86 Chris Cat
 

I have an 86 Chris Cat with 560hp motors. I haven't been able to reach the top speed I was hoping for (top speed is 80MPH). The props are currently turning inward and the boat gets squirrelly at that speed. I was told that turning the props outward would improve handling. Any suggestions?

Do you have a "Link Bar" joining the two drives?

a guy in the classified has an 84 twin hp500. He claims to run in the 90's so something is wrong with your boat and it's probably more than the side of rotation of your props... Are you sure the engines still pulls 560?

I Do Have A Tie Bar Between The Drives. The Motors Only Have 17hrs.on Them.the Dynos Show 560hp.i Talked To American Dffshore And They Told Me That This Hull Design Has To Run The Props outward Because inwards The Props Are In Dirty Water. This Is An Old Coast Guard Boat. It Has Two Gas Tanks Of 100 Gallons That Run Farther forward Than The 50 Gallons On Todays Boat. with the extra weight Maybe It's Not Getting Enough Air To Lift. also it has ssmll and borg warner trans.

pictures?

Each boat is different on prop rotation, try them out and see what it feels like. Send a PM to Greencard, he has a chris cat, it starts to hop around 70, then he can drive through it. What is the boat doing that is bothering you? Hopping up and down, like its trying to pack air, side to side, etc... Also what kind of water are you on, rough, dead calm?

i will try and get some pictures as soon as possible. the lake i live on is fairly calm. i'am in the process of turning them outward. i will keep you posted. our lake is low right now so it maybe a month or so before i will get to try it. it wants to walk around from side to side at around 70 to 80 mph.

Don't know if this will help or not but anyway...

http://www.go-fast.com/Prop_Slip_Calculator.htm

http://www.rbbi.com/folders/prop/propcalc.htm

:party-smiley-004:

I had the same boat. My 525SCs got it to 100mph.
First off, check your X dimension. Some people put SSMII drives on boats that came with TRSs. If the prop shaft is several inches below the bottom of the hull, that's your problem.
I've tried both rotations. The "clean" water comes through the tunnel. Turning them in gave great stern lift, faster planing, and 20mph more top. I also as running 4 blade props, they seemed to grab better than the 3 blade.
Gary

the center of the prop shafts are even with the bottom of the boat. i'am also running 4 blade props. they are 17in 30pitch.with the formula giving above 1.50 ratio 30 pitch prop 5000 rpm speed was 94mph add 10% slip its 84. i'am running 80mph gps. other people with the same boats are runnig faster with less power. i will keep trying different things till i find the problem. keep the suggestion coming.

Are you WOT at 5000 rpm? If so you're engines may need to turn more rpm to get the hp out of them. Have you tried a lower pitch prop?

looking for some info in 84 chris cat
 

i am thinking on a 84 cat with twins 500/ the guy told me is a 80 mph boat, i might work a trade with my stinger plus some cash.
any suggestions?
the cat needs cosmetic work but it runs good according to the seller.
the boat is in the classifieds ad under chris craft.
i want to go a little bit faster and i love my stinger but iam top out with speed, i hate to let it go but i might have to,
if anyone here wants to work something out trade up or down with cash let me know.
if the deal is intersting i am ready to do it.
i have all the pictures of my stinger restoration
i am looking for something bigger that 25 ft that i can go out and go in the mid 60s mph i will be happy for now,

did you check for insurance on this cat before doing the move? I would check! and by the way, I went up from 2 x 275 HP to 2 x 485 hp... and it does cost the double (almost) in gas. I hope you knew that! I contacted this guy also for the cat and he claims 90 mph... should be enough since you are looking for mid 60' !:D

The x dimension is the starting point on all these boats. 17 in diameter wheels need to be ABOVE the bottom of the boat and small bravo 15 inch props seem to be good even for starting points. On my 85 Chris and friends 84 Shadow,95 Awesome and 96 AO all are quicker and handle better turning props IN. These boats have a narrow tunnel and not as much air to lift the nose resulting in a hop. Forward weight or extra cargo seems to change mine, although in rough water or chop, porpoise is much less noticeable or gone. These boats are true tunnels and as most have quirks. They do not act as pleasant as modified designs with center pods but are superior in rough water ride and handling. You can not have it all:D....unless you step into a Skater,MTI,etc. which in my opinion is another league. Good Luck

Eddito,

My 85 Chris Cat runs 90-95 with a pair of 565hp blower motors. I rode in it once at 90mph when i bought it and have not taken it out since i purchased it in October. It's up for sale for $36,500 at the moment. It looks to be in much better shape than the one your are currently looking at. The only reason it's up for sale is i am trying to build a house. The port motor is currently in the machine shop getting reworked. I'm swapping the HiPo Chevy heads for a pair of mild ported Merlins, the Supercharger is currently at The Blower Shop getting tightened up. My plan was to get both motors worked this winter, crank up the boost a bit and try to get up to 100mph.

Let's see some pics....

Just seen them on another thread............Thanks.

My 84 CCAT has twin 400 HPs amd SSMII. max speed in high70's. I have one engine not turning as many rpm's as the other at WOT (-500 rpms). My X looks to be about even with the bottom and I know mine is factory original. I have 3 blade cleavers labbed- don't know the size. I do not have any hop.

Wannabe

Nice looking Chris Cat..... Lets see some pics.....