Sam1647545489 Posted August 29, 2010 Report Share Posted August 29, 2010 Took the boat out to buckeye early this morning while it was still calm and nobody out there. Trimmed it up alot and was able to hit 60 mph on the speedo. Not sure how accurate the speedo is but that is the highest its ever ran. This was with a 19 pitch prop. I plan on having a SS 21 pitch prop this week. I was surprised and happy with it and just thought i would let every one know. LOL. Quote Link to comment Share on other sites More sharing options...
wnaplay1647545503 Posted August 29, 2010 Report Share Posted August 29, 2010 Thats awesome. I was hoping to make a high pass this year but never quite got it running right. You going to alum this week? Quote Link to comment Share on other sites More sharing options...
jeffro Posted August 29, 2010 Report Share Posted August 29, 2010 congrats on the PB. we had our boat out last night and it broke down lol. my father is dumber than a box of rocks. true story Quote Link to comment Share on other sites More sharing options...
Rhett Posted August 29, 2010 Report Share Posted August 29, 2010 Dude, If ya want to borrow my GPS lmk and I will meet up with ya. it has decent battery power Quote Link to comment Share on other sites More sharing options...
Total Sign Posted August 30, 2010 Report Share Posted August 30, 2010 What rpm are you turning? Quote Link to comment Share on other sites More sharing options...
Sam1647545489 Posted August 30, 2010 Author Report Share Posted August 30, 2010 What rpm are you turning? Dunno, rpm gauge is disconnected. I would guess close to 5k from the sounds of the motor. Quote Link to comment Share on other sites More sharing options...
Rhett Posted August 30, 2010 Report Share Posted August 30, 2010 Dunno, rpm gauge is disconnected. I would guess close to 5k from the sounds of the motor. He is that Damn good people... Sam Says "Fuck a Tach I can tell from the Engine Sound... even on a mother fucking boat!!!":lol: Quote Link to comment Share on other sites More sharing options...
04silvrz Posted August 30, 2010 Report Share Posted August 30, 2010 i'm on a boat bitch. Quote Link to comment Share on other sites More sharing options...
Total Sign Posted August 30, 2010 Report Share Posted August 30, 2010 rpm / 1.50 x 19 / 1056 = theoretical speed of 59.97, but you need to factor in prop slip which is probably at 10%. Still not bad for a stock sbc. Quote Link to comment Share on other sites More sharing options...
Sam1647545489 Posted August 30, 2010 Author Report Share Posted August 30, 2010 rpm / 1.50 x 19 / 1056 = theoretical speed of 59.97, but you need to factor in prop slip which is probably at 10%. Still not bad for a stock sbc. Thats what I said. Not to bad for a worn out 350. I'm hoping the 21 pitch prop puts me in the 63-64 mph range. If not I will try a 23 pitch. Tommy, do you guys have a small blower laying around that I can put on this whore... Quote Link to comment Share on other sites More sharing options...
Sam1647545489 Posted August 30, 2010 Author Report Share Posted August 30, 2010 Also Tommy, do you know how much of deal would it be to mate a ls1 motor to the lower unit? Quote Link to comment Share on other sites More sharing options...
Linn1647545492 Posted August 30, 2010 Report Share Posted August 30, 2010 I love that you picked up 2 mph with my fat ass not on the boat. Quote Link to comment Share on other sites More sharing options...
Total Sign Posted August 30, 2010 Report Share Posted August 30, 2010 I don't have one, don't know if Bill does or not. Not hard, but like I said in that pm I don't want to type it all out. Is it the same bell housing bolt pattern as a standard gm v8? Quote Link to comment Share on other sites More sharing options...
Mr. Jones Posted August 30, 2010 Report Share Posted August 30, 2010 Never been on the water that fast, must be awesome. Quote Link to comment Share on other sites More sharing options...
Sam1647545489 Posted August 30, 2010 Author Report Share Posted August 30, 2010 I don't have one, don't know if Bill does or not. Not hard, but like I said in that pm I don't want to type it all out. Is it the same bell housing bolt pattern as a standard gm v8? As far as I know they are except one bolt which shouldnt matter. If they are, are you saying that an ls1 will mate right to the lower unit with the proper bellhousing? Quote Link to comment Share on other sites More sharing options...
MaTS1200 Posted August 30, 2010 Report Share Posted August 30, 2010 Thats what I said. Not to bad for a worn out 350. I'm hoping the 21 pitch prop puts me in the 63-64 mph range. If not I will try a 23 pitch Just a suggestion but I would confirm what RPM you're running with the 19" prop before you go up in prop size. If you are turning 4800-5000 RPM you're probably right where you need to be with the prop size. As a rule of thumb you lose 200RPM for each inch increase in prop size. Unless you're increasing the power pretty dramatically to offset the loss in RPM the boat will probably lose top end and put a lot of additional load on the engine. Quote Link to comment Share on other sites More sharing options...
wnaplay1647545503 Posted August 30, 2010 Report Share Posted August 30, 2010 This guy on ls1tech did it. I know I seen a few others discussing it http://www.ls1tech.com/forums/general-lsx-automobile-discussion/931024-my-ls1-powered-ski-boat.html Quote Link to comment Share on other sites More sharing options...
Sam1647545489 Posted August 30, 2010 Author Report Share Posted August 30, 2010 Just a suggestion but I would confirm what RPM you're running with the 19" prop before you go up in prop size. If you are turning 4800-5000 RPM you're probably right where you need to be with the prop size. As a rule of thumb you lose 200RPM for each inch increase in prop size. Unless you're increasing the power pretty dramatically to offset the loss in RPM the boat will probably lose top end and put a lot of additional load on the engine. Matt, I know I will lose rpm but for future use I wanna get a better prop. I plan on having a 350 hp motor in next year or something close to that, whether I upgrade to a new motor or upgrade the existing. Quote Link to comment Share on other sites More sharing options...
Sam1647545489 Posted August 30, 2010 Author Report Share Posted August 30, 2010 This guy on ls1tech did it. I know I seen a few others discussing it http://www.ls1tech.com/forums/general-lsx-automobile-discussion/931024-my-ls1-powered-ski-boat.html That is not swapped boat. I need to see how they mated the engine to the outdrive and what manifolds to get and what water pump to run. Quote Link to comment Share on other sites More sharing options...
MaTS1200 Posted August 31, 2010 Report Share Posted August 31, 2010 Matt, I know I will lose rpm but for future use I wanna get a better prop. I plan on having a 350 hp motor in next year or something close to that, whether I upgrade to a new motor or upgrade the existing. Gotcha. Sometimes you can find a deal on engines here. http://www.offshoreonly.com/classifieds/engines_and_transmissions_parts_or_complete-b13_0-en.html It's always fun to check out some power options. Quote Link to comment Share on other sites More sharing options...
Total Sign Posted August 31, 2010 Report Share Posted August 31, 2010 Those older 350's make peak power at 4400-4600 and should be proped for there. Normally you will hit a higher top end number turning a bigger wheel slower. Try a Laser 2 3 blade. Quote Link to comment Share on other sites More sharing options...
Sam1647545489 Posted August 31, 2010 Author Report Share Posted August 31, 2010 Whats the purpose of a double prop on boats. I see them all the time. Tommy, that prop I am picking up is a laser 3 blade ss 21 pitch. Quote Link to comment Share on other sites More sharing options...
Total Sign Posted August 31, 2010 Report Share Posted August 31, 2010 more for cruisers, low to mid range, when you get much above 60 cavitation literally eats the rear prop. Quote Link to comment Share on other sites More sharing options...
RS69 Posted September 5, 2010 Report Share Posted September 5, 2010 I bet it sounded really good on your pass. Quote Link to comment Share on other sites More sharing options...
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