I’d say you’re right Scott.
I’d say you’re right Scott.
You can use the money you were saving for the Sharrow prop on A 6.2 long block
correct, a 5.0 has too small of bores to make anything but a long stroke 5.3 liter and the head has too small of valves to breath enough for practicality
Lovely. Gets lovelier further up on the west coast again.
it’s a 5.0 mpi I have Scott. 260 hp standard. With my cam and exhaust system…I’m assuming it’s nearly or around 300hp. But annoyingly…unless it’s anything over 4000 rpm or more…it’s just not a good set up all round having that cam. Wasn’t much thought went into it I’d think. Was only about 15 of them made with this performance package. Nice to have…but reality is that it would likely be more useable with a 350 mpi. Funnily enough, the non performance package could be optioned with a 350 mpi or a VP 5.7 gxi. The specs claim the performance edition was slightly quicker top end though. So assume she’s at least 300 hp perhaps. Not sure. She’s still limited to 5150 rpm. Which she will easily hit with any prop that’s useable. Would take a 23” or more to keep her off the limiter with the 1.47 ratio. But that means it’s just terrible anywhere less than flat out. She’s a quick wee thing though. Considering her fairly heavy bulk. 1400 kgs dry. Still manages the below gps if I can be bothered to suffer the other effects down low. Most often I can’t though and run a 21” or even a 20”
Yeah seems you would be better off with a 5.7
I’d thought about that Scott. But figured it wouldn’t be worth it. They’d be about the same power I’d think. Not sure. Figured the 6.2 would be a sure bet for getting the low down grunt I need, so I’m able to run a prop that can not only take advantage of the top end the boat clearly has, but down low too. The issue I have now is all the power is up the top. If I run a pitch that will see it off the limiter and at its quickest now…it means it’s gutless down low and just not useable if I have people onboard or just for 99% of the time general use. That’s why I now just run a compromise prop that will see early to mid 60’s easy enough (but easily hit the limiter) and still have life enough to accelerate or cruise well. Just wish I had a little more grunt down low. It’s all nothing nothing nothing…then everything once it gets up the rpms.
Scott. Funny you should say that. I did try it once on the old faithful laser 2. Just thought it was a horrible thing. It did allow the boat to plane quicker…but was always venting or on the verge of it right around the low 20’s speed I like to sit at. The most efficient speed for this boat to cruise at is a fairly quick (for my liking) 27 mph or so. But I think it most comfortable at around early 20’s. This is where the prop gave a slipping clutch like feel with it venting. That was with medium sized hole in the pvs. Didn’t mess any more with it after that to be fair. Always just ran full plugs on any prop I’ve had for it really. I found the same effect on the outboard cuddy boat too. When I ran a tempest 21” with half vents. Just a horrible feeling I thought. Certainly didn’t like it on the cuddy…just with the idea that it was very inefficient for displacement speeds. When it spends half its time. Maybe I’ll give them another go. Thanks for that.
How big is the medium hole?
When I had my boat shop I played around with vented props, and had the same affect as you, lots of slip in the range for cruising, but once they gripped they went well. Given that venting a prop is usually done for ski boats, that's not surprising. A ski boat usually takes off fairly hard as skiers prefer to be 'popped up' as opposed to being dragged along while the boat accelerates. Venting the prop allows the engine to 'spin up' before the prop bites, and give rapid hole-shot, and then a good hold at speeds above about 25 knots. But yes, in the 15-23knot range, lots of revs, not much go.
Cheers chris. Yeah. It’s a 5.0 mpi with exhausts and a cam from new. Strange one all together. They made a non performance spec version with a 350 mpi and a 5.7 gxi in it. Think I’d rather have one of those in it. Probably about the same power top of the rpms…but they would defo be better low down I’d think.Although I think there were 15 of these made…I’m aware of and spoken to 2 other owners of one like mine. One in Canada and one in Norway. They both have gxi 5.7s with a cam apparently. One of those guys think they know another in Germany that has the 350 mpi with a cam. Think I got the bad deal…or I have a 5.0 air cleaner cover in place of a lost 350 one…haha.
Hard to explain without hearing it in person…but it sounds unlike any other SB I know of. Can sort of hear what I mean here. Very deep cough or occasional spit to it at low rpm. Can actually feel it in your chest when standing next to it. Very unique sounding wee thing.
You know…I thought the very same thing, after watching that earlier, for the first time in a while. Exactly that very thing.
Yes but you get some really good top speed out of it. Conversely I have a 5.0 stock except for intake and Edelbrock 1409. Boat was originally a 4.3/2 blbl/190 hp, that PO cracked. I put the engine in kept the 1.81 ratio drive. Best speed with 22” enertia was 47, 21” rev 4 is 48. I run two large plugs and two medium on the Rev 4. With 5-6 people in boat it pulls me up on skiis or wakeboard very nicely (285 lbs…) . Bottom line its compromises, im very happy with loaded watersports performance which is most of my use, wont ever sniff 60 mph though.
Interesting to read that Scott. Always wondered about the Rev 4 too.
Chris, you cant use the 5.0 heads on a 5.7 or 6.2 as the valves and combustion chambers are too small. You also cant put the heads from a 5.7 onto a 5.0 as the valves get shrouded by the cylinder walls and breathing suffers
Thanks Scott. Probably bored you all with this too many times over the year perhaps. I’m at a fortunate stage currently these days, where I don’t use this boat the way I once did..as an every weekend in summer boat. It’s now kept in storage and only comes out rarely…being fortunate enough to have a better suited all round boat for general use. Also have the wee cvx16 if need be for going quick. So at a real junction here wether to mess with what I have (but I feel it may be in vain) with something along the lines of cleaning up the heads for flow, valves and ecu tinkering (the latter of which will mean sending ecu off and expensive)…or just continue the so far fruitless search for a clean 6.2 mpi. Just so rare over here.
or just order the parts, build the motor in the garage or living room (depending on marital status) and when complete, swap motors
