Scgreen620 Posted August 2, 2015 Report Share Posted August 2, 2015 I have a 78 620 and this is just my point of view I want to know if others have felt a diference as well... So people please post your stories... I did a oil change about two months ago I had an Bosch filter and was using the rotella t oil as other members of Datsun recommended using (the oil not the filter). it worked great the only problem the Bosch filter leaked oil From the seal. Today I changed the oil but I decided to go with something different so I went with a "Napa gold" filter and valvoline vr1 oil 20/50. The filter worked great no leaks at all, the only problem is that now I feel that I have less power with the new oil and filter, but with the rotella and Bosch I felt better response and more power .. My question is why am I feeling that ? What might be the cause of this "lack of power" I'm feeling? Thanks guys Quote Link to comment
flatcat19 Posted August 2, 2015 Report Share Posted August 2, 2015 What was the weight of the Rotella you were using? Quote Link to comment
ericsb210 Posted August 2, 2015 Report Share Posted August 2, 2015 You are noticing a lack of power from an oil change? Did you do any other maintenance on the Datsun? With the latest oil change, did you notice the oil to look odd? Was the oil thinned, foamy, thick? Quote Link to comment
ericsb210 Posted August 2, 2015 Report Share Posted August 2, 2015 I run Rotella 15w/40 and love it. I use Wix oil filters. Quote Link to comment
datzenmike Posted August 2, 2015 Report Share Posted August 2, 2015 15W40 vs, 20W50. I don't think the thicker oil would make that much difference once warmed up. Placebo effect. You think it will so it does. 3 Quote Link to comment
shacks510 Posted August 2, 2015 Report Share Posted August 2, 2015 Outside temperature and humidity has sucked lately... That could be it? Quote Link to comment
125 CSL Posted August 2, 2015 Report Share Posted August 2, 2015 My own personal experience. Being as it is hot here most of the year, thought that the rotella t 15/w40 would work great. The motor ran like crap. Switched to T6 no problems. Quote Link to comment
john510 Posted August 2, 2015 Report Share Posted August 2, 2015 I dont see how any common motor oil would make an engine run bad.The ignition system,timing and carburetor dont know you changed oil.Maybe something got bumped ? I did have a Bosch oil filter leak once.I tightened it a little more and at the next oil change spent 1 1/2 hours peeling it apart to get it off.Never snug up the oil filter on a hot engine. Quote Link to comment
maltese Posted August 2, 2015 Report Share Posted August 2, 2015 Hmm. I've never had a Bosch filter leak. Been using them for years. Good filters, IMO. Quote Link to comment
Scgreen620 Posted August 2, 2015 Author Report Share Posted August 2, 2015 What was the weight of the Rotella you were using? I use 10 30 on the last oil change due to the fact that at the autozone, It was what they had at the moment Quote Link to comment
Scgreen620 Posted August 2, 2015 Author Report Share Posted August 2, 2015 You are noticing a lack of power from an oil change? Did you do any other maintenance on the Datsun? With the latest oil change, did you notice the oil to look odd? Was the oil thinned, foamy, thick? Nope not any other color just regular dark oil What does foamy oil do to the engine ? Quote Link to comment
Scgreen620 Posted August 2, 2015 Author Report Share Posted August 2, 2015 Outside temperature and humidity has sucked lately... That could be it? Don't think so I even drove at night with the cool air thinking it would drive way better and no.. Quote Link to comment
Scgreen620 Posted August 2, 2015 Author Report Share Posted August 2, 2015 I dont see how any common motor oil would make an engine run bad.The ignition system,timing and carburetor dont know you changed oil.Maybe something got bumped ? I did have a Bosch oil filter leak once.I tightened it a little more and at the next oil change spent 1 1/2 hours peeling it apart to get it off.Never snug up the oil filter on a hot engine. I never use tools to tighten the oil filter, only by hand 1 Quote Link to comment
datzenmike Posted August 2, 2015 Report Share Posted August 2, 2015 I'm with John. When the oil is cold maybe but when warmed up and thinned out they would run about the same. You are also using your own perception (aka ass dyno) which can have three results that can: easily be fooled, unintentionally be biased or they are possibly true. Changing the filter places you very near the plug wires. Maybe one is loose or fell off. Something simple like this? 2 Quote Link to comment
Scgreen620 Posted August 2, 2015 Author Report Share Posted August 2, 2015 Onother question I have are the L20 oil filters and the L18 engines the same ? Quote Link to comment
Scgreen620 Posted August 2, 2015 Author Report Share Posted August 2, 2015 Ahhhhhhhhhhhh! Maybe I did, I washed the engine bay due to the oil leak and scrubed a little Quote Link to comment
datzenmike Posted August 2, 2015 Report Share Posted August 2, 2015 Onother question I have are the L20 oil filters and the L18 engines the same ? Yes. Ahhhhhhhhhhhh! Maybe I did, I washed the engine bay due to the oil leak and scrubed a little Water on the wires or distributor? Quote Link to comment
Scgreen620 Posted August 2, 2015 Author Report Share Posted August 2, 2015 To be honest I did ... Maybe it would change today since it should be dry now Quote Link to comment
HRH Posted August 3, 2015 Report Share Posted August 3, 2015 20w50 is too heavy for the L motor. No need unless you're running a race motor, which I doubt. Put 15w40 back in it. Or just run 10w30. Valvoline VR1 is fine oil, it has the extra zinc package. All 15w40 diesel oil still has zinc too. Of course, the L motor couldn't care less. It's not a big block with a cam down low that takes 30 seconds to get oil to. You don't hear of people flatting cams in L motors, do you? SBC, sure. Use a high-zinc oil when breaking in the cam or in a new motor. Other than that, shouldn't have any issue if things are built right. Quote Link to comment
datzenmike Posted August 3, 2015 Report Share Posted August 3, 2015 It's a long term thing and I just want to preserve my L. In addition the low level ZDDP oils get lower every year. I figure you have to buy oil for a change anyway so why not something with the old level ZDDP still in it? Quote Link to comment
HRH Posted August 3, 2015 Report Share Posted August 3, 2015 None have the old level of ZDDP in them Mike. Even the diesel formulas have much less than original. Once the engine is broken in though, it's really not necessary. But you saw the autocross video. That's 159,000 original mile L motor running 15w40 NAPA fleet oil at 6500-7000 rpm. Holds together just fine. I didn't even change the oil for breaking in the reground camshaft. Quote Link to comment
datzenmike Posted August 3, 2015 Report Share Posted August 3, 2015 Very well.... I'm erring on the side of caution. I don't see much difference between a chevy cam and tappet and a Datsun cam and rocker arm. (cam follower) Both have hardened metals sliding on each other under load. Quote Link to comment
Scgreen620 Posted August 3, 2015 Author Report Share Posted August 3, 2015 20w50 is too heavy for the L motor. No need unless you're running a race motor, which I doubt. Put 15w40 back in it. Or just run 10w30. Valvoline VR1 is fine oil, it has the extra zinc package. All 15w40 diesel oil still has zinc too. Of course, the L motor couldn't care less. It's not a big block with a cam down low that takes 30 seconds to get oil to. You don't hear of people flatting cams in L motors, do you? SBC, sure. Use a high-zinc oil when breaking in the cam or in a new motor. Other than that, shouldn't have any issue if things are built right.So do you know if the zddp level on the valvoline is higher than the diesel oil? Also do you guys think I should change it right away? Or will it be too hard on the motor? The valvoline oil was expensive and I don't want to just toss it.. I want to run for at least 4 weeks before I change it Quote Link to comment
ericsb210 Posted August 3, 2015 Report Share Posted August 3, 2015 Nope not any other color just regular dark oil What does foamy oil do to the engine ? Oil that appears foamy would be an indication of a blown head gasket. Quote Link to comment
ericsb210 Posted August 3, 2015 Report Share Posted August 3, 2015 Did the problem clear up? Did you pop your distributor cap to see if any condensation had built up? Quote Link to comment
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