Modernizing my 1977 V20 update

[bgreene]

Congratulations, sound good.

As long as you can reach full recommended rpm range at WOT with that 19" prop you're good to go. If not, maybe over propped.

[Lance Pearson]

I had minor prop hub slipping on the last fourth of the trip with the new aluminum regular round hub Evinrude prop. I took it in to the dealer, described the instance and they looked and said it had probably spun a little. They called Evinrude who said this wasn't the first time the the prop was designed for the v6 engines said it was not unheard of and to replace on warranty the prop but do it with the newer aluminum with the adapter hub design which is a stronger joint to handle the torque these v6 engines put out. The dealer did that and I have one today to put on tomorrow.

When I ran it wot at 48 mph briefly I wasn't yet trimming and a half hour later cruising at 26 mph I started playing with trim getting used to it and when I trimmed up slightly I got 200 more rpm and two mph of speed with slightly less hull in the water so I think it's top end could be 50 mph and 5300-5400 rpms.

In the Evinrude conversation they said something that seems logical to me. The v6's can run hotter than their rating on power. A 150 hp 2008 for example on the dyno can run up to about 164 hp...but for marketing purposes they call all three 150, 175 and 200 hp yet they are the same block, the same bore and stroke and the same 161 ci, 258 ltr engine. Their tolerance on power is 10% as well.

The engine felt very strong to me tho I can't find a 175 hp torque curve. I suspect I have the "hot" they were talking about and what I am really running is something like 185-190 hp which really shoots the V20 along and out of the water. It seems impossible they would make a block with exactly 150 hp, then 175 and then 200. Same block, etc. That is marketing segmentation and there is a lot of overlap in these engines is what Evinrude prop guys were saying. From my experience so far I'm pretty certain mine is running a fair bit over 175 hp. I own and have raced three corvettes so engines and speed is a subject I'm noddingly familiar with.

I know this, the ability of the 175 to put it up on plane is very few seconds and full speed not many more and that's saying quite a bit for a deep v hull with an engine extending 21' behind the nose of the boat.

To repeat, three hours of running 90% at cruising speed of 2600 rpm and about4 26 mph it used 7.6 gallons of fuel. Man, that's 2.5 plus gallons per hour which I consider very economical.

Don't know other people's experience but the etec 175 is a torque monster. The 200 is probably running 210 or more actual max horsepower and torque and would push it past 50 mph.

One last thing...running wot at 48 mph not trimmed the boat easily tracked straight and true. Most impressed.

The new prop has a different center and a multi part adapter with torsion control insert and you tighten it to 70-80 ft pounds of torque when installing.

Lance

[phatdaddy]

You ran 75 miles on 7.5 gallons?

[Lance Pearson]

I ran the boat three hours probably 75% to 90% of the time at cruising rpm of around 2700 rpm and 26 mph and when I took the boat home I stopped and filled the tank and it took 7.6 gallons used in that three hours. I don't know how many miles I ran...just the time.

[Lance Pearson]

The boat is great but with the new repowered and heavier by 109 pounds engine, full fuel tanks, battery and oil tank, the trailer started to sway at speed and so I measured it, added 182 pounds of weight forward and got the tongue weight up from 175 which was too light to 300 and it tows okay for a single axle with good sized 2900 pound boat and trailer. However, it is old and will one day need replacement as parts fail. I emailed EZ loader about the trailer and they asked for photos then informed me I was lucky the original trailer still worked as it was badly overloaded. The trailer was designed for a max load of 2,000 pounds and I was carrying 2900 pounds on 40 year old springs, frame with some rust evident. In addition state law here says total weight of trailer and boat if more than 3,000 pounds requires brakes. Mine did not have them so if I did get in a wreck the dealer said that the insurance would deny coverage as illegal and overloaded in his experience. That did it for me as I did not ever feel like it towed as safely as I thought it ought to. Upshot, an hour later I was at our dealer's who sells three different brand of trailer, EZ loader, Venture and a cheaper c shaped painted steel type for smaller bass boats. I bought a Venture vrt dual axle with front axle surge disk brakes 4250 load capacity trailer for 21 to 23' boats which is being made in Maryland this coming week and when it's here the dealer will pull the boat, balance the boat and new trailer without the added weight in the nose and I'll pick it up. Everything says towing on a dual axle is like a dream. The ez load single must have been overbuilt to be wrong, too short, under capacity, for its entire life.

[Greyduk]

Necessity is a great motivator. You should really feel secure now. Please post pictures when you get it. Good Luck.