Do thinner oils (SAE xW-20, xW-30) do better at high RPMs?
- Thread starter JT20
- Start date
(a Bro-Lo) …
That's true. It may run but may not be 100%. But I guess if you didn't change the oil on your 2.7 and sludged it up and blew it up, a not-optimal 3.3 or 3.5 will be an improvement.
These JDM EJ20 swaps are super popular. From what I understand you have to get rid of the engine at a certain age in Japan? I'm not sure it's cost effective any more and who knows what you'll end up with for an engine. With the amount of Subarus that get wrecked up where I am, seems like another EJ25 (whatever specific variant is in the car) wouldn't be too hard to find and swap in.
Prior to the mid-2000's (~2010/2011), the owner's manual for all USDM Subaru's, n/a and turbo, had the same oil chart which was 5W-30 being preferred and even up to 10W-50 allowed in severe conditions. Currently, Subaru Japan allows 5W-30 in applications that spec 0W-20.
Okay well the thing is, I can get an EJ25 for $500 bucks but it's right at that age for a head gasket problem. 158k miles!
I was going to comment.. Would this thread like an update when it goes in?
Finances seem to dictate that I will get my car back AFTER Christmas... Not before.
The shop sure didn't hatchet job the Subaru, seems to be good with japanese vehicles.
Guy has a Supercharged 2007 Chrysler 300 running between 14 and 18 pounds of boost on racing slicks in the rear. He also has a black Dodge Viper which I see in the summer. It is so clean. I might try to snap a pic if OVERKILL wants to see. (I've been in it. Its fast. The kind of car that makes you say.. "Stop thinking your Subaru is fast, it doesn't matter what you do, it's not.") Well, aside from 700-1000HP built motors..
If you're buying a used engine , I'd just put it on a stand and do the head gaskets, valve adjustment, t-belt, rocker cover gaskets etc before going in. Would be a perfect opportunity to go through and get it up to par. Heck, I'd even do it on that "JDM" engine you're buying. The EJ20s don't have head gasket problems but they are going to need timing belt and rocker cover gaskets anyway.
I'm wondering if my Catalytic Converter is going to be glowing hot orange every time I drive it.
If it is, than any buildup or blockage will go away very quickly. It will also stink the first few times lol..
The oil specified for my two stroke Yamaha RD400 transmission is 10W-30 motor oil. Heavier oil specified in a shared sump bike is more so for the engine protection than for the transmission.
With at least 24 qts.
And oil coolers ?
And 30-35/36?psi pressure caps on cooling system
Unless there's something causing it to severely overfuel - which may happen if the computer doesn't realize it has a 2.0l engine instead of a 2.5l engine, no. Mine has spent some time cruising at 3500, 4000 RPM with no problems with the cat. No rotten egg smell, hasn't glowed, etc.
You shouldn't have that much carbon in the intake unless it's got a severely malfunctioning EGR valve, is a diesel and driven ver lightly.
I somewhat agree with you that fuel dilution could be only issue. MAYBE.
I'll be sure to sniff dipstick. If I smell a lot of fuel.. might go back up to a 40.
Unless I burn it off every trip..
I'll be sure to sniff dipstick. If I smell a lot of fuel.. might go back up to a 40.
Unless I burn it off every trip..
Interesting thread. I’m interested to see how the jdm swap works out.
i would start with a 10-30. It’s probably a 5-30 motor if not a 5-20. A couple of factors.
1. There’s no chain to worry about. Chains add wear to oil and chains like to be hydrodynamic in oil, but that requires a few rpms to achieve.
2. Bottom ends tend to do better with heavier oils
3. Top ends tend to respond better with thinner oils
so where will the most stress be in this case? I’d wager the bottom end, especially considering it’s a smaller motor. and I’d be all over a decent synthetic... penzoil, castrol, as my top two.
my ‘22 called for 5-30. I ran 10k ocis even back in ‘00, and found 10-30 to absolutely hold up better in that engine than 5-30.
unless you regear the drivetrain, it’s going to turn the same rpm at cruise unless the automatics computer commands a lower gear.
i would start with a 10-30. It’s probably a 5-30 motor if not a 5-20. A couple of factors.
1. There’s no chain to worry about. Chains add wear to oil and chains like to be hydrodynamic in oil, but that requires a few rpms to achieve.
2. Bottom ends tend to do better with heavier oils
3. Top ends tend to respond better with thinner oils
so where will the most stress be in this case? I’d wager the bottom end, especially considering it’s a smaller motor. and I’d be all over a decent synthetic... penzoil, castrol, as my top two.
my ‘22 called for 5-30. I ran 10k ocis even back in ‘00, and found 10-30 to absolutely hold up better in that engine than 5-30.
unless you regear the drivetrain, it’s going to turn the same rpm at cruise unless the automatics computer commands a lower gear.
Higher RPMs also increase the shear rate, which increases the temporary shear (temporary lowering of the viscosity) of an oil.
For example if you have a 5W-30 and a 10W-30 with both the same HTHS = 3.0 cP @ 1,000,000 s⁻¹ shear rate but with the 5W-30 having a lot more viscosity-index improver (VII) than the 10W-30, the 5W-30 will run a lot thinner than the 10W-30 at higher RPMs where the shear rate increases beyond 1,000,000 s⁻¹ at which the HTHS is measured.
For example if you have a 5W-30 and a 10W-30 with both the same HTHS = 3.0 cP @ 1,000,000 s⁻¹ shear rate but with the 5W-30 having a lot more viscosity-index improver (VII) than the 10W-30, the 5W-30 will run a lot thinner than the 10W-30 at higher RPMs where the shear rate increases beyond 1,000,000 s⁻¹ at which the HTHS is measured.
I am inclined to agree. I think my (smaller) engine will be getting more of a full workout, every time it moves the car, and I always read a "smaller engine running slightly hotter" will be the most efficient. So I am on board to use full synthetic in it.
I'm thinking some thin 30 that will not shear down ... Got me thinking about 10W-30 vs 5W-30 vs 0W-30 (or thick 0W-20) again.
Wintertime.. thinking of maybe Magnatec, .
What about if it's Redline 5W-30 which from what I read is thick and Group V synthetic and doesn't shear down, and is amazing that way? (Just asking)
Red Line High-Performance 5W-30 has about 85% API Group IV PAO and about 15% API Group V POE. You don't want to have a mostly POE engine oil unless as in the case of Valvoline/Cummins Premium Blue Restore, which is used for a single OCI for the removal of carbon deposits.
Redline goes api sn+
redline lspi friendly oil Well there goes the neighborhood, but I do not know moly levels. If they are high, that would be a pretty good choice for an lspi quenching oil with the mix pao/III basestock.
bobistheoilguy.com
No, it is not VII-free either. Its VII content is comparable to that of lower-VII-content 5W-30 oils, such as Pennzoil Platinum 5W-30, but I've seen even-lower-VII-content 5W-30 oils.
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