RPM lmitations

[delemorte]

So i am getting the boat squared away and was advised that it has no rev limiter. Seeing how i am a newby and dont was to one bust up my engine or two Die i want to install a rev limiter.
I found a few options out there but really did not know what kind of RPM a chevy 350 should be run at safely. Im not out to set any speed records and even if i could i would not as i have little to no experience. so whats a safe RPM to max out on something like this? Safe being a key word here as i can always turn it up as my experience grows.

[Moneypitt]

That ditch pump on the back of the boat will regulate your RPMs....Just keep the intake in the water and you'll be OK.......As far as RPMs, SBC will rev quite high with no damage. It will quit making power, but still rev...Now with a pump attached, you might see 4500.......There are charts all over this jet forum about how much power it takes to spin the different impellers.....I don't have alot of faith in them, but they are here........Example, stock pump, mild BBC will usually see 5200 or so. A SBC is lacking the torque to get there, but 4500 is a reasonable expectation.........MP

[BrendellaJet]

yep, no rev limiter needed, that jet pump will hold you back more than you want it to...

[delemorte]

yep, no rev limiter needed, that jet pump will hold you back more than you want it to...
Ill take that at fact but for a SBC at what kind of RPMs will that thing tear it self apart. I'm not saying its gonna get there but for reference purposes so i know when too much is too much.

[SmokinLowriderSS]

Ill take that at fact but for a SBC at what kind of RPMs will that thing tear it self apart. I'm not saying its gonna get there but for reference purposes so i know when too much is too much.
Depends on how you build and balance it.
Crappy job and 5-grand will rip it a new one (or several new ones).
Built properly (and it does NOT take all-super-high-dollar forgings and H-beam rods) and 7-8,000 RPM is plenty survivable.
Proper bearing clearances, good solid rod bolts (one place cheapies have no business), proper balance job, and CORRECT oil pressures (IMO, 70 psi hot at idle is too damn much, but some folks like it that way).
Even Mk-IV Big Chevies were FACTORY acceptable to sustain 7,000RPM with the good rods and the HD (7/16" boron steel alloy) rod bolts. That's a lot of BIG heavy pieces going up and down mighty fast, with FACTORY parts.

[H20MOFO]

I think a rev limiter is a good investment. Having said that I don't have one. I've burried my tach almost every time I've left the water( which isn't hard to do)

[delemorte]

Well i can promise you untril i can afford to replace the motor she wont see 7 grand. 5 grand is even scary to me. Remember i am a newby and not aware what was put into this motor so i cant attest to its strength so i just need a nice safe number.

[gbelt]

I've run my 350 Chevy with a Comp cam, sportsman heads and some other mods, and the STOCK crank/cast piston setup that came in the engine back in the late 80's 4700 to 5000 rpm depending on which impeller was in there, since that time. I did bust one piston ring land, I don't think it was detonation as the one that broke always had the lowest compression of the 8, just took it to the machine shop and had them put on another cast piston (used the same rod, rings and rod bearing from the old one) several years ago. Still runs fine, doesn't burn oil, not setting any speed records at 65 or so but it is very reliable, and good on gas and a hell of a lot of fun. At 5K a SBC isn't moving a lot of mass compared to a larger engine, as long as you keep the oil changed and monitor it's condition they last a long time.

[SmokinLowriderSS]

Don't sweat 5-grand. Factory I beam rods with factory bolts are plenty strong to hold it together there, even with short trips to 6-grand, as long as oil pressure is decent, which is 55 to 65 PSI at that 5-6-grand level.
Cavitated my 454 one time with my foot burried solid (trying to turn left avoiding a jet-skiier) that she hit 6-grand, floated every valve she had, and STAYED there untill we made the turn, straightened the nozzle, drew water, and launched clear of the jerk. Revved about 5 secconds if I guess even close, survived with nothing done but my temper flared. That was in completely stock 1978 condition, in 1989, unlike now.
As said on here before tho, unless you have one monsterous 350, or a heck of a small impeller, you are unlikely to get over 5-grand, unless you cavitate it by getting airborne. The shock loading on the impeller coming back in the water is far harder on it when the motor has free-wheeled to 6-grand because your foot is still burried in it. Aluminum impellers do NOT like this, and crack and explode shortly, taking bowl parts with them. VERY 'spensive.

[ck7684]

I'd worry more about unloading your pump than over reving the engine, and you can control that by how you drive... Are you running in rough water a lot?

[delemorte]

Awesome answers guys. thats what i was looking for.
And i have not even gotten it in the water yet so i cant tell you what kind of water it will be in.

[delemorte]

As said on here before tho, unless you have one monsterous 350, or a heck of a small impeller, you are unlikely to get over 5-grand, unless you cavitate it by getting airborne. The shock loading on the impeller coming back in the water is far harder on it when the motor has free-wheeled to 6-grand because your foot is still burried in it. Aluminum impellers do NOT like this, and crack and explode shortly, taking bowl parts with them. VERY 'spensive.
Thats funny in a not so funny way... Yeah i dont expect her to push it past 5 grand in the water but if i hit a wake or something happens and it starts pulling air i want something there beyond my self to stop it from over reving.... I guess if i had more experience i would not worry about such things but i guess being new and being catious is a good thing.

[Ryan00TJ]

One of my previous 360ci SBC's WOT at 5500-5700 all day long. It was a Jasper Marine shortblock. Cast crank, rods, pistons. This was with a sterndrive and not a jet. It had 360hrs on it when I pulled it and everything looked great inside. I'll still have it in the garage for a spare.

[Sleeper CP]

Well i can promise you untril i can afford to replace the motor she wont see 7 grand. 5 grand is even scary to me. Remember i am a newby and not aware what was put into this motor so i cant attest to its strength so i just need a nice safe number.
Then spend a couple hundred buck and put a rev limiter in it. Does it have a hydlr. flat tappet cam in it? You would be amased as to how fast an engine can go from 4,000 to 7,000 once it becomes unloaded:mad: Let's just say before you can say "oh shit". If you can't vouch for the engine and don't want to have to replace it, a rev limiter is cheap insurance. Just my .02
Sleeper CP
Big Inch Ford Lover

[H20MOFO]

The last time out this year I was tryin to get some better gps #. The lake wasn't all that choppy and I popped her out of the water at least 3 times that day, and like Sleeper said, your foot is all the way in it, you got it wound up, you get uprooted, and then mega r's(my tach only goes to six and it gets burried in a split second) I read in the last ***boat over revving was one of the top 2 causes for blown motors.

[SmokinLowriderSS]

Thats funny in a not so funny way... Yeah i dont expect her to push it past 5 grand in the water but if i hit a wake or something happens and it starts pulling air i want something there beyond my self to stop it from over reving.... I guess if i had more experience i would not worry about such things but i guess being new and being catious is a good thing.
I intended for it to be both funny and serious.
Learn to "feel" the boat, and learn to lift that foot. I have.
If you just HAVE to have a rev-limiter, fine. Go buy one.
The best rev-limiter IMO tho, is between your ears. No other one is truly needed, unless you EXPECT to cavitate and have a hard time backing off.
I seldom get Lowrider aired completely out with water rough enough to send me airborne, and when I have, it's been "Oh crap, a big wake" and dropping the foot out and hanging on.
When I think a small one will air me out on a WOT run, I pedal it.

[H20MOFO]

Smokin is right(you have to be ready to get out of it). And at 70 shit happens pretty fast. Maybe it's just my boat but there is never/seldom a day I go boating that I don't leave the water at least once:D

[Sleeper CP]

Cheap insurance. just my.02
Oh, someone can post a picture for you of what unloading an alum. impeller can do if you don't catch it with your foot fast enough.:(
Sleeper Cp
Big Inch Ford Lover

[uLtRADeNniS]

Smokin is right(you have to be ready to get out of it). And at 70 shit happens pretty fast. Maybe it's just my boat but there is never/seldom a day I go boating that I don't leave the water at least once:D
Agreed.. You wanna know when to lift that foot and drop it.. Those rollers come quick. Your gonna have to get over it somehow..and if you going fast(70+)..your gonna shit yourself if you don't know what to do.
Id say if you where kickin out some real horsepower then defiantly go with a rev limiter. But with your set up its not really necessary. As long as you don't cavitate, you'll be golden. One word of advice...STAY AWAY from wakeboard boats!

[delemorte]

Seeing i am new to all this I dont expect to see 70 any time soon even if it would go that fast. im sure id scare my self at 40...
remember my experience is in sail baots where 15 knots is hauling butt.
yes i agree its cheap insurance. if i had more expereince i would not worry about it but its money well spent in my opinion. thanks guys...