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4.3L V6

D

Dan

Member
I have a Chevy 4.3L V6 non Vortec and a 68" 3 blade WarpDrive prop DD. I was wondering if any of you could tell me what size wood prop to run? This engine will turn the WD prop at 3000 rpm with 10 degrees pitch.
As it is now it seems to take about 100 yards at full throttle to get the boat on plane. I have tried going up and down on the pitch several degrees each way with disappointing results.
Thanks
Dan
 
I run a chevy 250 inline 6 and have run all different size wood props on it from a 60x38 to a 66x34. The 66x34 spun up to 2800rpm and was the best for cruise and fuel consumption. The motor actually seems to have more power the more prop it has on it, I have had props that would hit 3400rpm and split your eardrums but not go anywheres. I am currently running a 60 inch 6 blade warp drive turning 2700rpm and it is running the best ever. What size and type hull do you have? What does it weigh? I am running a 11ft aluminum deckover that weighs in at about 900lbs.

Larry
 
Dave (Waterthunder) has a lot of experience w/the 4.3 in airboat applications. I did a lot of work with heads and intake manifolds for him and Norman, but I'm pretty sure all of it was gear reduction. I have a decent amount of experience with that engine outside of airboats also, and one true trend they have is....They have decent TQ for their size, but basically they're just a 350 SBC missing 2 cylinders. So their TQ will be approx 25% less than a Std 350. The biggest problem w/the 4.3 in carbureted trim is that the intake has way too short of runners to be tuned properly at low RPM. At the very least, make sure you have a longer runner design intake like a Edelbrock Performer, and I'm not claiming to be a prop expert, but the WD should be worth quite a bit over the wood prop with the limited lowend TQ you have. AC 6 cylinders have BIG displacement, and Inline auto 6s have more lowend TQ than V6s. So before you invest in a wood prop, think it through. I think the majority of your gains will be by manipulating your TQ curve a little better, and the overall comination of your boat. JMO

Felber
 
thanks for the replies. As far as the hull goes it is a 12ft fiberglass w/ poly.
I have no idea what it weighs. I'll keep playing with the engine and WD prop and see if I can get it right.

Thanks again
Dan
 
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