Clipping oil ring expanders for reduced tension?
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Re: Clipping oil ring expanders for reduced tension?
Lets discuss your shenanigans...............a little.
Racing a NA NHRA stocker should be mandatory before any posting.
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Re: Clipping oil ring expanders for reduced tension?
Can't really, nothing illegal, but if known probably would become that way.
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Re: Clipping oil ring expanders for reduced tension?
Playing with oil ring tension on another project & remembered this one.
Got results back a while ago but forgot to share.
4 rwhp on a back to back, happy with that, decent gain for a 130 (or thereabouts) rwhp engine.
Got results back a while ago but forgot to share.
4 rwhp on a back to back, happy with that, decent gain for a 130 (or thereabouts) rwhp engine.
Re: Clipping oil ring expanders for reduced tension?
Thanks for the follow up.KnightEngines wrote: ↑Thu Mar 01, 2018 12:03 am Playing with oil ring tension on another project & remembered this one.
Got results back a while ago but forgot to share.
4 rwhp on a back to back, happy with that, decent gain for a 130 (or thereabouts) rwhp engine.
I've learned more about oil control rings in the last 14 months than I expected-
He who is in me is greater than he who is in the world.
Re: Clipping oil ring expanders for reduced tension?
This is routinely done on our NHRA Stocker engines.
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Re: Clipping oil ring expanders for reduced tension?
I doubt that we will ever see piston ring tension specified in the rule books. Just too hard to test ring tension in the field.KnightEngines wrote: ↑Mon Jul 17, 2017 12:11 am Can't really, nothing illegal, but if known probably would become that way.
In the "old days" we called these sort of tricks "speed secrets".
Bill
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Perfect Circle Doctor of Motors certification
SAE Member (30 years)
ASE Master Certified Engine Machinist (+ two otherASE Master Certifications)
AERA Certified Professional Engine Machinist
Re: Clipping oil ring expanders for reduced tension?
I started doing this in the early 70s using the TRW rings, just like end gapping the top rings I would grind the expanders down on the side of my grinding wheel until the ends just butted in the bore. When doing a budget street strip engine I use the Hastings rings which have a similar expander to the old TRWs and they're very reasonable in price.
Re: Clipping oil ring expanders for reduced tension?
When I used the speed pro style oil rings, always used .030" smaller expander with the actual bore sized rails. With the old Ramco or TRW oil ring expanders, grinding was fine on the stnd sized expander. Just place your stnd tension expander in bore and see how it must be squeezed to install then try a .030" smaller and it ,of course, will easily fall into the bore. The drill bit squeeze works pretty well on the total seal expander also.
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Re: Clipping oil ring expanders for reduced tension?
We used to do this all the time on our stocker engines. That and back cutting. Today it's available over the counter on many sizes. It's pretty amazing using a fish scale how close to the advertised force they are.
Re: Clipping oil ring expanders for reduced tension?
Using those old smelly fish scales to work as oil ring expanders seems like a fishy way to lessen tension there ?? LOL
Seriously ,there are gains to be made in this area but in today I know there are parts available from the ring specialty guys to allow a lot of variation and outcomes without having to do too much experimentation and modifying.
Seriously ,there are gains to be made in this area but in today I know there are parts available from the ring specialty guys to allow a lot of variation and outcomes without having to do too much experimentation and modifying.
The Older I Get, The Dumber I Get
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Re: Clipping oil ring expanders for reduced tension?
The Shenanigans I was reffering to involved valve train, rings are not restricted in any way other than you gotta have 3 of them.I doubt that we will ever see piston ring tension specified in the rule books. Just too hard to test ring tension in the field.
In the "old days" we called these sort of tricks "speed secrets".
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Re: Clipping oil ring expanders for reduced tension?
Hmm... rocker ratio shenanigans? Im not familiar with HQ rules but i imagine things are very controlled, lots of incentive for rule bending!KnightEngines wrote: ↑Thu Mar 01, 2018 5:10 pmThe Shenanigans I was reffering to involved valve train, rings are not restricted in any way other than you gotta have 3 of them.I doubt that we will ever see piston ring tension specified in the rule books. Just too hard to test ring tension in the field.
In the "old days" we called these sort of tricks "speed secrets".
Craig.
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Re: Clipping oil ring expanders for reduced tension?
Nah, rockers have to be stock & they do check for 308 rockers. But the geometry is not checked & not controlled & you can reface the rocker tips to 'recondition' them.......
Nuf said LOL.
There are many, many grey areas in HQ racing, multiple little tweaks worth .5-1hp all add up & make the difference between a race/championship winner & a mid fielder.
I think the last 4x state championships have been won with my stuff & at least 2 national titles.
Nuf said LOL.
There are many, many grey areas in HQ racing, multiple little tweaks worth .5-1hp all add up & make the difference between a race/championship winner & a mid fielder.
I think the last 4x state championships have been won with my stuff & at least 2 national titles.
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Re: Clipping oil ring expanders for reduced tension?
ah ha! I like it!KnightEngines wrote: ↑Thu Mar 01, 2018 8:11 pm Nah, rockers have to be stock & they do check for 308 rockers. But the geometry is not checked & not controlled & you can reface the rocker tips to 'recondition' them.......
Nuf said LOL.
There are many, many grey areas in HQ racing, multiple little tweaks worth .5-1hp all add up & make the difference between a race/championship winner & a mid fielder.
I think the last 4x state championships have been won with my stuff & at least 2 national titles.
I have seen HQ's in 'action' twice, not my thing but yeah i can see that 1hp would be advantageous for sure. Nice work keeping engines in 4x state champs too.
Craig.
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Re: Clipping oil ring expanders for reduced tension?
Never clipped or ground on expander rings but have slightly bent inward the tangs of the expander ring where they butt together to reduce friction on mostly limited engines for circle track. I bend the tangs inward and install the expander ring into clylinder by itself until it will almost fall down the bore while sitting static in bore. Then install complete oil ring pack onto piston and as stated previously install assembly with pin inverted in the bore and hook fish scale(battery powered compact) to pin and pull to measure drag by oil ring pack. Can usually reduce drag almost in half and i've never experienced oil control or excessive blow by doing so. Don't think i would try it on street engine but can really free up some friction on limited race engine. Have won a championship in open wheel modified (e-mod) with this method and engine stayed together a couple of complete seasons without any rebuilds. You'll find out that most of your friction is caused by the oil rings and not the compression rings. You can measure drag on compression rings by installing them without oil rings and measure and you'll find out most of the friction is caused by oil rings.