quade cat ob power ??

[afr]

on the set up is it better to turn the center props in and out on the outer two
??

:driving:

 

[T2x]

On this one we used LRLR...but it didn't make much difference if we used LLRR....... Of course we were using SSM's

 

[afr]

thats what i thought rich thanks man its been a while so i had ?,s i like the
lrlr myself

 

[OneBadInjun]

The ideal rigging scenario, when rigging four outboards on an offshore race cat, is to keep them directly behind each of the two sponsons. This includes keeping as much of the inboard propellers exposure to the tunnel wash to a minimum as much as possible, as well. Unfortuneately, this engine placement isn't always possible, due to sponson size, but ideally, this is best. With regards to prop rotation with quads, every boat/rigging is unique. Installed height, engine centerlines, gearcase design & ratio, horsepower/weight aspect ratio, prop design, hull design/lift, and so on. This translates into testing, testing, and more testing.

 

[T2x]

The ideal rigging scenario, when rigging four outboards on an offshore race cat, is to keep them directly behind each of the two sponsons. This includes keeping as much of the inboard propellers exposure to the tunnel wash to a minimum as much as possible, as well. Unfortuneately, this engine placement isn't always possible, due to sponson size, but ideally, this is best. .

That works great when you have a Cat with 4 foot wide sponsons.........

On the twin and triple Shadows we found that the outer engine gearcases should be just out of sight behind the inner sponson wall and I agree that you want to "hide" the gearcases whenever possible... However we found that exposing the prop blades to the tunnel water flow allowed us to maximize speed. In the above photo you see pretty well that where we put the gearcases on the outside engines followed that rule. This placement also seems to work best on 28 Skaters as I gained 4-5 mph on mine simply by relocating the engines to that location.

The #4 SSM's were very narrow and designed to run in tunnel water flow so it made much less difference. The stock lower units in the tunnels of the triple and 4 engine Shadow/Chris Cats and Skaters always took a tremendous beating and tended to want to bury the nose in turns.

Because of normal 24-32 foot Cat tunnel dimensions you could not hide more than 1 engine behind each sponson on Shadows, Chris Cats, or Conquests (2 Foot wide sponsons)

What 4 engine outboard cat project were you involved with... Ed?

 

[imco offshore]

two of the neatest cats ,i was lucky to see run when i was young ..we were racing in the Miami Marine Stadium and they were called ,,EL LOBO and EL DIABLO ,,i think they were called Switzercrafts Wings with Mercs ,,,BAD AZZ FAST ,,AND COOL TO HEAR RUN,,

 

[T2x]

two of the neatest cats ,i was lucky to see run when i was young ..we were racing in the Miami Marine Stadium and they were called ,,EL LOBO and EL DIABLO ,,i think they were called Switzercrafts Wings with Mercs ,,,BAD AZZ FAST ,,AND COOL TO HEAR RUN,,

Really? There might be one or two of those still around...... But they aren't cats... They were, and are, 4 point hydroplanes.

 

[imco offshore]

damn ,,,thats it ,,one was red and the other ?? brain fade,, cool ,,what power is on them now and how fast,,I wish you could run one of those to a race this year,,I would ,,and I,m sure others would like to see it ,,wow I can,t believe ,,survivors..

 

[T2x]

damn ,,,thats it ,,one was red and the other ?? brain fade,, cool ,,what power is on them now and how fast,,I wish you could run one of those to a race this year,,I would ,,and I,m sure others would like to see it ,,wow I can,t believe ,,survivors..

There are 3 running currently on the Vintage circuit and about 10-12 others resting in "collections". The one in the picture is mine running at the OFF event in Jupiter in October (See this month's Powerboat for details on the get together). The other two have period correct in line 6 power (150 hp ea. at the powerhead). Mine has a pair of current Merc S3000's (approx 375 hp ea at the prop shaft). Since the designs ran between 100 and 120 back in the day with between 80 and 150 hp engines....mine will never see full throttle.

For more pictures and info see http://www.seriousoffshore.com/forums/showthread.php?t=486

T2x

 

[imco offshore]

Rich thanks for the thread lead ,,it was a good read,,,brought back some good ol days ,,and reminded me of ,how old i am ,,why am I still doing this stuff,,lol back then i got my first chance to drive a Magnum Missle ,,,scared the hell out of me,,,,,thanks again,,

 

[cowisl]

Really? There might be one or two of those still around...... But they are'nt cats... They were, and are, 4 point hydroplanes.

Awesome picture! I remember you showing me the boat in the back of Doug's parking lot. its come a long way!

 

[T2x]

Rich thanks for the thread lead ,,it was a good read,,,brought back some good ol days ,,and reminded me of ,how old i am ,,why am I still doing this stuff,,lol back then i got my first chance to drive a Magnum Missle ,,,scared the hell out of me,,,,,thanks again,,

Anytime....

 

[Jesse James]

as previously mentioned set up wise, i believe all of the current 4 engine inboard cats are LRLR, I know the 2 46 skaters were set up that way...

 

[Fast Shafts]

Is the photo the "Rolling Thunder" cat?

 

[Ratickle]

mine will never see full throttle.
T2x

Never say never......:sifone:

 

[boostbros]

we ran 4 2.5 offshores on a 30 shadowcat you are correct about getting them behind the sponsons the two engines that ran in the tunnel would break the mid cases in half often losing 2 lower units and props when i would look back or video i was always amazed they actually stayed attached to the boat we broke many unbreakable things i dont think we ever finished a race or poker run with all 4 running at the end its pretty sickning to run to the stern and look see 2 missing lower units often breaking the midcase in half!! Hey T2 is it true you guys cold molded an M1 tank then splashed it to get the shadow? if ya did you overlooked something as that shadow was a hopper till it got over 90 106-108 was our top with all 4 screaming

 

[T2x]

Is the photo the "Rolling Thunder" cat?

yes

 

[T2x]

we ran 4 2.5 offshores on a 30 shadowcat you are correct about getting them behind the sponsons the two engines that ran in the tunnel would break the mid cases in half often losing 2 lower units and props when i would look back or video i was always amazed they actually stayed attached to the boat we broke many unbreakable things i dont think we ever finished a race or poker run with all 4 running at the end its pretty sickning to run to the stern and look see 2 missing lower units often breaking the midcase in half!! Hey T2 is it true you guys cold molded an M1 tank then splashed it to get the shadow? if ya did you overlooked something as that shadow was a hopper till it got over 90 106-108 was our top with all 4 screaming

That porpoise is affectionately called the "Linder hop".