24degrees

I recently bought a 1974 Magnum 27 sport that has been re-powered with Mercruiser 320 EFIs and Bravo 1s.

They were aparently a Mercury Hi-performance divison creation. The RPM range on the flame arresters says 5000-5400.

Any of you guys have these engines and what can you tell me about them?

Thanks,
Aaron

Dave M

It sounds like they are the 6.2L small blocks. 5400 sound high for stock "black" motors.

24degrees

Sorry....forgot to mention. They are 350/5.7L made in 1989.

Aaron

Magicfloat

320 EFI's were built in 1988-1989 model years,pretty cool motors,strong runners,but had lots of early electronic glitches. The few we bought drove us crazy. But if these are still going after 15 years you should be fine. Parts are still available but some of the efi parts are expensive. Enjoy the engines,they were pretty special back then.

24degrees

What are my options if the EFI becomes too hard to get parts for.....?.....can I update ECUs ?

Thanks much,
Aaron

32 thunder

post pictures

24degrees

Here are a few......

dreamer

Sweet

Magicfloat

This was before Merc Racing started using blue paint. You've got a real nice setup there. Any history on the boat?

Scott B

Like Robert said, when they ran they ran very well. If the boat was used in salt, be very afraid of the intakes. NLA, if they leak, they will need to be replaced with a different setup..

Sharp boat BTW!!!