|
|
|
|
| Author |
|
|
Registered
Join Date: Jul 2005
Location: Atlanta
Posts: 1,241
|
oil control rings
Question:
Oil control rings have come a long way. Old small blocks used up to 5mm thick oil control rings with 25lbs pressure on them. Nowadays, everyone is using 2.8mm 12-14lbs pressure oil rings for obvious reasons. I have a motor I am working on that has 10.5:1 compression NOS racing pistons that are 81mm bore and have 5mm oil rings with 1.5mm top and second rings. I managed to track down a oil ring pack that will work, but it is 25LBS! Deves 5mm oil ring is also about 25lbs. Makes sense with that size ring. The issue is with the power loss that will be experienced with all this added friction, I am wondering if it will even be worth it running these pistons with this compression or suggesting they bite the bullet and have modern pistons made by whoever that will be able to take full advantage of the compression. With a 3L V8 motor, I see there being at least a 15bhp loss with this much added friction which pretty much negates any noticeable performace difference gained with the high compression. What do you guys think. I could be wrong
__________________
No physical quantity completely explains its own existence |
||
10-13-2010, 08:45 AM
|
|
|
Registered
Join Date: Oct 2003
Location: Central Fla
Posts: 1,864
|
rings
Do not use the Deves ring pac they are junk ! you may want to call Jerry Roche at JE, he may have a solution for a ring package.
Mike Bruns JBRacing.com
__________________
The two most useless things to a driver are the braking distance behind you and nine-tenths of a second ago. |
||
|
10-13-2010, 10:56 AM
|
|
|
Registered
Join Date: Jul 2005
Location: Atlanta
Posts: 1,241
|
Oh no I already have the solution for a ring pack for this setup. Total Seal has a 5mm ring pack for this, but my point of searching around a bit was in researching if there is such thing as a 5mm oil ring that is NOT super high tension. And the answer is no. A 5mm oil ring is produced in one way. HIGH tension to the tune of about 25lbs.
JE/Wiseco get all their rings from NPR which makes a fabulous ring pack and are very cheap, but very very few companies make a 5mm oil ring for a 81mm or 82mm bore. I found a total of 3 and I think the 3rd is just repacking and selling what the 2nd manufactures. Specifically, my question is how bad is this 5mm ring tension at 25lbs per cylinder going to kill performance. Every try moving a piston by hand with a 20lbs+ oil ring?? It's NOT an easy task lol. I think I am going to shelve these things as I honestly see 15-20bhp wasted in these silly high tension rings. |
||
|
10-13-2010, 11:05 AM
|
|
|
Registered
Join Date: Jul 2005
Location: Atlanta
Posts: 1,241
|
For those who wanted to know, I have an answer. Spoke with an engineer at Perfect Circle.
About 50% of the friction inside an engine is due to the piston rings. 50% of that ring tension is from the oil ring. Oil ring packs have lately been around 12lbs tension for performance vehicles. More ring tension = more power loss. Objectively, there is no information that shows X vehicle makes X bhp with X rings vs Z veh with Z rings, but it is sufficent to say that reducing friction to the tune of 5% (which is approx what going from 25lb oil rings to 12lb rings would yield) in a 3L engine is undoubtedly going to yield an objective difference. Excersizing phone to order uber pistons. |
||
|
10-13-2010, 01:35 PM
|
|
|
Max Sluiter
|
__________________
1971 911S, 2.7RS spec MFI engine, suspension mods, lightened Suspension by Rebel Racing, Serviced by TLG Auto, Brakes by PMB Performance |
||
|
10-13-2010, 05:40 PM
|
|
|
Registered
Join Date: Jul 2005
Location: Atlanta
Posts: 1,241
|
That is a bit interesting. It essentially models old style two piece rings and I'm not seeing a huge difference. The Hastings 3 piece style ring was where the whole low tension thing started. Wondering what loophole in older technology they found that affords them to use such a ring.
|
||
|
10-14-2010, 06:19 AM
|
|
|
1971 Porsche 911S
