Need more speed

[Crazy]

Have a 1976 SeaRay SRV220 351 Ford 235 HP OMC electric shift . Right now I'm running 38.7 mph on GPS at 4300 rpm's . How much power can this OMC handle ? And when I'm WOT it seams the boat is running flat on the water '' like it is trimed down '' But it is trimed all the way up , at 25 to 28 mph the nose is up ? What if I was to tilt the drive up 2 inches or so ??? would that hurt my drive ??? Another guy at my Marina has the same boat ... but with a 350 Chev and a merc out drive .... and he BLOWESSSSS me away !!!!! I hole shot him ... but he top ends me like 50 plus mph . WHY WHY . Help me out here

 

[sculbert]

Re: Need more speed

Prop prop prop. He is running a larger prop than you it sounds like. You are getting him on the hole shot because of the smaller prop. what prop are you running?

 

[flashback]

Re: Need more speed

The chevy makes about 30 more ponies! Your WOT is about right maybe even a little low, so changing the prop won't help...This all being said, I would first look at your throttle linkage to be sure the carb is opening up all the way. How well is the engine tuned? you really should be turning about 4600-4800. What condition is your bottom in?

 

[Bondo]

Re: Need more speed

Ford 235 HP OMC electric shift, vs. a 350 Chev and a merc out drive

That's WHY..........................

 

[cobra 3.0]

Re: Need more speed

Bondo you tease! I guess either you are a chevy man or merc....or both!

 

[rodbolt]

Re: Need more speed

the merc has a better power trim system and usually slightly different gear ratio. all in all it was a better design than the old OMC.<br /> good luck and keep posting

 

[achris]

Re: Need more speed

You'll also find the Merc prop is waaaaay more efficient too.

 

[Jdeagro]

Re: Need more speed

Sounds as though the engine RPMS could be a bit higher, but i would also like to ask if you are running with a Hydrofoil on the cavitation plate?

 

[anesthes]

Re: Need more speed

At WOT, 5500 rpm, with my trim up, and my 21 prop, my boat has reached 55mph. Which IMO is fast enough for a cuddy cabin. Damn fast.<br /><br />I cruise around 40-45mph, which is rougly 4000rpm.<br /><br />My boat however, doesn't like planing. Takes about. Sheesh. If I go wot from a dead stop, I don't plain for a good minute or so. <br /><br />All my outboard boats planed like a freakin drag car. heh (this is my first i/o)<br /><br /><br />-- Joe

 

[achris]

Re: Need more speed

Hate those things! Hydro-thingys. Should be outlawed. Too dam dangerous!<br /><br />Chris............................................

 

[Crazy]

Re: Need more speed

No Hydrofoil just trim tabs . They tell me you can't run the old OMC drive tilted ... I was thinking about tilting it an inch or two , Do ya guys think I should ? Or should I just stop beating on old Horse . Plus the gut at our marina said not to run over 4400 RPM the old OMC can't handle it ... is this true ?

 

[Jdeagro]

Re: Need more speed

Crazy;<br /><br />You must have Hydraulic Trim Tabs, are they working correctly? I would say that WOT should be not more than 4400 rpms but adjusting the bow rise with the trim tabs should be no problem. I don't think you will get more than the 38 to 39 mph as i remember the boat is heavy. I had a 24.5 sundancer that whould only do about 34 WOT.<br />Ride is good and comfortable but not the fastes train on the tracks.

 

[Doug Durako]

Re: Need more speed

Do you have the big rubber boot around the drive on the stern? If so, those drives are tilted by raising and lowering the entire motor and drive together on a worm screw type of configuration. This could have been removed on your boat because they never worked very well. That is the only way to tilt those old OMC drives that I know of-----ball gears in the upper must be fully engaged or they'll melt.

 

[POINTER94]

Re: Need more speed

Crazy,<br /><br />You might make an extra 1-2mph but you got what you got. No, you cannot run the old OMC's in a trimed condition for very long and definately not at speed. Weak design. Also get used to changing the tilt motor, no fun at all.

 

[Crazy]

Re: Need more speed

Well thanks guys ... that's what I thought ... What about adding a couple HP to the motor , can the 1977 OMC electric shift handle 280 hp ???

 

[POINTER94]

Re: Need more speed

I would doubt the payback would be worth the effort.

 

[heatz1express]

Re: Need more speed

I'm running 230HP CHEV 305 in a 20ft 1982 peterborough w/cuddy and I top out at approx 45mph at 4300rpm.(wot). I expect that besides the ford your problem is that you have a heavier boat!

 

[heatz1express]

Re: Need more speed

forgot to mention I too have omc drive (800series). I find that there are many combos of trim tabs and selecttrim depending on conditions. when it is calm I can raise both tabs and trim for just a little bit more but when there is a chop these settings result in porpoising. Your bow down or flat" issue is probably trim tab related.