PDA

View Full Version : OMC V6 REV problem



looseunit225
11-04-2008, 01:47 PM
hgey guys had my engine out on the boat over the weekend and it seems i have a bit of an issue with the engine!

it was the first time i had opened it up and i had spent all day sunday doing plug chops on the engine!

i opened it up (28et prop) and it got to 6,100 RPMS and that was it no matter what i did i couldnt get it to rev any harder than that!

i want to spin this engine to 7,000 so i can get the speed at the moment my old engine is faster than this one!

during the week well whats left of the week im going to try anmd fix my egt gauge, change the power pack and lift the engine hieght half an inch!

Tomtall
11-04-2008, 04:09 PM
Are you sure your not bumping the engines rev limiter? You did not state what V-6 you are running.

looseunit225
11-05-2008, 02:08 AM
i have a 3.2ltr v6 looper engine with port work and a low amp ignition so there should be no rev limiter

looseunit225
11-07-2008, 03:52 PM
i will be replacing the power pack today and i will be trying to get my EGT gauges working so i can see what the fuel system is doing!

i will also be lifting the engine hieght by half a inch! than i will be running the engine tommorow some time and see if she will rev a bit harder!

this engine has been a very expensive excercise and yet im still not any faster than my old engine very frustrating!

looseunit225
11-09-2008, 12:04 AM
ok i had the boat out today and it seems the power pack did the job i spun a 28 et to 7,000rpms @ 88.8mph with one skier

and i spun a 32 et too 6,800 with just the boat my damn GPS kept konking out on me the spring that sits on the negitive battery in the gps keeps playing up!

can anyone top a prop calculation for me so i can figure out what the speed boat only would have been?!

Ted March
11-09-2008, 07:22 AM
A 32 @ 6800 RPM
0% Slip = 110.2 MPH

5% Slip = 104.7 MPH
7% Slip = 102.5 MPH
10% Slip = 99.2 MPH
12% Slip = 97.0 MPH


With a skier
A 28 @ 7000 RPM
0% Slip = 99.3 MPH

88.8 MPH = 10.5% Slip

looseunit225
11-09-2008, 01:23 PM
so in result you would say i was doing near on or just over 100mph?

Woodduck
11-10-2008, 04:20 AM
Looks like it! Well done. You'd have to figure on around 7% slip for the Lab. Was that on the long straight heading down to Torumbery?

looseunit225
11-10-2008, 04:33 AM
yeah sure was! and it was against the current i took the run past head works boat ramp held the right handed tight and WOT and than took as straight as of line as possible!

were you in town the other day i rekon i seen your boat going over the bridge?

Woodduck
11-10-2008, 04:47 AM
Yeah, it's funny, running down to there we'd hit 82.5 with two skiers on and on the way back we'd hit 83? Depends on the wind too! Yeah, I'm there every weekend it seems like but that boat only comes up occasionally, but it'll be up more often. Going to leave it out at Deep Creek. My girl lives in Moama but her dog would eat it in a week!

looseunit225
11-10-2008, 04:50 AM
hahahaha
did you use to or still do drag that boat?

i live in moama my self if i had the room at my place i'd let you keep it here!

what set up has that got on it?

Woodduck
11-10-2008, 05:07 AM
I started with a Moc 3.0 OMC on it butttttttttt blew it a couple of times so I swapped the OMC off and put on a 245 2.5 with a cut 15" mid and a sporty lower that I had on another boat. I broke the 15" in half the same day I had a methanol burb and set it on fire at the drags! A week before I was supposed to race the Hawkesberry Power boat race so I swapped the modded jackplate off for the 15", put on a spare L & S hydr plate I had in the backyard under the clothesline, grabbed the old 20" mod vp trunk from a 2.4 that was in the shed and stuck it together. Had a mod vp snakeyes cle lower under the bench that was missing the shaft so borrowed, read permanently a cle shaft of Herbie and I was boating again.
Just put new rings and bearings in it 4 weeks ago and ran it in at Glenmaggie, then took the kids out cruising.
It's getting race again in a couple of weeks on the circuit at Yarrawonga then two weeks later it will be at the drags. Then xmas at Merimbula for some social skiing, then back to Glennmaggie!
It get's thrashed!

looseunit225
11-10-2008, 01:26 PM
sounds like its copping a flogging!

what kind of hull is it again?

Woodduck
11-10-2008, 01:29 PM
97 STV Euro

looseunit225
11-10-2008, 01:33 PM
nice i love the shape of it!

did you hear about streaker marines 1750 lab???? UP UP and AWAY!

what sort pf class would my boat go in at power boat racing?

Woodduck
11-10-2008, 01:37 PM
It would run unlimited mono.
Heard about the streaker boat down at carrum. ouch!

looseunit225
11-10-2008, 01:38 PM
yeah pauly got out of it pretty un scathed i think he got a couple of broken ribs and some bruises!

what sorta speeds are the unlimited mono's doing?