Repowering old tri-hull

[AV8R]

I'd like to repower my old Signa tri-hull. It currently has an inline 6 cyl 165 Mercruiser. How tough will it be to go to a V-6 or V-8? Should I just go to a fuel injection system? If so, where can I get one that is marine rated?

 

[12Footer]

Re: Repowering old tri-hull

AV8R, you asked, and this is just my opinion...Stick with the mercruiser 6, or even look into the volvo. The reason I would stay with the smaller engine is fuel economy.<br />The bigger block will give you the capabilty of runnin a huge prop, and give breakneck speeds,but at a very high cost. Expect to pay twice as much to go the same distance....Even if if IS a shorted trip.

 

[Liljoe]

Re: Repowering old tri-hull

Go out and look for a 250 block out of a chevy truck in the junk yard from the 70's. Make sure the mounting holes are the same and just rebuild the block. The heads from the old engine will need redone to run unleaded and you will need to get a cam that will give you good torque at low rpms. We have rebuilt the original motor twice and the improvement we ended up with when we started with a fresh block was what we were looking for. By changing to a V you will have to change your outdrive and wouldn't it be cheaper buying another boat? Ours is in a 1970 signa tri-haul. With nine adults in the boat for the day we have no problems pulling three tubes and 18 gallons of gas lasting all day.