Johnson "70mod"

[hupiveneilija]

big case and no pad, you're flying! Nice job.

Thanks!
Thats the idea! Fishing motor and deep-v. There is some myth that 17foot cant be made go fast that it has to be 16, i disagree that. And also its very driveable on rough, maybe not that speed but little less and it handles good.

[filthy phill]

Lot of people don't realise a pad is useless for offshore racing.
Need deep v min 22 degree to run in proper choppy waters.
it's the reason the original fletcher arrow bolt broke so.many records.
Skinny with very deep v, like most of the old Don shed designs.
Pad would be crap on English channel and north Sea races. They did not have much success in London to
Calail races. Apart from the odd cat it was all very deep V hulls.
Also need engine down in the force 4 and over for speed.

[hupiveneilija]

This is how the bottom of my hull looks.

[filthy phill]

good old 1970's deep v design.. very trustworthy in rough water.

[Fastjeff57]

Could have used such a design this morning on the Chester River. Boy, was it rough out there! I was half expecting my homebuilt wood boat to break something, but she made it back okay (bless her little heart!)

Jeff

PS: Ironic that the inventor of deep Vee hulls (that have revolutionized boating) was C. Ray Hunt, a sail boat designer! .

[hupiveneilija]

This is how the bottom of my hull looks.

Those little strakes are on original place but next ones been lenghtened allway to the transom, they stopped ~10to15cm from little ones, same style. Reason for mod was heavy engine and jackplate. Was really good mod. Hull goes higher and lighter feeling with longer waterline, more stable at speed because dont need so much positive trim. Infact with two it goes very good with zero trim and driver only few degrees positive is needed. Everyone that has seen it say that it looks real good and balanced on speed.
Im very pleased how it works.

[Fastjeff57]

..."Those little strakes are on original place but next ones been lengthened all the way to the transom,"

You know, I was wondering why they didn't do that.

Jeff

[hupiveneilija]

..."Those little strakes are on original place but next ones been lengthened all the way to the transom,"

You know, I was wondering why they didn't do that.

Jeff

I think it was working good with shorter strakes back then because of about 50kg less weight on transom.
No setback, motor bolted straight to the transom.
How much stinger or some 650merc weight that day in '70?

[filthy phill]

the reason for the shorter strakes is obvious, its for offshore rough water.
you dont want too much lift when it gets rough, plenty have put on extra strake length then took it off when they have found it slows them down on race days.
some have also found to carve into the transom to make a cut out to send more water towards the prop on rough water.
I definitely would not alter them, give better ride at sea,
if only going to be running on flat water or freshwater lakes its very different, and long might work.

[hupiveneilija]

the reason for the shorter strakes is obvious, its for offshore rough water.
you dont want too much lift when it gets rough, plenty have put on extra strake length then took it off when they have found it slows them down on race days.
some have also found to carve into the transom to make a cut out to send more water towards the prop on rough water.
I definitely would not alter them, give better ride at sea,
if only going to be running on flat water or freshwater lakes its very different, and long might work.

Ill try again. Picture above is from modified bottom not original.

Little ones pair #1 near keel are stock, original shape. Pair #2 next away from keel were same style but 15to20cm longer than pair #1, in stock original version. With that bottom and the weight on transom boat was going 50kn last fall with quite much positive trim and was pretty nervous to drive. And in rough water has to be trimmed way down to negative.

Now with pair #2 lenghtened all the way to transom it carries weight much better and goes much more balanced on rough with much less negative trim wich makes it more stable and predictible to drive.
And better yet, for topspeed dont need so much positive trim as before because it goes higher so surface area is small enough WITHOUT trimming nose skyhigh.

Its all about weight and how to balance it to keep forces influencing in right directions!😉

Does this make sense to anybody?🤔
Or am i lost like snowball in africa😂