1990 454 / 7.4 Mercruiser Oil Capacity

May 15, 2019
51
Windsor, Ontario, Canada
Boat Info
1990 350 Express Cruiser
Engines
454 CID / 7.4 Liter Twins
Hello Folks - Had my local marine tech change the oil on both engines upon purchase of new boat to me last year. - 1990 Sea Ray 350 Express Cruiser with twins

I instructed him to put in 7.57 litres / 8 quarts.

Yet this showed way overfilled on dipstick on both engines- had to remove approx 2 litres / 2 quarts from each which brought each dipstick to top of fill mark.

Owners manual ( Mercruiser 454 Service Manual #15 - Section 1b-10, page 23) reflects as follows:

7.57 Litres / 8 Quarts With New Filter
or
6.60 Litres / 7 Quarts With New Filter - For Generation V Engines (Engines with Cast Aluminum Rocker Arm Covers and lack of engine block fuel pump mounting pad)

I was never aware of / had read of a 6.60 litre / 7 Quart Gen V configuration

Makes sense if my engines are Gen V but how can I be 100% sure?
I think I read Gen V came out in 1992 whereas my engines are 1990.

Can anyone assist?


Engines Are:

7.4L MIE W/HURTH GM 454 V-8 1989-1992 - 0C391564 THRU 0D715493

Thanks - Craig
 
Craig,
We probably have the same motors, you are only going to get 6 quarts of oil in them. The published amount is for a dry motor. I have never been able to get more than 6 quarts out when changing my oil.
Rick
 
With my 1990 454, there was a bunch of oil in the oil cooler, and the hoses that route up to the oil filter (that sits above the engine). Make sure to drain that too! I forgot the very first time I did it. :)

I wasn't sure if this was part of the the oil quantity measurement that the factory manual said.

Either way, I also only needed about 6.5 litres on my most recent change. But I also flushed the engine with a bit of oil during the change.
 
I built my motors from new and initially they took more oil.
I’ve only ever been able to extract 6+ qts.
Check your oil level is good...then, replace the amount you’ve extracted...
Simple.
 
Last edited:

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