I have an LS1 engine,I think, in my 03 Chevy pick up..I used M1 5w30 for the first change and have run RP 5w30 for every other change since..I can tell of no ill effects from using the grade oil GM says to use..I have not done a uoa yet but will on my next change...What data has been collected and analized to warrant a statement LS1 engines like a heavy weight 30 or lighter 40??Does it reduce wear?? Would running a heavier 30,lower end 40 be beneficial to my engine?? I think Gm knows their stuff but I'll listen to what you all have to say...
Reason(s) why LS1's like 40wt
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If warm enough run 10W30. But when it gets really cold, then use 5W30.
I live in NC so it doe snot get that cold here, compared to other places, so I run 10W30 year round.
I live in NC so it doe snot get that cold here, compared to other places, so I run 10W30 year round.
people usally say an engine likes 40wt because it is using 30wt.a few are referring to better wear with a 40wt.
Do a search in the UOA section. Also until you start trending with UOA's in YOUR engine, you will not know for sure what is best.
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=001966
I don't feel comfortable saying the LS1 "likes" 40wt versus a 30wt. I don't have enough info and there's too many variables. But on the other hand, I feel comfortable saying that the LS1 won't dislike a 40wt. My best guess is it has to do with engine oil temp. I have an oil temp gauge, and observed 230-260F oil temps routinely in the summertime, and that was with a 160F thermostat installed. So if you factor in a 190F stock thermo with stop & go traffic in summertime heat and coolant temps always in the 210-230F range, oil temp is going to be up there, like 250+. I don't have the knowledge about viscosity requirements and when too hot == too thin == increased wear & failure. Is it 9 cSt? 8 cSt? Most 30 weight oils are around 10.0 cSt, mobil synthetic has been around 9.7 cSt. This measurement is at 100C (212F). How much thinner does the oil get at temps like 250F, and higher? For this reason I think the 40 weight, and even 50 weight, oils would be better and is probably the reason why some UOA's seem to show better #'s.
Too bad my logic goes out the window when you start looking at UOA's of 20wt oils. I would like to see some trending UOA's on the 5.7 hemi which Chrysler is saying to use 5w-20 in.
I think most of the wear #'s in my report were due to engine break-in. I also did two 1000 miles intervals on pennzoil 5w-30 (no analysis on those) before the last UOA on the 10w-40. I think those two flushes helped the most with the copper #'s, and the others in general.
I don't feel comfortable saying the LS1 "likes" 40wt versus a 30wt. I don't have enough info and there's too many variables. But on the other hand, I feel comfortable saying that the LS1 won't dislike a 40wt. My best guess is it has to do with engine oil temp. I have an oil temp gauge, and observed 230-260F oil temps routinely in the summertime, and that was with a 160F thermostat installed. So if you factor in a 190F stock thermo with stop & go traffic in summertime heat and coolant temps always in the 210-230F range, oil temp is going to be up there, like 250+. I don't have the knowledge about viscosity requirements and when too hot == too thin == increased wear & failure. Is it 9 cSt? 8 cSt? Most 30 weight oils are around 10.0 cSt, mobil synthetic has been around 9.7 cSt. This measurement is at 100C (212F). How much thinner does the oil get at temps like 250F, and higher? For this reason I think the 40 weight, and even 50 weight, oils would be better and is probably the reason why some UOA's seem to show better #'s.
Too bad my logic goes out the window when you start looking at UOA's of 20wt oils. I would like to see some trending UOA's on the 5.7 hemi which Chrysler is saying to use 5w-20 in.
I think most of the wear #'s in my report were due to engine break-in. I also did two 1000 miles intervals on pennzoil 5w-30 (no analysis on those) before the last UOA on the 10w-40. I think those two flushes helped the most with the copper #'s, and the others in general.
In general, on this forum, the LS1 term is normally referencing the 5.7L engine in the Firebirds, Camaros & some Corvettes. "The Patman" has plenty of LS1 experience & knowledge.
The GM Vortec engines in the pickup's belong to the same engine family and actually have the following codes, 4.8L-LR4, 5.3L-LM7, 6.0L-LQ4.
The manual for my 5.3L spec's both 5W-30 & 10W-30 and the engine seems to run quieter & smoother with a 11-12cSt oil (heavy 30 wt) during the warmer months.
But this is just a personal preference as we see many good UOA's posted for the 5W-30 viscosity.
The GM Vortec engines in the pickup's belong to the same engine family and actually have the following codes, 4.8L-LR4, 5.3L-LM7, 6.0L-LQ4.
The manual for my 5.3L spec's both 5W-30 & 10W-30 and the engine seems to run quieter & smoother with a 11-12cSt oil (heavy 30 wt) during the warmer months.
But this is just a personal preference as we see many good UOA's posted for the 5W-30 viscosity.
Patman
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If you look at all the UOAs on here for LS1 (and LS1 based) engines, you'll find that this engine just doesn't always show good wear with a thinner 30wt oil (such as one that is around 10 cst at 100c, like M1 5w30 and 10w30). Most noticeable is that you'll often see higher lead numbers with the thinner oils.
Oil temperature definitely plays a huge factor, since the LS1 will see 250-300 degree oil temps if you road race it (without an oil cooler)
I got incredible results with my LS1 Corvette with GC 0w30, which finished up the interval at 11.5 cst, making it a mid to high 30wt. My oil temps during that interval were mostly in the 200-207 degree range.
So they don't absolutely need a 40 weight oil unless you are seeing higher oil temps than I do on a regular basis. Most people do see higher oil temps than me though, which is why I like to recommend LS1 owners choose an oil between 12-14 cst for the most part.
Oil temperature definitely plays a huge factor, since the LS1 will see 250-300 degree oil temps if you road race it (without an oil cooler)
I got incredible results with my LS1 Corvette with GC 0w30, which finished up the interval at 11.5 cst, making it a mid to high 30wt. My oil temps during that interval were mostly in the 200-207 degree range.
So they don't absolutely need a 40 weight oil unless you are seeing higher oil temps than I do on a regular basis. Most people do see higher oil temps than me though, which is why I like to recommend LS1 owners choose an oil between 12-14 cst for the most part.
I have a question for you SBC guys. Is the 5.7L vortec in my 96 PU a LS1? How is it different? I had 8ppm of iron and lead on my last UOA using a mid 30wt dino. Do you think I could improve on the lead wear? This PU has a oil to water oil cooler so the oil has never got above 210 degrees F. With low oil temps I figure a 30 wt is good until it gets alot of miles on it. One of the reasons I switched to amsoil vs mobil 1 is because amsoil are usually on the thicker side.
Look up the wear numbers ofa 4.0L Jeep engine in the UOA section and compare wear with 30wt vs 40wt oil. The 4.0L likes a 40wt.
the LS1 motor, Al block with Al heads came out in 1997. Since yours is a '96, the 5.7L went by the production code of LT1- iron block with Al heads.
The LS1 has a 10.1 compression ratio, I think the LT1 is 10.5. Some LT1's, but not all, had reverse cooling. That's about all I know, if you do google on LS1 LT1 you'll find tons of info.
unless you have an oil temp gauge or get reports from someone who does with the same motor, you can't be sure what oil temps really are. I've learned from mine that oil temp generally runs 20-30 deg hotter than coolant temp in the summertime.
No, the LS1 engine was only used in the Camaro, Firebird and Corvette and the Holden Monaro (re-badged and sold as the new GTO). Never in any trucks. Its a high performance engine.
The LS1 is history, replaced by the LS2.
The newer engines (4.8,5.3,6.0,8.1) in trucks/SUV/Van from 1999 up (new body style) are based on the LS1 design.
GM POWERTRAIN WEB SITE
He has neither. It's an L31, aka Vortec 5700. Conventional cooling, regular distributor, iron block & iron heads. This engine was in production from 96-98 in 1/2 ton pickups and much later in HD pickups, vans, and other applications.
If GM put LT1s in these trucks (one of their best selling, if not THE best selling, vehicles), there'd be a whole lot of ****** off Chevy truck owners. Not the best engine for a truck. Still surprises me that they even used it in the B-body (caprice, et al) and D-body (Fleetwood).
[ December 16, 2004, 09:12 AM: Message edited by: kevm14 ]
Here's one of my favorite tables to look at (snagged from another post on this forum). I only wish it had a lot more oils.
250*F is about 120*C, so you can easily compare how all these oils do at these elevated temps. M1 0W-40 shows an advantage over GC (and is doing as well as M1 10W-30 and 5W-30 at 100*C). I am still debating between these oils for my 93 Caprice (206k) and 95 Z28 (152k). I might have to default to the M1 since I haven't yet found GC in my area.
Does anyone know if M1 0W-40 would just end up shearing down to GC's level? I'd be doing about 5000-6000 mile OCIs in my small blocks. Any data comparing these two oils?
LOL, why are you surprised this engine was used in the B and D bodies? ****** truck owners?
Because of the history of what GM has used in their fullsize RWD platforms. Caprice didn't get TBI until 1989 (except for the 4.3L V6, but who cares), when it was around since 82. In fact, EVERYTHING got it before, including the trucks. These cars just have a history of using reliable, if old fashioned technology (not high performance). Then in 94, they installed the LT1 that was used in the Corvette only 2 years before, and got the same sequential EFI and MAF sensor that the f-body and Corvette got for 94. In other words, it got exactly the same technology at the same time as the f-body and Corvette. And while I realize a lot of owners are happy about this (I bought a 93 to avoid hassles like the optispark), it didn't make a lot of sense. Although I will admit the success of the Impala SS depended on this engine.
The L31 would have made more sense, since it had basically conventional parts, with multiport EFI and excellent heads (no dumb distributor and regular water pump).
And same goes for the trucks. LT1 just isn't fit for truck duty (trucks like reliable designs...). I'm saying it's good they went with the L31 and it would have been a good choice for the b-body, except the L31 didn't come out until MY1996...
The L31 would have made more sense, since it had basically conventional parts, with multiport EFI and excellent heads (no dumb distributor and regular water pump).
And same goes for the trucks. LT1 just isn't fit for truck duty (trucks like reliable designs...). I'm saying it's good they went with the L31 and it would have been a good choice for the b-body, except the L31 didn't come out until MY1996...
Interesting...
While I certainly have no "proof" of any of the following ramblings, they do come from personal experience.
Everyone loves to jump on the "optispark is crap" bandwagon. Why? Ever owned an LT1? From an owner perspective ('96 Impala SS) I have no problems with it at all. In fact is the most reliable and maintenance free distributor design I've run so far. More to the point its the only system that I did not have to replace before 100K miles and it was still working when I pulled it out! Where is the problem? Not reliable? Well, lets see... 150K on the clock now, engine related repairs= (1) optispark (was still working), (1) waterpump, (1) power steering pump (too many Auto-X
Thanks for the info kevm14 but I gotta question what you said about the HD line not having the Vortec 5700 until later. Both 3/4 an 1 tons trucks had that motor as a base in '96.
Now to try to bring this back to the original question. It seems that the LT1s like a thicker oil because of high oil temps mostly. Choosing a wt on operating temp has always made sense to me.
One thing that might make a difference is how Big John uses his 5.3L and does it have an oil cooler. My 1/2 ton w/5.7L does because it was ordered with the tow package but not all have it. I have towed a 3500lb trailer up a 7% grade for 20 mins in 90f temps and the hottest my oil got was 215F oil and 200F water. So considering my oil temps and wear numbers I'm going to stay with 11.7cst 5w-30ASL.
John I think you choice of RP 5w30 is good. If you tow hard in the summer and don't have the tow package/oil cooler you might want to find a xw-40. I stay away from mobil 1 because it is only 10cst.
Now to try to bring this back to the original question. It seems that the LT1s like a thicker oil because of high oil temps mostly. Choosing a wt on operating temp has always made sense to me.
One thing that might make a difference is how Big John uses his 5.3L and does it have an oil cooler. My 1/2 ton w/5.7L does because it was ordered with the tow package but not all have it. I have towed a 3500lb trailer up a 7% grade for 20 mins in 90f temps and the hottest my oil got was 215F oil and 200F water. So considering my oil temps and wear numbers I'm going to stay with 11.7cst 5w-30ASL.
John I think you choice of RP 5w30 is good. If you tow hard in the summer and don't have the tow package/oil cooler you might want to find a xw-40. I stay away from mobil 1 because it is only 10cst.
I have a 96 LT-4, the late version of Opti Spark with couple of the early problems fixed.
I haven't had any problems, and doubt the previous owner did since the car only has 52k miles.
Optispark is great when it works right. The biggest problem is that they are very sensitive to moisture and very expensive to fix. Distributor cap and rotor alone run close to $300, IIRC.
The General in his infinite wisdom placed the Optispark, which is very sensitive to moisture, right under the GM water pump. We all know GM water pumps last forever and never leak
A leaky water pump on an LTI can cost you well over $500 in parts. $150 for the water pump and what ever for a new Optispark. The labor is also high because you have to move so much crap to get them off the enegine.
When I said "much later" referring to HD, I meant "kept in production much later than 1998." Although I did a little research and the L31 was still available in the new body 1500s (99s). So 96-99 for the 1500s and 96-99+ for others. Sorry if I was unclear.
The original WP in my Caprice went around 190k and I bought a new one for like $37. Took me an hour to install and I was going really slow.
The prevailing attitude I find on the SS forum is "who cares, it's still a slow TBI." I dunno, mine ran a 15.7 with just a gutted cat. That's not that bad...and it sure snaps around town nicely.
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