Mercruiser 470's

[calvert95628]

I have a 1980 SeaRay with dual Mercruiser 470 4 cylinder motors. They are in need of rebuilding or replacement. If I replace them, what more modern motor can I use; i.e., GM, Ford, or what? Is there an engine that will bolt up to the outdrives (Alpha 1 ?) without much, if any, modifications needed to the hull/mounts/cables? Thanks in advance for any assistance given.<br /><br />Bob

 

[DJ]

Re: Mercruiser 470's

Calvert,<br /><br />3.0L four cylinders should bolt up, but they are only rated at 135 hp. 4.3L V-6's should also bolt up, but I doubt you have the spacing to allow V-series engines.

 

[EricC]

Re: Mercruiser 470's

Faced the same problem this past spring. Decided to pickup a rebuilt long block and dress it myself. No problems to date. If you go with a different engine you'll not only have engine mount issue but the cooling systems will be different, and will not line up without modification. Also if you do change engines make sure that you outdrives are geared correctly. The 470 mated to an alpha 1 with a gear ratio of 1:1.84 The wrong gearing will effect the rpm's that you run at. <br /><br />Eric