First let me give some background. I've been trying to track down an inconsistency in my bracket car. Normally, by the time I get to 3rd round (with 2 time shots, that is 5th run of the day) the car will generally run 3-6 hundredths faster than I predict with the air change. I know that sound inconsequential, but for most bracket racers, that is enough to send you home for the day unless you can account for it and dial for it. So after playing with a few things, I started diving into oil. I run Pennzoil 20W-50. I figured that it was taking that long for the oil to loosen up. (From 2nd round to 3rd round it is close to a hot lap). So I started looking into Synthetics. I thought they would heat up easier and faster and maybe I could use lighter oil too. While I was looking around I happened upon a little excerpt from the Crower site:
Quote:
Use of Synthetic Oils
Crower does not recommend the use of synthetic motor oils in any racing applications, particularly hydraulic and flat tappet camshafts. The minimum gains in horsepower are offset by the excessive wear to cam and lifter surfaces. Crower recommends (20W50) Petroleum based motor oil in all high performance applications. If your manual suggests running synthetic oil, then do so. We have found, however, that the benefits do not outweigh the costs. For additional information click here !
Supposedly, the oil is soo slippery that with high spring rates the roller will slide on the cam lobe instead of rolling. There are also suppossed issues with lifter pump up and collapsing. This is all heresay to me as I have no direct experience. Anyway, I started asking track friends and acquaintances. I was surprised to hear that many who have tried synthetics have switched back to petroleum based for various reason ranging from destroying lifters to oil leaks. I know many people here have had trouble with hydraulic lifters after their cam installs. I wonder if this would be the cause. Any thoughts? Anyone ever hear of this?
Just some more oil info to fan the fire for those interested.
Just in case DJWorm and Subdriver stop in to check this thread. What would you recommend? I want the oil to heat up as quickly as possible and retain the heat as long as possible between startups and runs.
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Vince
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Last edited by benenati379 : 11-22-2005 at 02:02 PM.
There is still a lot of debate on this issue and I can only tell you what my experience is and what some other racers use.
Chevy recommends a synthetic for all applications, including racing.
Most racers use a synthetic such as Mobil 1 or AMSOIL. Mobil 1 has an oil base.
Some racers use an ester based synthetic such as RedLine and swear by it.
Some racers still use a petroleum based such as Kendall 30 weight.
If I were using Crower lifters I would honor their recommendations, if not I would use a synthetic. What's recommended by Crower may not be good with other products and may even be harmful. None of these statements are universal.
Some racers using RedLine have seen scouring on the main & rod journal bearing surfaces at tear down....no failures...just normal tear down...whereas other synthetics and even the Kendall did not have any scouring.. I have not had but have seen bearings with the scouring.
Many racers using synthetics have imperceptable or no wear.
Most racers using synthetics will narrow the multi vis rating using 10W30 instead of the OEM 5W30. Others will use a 20W50 in HOT weather.
I am currently experimenting with a Full synthetic 0W20 Racing oil that has bound friction modifiers. This viscosity weight must be run at higher pressures. The OEM oil pump MUST be ported and reshimmed to produce a higher pressure and a higher flow rate or an aftermarket dry sump pump with adjustable pressure used. The higher pressure and flow rate with the friction modifiers offer the same oil film protection and lubrication. The benefit of the lower viiscosity is a 5% - 7% increase in HP. A secondary benefit is better cooling with lower oil temps & collant temps. It has a lower surface tension (but not a lower film strength) and therefore deAirs better in a dry sump system.
The downside is $12/qt. But that is cheap HP. I also change the oil after each event (1 weekend). No wear problems.
You might find that installing an integrated engine oil cooler will, ironically, allow the oil to warm up sooner and will stablize the oil temperature sooner and at a lower temp. This would be an oil cooler integrated with the radiator or an oil/water engine oil cooler installed inline to the radiator coolant line.
I currently use AMSOIL in all my street vehicles and tow vehicles vehicles with no problems. I have also used Mobil 1 in all my street vehicles and race vehicles with no problems.
I feel the AMSOIL has a better temperature spread than the Mobil 1. I would probably continue to use the AMSOIL in my race vehicles if I wasn't experimenting with the low Vis. racing oil.
All in all I have seen less engine/bearing failures since the advent of synthetics.
Having hydraulic lifter collapse is not the fault of the oil but possibly too low oil pressure, faulty pump, using the wrong type of lifter or using too heavy a spring or having too high a lift or RPM. If I was worried about lifter collapse I would install a REV kit or use solids.
As to roller "skip"...I'd use someone else's rollers.
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Thanks DJ. I have been thinking of going with a regular 20w50 and 10w30 blend or switching to a 10w40 synthetic. I'm looking for exactly what you said. I want the engine oil temp to stabilize a bit more. Either get hotter quicker and keep the temp, or keep it cool during hot laps. The thing about drag racing is that you could have an hour between passes or 10 minutes between passes and I need a bit more consistancy.
I think Im going to try a combination of both the lighter oil and an oil cooler. I really didn't want to change the pennzoil 20w50 for the simple reason that after every 2 seasons when I do a full tear down, there are no signs of abnormal wear. I wan't to keep that level of protection. In all fairness though the bearings are coated to for extra safety.
Do you have a recommended intermediate between 10w30 and 20w50 from amsoil?
Location: Gilbert, AZ Z06 Fest II,III,IV,V WinterFest 1&2
Posts: 2,757
Am I missing something here??
In my day, when someone mentioned Flat Tappets, you were talking just that. A flat tappet hydraulic or solid lifter camshaft.
Rollers were way too expensive and not streetable with a carb and manual timing advance!!
Today's Corvettes are running hydraulic roller lifter cams!!
All I see is a quote taken out of context and applied to todays specs???
Where did the quote come from and does Crower still advise the same when putting their cams in an LS-6 Vette motor??
Having hydraulic lifter collapse is not the fault of the oil but possibly too low oil pressure, faulty pump, using the wrong type of lifter or using too heavy a spring or having too high a lift or RPM. If I was worried about lifter collapse I would install a REV kit or use solids.
As to roller "skip"...I'd use someone else's rollers.
I use solid lifters, but i was concerned by what they stated. I was pretty much set on switching to synthetic, but I didn't want to go against what the manufacturer says. I figued I'd ask about it from someone that is educated in oils, such as yourself.
Ken, sorry if I confused you... I am pretty confused myself.
This was a two part question. The first was a general oil temp control question with regard to the different weights and synthetic vs regular.
Becasue I wanted to swich to synthetic in my race motor (wich is not an LSX but a BB cheby) I searched around just looking for any info. The quote from crower is not LSX specific. This is a current recommendation for all their lifters. (can be found on their website) It gave me a general cause for concern with all synthetics.
Edit: To add to the confusion, I may have posted this in the wrong section.
Last edited by benenati379 : 11-22-2005 at 06:40 PM.
Use of Synthetic Oils
Crower does not recommend the use of synthetic motor oils in any racing applications, particularly hydraulic and flat tappet camshafts. The minimum gains in horsepower are offset by the excessive wear to cam and lifter surfaces. Crower recommends (20W50) Petroleum based motor oil in all high performance applications. If your manual suggests running synthetic oil, then do so. We have found, however, that the benefits do not outweigh the costs. For additional information click here !
That looks to me as if they are speaking strictly on flat tappet cams, not rollers. Although rollers are hydraulic too, the lifter requirements are not the same. On Flat tappet cams the lifters (tappets) have to spin as they rotate on the lobe. Roller cams do not and it dosent mention anything regarding roller cams. It would seem that Crower thinks that this may not occur if you use a synthetic oil.
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380 RWHP and 361 RWTQ LGM 2/26/2005
Location: Gilbert, AZ Z06 Fest II,III,IV,V WinterFest 1&2
Posts: 2,757
Well Crower has their preference, and GM has theirs!!
They still put Mobile 1 in the new Z!
Who am I going to listen to??
I see a political taint in this!!
How many cams does Crower sell in relation to every other cam maker in the country?
Does anyone else support the theory??
Do they have any white paper analysis or are they just in bed with Penzoil................
I think it's as much BS as any other pencil neck salesman attempt to promote his product!! Now they don't carry suitcases door to door but laptops, Starbucks to Starbucks! You know they won't pay for access to their bread and butter!!
I think DJ covered the topic very well above and I agree with what he has said.
In Aug-Sep 2004 I had my motor torn down for a rebuild just prior to the 2004 SCCA Runoff's by my brother-in-law who has been building 700+ HP small block Chevy's for a couple decades now. After a season of use, the inside of my motor looked brand new. The rings were so good he reused them. I have absolutely no concern about running a PAO based synthetic such as AMSOIL in my motor. See note at the bottom of my post about synthetic "groups".
As for the heat capacity, I don't think there is a significant difference between the synthetic and petroleum based oils but I don't have any concrete data in front of me now. I use AMSOIL Series 2000 20w50 in the heat of summer and this oil takes a while to heat up. As a point of info, the viscosity of this oil is 128.1 cSt at 40C (104F) and 18.3 cSt at 100C (212F). Those numbers will be fairly representative of any 20w50. You can see how significantly the viscosity changes as the oil warms, so I could see this being an issue for you.
I suggest a few options
1) Fully warm up your oil before your first run so that oil viscosity is consistent througout the event.
2) I can't tell what your mods are. Do you really need a 20w50? I use it as I run for upwards of 45 straight minutes, essentially all of it at full throttle, high rpm in near 100F ambient temps. You'll see less absolute change in viscosity of a 10w30 or 10w40. If your engine is modified, and a 10w40 is recommended by your builder, you might try the AMSOIL SAE Synthetic High Performance 10w40, which is also a group IV PAO based synthetic. But, for consistency, I'd still let the oil fully warm up before your first run.
Some other things to ponder about synthetics:
All synthetics are not equal. The API has not come out and defined what is "synthetic", but rather, classified oils into five major groups.
Group I base oils are the least refined of all of the groups. They are usually a mix of different hydrocarbon chains with little or no uniformity. While some automotive oils use these stocks, they are generally used in less demanding applications.
Group II base oils are common in mineral based motor oils. They have fair to good performance in the areas of volatility, oxidation stability, wear prevention and flash/fire points. They have only fair performance in areas such as pour point and cold crank viscosity. Group II base stocks are what the majority of engine oils are made from. 3000 mile oil changes are the norm.
Group III base oils are subjected to the highest level of refining of all the mineral oil stocks. Although not chemically engineered, they offer improved performance in a wide range of areas as well as good molecular uniformity and stability. By definition they are considered a synthesized material and can be used in the production of synthetic and semi-synthetic lubricants. Group III is used in the vast majority of full synthetics or synthetic blends. They are superior to group I and II oils but still have limitations. Some formulations are designed for extended oil changes. AMSOIL XL Motor Oils, Castrol Syntec and many others fall into this category.
Group IV are polyalphaolefins (PAO) which are a chemically engineered synthesized basestocks. PAOs offer excellent stability, molecular uniformity and performance over a wide range of lubricating properties. AMSOIL SAE Synthetic Motor Oils and Mobil 1 primarily use group IV basestocks. PAO is a much more expensive basestock than the highly refined petroleum oil basestock of Group III.
Group V base oils are also chemically engineered stocks that do not full into any of the categories previously mentioned. Typical examples of group V stocks are Esters, polyglycols and silicone. Redline primarily uses an ester basestock.
In the 90s, Mobil filed suit against Castrol for falsely advertising Syntec oil as synthetic, when in fact it contained a Group III, highly hydroprocessed mineral (Dino) oil, instead of a chemically synthesized (group IV or V) basestock. Due to the amount that the mineral oil had been chemically changed, the judge decided in Castrol's favor. As a result, any oil containing this highly hydroprocessed mineral (Dino) oil (currently called Group III basestock by the American Petroleum Institute) can market themselves as a synthetic oil. Since the original synthetic basestock (polyalphaolefin or PAO) is much more expensive than the Group III basestock, most of the oil blenders switched to the Group III basestock, which significantly increased their profit margins.
- PAO basestock causes engine seals to shrink slightly. Ester basestock causes seals to swell slightly. As a result, in the early days of synthetics, seal leakage was common and led to the widely held view today that synthetics will cause seal leaks. However, AMSOIL has been blending synthetics for over 30 years now and today they use a basestock that is predominantly PAO based, but with an ester additive which counteracts the seal shrinkage of the PAO.
Not strictly flat tappet, they are saying all high performance applications... but *particularly* hydraulic lifters and flat tappet lifters.
Yeah, I got that but the hydraulic portion of it is really irrevelavent in this case since I believe they are referring to the decreased friction between the tappet and the cam lobe. This decrease would /could slow or stop the spinning of the flat tappet and thus wear down the cam lobe. Since Rollers do not have this problem I do not believe that it is relevant to roller cams; I would also have to agree with Ken on this, Ford, GM and Chrysler use roller cams and I have seen no bulletins from them regarding this issue.
I have seen a lot drag race type cars use a stick on heater bonded to the oil pan. The Pro Stock guys use to use them and I've seen them on bracket cars as well. Pro Stock guys have them bonded/glued onto the DS oil tank. If regulated with a temp sensor they could keep your oil at a constant level. You could also plumb in an external pump to circulate oil in the pan when you are sitting in the pits. Some bracket guys also use a coolant heater and pump set up to keep the water at a constant temp. Comp, Super Gas, Super Comp as well as Super Stock cars will warm up there drive trains in the pits by jacking up the rear and running the engine in gear. All of these cars run on a dial in or perscribed E.T. except Comp and need to be very consistant as does your bracket car as you know.
Thanks Subdriver. I had no idea the viscosity changed that much from 100-200F.
Since you asked, the thing is that I am not sure I need a 20w-50. That is what the builder recommends, but I know he is just trying to protect the motor as much as possible. This is for the Nova in my sig. It is a 460ci BB that spins between 5600 (converter lockup) to 7600 during a pass. But it is never kept running for more than a few minutes at a time. But how much can it really protect if I don't get it into a good operating range. It just seems like it takes me forever and a day to heat this oil up.
Right now, I think I am leaning towards the Amsoil 10W-40. Most super street racers are running straight 30 weight oil, but I dont' know I'm ready to make that kind of change. When I did bring this up to my builder last night, he suggested that if I used a synthetic to use Amsoil, so that is probably what I will do.
Hey DJ, Good idea on the heater. I saw the oil heaters in the catalog the other day. I was a little leary about a glue on heater, but this may be a good option for me. I would need a 110 converter to run it off the batteries I have in the car. I can plug it into the generator when I'm in the pits, but wouldn't be able to use it in the staging lanes.
I also normally drive a good bit to warm up the car (usually drive around the pits before I tech in). Afterwards I'll put it on the jack to warm up the drivetrain. I'm just having a hard time keeping the heavy oil Hot between rounds as I don't want to keep the motor running for too much longer than necessary. (Damn Sunoco Blue gets expensive!)
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I would need a 110 converter to run it off the batteries I have in the car. I can plug it into the generator when I'm in the pits, but wouldn't be able to use it in the staging lanes.
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