Crusader 350 (454cid) Max RPM

dwarren

Member
exMember
Joined
Jul 8, 2004
RO Number
14233
Messages
461
ALWAYS been the owner of 270's. Not sure of what to expect with the 454's. I run her about 3100 rpms and get to around 16mph (ish).....what should I expect WOT RPM's? I'm a little hesitant to actually find out by pushig it. Boat is new to me and is running pretty good (couple of slow idle stalls but immediate restarts)......
 
I'm sure someone will correct me if I'm wrong, but I believe in the 4500 range.
You need to open it up from time to time. Best way to know if all is good. Anytime you can't reach your optimum WOT RPM, you know you have an issue that needs to be checked out. A couple of minutes now and then won't hurt.
 
4500-4800 for 454's in my boat. 36 Trojan with twin 454's. It depends on water conditions, weight of the boat at the time.
 
The manual for my Crusader 454 XLs specifies 4200 to 4600 at WOT.
 
I have 454 Crusaders in a Chris Craft.
Manual says 4400.
The boat planes at about 3400rpm and that is where I cruise most of the time.
At 4400 you use LOTS of fuel.
At 3400 I am not yet into the secondaries, depends on water conditions
Hope this helps
 
Are these 454s in the older Carver 32 in your profile, and if so, is yours a Montego? So they would be carbed pre-Vortecs if originals, yes?

You might be interested in this 5/1/87 review of the 32 Montego with Merc 454s rated at 340 hp, cruising at 3000 rpm making 20kts ( not mph). And WOT top speed of 44kts at 4400 rpm.
http://www.boatingworld.com/boattests/carver-32-montego/

Boats tend to gain a LOT of weight as they age, absorb and more "stuff" is added, but it might be worth a very full tune up/servicing if that hasn't been done .
Plus note the attainable full WOT RPM now, and next time you haul have the props scanned and pitch adjusted if needed to attain at least the middle of Crusader's recommended range for WOT RPM for those engines which was 4200-4400 rpm (as per my old Crusader 1988 all-engines owner's manual, which also specifies 89 octane gas.)

Also, a full vacuum gauge test could provide a good helpful perspective of engines' condition.
If you go here: http://www.secondchancegarage.com/public/186.cfm , and scroll down to click on the "scenarios", you can get an interesting idea of all the things an easy vac gauge test could check or reveal or rule out.

Once you know your attainable WOT RPM , as long as it is within the spec range Crusader and most rec gas marine engine mfgrs. say it is normally safe loading to cruise at up to 75% of observed WOT RPM. That does NOT mean it is the most GPH /NMPG -efficient planing cruise RPM to run at , which is most always lower.
I suspect your economy could improve at a little higher rpm, particularly if you are adjusting trim tabs for highest rpm at any particular cruise throttle position.
 
Thanks Sandy, actually, after talking to previous owner, I found that his father (the original owner) had put larger props on the boat (they did give me the originals). Boat runs beauti at 2900 to 3000 but if I push it I can't get above 3800 (ish). I'm not going to sweat it since it seems to be running good (minus a minor bogging last week on one motor...most likely racor). When I haul, I'll put the originals back on and retest WOT.
 
Back
Top