bcarpman,

Not sure who that would have been that you talked to...maybe Lou Downing? I worked there until 2000 so it could have been someone who worked there after I was gone.

As to why he had different info - not sure but there is a chance the factory modified the hull mold to remove the shingles (after I left the company).

I worked directly for Kevin Hirdes and was directly responsible for testing and development for about 4 years. I tested more boats between 1994 and 2000 than anyone else at the company, including Kevin. I was involved with all the step bottoms that came to market prior to 2000 as well as the 300 (although that was not complete when I left and was changed after I was gone).

A hook in the wrong location on a hull bottom will kill top speed but a hook in the proper location will not kill your top speed and can improve the performance of a boat that tends to porpoise. The hook on the 260 is out far enough from the keel that it has minimal contact with "solid" water when running near the upper end of the speed range. And you might be surprised what impact just the spray hitting the hook has on the performance of that hull.

You are right that hull bottoms will react differently with different horsepower. The factory did not install 600hp engines in that hull. So what you are experiencing with that hp is likely different than what we experienced in our testing. Max hp from the factory was HP500 (470 at the prop). We did most with 7.4 (300-330hp) and 454 (385hp) and some with 502s (415hp). Top speed was low/mid 60's with the 502. So you are going to see different results than the factory would have.

Have you already ground off those areas on your hull? Did you grind through the glass and into putty?

Marc

Marc, What was the performance numbers on the HP500 in the 26? Can't say I've ever seen nor heard of factory power that large in this model. I'm assuming due to cost not many rolled out the door.

Marc,

It's really unlike me to have lost that individuals number. He told me he had blueprinted several 257 hulls over the years, and that removal of the "shingle" in high power applications resulted in at least 5mph if not more. I don't recall the entire conversation, but I do recall that he seemed to know so much about the hull going way back to intial mold developement, and minor changes over the years, that if he wasn't a long time Powerquest employee with first hand knowledge of that boat then he was a really good BS'r. Not that that is impossible, but as an engineer myself, I'm usually hard to BS on technical stuff.

I have not started the work yet. I drilled a small test hole in 1/8in increments to see how deep each part of the hull was. I know I will have to go into the core to remove the shingles, but the core in that area is very thick at that point, and I will not be going near the top layer of fiberglass.

I am getting the gantry from a friend this week, and will rotate the boat onto one side of the V to do the work on the other side.

I am not concerned with the porpoising. I have 22 inch trim tabs that are not flush with the hull. Worst case senerio, I end up gaining nothing and having to run a little tab, which should still be more efficient than the shingles since only the tip of the tab far out off the back of the boat will have to touch the water.

If you have any thoughts or warnings on the process, I'd love any advice. I may not know what results I'm going to get, but if I'm missing something with the actual hull construction that's going to mess me up, let me know.

Any other thoughts on why this boat would want to bury the bow even with all that power trying to lift it up? No amount of positive trim will loosen up the front.

I'll take measurements to see if there is any hook, but from my current view, the only other thing I can see is that the center strakes run further back than most boats.

I'd love to hear any data on that. I've never seen a 257/260 with an HP500 from the factory.

Boating Magazine did a comparison test in 2003 on 7 comparible boats in that size range. Powerquest was the only manufacturer that didn't send at least a 415hp 502 Mag. They sent a 385hp 454 Mag and it only ran 59mph: 7 to 20mph slower than the other boats in the test.

This summer I was running 540hp with the standard depth prop (propshaft 8.25 inches below the hull) and could only get 64mph. With the shorty drive (6.25inches propshaft to hull) and some engine intake work I managed to get 69.5mph.

[QUOTE=bcarpman;2721437]I'd love to hear any data on that. I've never seen a 257/260 with an HP500 from the factory.

We didn't sell many - I can only recall one.

It was a long time ago - I think 95 or 96 a guy put a 540 Bulldog in a 260. It didn't perform as well as expected on top end speed. I think it was 65 or 66 - certainly not worth the money to upgrade to any HP motor. The boat went to a customer in Texas who custom ordered the boat.

That is why most of them left the factory with a 454 or 502 Mag MPI.

bcarpman,

What year is your boat?

I did not work in manufacturing but I knew the layup schedule pretty well. Changes were made from time to time so you may encounter something different but what you should find as you grind away the material is quite a bit of glass, then putty, then balsa. I would be surprised if you hit balsa but you might.

Once you've got it ground completely off, as long as you reglass everything really good you shouldn't have any problems unless you leave your boat in the water for extended periods - then you'll likely get blistering around the area you repaired. But those will go away as soon as the boat is out of the water for a while.

Regarding the guy at PQ - are you sure he was at PQ and not one of PQ's subs? There was an older guy named Ernie who used to do a lot of work on customer boats and had done extensive bottom work for the factory over several years. He and his son Martin worked together at their fiberglass shop call Bowkers Fiberglass.

The boat is a very good condition '93

I was wondering what the drill was hitting right under the fiberglass. It didn't seem like any core material I was familiar with. I guess they must have laid the first fiberglass, then leveled the shingle area out with the putty, then but the balsa in then the top fiberglass. What should happen is that I should end up sanding right to the balsa and not into it.

My intent is to blueprint the entire bottom (level everything out, remove any hook, sharpen strakes and transom, maybe shorten center strakes). Any thoughts on shortening the center strakes. On this boat they go about 2 feet further towards the transom than on other boats. Since I already have far too much stern lift, I'm figuring that should help.

After everything is perfect I'm going to spray the entire bottom with 4 coats of Interlux Bottom Epoxy. From what I'm told this should protect the entire bottom better than the original gel (epoxy does not absorb water)

Those names sound familiar, as does the shop. That's probably him.

So that means I may already have the worlds fastest PQ 257/260? A dubious honor at best :)

yes, I realize my experiment is a little out there. I should just buy another boat, right. But I do really like this boat and if I just bought another boat I wouldn't learn anything.

I don't recall ever having the strakes cut shorter on a 260 to see how the hull would perform. Maybe someone else has done that and can comment.

The strakes provide stabilization as well as lift so if you do cut them off be prepared for the boat to possibly get a little squirrely at top end. Not sure if it will but you never know.

We ran the 300 hull without any strakes on the back end and that thing was like one of those round convex snow sleds - it was all over the place.

If you do cut, remember it is a lot easier to remove the strakes than to put them back on so if you do cut them off use a die grinder and cut them as close to the hull bottom as you can, and cut in as deep as possible (parallel with the hull bottom of course). Cut all the way around the section you want to remove, then if you end up prying them off the bottom, they should come off in one piece and you can put them back on if needed. The strakes are filled with putty so once you get through the glass you will be into putty.

Also, if you can, cut a section off and go test to see how you like it. Then you can decide if you want to cut off more or not.

I think you will like the results of sharpening all the edges on the strakes and transom. Every boat that we did that to always felt like it handled better and sometimes it would result in more speed too.

Bcarpman, What ever you do please follow up with photo's and results. This is certainly becoming one of the more interesting threads on the PQ forum.

Marc, Whats your thoughts on the 260 hull? Is there some reason its so tuff to obtain any really good mph gains?
Ride quality as you know is great and it's a boat anyone can drive, it just seems other boats of comparable size are faster with the same power. Just seems there should be something there to work with.