Mercruiser 888 Performance Check

[jstucky]

Took my old Newman 18ft out for the first time this weekend. 888 Mercruiser Drive. Has a 19 pitch 3 blade stainless prop. Not sure on brand. Boat weighs 2300lbs and I had 800 lbs of people onboard. Engine ran smooth. With what I thought was correct trim was WOT 3700 with a top speed around 40mph. I know the WOT for this engine is 3800-4200. Does this sound like its performing to a good specification? Any suggestions for improvement? Thanks.

 

[Scott Danforth]

the WOT rating on the Ford 302 motor is 4600-4800

so why isnt the motor achieving proper upper RPM?

what does the compression look like? are all cylinders between 140 and 150 psi?

 

[jstucky]

Thanks for the response Scott. I will check compression. There seems to be a difference of opinion on the reccomended WOT for this engine. My mercurity service manual says that the WOT on this 1975 Ford 302 engine was 3800-4200 which is lower than the later 305GM engine-which does say 4600-4800. But I have also heard others quote the higher rpm too. I didn't think 3700 was too bad with the boat loaded down with 6 people but I will check the compression and see what I find.

 

[jimmbo]

I will throw in my 2 cents here. A lot of the Ford Marine engines of the 70s did have WOT ranges in the 3800 - 4200, some were even lower. Granted, that info was from the OMC list of spec for the Ford Engines they used, as I haven’t been able to scratch up much info on the 70s Mercrusirrs, yet