Ford Lehman SP90 OIL

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Aftika

Member
Joined
Aug 11, 2014
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6
Location
Canada
Looking at a 1988 Marine Trader 36 with twin SP90's and was curious as to the oil required...

I have a Lehman Power Owners manual for the SP90 dated June 1987 and it specifies on page A24 that for my operating temp (32ºF to 90ºF) to use 20W/20 API Spec CC

I also have a Operator Handbook (Edition 8) for Ford 2720 Range 4 & 6 Cylinder Diesel Engines (including the 2722 4Cyl 254cu in SP90) and this is dated November 1988. This handbook specifies API Spec SF/CD Multi-Viscosity 10W-30 or 10W-40.

Anyone have any insight to the discrepancy between the two documents and the straight weight oil vs. the multi-viscosity oil?
 
Those oil specs are obsolete, so don't beat yourself up looking for them. Most folks have been using a modern SAE 15W-40 diesel rated oil with API spec CJ-4. I use Rotella, not because it is the best, but it is available everywhere. A modern SAE 30 is also ok in a Ford.
 
We have FL120s which are the previous generation of Ford of England diesels than what you have. We were told by people with tons of experience with these engines to use single weight oil in them. The manual says the same thing although later versions say multi-vis can be used as well. So we have used Delo 400 30wt in our engines for the last 16 years. 30 wt. is what's specified for our climate in the FL120 manual we have.

If it was me in your situation I'd find out what the previous owner used and as long as it was one of the oils you've mentioned from the manuals in terms of viscosity I'd stick with it.
 
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Those oil specs are obsolete, so don't beat yourself up looking for them. Most folks have been using a modern SAE 15W-40 diesel rated oil with API spec CJ-4. I use Rotella, not because it is the best, but it is available everywhere. A modern SAE 30 is also ok in a Ford.


I was thinking on using Amsoil SAE 15W-40 Synthetic Heavy Duty Diesel & Marine Motor Oil

Rotella hard to get here... Anyone use Amsoil Diesel products in the past? I use their Motorcycle oil and find it good...
 
I'm sure the Amsoil will be fine, but I don't think it is worth the extra expense to go synthetic. Syn oil is better, but the reason you change the oil is not because the oil is worn out, but because it is full of soot. Good oil full of dirt needs to be changed as soon as a lesser oil full of dirt.

If Rotella is not available, maybe another brand such as Delo, Valvoline, Delvac, Ursa, etc is.
 
I like and use synthetics in small high value engines such as all my dirt bikes and quads. For an old school diesel or any other engine for that matter the cheapest stuff that fell off the truck is fine as to the stated reason of oil change above, your removing dirt not "worn out" oil. My wife's new Toyota May prove the exception to that rule for me though as I notice it has long duration (5,000+ miles) oil change schedule.
 
No need for synthetic or multi-vis. Unless you don't warm up your engine before you run at high rpm and loads .... Then you probably should use 15W-40.

I use Chevron Delo 30 weight and take 10 or 15 minutes to ramp up to cruising speed. Always had quick starts even in Alaska.

I think the "dirt" in oil that needs to be removed is carbon ... that is an abrasive. Frequent oil changes are a positive thing.


Craig my new VW Jetta has oil change intervals of 10,000 mi. I've got 8000 on it and changed the oil myself at 5,000 mi. I use 5W-30 as directed by VW. A specific brand too ... Castrol Synthetic. The oil at NAPA isn't exactly the same as what they use at the VW dealer. It's cheaper. Wonder if it's not as good? Or is it better and just no NAPA Mark up?
 
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For an old school diesel or any other engine for that matter the cheapest stuff that fell off the truck is fine as to the stated reason of oil change above, your removing dirt not "worn out" oil.

Very Valid Point indeed... Found a local after that carries both Mobil Delvac 1300 Super 15W40 AND Shell Rotella T 15w40 - Both at the same price.

Thanks Kindly!
 
Aftika and Craig,
If you follow the trucks around you can change oil often.
 
All synthetic oil is manufactured under license from the patens owned by Exxon-Mobile. I use Mobile 1 in my 2001, 175,000 mile GMC PU since it's first oil change @1000 miles. All 4 of the TDI Jettas we have owned including this one is only touched by VW. This policy, in the past, has given me a leg up on VW accountability, even out of warranty. I sold an 03 ant the new owner had a timing belt job done on the cheap. 20,000 miles later it let go and ruined the interference engine. VW would have warranted that IF their job let go...but I digress. High rpm, engines that run hot..synthetic, my 5.9 Cummins boat, Rotella, and my FL.
 
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Pick and use any of the oils mentioned and your engine will be happy for years to come.

The likely hood of seeing any kind of engine failure or noticeable loss of longevity do to useing "the wrong oil" is about zero.
 

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