Hydraulic lifters -- viscosity extra-important?

[dparm]

This is my first car with hydraulic lifters. All my previous cars (Hondas) had to get regular valve lash adjustments. In some of my reading on this site I have not seen much mention of how different oil viscosities affect lifter operation.

For a motor with hydraulic lifters (this is a high-output high-revving 40V V8, by the way) is selecting proper viscosity even more important? How does a thinner or thicker oil affect this?

I apologize in advance if this is a dumb question, but coming from several Hondas that ran forever with no upkeep, I am still learning.

 

[spasm3]

My 76 buick had hydraulic lifters, liked any oil from 10w 30 to 20w 50. In fact they like heavier oil better! ( until they got sludged up and i had to pull like crazy to remove them for replacement!)
I think the vvt ( variable valve timing ) is sensitive to viscosity.

Anyone remember rhoads lifters?

 

[cchase]

Originally Posted By: dparm
This is my first car with hydraulic lifters. All my previous cars (Hondas) had to get regular valve lash adjustments. In some of my reading on this site I have not seen much mention of how different oil viscosities affect lifter operation.

For a motor with hydraulic lifters (this is a high-output high-revving 40V V8, by the way) is selecting proper viscosity even more important? How does a thinner or thicker oil affect this?

I apologize in advance if this is a dumb question, but coming from several Hondas that ran forever with no upkeep, I am still learning.


The ironic thing here is that hydraulic lifters are more "forever with no upkeep" than solid lifters. I personally think solid lifters on cars today seems a bit ridoiculous.

You shouldn't have any problem with oil viscosities. As long as they have oil in them, it's usually enough.

 

[Doug Hillary]

Hi,
Dan - According to engine development processes the lubricant's viscosity is especially important in the scheme of things. Now more than ever before perhaps

The German Company INA has long been at the forefront in the development of valve trains with hydraulically actuated components

One of their most serious development processes occurred with the Porsche/MB V8 jointly developed in the late 1960s early 1970s. These engines ended up as 32V - in 1983-4

Over some years INA have developed sohisticated devices for the dynamic measurement of various factors involved in these systems. This enables the calculation of valve train kinematics, cam lobe contact loads, the curvature radials involved with valve lift and etc. They can calculate the elasticity and deformity of various components in operation and the like as well. There are a host of variables in their design and operation and of course a large variety of types involved

In relation to lubricants leakage compensation betweeen chambers and etc is quite critical. This is especially so with cold to hot lubricant cycles. Of course this all takes place at high speed in the real world so accurate simulation is very important and lubricants with known qualities do make a difference in performance and durability. The more valves the more complex the task of course

In reality dynamic simulation adds to the mattrix of issues that determine what lubricant viscosities an engine Manaufacturer will prescribe. Manufacturer lubricant Approval systems take these things into account

IMO the rule of thumb should be to use the lowest viscosity prescribed by the engine's Manufacturer for the anticipated application and ambient temperature range anticipated

 

[dparm]

Well fortunately Audi is fairly "lax" in their recommendation...must be VW 502/505/505.01. That means HTHS 3.5+, 0w40, 0w30, 5w30, 5w40. But of course, there's a range of what's considered 0w40 and such.

But based on what you're saying, the 0w30/5w30 is preferable?

 

[Doug Hillary]

Hi,
Dan - If it "ticks all the boxes" then yes!

Perhaps the most critical thing is the "W" rating. Perhaps you see why a 25W-50 viscosity mineral oil tends to "bind up" the engine when cold and a 5W-50 synthetic would be much better

 

[dparm]

Thanks Doug. I assume a "heavier" 30 is probably the best trade-off between good HTHS and going as light as you safely can? I track and autocross my car during the warm months and I do drive it really hard the rest of the time.

 

[Doug Hillary]

Hi,
Dan - Some people believe that a 0W-40 viscosity lubricant is the best compromise. Most Euro engines need the A3/B3 ACEA rating as a minimum when driven energetically

 

[dparm]

Well Mobil 1 0w40, for example, is a lighter weight. Red Line 0w40 is a heavier weight (also a slightly higher HTHS due to the better basestocks). Splitting hairs?

 

[Doug Hillary]

Hi,
Dan - You said: "Splitting hairs?"

Yes

 

[CATERHAM]

Originally Posted By: dparm
Thanks Doug. I assume a "heavier" 30 is probably the best trade-off between good HTHS and going as light as you safely can? I track and autocross my car during the warm months and I do drive it really hard the rest of the time.


I agree, a heavier 30wt like GC 0W-30 would a good choice, particularly during the up coming Chicago winter.
Also since you occasionally track your car (in the summer) I'd recommend installing an oil pressure gauge. I think you'll find you have no need to go to a 40wt oil.

 

[dparm]

I already run a very light 5w40 but running the cheaper and more easily-found GC would be nice. Red Line 5w30 looks decent even though it's more of a middle-weight 5w30. Their 0w30 does not have a high enough HTHS value to satisfy VW's requirements.

 

[bigmike]

I prefer solid lifters. In fact, many years ago, I changed the hydraulic lifters out of my 2.2 Mazda to the older 2.0 solid lifters. No more ticking and I was tired of replacing them.

GC 0w30 would be my choice, as Caterham suggested. Finding it is difficult down here though.

 

[CATERHAM]

Originally Posted By: dparm
I already run a very light 5w40 but running the cheaper and more easily-found GC would be nice. Red Line 5w30 looks decent even though it's more of a middle-weight 5w30. Their 0w30 does not have a high enough HTHS value to satisfy VW's requirements.


RL's 5W-30 is more than a "middle-weight 5W-30", in fact with it's HTHS vis of 3.8cP it's more like a light 40wt on par with M1's recently reformulated 0W-40. In fact in extended use it's likely heavier than M1's 0W-40 since the RL oil contains no VII's and has been proven to be impervious to shear.

The HTHS vis spec' trumps the KV100 spec'; check the following post where both the RL 5W-30 and the previous M1 0W-40 formulation were tested:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1993351&page=1

 

[mechtech2]

Tight new lifters and worn old ones can have very different needs.
New ones are likely to prefer a thinner oil, and old ones can like the thicker stuff [when hot and warmed up]
For starting, thinner is almost always better.

Modern oils are multi viscosity and the factory recommendation is going to be perfect for most use.

BTW, some mechanical lifters/buckets hardly wear with good oil maintenance. It seems a tiny bit of wear is compensated by a tiny bit of valve recession.
Less parts, less complicated oiling, and high reliability.

 

[dparm]

Car has seen Mobil 1 5w30 for 50k, then I switched it to Motul 300V 5w40. It was well cared for.

 

[addyguy]

In the 1970's, this was certainly the case.

In the 1973 PS article on the new 'Maxi oils', Shell sets out that one of the benefits of their new 10W-50 was that it stayed in hydraulic lifters longer, and didn't drain out as easily. This contributed to less 'chatter' and noise when starting up a car after sitting for a while.

 

[dparm]

Originally Posted By: CATERHAM
Originally Posted By: dparm
I already run a very light 5w40 but running the cheaper and more easily-found GC would be nice. Red Line 5w30 looks decent even though it's more of a middle-weight 5w30. Their 0w30 does not have a high enough HTHS value to satisfy VW's requirements.


RL's 5W-30 is more than a "middle-weight 5W-30", in fact with it's HTHS vis of 3.8cP it's more like a light 40wt on par with M1's recently reformulated 0W-40. In fact in extended use it's likely heavier than M1's 0W-40 since the RL oil contains no VII's and has been proven to be impervious to shear.

The HTHS vis spec' trumps the KV100 spec'; check the following post where both the RL 5W-30 and the previous M1 0W-40 formulation were tested:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1993351&page=1



Well, the 300V that's in there now has an HTHS of about 4.5. The 5w30 version is 3.61.

 

[mattd]

FWIW, honda does not recommend an adjustment every so often, but to at least inspect valve clearance. Many times, there are no adjustments needed. On my 2007 V6 accord, honda states that valve clearance should be inspected every 105,000-110,000 miles. Many people will only adjust valves when they get to be quite noisy, or have excessive rocker to valve clearance. I've seen the honda 3.5 engines run 200k+ miles with no valve adjustment, and run/sound perfect.

 

[Craig in Canada]

I believe my 1990 Integra called for valve adjustments ("inspection" actually) a lot more frequently than that. Maybe every 36,000km? It's been a long time.

I started doing them myself about every 10,000km since it was so easy. Everyone assumes they'll wear "loose", but depending on what's wearing that's not necessarily the case. They can also wear "tight", and that's where damage occurs if they start not closing all the way. Even at my greatly shortened interval of inspection I think I usually ended up adjusting half of the valves every time, one direction or the other. Things were always a little smoother when I was done.

I had an MT so I would just pull the VC, loosen the plugs a turn, and push the car in 3rd gear to line up TDC in the sequences needed. Adjustment was a feeler gauge, screwdriver and wrench.