Mercruiser 320 EFIs
#11
Originally Posted by Magicfloat
This was before Merc Racing started using blue paint. You've got a real nice setup there. Any history on the boat?
#13
Originally Posted by Bob Zubik
that thing looks bad azz, is it for sale????
Thanks.....no it's not for sale........it's my dream boat since I was 15.....

Aaron
#14
My 87 Donzi Minx came from the factory with the 320 Efi. The engine had failed because electrolosis had eaten a hole in the aluminum intake, and trashed the engine. It had been sitting about a year when I bought the boat, along with the real "basket case" engine. I had all the original parts, and was going to put it back to original, but I decided to change to a carb. I read later that there is a design flaw in the injection, that shoot the fuel directly on the rings, washing the oil off the cylinder walls, and causing failure. Theres a guy here on Oso called 30 Sonic SS, or something like that, that has been battling getting two of them running for a couple of years. I sent him all the injection parts I had, along with the Ecu. Last I heard, I think he gave up and bought two new carb motors. The 320 Efi is the same longblock as the 350/300 Tempest engine. Good block, four bolt mains, forged rods and pistons. If it's running good, you might want to consider swapping to a carb now before you have trouble.
#17
Originally Posted by 24degrees
Cuda......yer bummin' me out.
The engines have a Mercathode set up on them......do you think that would help fight corrosion?
Thanks,
Aaron
The engines have a Mercathode set up on them......do you think that would help fight corrosion?
Thanks,
Aaron
Btw, it was Scott B's buddy who owned the boat before me, and he saw the holes in the intake before they were repaired.
#18
Registered

Joined: Jul 2005
Posts: 202
Likes: 2
From: Cedar Creek, TX
cuda's comments are bugging me out as well. I just recently purchased a 1987 Checkmate with the same 5.7 320 HP EFI motor in it. So far it runs like a champ. It was freshened in 1995 with forged pistons, Dart heads, Crane hyd roller cam, and some other misc goodies and then dyno'd with the stock EFI stuff (may have used larger injectors and or more fuel pressure) and it made 424 HP and 445 TQ. From what I have seen, none of the fuel injection, or electronics parts are available anymore, so if we were to have problems, we would either have to find used parts or make something else work. If I ever loose the EFI, I would think about going to a TPIS (Tuned Port Injection Specialties) Mini Ram set up... it looks very similar in design and then use some sort of aftermarket EFI controller. By the way, I thought these motors were only produced in 1987 and 1988 models... perhaps you have a 1988 model that was purchased in 1989???
#19
The parts listings I have found list an '87 version and '88-'89 as another set of serial #s.
The motors run perfectly......I guess I'll just maintain them and hope for the best.
The motors run perfectly......I guess I'll just maintain them and hope for the best.
#20
Classic Magnum 24Degrees! I'd never heard of those engines before
Thanks for the edjamacation guys
Hope they keep runnin' for ya till we run out of fossil fuels
BTW, where are you showing that piece off??? I'd like to see it in person someday. Hopefully close to NJ somewhere....
Thanks for the edjamacation guys
Hope they keep runnin' for ya till we run out of fossil fuels
BTW, where are you showing that piece off??? I'd like to see it in person someday. Hopefully close to NJ somewhere....


