my boat is SLOW help

[brad_man_72]

best first post ever!
i have a 66 stevens silouette with a 1963 300hp 327, velevetdrive trans, 1:1 casale toploader and a 26? pitch 3 blade brass/bronze prop.
hot foot all the way down 3500rpm and aprox 45mph.
something has to be wrong.... right?

[stix818]

New prop and change gears..:wink:

[obnoxious001]

best first post ever!
i have a 66 stevens silouette with a 1963 300hp 327, velevetdrive trans, 1:1 casale toploader and a 26? pitch 3 blade brass/bronze prop.
hot foot all the way down 3500rpm and aprox 45mph.
something has to be wrong.... right?
Seems like the engine should turn quite a bit higher. When you say it's 1:1, have you checked that ratio by marking the prop shaft and rotating the engine 1 revolution to verify? Never heard of a 26 pitch prop on a flat, where did you get that figure?
How long have you owned the boat. Does the engine appear to run properly, smooth, no misfiring, decent acceleration?

[brad_man_72]

i have owned the boat for a little less than a year
1:1 on velvet drive tag
i havent turned prop shaft or counted teeth in the v-drive
26 is stamped on the prop. their was another number that had a dash in it, all hard to read because of polishing. boat seems to run good.
im not getting WOT moon hot foot has leaky hydraulic cylinder, so secondaries werent opening on the carter afb, and the accelerator pump isnt working.
put used edelbrock on the boat got better throttle response and another 500 rpm.
so ive got some more obvious tinkering to do.
am i wrong to believe that this combination is capable of 5500 rpm burst and 60mph

[stix818]

My bad for the sarcastic remark!!! :( I assumed which is bad to begin with!!

[brad_man_72]

My bad for the sarcastic remark!!! :( I assumed which is bad to begin with!!
i didnt hold it against you, i assumed you didnt read my whole post. there it is again the root of all f ups assuming.

[stix818]

Sure is!!! Any luck? Just my recommendation, but I would probably find a smaller pitch prop. Just a thought.

[brad_man_72]

just about everything having to do with fuel delivery seems to be at least a little messed up. not so messed up as to make the engine run poorley (missing backfiring ect) just not enough fuel, air, and throttle. i need to rebuild hydraulic throttle linkage, swap carbs, and take it for a test and tune. hopefully i will see some acceptable numbers.
with the price of gas and other projects i cant really afford to buy a good prop or some gears. hopefully i can live with it running correctly for the rest of the season.

[stix818]

I completely understand that!!! Where do you boat at?

[brad_man_72]

i usually go to tablerock lake, the busier side is closer to where i live (1 hour insead of 1.5 hours) so ive been going there so far this summer. the water has been at a record high so the huge boats cant get under one of the bridges and alot of the ramps and campgrounds are closed so its been pretty quiet so far.
you're in az should i ASSUME havasu?

[stix818]

That's funny big boats can't get under the bridge!!! I hate those things!! I'm originally from Mohave Valley (north of havasu on the river) but I'm currently living in Quartzsite/Blythe area. Where's table rock lake at?

[brad_man_72]

table rock is located in southwest missouri, the really nice quiet clean parts are in arkansas. yeah the big boats suck, they are generally plowing up the lake half plained out, having no clue what the consequences are on a low profile boat without a bilge pump. hell even hangin out at the swing i have to keep an eye out for people in ski boats who are plowing through the crowd. makes me ALMOST want a jet with a place diverter, but that would get me into alot of trouble.

[stix818]

I would guess you guys have plenty of water right now!! You guys having the same problem as the rest with flooding?

[brad_man_72]

around here most of the flooding is concentrated around the lake, some people have had to use boats to get to their houses for over a month. all wet weather creeks streams and ditches have had flash flooding any time it has rained, that has caused standing water to be in my yard alot, only damage ive had is my sump pump wasnt working earlier in the spring, my crawl space flooded and took out my air conditioner $100 i could have used for gas.
if i could find a mulching prop for the boat i wouldnt have to GO TO the lake or mow!
hydraulic throttle linkage fixed, cracked open line and added atf, not enough fluid to get full range of motion before. hopefully new carb this week, either way im going to the lake to try WOT for the first time, wasnt even opening secondaires before.
im kinda nervous, the boat was alot of fun at 45mph.

[brad_man_72]

i survived. 55+mph as measured from a slower (52mph) boats wishometer @ 4500rpm. still having some problems with detonation, i messed with timing a little and it looks like i need to spend more money at the pump. still waiting on new (to me) carb.

[curtis73]

Another thing to keep in mind; any engine prior to about 1971 was rated at gross HP which was without accessories, driveline, exhaust, and was also influenced by insurance companies, marketing voodoo, and moon phase. Your 1963 engine rated at 300 hp might be making as little as 210-230 hp by today's measuring standards.
Back in those muscle car days, there were HP ratings that were way off. I had an AMC with a straight six that was rated at 125 hp that actually made about 86 hp. The marketing staff knew that no one would buy an 86 hp vehicle so they fudged. Contrast that with the LS6 454 that was rated at 425 hp. It actually made somewhere north of 500 hp, but insurance companies wouldn't touch it so they published lower numbers.

[twocents]

Maybe this will help a little bit -- there's no way your 3-blade bronze prop is a 26 pitch. If it was, you'd be running about 80 mph at 3,500 rpm which is definitely not the case. Assuming you have a 1:1 gearing, your prop is most likely a 12" diameter x 15" pitch, a very common size for a bronze 3-blade. If you can get 300 HP out of your engine, I would expect a redline rpm of 5,000 which would give you a top speed of about 61-62 mph which is where you want to be. Make sure you're getting everything out of your engine that it has to give, then start thinking about trying a different prop (maybe something like an 11-1/2" diameter x 16" pitch, or maybe even a 2-blade) for more top end.