U.P.Scarab

I have Alpha 1 drives on a 30' 1987 Scarab II and I recently changed my port motor to a LH rotation by buying a counter rotating lower unit. I also rebuilt both motors which added about 100hp per motor to bring them around 400hp each(educated guess by engine builder not dyno tested) I am confused because the boat is slower than when it had both RH lower units . I also thought I would be able to go up in pitch size but am still running 19's X 15 1/4 wheels. She ran around 68 before and can't seem to get over 62 now. RH motor is runinng 4800 rpm and the LH is runing 4600 rpm at WOT. Any suggestions???

phragle

iTrader: (3)

are the carbs tuned right?? What are the motors??

U.P.Scarab

Motors are 454's and I think the carbs are right. I was kicking around the idea of going to Holley 750's it has rochester's on it right now.

phragle

iTrader: (3)

without knowing what was done to the motors, 454 330's are only supposed to spin around 4600 rpm. Realistically your only talking about adding 70 hp for the 400 mark. was that a cam? heads? Whats your engine guy say its suposed to rev too?? if you are taching the motor out you can go up on the prop, though increasing the load may not make the alphas happy.

U.P.Scarab

Yes added a bigger cam & edelbrock intake everything else is pretty much stock but freshened up. And I know what your saying about only adding 70hp, I was figuring them at about 300 at the most because they were getting tired. I guess the biggest quetion I had was/is, did I put the CCW lower unit on the proper side? That being the port side. Wasn't sure if they are spose to spin outboard or inboard.

phragle

iTrader: (3)

you will get a hundred different opinions between spinning out and spinning in, generally spiining out is a bit more forgiving spinning in can be a bit faster. Still sounds like your around max rpm,with that motor, have you tried bigger wheels??

U.P.Scarab

Yes started at 25's and worked down to the 19's, almost stayed with the 21's they were spinning around 4400. Think I might try swapping them out and try spinning them in and see what I get.

motor

iTrader: (3)

what are cam specs. . which intake?

mike tkach

iTrader: (3)

i suspect that you lost some power due to the cam change.

motor

iTrader: (3)

That was my thought....also......curious as to cam specs and which intake