|
|
|
|
#1
|
||||
|
||||
What pitch prop were you running? You say it hit WOT turning 5K RPM's, how fast were you going? There's a good chance that the 3.0L outdrive has a 2:1 ratio and isn't allowing the engine to get loaded properly, I believe the 3.7L uses a 1.81:1 ratio. Spare would know better on this matter as he deals with more I/O's.
__________________
2011 SUNDANCE B20CCR SKIFF, 2011 YAMAHA 90HP 4 STROKE, 2011 KARAVAN SINGLE AXLE ALUMINUM TRAILER, LOWRANCE ELITE-7 HDI, MINN KOTA RIPTIDE TROLLING MOTOR 2000CC HYDRA-SPORT 225+HP EVINRUDE SOLD  AND THE PINK JEEP!!!! R.I.P. http://www.wellcraftv20.com/communit...ad.php?t=11664 
|
|
#2
04-10-2009, 11:30 AM
|
|||
|
|||
|
i dident bring any electronics on board, but im guessing i was around 40-45mph while at WOT which topped at just over 5k.
as far as the prop, i have no clue, as it came with the drive. i honestly dident bother to check, hoping that since it came together, the prop would have been matched up correctly.
__________________
1982 V-20
|
|
#3
04-10-2009, 04:55 PM
|
||||
|
||||
|
I have the 3.7l w alpha 1 out drive. I believe WOT for that engine should be about 4400 rpm. As for the fin, I found that the boat gets up on plane easier with the fin. I changed out drives last year and the new one did not have the fin. This year I'm putting the fin back on.
__________________
Formerly - 89 cuddy 165hp I/O and 95 V21 / 150 Honda When the people fear their government, there is tyranny; when the government fears the people, there is liberty. - Thomas Jefferson
|
|
#4
04-10-2009, 07:44 PM
|
||||
|
||||
|
The V-20 hull planes out around 13 MPH I believe, so it sounds like you were planing out. The WOT does sound high, to my knowledge only the newer VORTEC engines turn more than 4600.
__________________
2011 SUNDANCE B20CCR SKIFF, 2011 YAMAHA 90HP 4 STROKE, 2011 KARAVAN SINGLE AXLE ALUMINUM TRAILER, LOWRANCE ELITE-7 HDI, MINN KOTA RIPTIDE TROLLING MOTOR 2000CC HYDRA-SPORT 225+HP EVINRUDE SOLD AND THE PINK JEEP!!!! R.I.P. http://www.wellcraftv20.com/communit...ad.php?t=11664
|
|
#5
04-13-2009, 12:51 AM
|
|||
|
|||
|
a mechanic i asked where i keep my boat said it was normal for the 3.7 to turn 5k at WOT, but i dont like taking one persons opinion for something
so should i be worried my engine is maxing at 5k?
__________________
1982 V-20
|
|
#6
04-14-2009, 11:02 AM
|
||||
|
||||
|
I'll check the repair manual I have at home tonight, but I'm almost certain that the spec I read was 4400 rpm.
__________________
Formerly - 89 cuddy 165hp I/O and 95 V21 / 150 Honda When the people fear their government, there is tyranny; when the government fears the people, there is liberty. - Thomas Jefferson
|
|
#7
04-14-2009, 06:21 PM
|
||||
|
||||
|
the 3.7 is best to turn in teh 4500-4600 wot rpm range, they will turn higher, but it tends to get tough on valve train. there was a guy in Atlanta running one of those engines in a dragster, I think he was turning it over 10, but he had roller rockers and changed from a chain drive cam to a gear driven($$$$$$$). 5000 isn't going to break you bottom end, but I doubt you are making good power at that rpm, you're above the curve with the stock cam/carb/ intake/exhaust package. The 3.0L drive came with a 1.98 ratio adn the 3.7 with a 1.82 ratio. The 1.98 was the alternative ratio for the 3.7 in high altitude set ups. First thing you need to do is check your tack against a shop tach, usually only about one in ten is even close to being accurate, next borrow a gps(hand held will work fine), check your existing set up. I doubt your are crusiing at 40 mph, that would probably be closer to the top end speed. What prop are you spinning? I'd try a 19 or 21 Mirage
|
 |
| Thread Tools | |
| Display Modes | |
|
|
Hybrid Mode
