Need more spd

**ponyboy** · 01-05-2006

Hi, I need 5mph more out of my boat. 65 glassparg3,77 85hp merc W/trim
runnin a 14x22 small ear chopper,cav plate 1" or so above the bottom of the hull.
Also I have some chine walk problems with a full load of fuel in the rear and centerd. it goes away when its down to 3-4 gallons
I dont know the gear ratio.
I know this boat is not the usual boat on this site but you guy's know everything?

**Mark75H** · 01-05-2006

You need to buy a tach and learn your motor rpm.

Your gear ratio is 2.3:1

How fast are you going now? 35? 40? 45? The slower you are going the more likely you are to find another 5 mph ... the faster you already are the less likely more speed is possible.

Since you have trim you can optimize the tilt angle under way ... a very good start

How much does your boat weigh now (exactly)? What is the weight listed in the 1965 sales brochure? Your boat may be waterlogged; carrying an extra 200 to 400 pounds of hidden water in the core.

**ponyboy** · 01-05-2006

I rebuilt the boat from the ground up..it has hollow glass stringers, weight from the G3 site varries from 375-400 lbs, I used racing seats 2 (fiberglass) short buckets, and no wind screen,
Tach reads 6k rpms when I get low on fuel,I weigh 195, 2 six gal fuel tanks for now, Trim is a dole manual pump hyd. tilt system,20 lbs?
it will run up to 49.9 on gps but usualy 47-48
I have an extra 75 merc 115 lower witch i think is a 2:1 g/r
I have a short 12 sec. avi I could send to a web add. I dont know how to post it or a url etc.

**Mark75H** · 01-05-2006

49 is screaming in a G-3! Your hard work has paid off very well!! I very much doubt you will find 5 more, esp with your 85

**ponyboy** · 01-05-2006

Well crap........I already went through a truck load of props and this was the 3rd one I tried....still Its a fun boat to fly around the lakes here in central IN.
Thanks for the help!...on to the next boat....lol

**Mark75H** · 01-05-2006

I thought you said you had a '77 85hp ???

**hydroc888** · 01-05-2006

Seems to me the guy would know what year his motor is . Maybe a year off one way or the other. Dont matter. Seems to me that it is great that a non boatracer can feel comfortable asking questions about how to make his own boat go faster on this site. Maybe next year he will find an old used up race boat and get to racing. Last and first pays the same in club racing. All for the fun of it.

**Fast Fred** · 01-06-2006

move the full gas cans around in the boat, see if ya can bal' it out , dull the chine walk

**Mark75H** · 01-06-2006

Originally Posted by hydroc888

Seems to me the guy would know what year his motor is . Maybe a year off one way or the other. Dont matter. Seems to me that it is great that a non boatracer can feel comfortable asking questions about how to make his own boat go faster on this site. Maybe next year he will find an old used up race boat and get to racing. Last and first pays the same in club racing. All for the fun of it.

True, but the picture shows a 67 or so 65 horse motor. If he moved up from the 65 to the 85 that's cool, but he didn't say so ... its a big jump. Running 49~ with a 65 on a G-3 is an even more impressive feat! ... that is where I was going with that comment.

**Ted March** · 01-06-2006

RE: Chine walk
From the pictures:
1.Two tanks, one in the center and the other on the port side along with the battery. None of this tied down. Put one tank on the centerline. Put the other tank starboard and the battery port as close to the centerline as possible and tie everything down. This will cost virtually zero money.

2. Put in dual steering, either same side or opposite (prefered) to take the play out of the steering. This will run into some bucks. If you can run her straight without chine walking, you might (operative word is might) be alble to squeeze a little more out of her.

RE: Speed:
Get your self a light, inexpensive manual jack plate and play with transom heights and propellers, as many as you beg, borrow or steal. And remember that a prop that works at one height may not necessarily work at another.

Do not discount a propeller until you have thoroughy tested it at all heights you are testing

Many years ago I was running 28 choppers on my Vulture/235. All seemed to be in the 82/83 mph range and ran about the same height, I had a hydraulic jack plate and could set any height I wanted and change it whille underway. Ron sent me a 30 cleaver. Put it on and ran the same 83 mph at the same height as the choppers. After a few runs at 83 mph, I lowered the motor quite a bit and started a leisurely trip back to the trailer. I got bored and nailed it and the Medallion went up to 87 and blew out. Fastest I had ever gone. It was dumb luck that I found the potential in that prop. The point is, it did not like chopper heights. It's sweet spot was over an inch lower. Had I not accidently found it, I would have put it in the shop as just another 83 mph prop. Turned out to be my best top end prop at that time.

So, balance the boat and tie the stuff down. Take the play out of the steering and TEST. Maybe something good will happen.