Guys do run low tension rings in applications without vac pumps.A guy has to be good with his cylinder prep to do it.We change radial tension in about every engine we build that is nat asp.Blower and nitrous engines we dont.A vac pump is a good addition to any engine you are to make max power out of.

 

Don't use them w/o a vac pump. I tried it once and wasn't at all happy with the reults.

 

The vacuum pump helps the top ring...with or without low tension rings....AND there is VERY little HP gain with low tension rings...and a VERY big chance to screw up using them....I would run STD tension rings....

Little known to the average racer is the real reason for a pump at all.
It is to lower the PSI build up under the top ring...so it stays sealed the the bottom of the top groove...SO you can rev higher before the top ring breaks it's seal with the land...and it will break it's seal at some RPM, when the PSI is higher, under the ring than on top of the ring...and, when the ring's G force lets it keep going when the piston stops at TDC...at "some" RPM.
..this will start a flame ...a forum flame LOL

 

Thanks George for the explination, the pistons I got use a 1 mm ring pack if I could have found std tention I would have used em. after 15 runs it seems I am using some oil, that why the question.

 

That is also why you need an accumulator groove machined into the 2nd land...to give expansion room for the PSI build up under the top ring.....

 

I sure hope not......Otherwise 100% of the new production engines will be oil burners from day 1 and their companies will all perish from catalyst warranty soon.

 

Great POINT...The O.E. rings are awesome compared to "some" racing industry "low tension" rings too.

 

Well George, it seams you may have gotten your hands on a copy of the book we wrote on crank case vacuum. Then again, there probably isn't a whole lot in there you didn't already know. After all, it was working with professionals like yourself that led us to the bulk of the subject matter. When it came to Hg, you always were "MORE IS BETTER, YOU CAN'T HAVE TOO MUCH".

Steve

 

LOL Steve , we learned some of that stuff together..we had 4 GM pumps on Angelle's bike before you guys came out with yours ...that we use now

 

The rings are also rated in lbs of tension as well..... I'm a fan of 12-15lbs oil rings rather than 20+lbs stuff, lighter than the 12lbs you need to make sure you can control the oil in the crankcase.

Bret

 

Unless your running a boosted application.

Blessings........Ron