oil changes?
 

at what time intervals are you changing your oil, i was originally gonna change at the fifty hour mark, but i may go less than that, it is on a 7.4L

Re: oil changes?
 

It depends on how you are running it. Hard every 20 hrs. Average 30 maybe 40, thats pushing it.

Re: oil changes?
 

Change it when it starts to get dark, don't let it get black. 50 hours is way too much.

Re: oil changes?
 

Do an Oil Analysis....That will tell you if you need to change more often or less....Will save you tons in the long run...$15 will usually get you a good test. Results usually in 2-3 days.

BH

Re: oil changes?
 

I've always changed mine every 20 hrs.

Re: oil changes?
 

Myself 20 hrs regardless of how it was ran. Also use a good oil and filter, its worth it in the long run.

Re: oil changes?
 

well, i've got 27 hrs on mercruiser oil and filter, on a 7.4 L

Re: oil changes?
 

You should be fine, but it's probably time.

I love my HO's. They actually tell me when to change it. They don't burn a drop of oil until between 25 - 30 hours. Then when I see the oil level start to drop I know it's time.

Re: oil changes?
 

Every engine and application has a different maximum frequency change and a minimum. The minimum is usually 20 hrs on higher HP engines especially those with blowers. So if you change every 20 hrs no matter what engine you have and use a premium conventional or synthetic oil and a quality filter such as a Mobil-1; Amsoil; Baldwin or A/C Duraguard you are being extra careful and are less likely to experience premature wear or an oil failure.

A good perspective might be comparing service hours in cars to boats. Cars usually ought have an oil change every 3,000 miles. If you average a speed of 45 MPH that's about 65 hours between changes. But the service duty in a car is light to moderate at best in most cases whereas a boat is considered high to severe duty.

If you use a premium synthetic (Amsoil 20w50 Severe Duty Series 2000; Royal Purple 20w50; Redline 20w50 all at $ 6.00 to $ 8.00/qt) and are comfortable with extended oil changes you would be fine going 40 hours but changing the filter every 20 hours and topping off. I have enough faith in these products to go that route as long as the fliter is a premium filter such as a Mobil-1; Amsoil or Baldwin or Wix plus I now use a magnet on the filter too. I think the time is here to consider this. I am doing this myself now on my 350 Magnum's. I did an oil test on each engine after 25 hours and running a new Mobil-1 filter and topping off, for an hour before sending the sample, they came back as basically being "new oil" data results with no contamination. No water, no acids, no metals. I was running Royal Purple. The "moly" in the oil was shown present as I knew it would be. I am finding that the more I use Royal Purple or Redline the more I like it. Redline and RP hold up best in HTHP tests across the board due to the moly additive. So I will plan to change the oil at 50 hours next but send a sample before at say 40 hrs just to see what was in there.

I like the idea of using a premium oil and oil filter and going the season with only one change. I go by test results. If the oil came back in "new quality" after 25 hours and granted an hour through the new Mobil-1 filter. Then that's all you need to do.

Mercedes Benz in it's S-55 AMG 496 HP twin screw blower motors says to go 15,000 between changes using Mobil-1 0w40 oil. At an average speed of 45 MPH that's over 300 hours. Porsche also says to go 7,500 in their Twin Turbos using Mobil-1 10w30 and that's around 150 hours. You don't have to change filters or top off either. If you use a premium synthetic like Amsoil 20w50 Severe Duty you can go twice the frequency with a premium filter change in-between.

The time is here and I am doing it. I analyzed my 20w50 conventional oil after 25 hours last year and it was broken down to a 5w40 and had metal in it. Test your conventional to a synthetic for a few bucks and you will see similar results.

I am doing this in 350 cubic inch GM engines. I would be ok in a 496 or 525 as well. I would not extend in marine blower applications because they run "fat" and gas gets into the oil regularly from blow-by. That's got to be a 20 hour change no matter what you use.

As always. Use what you like and change when you like.

Re: oil changes?
 

how about the drive oil, what r the intervals for it and on a bravo one, i don't need any special tools do i? just crack the vent till it starts running out and then the resivoir all the way, right?