravo while looking for slip that comes to right at 9%.

The boat cruizes smoother, and when turning feels like it is more in the water than the other two mentioned.

The next upgrade will be headers. A desktop dyno shows a 70 foot lbs increase at 4200 going from maifolds to headers. I expect a good bit of difference.

Tinman, Did you ever manage to get your 245 to not purpose on top end? What did it take?

I just trimmed it down little by little...until the porpoising stopped. That hull, in my opinion, is very sensitive to wave height. The boat I had liked a small "wash-board" surface...and thats when it ran the fastest. :drink:

(You'll be wasting your time with the 28 Bravo sir..you'd need around 600+ HP to turn that prop)

I had one... that hull did NOT like Lake Erie!!! I can't beleive I never sunk mine...lol

She was loose! even on a flat day.. fun boat!

http://i36.photobucket.com/albums/e4...g/100B0922.jpg

Thats the boat I thought of when I read the post title....

ha!! that poor boat.... I beat the hell out of it!

Thats a great picture sir. Come to think about it....mine was sorta like a greased chicken on ice when we were wide open...(it danced around a little) lol. :drink: