Didn't know that the heavy oil made such a difference. 
Expected HP loss??
Thread Starter
Burning Brakes
Joined: Sep 2003
Posts: 1,106
Likes: 0
From: Norwich NY
Expected HP loss??
What would be the "expected power loss" (if any) if you changed from 10-30 oil to 20-50 oil? I would think a heavier weight oil would rob some hp.
I was wondering if there was some sort of a formula or if someone has personal experience on a dyno doing this.
Thanks in advance..
:drive:
I was wondering if there was some sort of a formula or if someone has personal experience on a dyno doing this.
Thanks in advance..
:drive:
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
The car is designed to run with 5-30, 10 30 would be ok... anything beyond that and you are running the risk of engine failure.. if you have low oil pressure, you have mechanical damage.. increased oil viscosity could cause a dry startup, lack of lubrication to the top end... the bearing clearances were design with 0-30 viscosity. I would Not recommend doing this, and I will not argue the point.. this is just my educated input.
Le Mans Master
Joined: Dec 2000
Posts: 9,899
Likes: 1,839
From: Hot Springs AR
Originally Posted by Fastbasser
HMMMMMMMM I lost 10.. Was wondering if I was alone..
For the record, I switched to heavier oil toincrease oil pressure, not for testing.
For the record, I switched to heavier oil toincrease oil pressure, not for testing.
IOW, I agree with ET's assessment. I would expect 20w-50 to only be needed in custom-built engines.
Also, to your original point, high viscosity oil can soak up a lot of hp.
HTH, and have a good one,
Mike
Drifting
Joined: Dec 1999
Posts: 1,315
Likes: 27
From: Central Florida
Originally Posted by Evil-Twin
The car is designed to run with 5-30, 10 30 would be ok... anything beyond that and you are running the risk of engine failure.. if you have low oil pressure, you have mechanical damage.. increased oil viscosity could cause a dry startup, lack of lubrication to the top end... the bearing clearances were design with 0-30 viscosity. I would Not recommend doing this, and I will not argue the point.. this is just my educated input.
modded shortblocks. The engine builder of my forged shortblock wanted
me to run 10-40 Dino oil for the first 1000 miles. Now it is time for
Synthetic oil and I was planning on using 10-30, or 10-40. My oil
pressure is on the lower side ( 25 at idle, 45 at 2Krpms) and I am
kind of concerned about using 30 weight at idle.
Thanks,
Russ
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Burning Brakes
Joined: Apr 2004
Posts: 857
Likes: 0
From: Olympia WA
I've seen high milage Honda's that run heavier then recommended oil, the oil rings are all gummed up, but the bearings look great. Being a drag racer, my motors are set up a little loose and I run heavier oils. You can gain HP on dyno by running 1qt less oil. 
Last edited by binkysgarage; Feb 23, 2006 at 03:43 PM.
Team Owner
Joined: Sep 2003
Posts: 43,084
Likes: 33
From: Raleigh / Rolesville NC
Originally Posted by Fastbasser
What would be the "expected power loss" (if any) if you changed from 10-30 oil to 20-50 oil? I would think a heavier weight oil would rob some hp.
I was wondering if there was some sort of a formula or if someone has personal experience on a dyno doing this.
Thanks in advance..
:drive:
I was wondering if there was some sort of a formula or if someone has personal experience on a dyno doing this.
Thanks in advance..
:drive:
for the track / racing 15-w50 is as thick as you want to go for extreem heat of hard racing.
During the summer on the track I run 15-w50. takes for ever to warm up, but can take the consistant 250-260 oil temps for 30 min at a time.
and I think the cars run better with a bit thicker oil, but that is just my opnion. No data to support it
No real need for anything that thick.
Pro
Joined: Oct 2004
Posts: 514
Likes: 2
Originally Posted by AU N EGL
Why would you want to go to a 20-50 OIL ???
for the track / racing 15-w50 is as thick as you want to go for extreem heat of hard racing.
During the summer on the track I run 15-w50. takes for ever to warm up, but can take the consistant 250-260 oil temps for 30 min at a time.
and I think the cars run better with a bit thicker oil, but that is just my opnion. No data to support it
No real need for anything that thick.
for the track / racing 15-w50 is as thick as you want to go for extreem heat of hard racing.
During the summer on the track I run 15-w50. takes for ever to warm up, but can take the consistant 250-260 oil temps for 30 min at a time.
and I think the cars run better with a bit thicker oil, but that is just my opnion. No data to support it
No real need for anything that thick.
Thread Starter
Burning Brakes
Joined: Sep 2003
Posts: 1,106
Likes: 0
From: Norwich NY
Mine is a 427.. Accordind to the guy that did the shortblock, he did it to "racing clearances".. Not real happy but it does run well. .. A very streetable engine that can run in the 10s.
Still wish I had more oil presure though.
Still wish I had more oil presure though.
Le Mans Master
Joined: Dec 2000
Posts: 9,899
Likes: 1,839
From: Hot Springs AR
I'd ask him what "racing clearances" means. Some think it means real tight, others loose. If it's loose then I'd run the heavier oil. If it's tight then I'd go with 10w-30.
You might also get an oil analysis done to see what your wear metals are looking like. ET, chime in here, but I'd think that if you were running overly heavy oil weights you should see the bearing metal content being too high.
HTH, and have a good one,
Mike
You might also get an oil analysis done to see what your wear metals are looking like. ET, chime in here, but I'd think that if you were running overly heavy oil weights you should see the bearing metal content being too high.
HTH, and have a good one,
Mike
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
Racing clearances are always lose allowing for lower end rotation and recovery.... A higher more viscous oil is good in this application.
The problem I have is giving advice based on a relatively stock LS/X engine. Then after all hell breaks loose because someone is running a highly modified engine, and wants to equate my advice to their engine... It gets old real fast.
Clearances on an LS/X are tight requiring a light oil... for those thinking your Grandfathers technology. Back in the sixties GM produced several aluminum engine platforms. These engine were prone to head warp and the life expectancy was around 50/60,000 miles..
Today's aluminum alloy engines are designed with 200K in mind.... This has all been achieved through advanced engineering designs. Bearing clearances, metal alloys, plastic alloys,cooling and lubrication are giant leaps in engine longevity.
The problem I have is giving advice based on a relatively stock LS/X engine. Then after all hell breaks loose because someone is running a highly modified engine, and wants to equate my advice to their engine... It gets old real fast.
Clearances on an LS/X are tight requiring a light oil... for those thinking your Grandfathers technology. Back in the sixties GM produced several aluminum engine platforms. These engine were prone to head warp and the life expectancy was around 50/60,000 miles..
Today's aluminum alloy engines are designed with 200K in mind.... This has all been achieved through advanced engineering designs. Bearing clearances, metal alloys, plastic alloys,cooling and lubrication are giant leaps in engine longevity.
Last edited by Evil-Twin; Feb 24, 2006 at 05:33 PM.
Thread Starter
Burning Brakes
Joined: Sep 2003
Posts: 1,106
Likes: 0
From: Norwich NY
Racing clearances to this guy meant loose. Like I said, the car runs good. When it comes time for a "rebuild" in the next year or 2, I'll have it done somewhere else.
He did offer to redo the motor. I decided to wait and have it done later. As most know, it's alot of work to take these motors out in a small garage.
Next time who knows what I will end up doing......
Let me dream,,,, 9.5 -1 pistons and a supercharger!!
Thanks to all those that gave some imput..
He did offer to redo the motor. I decided to wait and have it done later. As most know, it's alot of work to take these motors out in a small garage.
Next time who knows what I will end up doing......
Let me dream,,,, 9.5 -1 pistons and a supercharger!! Thanks to all those that gave some imput..
Thread Starter
Burning Brakes
Joined: Sep 2003
Posts: 1,106
Likes: 0
From: Norwich NY
By the way, how would I go about having my oil checked/tested after the car comes out of storage? May be something to do just to see what my motors "life expectancy" is!!
Any info w/b appreciated.
Any info w/b appreciated.
Pro
Joined: Jan 2006
Posts: 536
Likes: 3
From: bel air md
oil
Originally Posted by AU N EGL
Why would you want to go to a 20-50 OIL ???
for the track / racing 15-w50 is as thick as you want to go for extreem heat of hard racing.
During the summer on the track I run 15-w50. takes for ever to warm up, but can take the consistant 250-260 oil temps for 30 min at a time.
and I think the cars run better with a bit thicker oil, but that is just my opnion. No data to support it
No real need for anything that thick.
for the track / racing 15-w50 is as thick as you want to go for extreem heat of hard racing.
During the summer on the track I run 15-w50. takes for ever to warm up, but can take the consistant 250-260 oil temps for 30 min at a time.
and I think the cars run better with a bit thicker oil, but that is just my opnion. No data to support it
No real need for anything that thick.
