Viper Setup With a 90 hp inline 6

[obrien]

I have a friend that I am going to be helping with the restoration on his 1979 Hydrostream Viper. He is going to be rigging it with a 90 hp inline six. I was wondering if any set back is needed for this setup? What kind of prop shaft height can we run? What prop do you think it will turn for a prop? Any suggestions on any changes that should be done with the boat while he is doing the fiberglass work?

[bernie]

I have a '77 Viper with a '73 in-line 115 short shaft. Motor sits flat on the transom, no set back, and not jacked up with the 15" it is up about 4-5 inches. Plugged off the top 4 water pickup holes, then with a 5/16 drill bit massaged the remaining holes with additional forward lead to get water in - maybe get 7-9 psi at WOT trimmed out, but tucked in a bit and cruising I get 12 psi at 4200 at around 40 mph, a great cruise. Run a 20" big ear chopper with extra cup. Be sure to run a water psi gauge. WOT is a bit over 6000 at 58-60 mph, fast enough for me.

[Capt.Insane-o]

It was a long time ago, but the fist motor I had on my first viper was a 90 on 4 1/2 in of set back with a inline 26 chopper. The party is all over at 5500 with the 90's, they have very conservative porting so there is no use what so ever trying to prop for anything higher. I ran about 1 in blelow the pad and had a mazco cone on it. Get a set of mounts from Bruster, even with the 90 I had a lot of problems with the mounts and chine walking.

[obrien]

Thanks for the input guys. I will be sure to let him know. I assume Bruster is a member here?

[Bruster]

That I am. Send me a P.M. and I will get you set up with a set of solid mounts for this motor.


Series I full set
Solid mounts for the classic inline motors up to and including the 1500XS, 2 uppers + 2 lowers, $70 Shipping $10



Thanks for the input guys. I will be sure to let him know. I assume Bruster is a member here?