what is the correct oil weight for a performance turbo buick?

[the wrath]

Right now i am using 5-30 and i get 15-18psi at hot idle. i just bought this book called how to build max-performance buick engines and it states that to use 20w50 and to use 10-40 during the winter months. Because 5-30 does not provide enough protection. Pro turbo buick engine builders please chime in i want to know if this is correct.

 

[Buick Mark]

Most use 10/30, whether its the Buick V6 or 350/455. 10/40 is ok. 20/50 is typically to heavy unless you have oil pressure problems from clearances being too big. Careful of what you read in those Buick "performance" books, ALOT of dated and mis-information in 'em.

 

[kshef]

I never understood 20-50...for those that run it, whats your cold startup oil pressure?

 

[dr_frankenstein]

your reading the book that has all of its V6 performance headlined by ESP?

I think ESP has a member here....

whats his opinion?

A.j.

 

[gnpoweredrail]

I never understood 20-50...for those that run it, whats your cold startup oil pressure?

depends on what spring you have in it.
I have the blue one ans one shim and I have 70-80 cold idle with new oil in it.
after some hard dune runs I usually only have about 15 psi hot idle so I need the extra oil.
I always let it get hot before I run it hard anyways.

 

[bison]

Oil pressure at idle doesnt mean ****. There is no load on the engine at idle. You need about 12psi per 1000rpm. i like to see 75-80psi@ 6000 rpm. More is not better. I mix oils to get the pressures i want depending on the climate. Fwiw 10w-30, 5w-30, xw-30 are all the same once theyre hot. I guess i hurt a lot of engines using 5w-30 when its 10* outside

 

[RegalT-type85]

10/30 here with a lil MMO or lucas in it.

 

[jpwalt1987]

My engine is shipping from DLS with Pennzoil 10/40.

 

[kshef]

Oil pressure at idle doesnt mean ****. There is no load on the engine at idle.

cold idle...80 cold idle is too thick...you dont get that using 5w30

 

[Nick Micale]

cold idle...80 cold idle is too thick...you dont get that using 5w30

Sorry, but our experience has not proven 80 psi or more is "bad", or that it is too high at cold idle. Most of our performance builds are 80psi or more at start up, and will be 40-50 psi at idle when reaching operating temps.

Like Bison, I too mix different weights depending on season and use. Our experience on hundreds of engines show less bearing wear using heavier weight oil, sometimes up to 50W here in the summer.

Having done MANY rebuilds on street and high performance engines over the years, bearings and cylinder walls "love" the heavier oil and show their "dis-like" for the light stuff, especially the watery synthetics.

Our goals in engine building and maintaince is performance and reliability, not gas mileage. :biggrin:

 

[bison]

Sorry, but our experience has not proven 80 psi or more is "bad", or that it is too high at cold idle. Most of our performance builds are 80psi or more at start up, and will be 40-50 psi at idle when reaching operating temps.

Like Bison, I too mix different weights depending on season and use. Our experience on hundreds of engines show less bearing wear using heavier weight oil, sometimes up to 50W here in the summer.

Having done MANY rebuilds on street and high performance engines over the years, bearings and cylinder walls "love" the heavier oil and show their "dis-like" for the light stuff, especially the watery synthetics.

Our goals in engine building and maintaince is performance and reliability, not gas mileage. :biggrin:

I agree with all this. I typically use straight 15w-40 in the summer here in the northeast. It's blended the remainder of the year

 

[Turbo-Fun]

A factory stock engine is designed for 10-30. I tried 5-30 for a while and my motor did not like it and became noisy. Went back to 10-30 and everything was all better.

 

[Sweet6]

I ran 5-30 and 10-30 Dino oil since my car was new. Never had an issue with either.

 

[vacuum 6]

I agree with all this. I typically use straight 15w-40 in the summer here in the northeast. It's blended the remainder of the year

Nick/Brian,

With everything said running XXw-40 is important for summer racing.

So what’s the difference running 5w-30 vs 10w-30 (less the obvious)?

 

[bison]

Nick/Brian,

With everything said running XXw-40 is important for summer racing.

So what’s the difference running 5w-30 vs 10w-30 (less the obvious)?

There is not a difference hot. I would expect the 5w to not last as long but it's of little concern since the oil should be changed quite often if you are running a lot of cylinder pressure. I typically change it affer the equivalency of 2-3 minutes of wot time at 500 whp. More power more often. Sometimes I'd change it after a hard Saturday night of heavy street action. Mileage shouldn't matter.

 

[vacuum 6]

Thanks, good 411.

IMO - it would be sweet if there was dino 0w-40.

 

[GSTOY]

Since my rebuild I've used 10-30 and at startup have 80psi easy. I did do the oil mods to the front cover and run standard oil pumps gears. Hot in drive I have 25 to 35 PSI and that's on a hot day.

 

[WSLN 6]

I get 22psi hot at idle with 5w30 synthetic, but may try some 10w30 this year.

 

[A2000RICH]

Thanks, good 411.

IMO - it would be sweet if there was dino 0w-40.

not likely you will ever see such a critter------more likely to see the abominable smowman at the next racing event-------synthetics tend to need less viscosity modifiers to acheive a wide range due to the characteristics of the base oil---------not so easy to make a 0W-40 non synthetic-------could be done but it would probably break down quickly due to shearing stress in a HP engine--------might even end up with more viscosity modifiers than oil..........RC

 

[Dabigguy]

A race engine spends most of it's life at 6-7000 rpm and very little at idle, so that's where some get confused on what oil for a street/strip car vs. race only car. You can run extra engine clearances and therefore need a heavier oil.

I like to see at least 10-12# oil pressure hot idle and 10# per 1000 rpms....6000=70psi oil pressure.