Oil viscosity

I am putting the finishing touches on my re manufactured engine and want to know what type of oil I should use to break it in and then after the recommended 10 hour initial break in what oil weight? I am in the Florida Panhandle and temps are warm through October usually.
Also I have looked and can't find what thermostat I should use. 140 or is a 160 auto ok to use.

Thanks,

Jim

Re: Oil viscosity

well since you didn't state what engine you have, nobody could possibly answer specifics

do your break in with the same oil that would be appropriate for the temperatures you will be operating in.... do NOT use synthetic oil for break in... the thermostat should be specified by the manufacturer.... ie mercruiiser, volvo or whoever..... generally you want the proper marine thermostat but again without your engine details nobody can say

Re: Oil viscosity

If a 2 cycle OB, a BIA certified TCW3 rating (currently popular) is all you need. Current Mixing for most applications is 50:1 or a pint to 6 gallons of gas. They never tell you what the viscosity is and some put additives in it to improve performance that can affect the "apparent" viscosity if it doesn't actually affect it. I know Quicksilver oils are like that.

On 4 cycle Ford/Chevy marine adaptations, don't know. I know Merc markets an oil specifically for Marine engine applications. When I was young a 500 mile break in was a big thing, but that was when the only oils you could get were straight weight. In the last 20 years or so haven't heard anything about changing oil types for break in. Have read remarks like to take it easy for the first 500 miles and don't stress the engine.

On a boat that would translate to me as motor out past the no wake buoys, firewall the throttle to get on plane as soon as possible. Cut throttle back to a medium rpm area and spend most of your time there with intermittent WOT bursts short at first then increasing as the engine gets some time on it. 10W-30 seems to be a popular oil, and recommendations that I have read is to NOT use Syn or Syn Blend oil on the initial fill up. You want the engine to "wear in".

My 2c,

Mark

Re: Oil viscosity

Oooops. My bad. Thought about the geo area, but forgot engine info. Here it is.
It is a Mercruiser with a 5.7 and Alpha one outdrive. Boat is an 1988 21' Wellcraft. The engine company says to run at no more than 3/4 speed for first 10 hours and only for a few minutes, then change oil and run the same for another 10 hours. I have always heard there is a certain breakin oil for the break in period, but that was 40 years ago with my 69 Mustang. (Wish I had that back). It is a fishing reef in the Gulf Of Mexico, maybe I'll go visit it. Do you all use a straight weight like a 30 or 40 or do you use multi weight 5-30 or 10-40?

Thanks,

Jim

Re: Oil viscosity

I use multi viscosity 10w-30 synthetic in my Volvo. The manual suggests 30w synthetic but finding that anywhere is next to impossible other than ordering it.

Re: Oil viscosity

I'd run 10-30 in that..... I would do a cam break in in the driveway and then change the oil... Then I'd go with the 10 hour deal.... Avoid idleing as much as possible and smoothly vary throttle ..... Do not operate as a sustained speed..... I would run the correct marine thermostat for the year and model of the original mercruiser engine

Re: Oil viscosity

Thanks. What is a cam break? Yes I am going to avoid idle and very the speeds. Hope to get the hours in before the end of the season. I can't find which thermostat I need for it. Marine Max is terrible at customer service. They won't answer the phone in the parts dept. Guess I'll go to a different shop and ask for the correct one.

Thanks again,

Jim

Re: Oil viscosity

jimh1626 said:

Thanks. What is a cam break? Yes I am going to avoid idle and very the speeds. Hope to get the hours in before the end of the season. I can't find which thermostat I need for it. Marine Max is terrible at customer service. They won't answer the phone in the parts dept. Guess I'll go to a different shop and ask for the correct one.

Click to expand...

Generally speaking, Cam break in is usually running the engine (in neutral) at 2000 RPM for 20 minutes. But this may be a question better answered by your rebuilder. If for some reason you upgraded from a flat-tappet cam to a roller cam with the new engine, you don't need no stinkin cam break in.


BTW, these guys sell T-stat's too...
http://www.iboats.com/Boat-Parts-Accessories/dm/

Re: Oil viscosity

Mercruiser recomends their Sterndrive oil (Quicksilver 25W-40) or a straight weight SAE 30 or SAE 40. They do not recommend automotive-type multiviscosity oil. Sterndrive enginers have much higher average load on them than Automotive engines.

I always used the QS 25W-40 oil in my 4.3LX, since I live in NJ, and it gets cold in Nov.

let's see if that starts a "discussion"

Re: Oil viscosity

Thanks for the info. I thought there was a special break in oil and then a special viscosity oil after that. But I just went to a marine store where they service boats and sell parts and the guy told me that any 10 - 40 would be just fine for the engine. I am going to try and call the engine manufacture tomorrow and go by what he says. Life was so simple when I had my old Mustang with no emissions crap on it and with my old 65 hp merc 0n my 16' tri hull. Thanks for your time and efforts,

Jim

Re: Oil viscosity

here is the page you need for your new thermostat

Re: Oil viscosity

Chris1956 said:

Mercruiser recomends their Sterndrive oil (Quicksilver 25W-40) or a straight weight SAE 30 or SAE 40. They do not recommend automotive-type multiviscosity oil. Sterndrive enginers have much higher average load on them than Automotive engines.

I always used the QS 25W-40 oil in my 4.3LX, since I live in NJ, and it gets cold in Nov.

let's see if that starts a "discussion"

Click to expand...

And lately, I've found that QS oil to be more cost effective than auto blends.

V