>100%VE

[steelcomp]

Can anyone post examples of engines with VE exceeding 100%?
Thanks

[let r eat]

the 427sbc thread I believe was in the 117 arena........Just do a search.....Pretty commonplace.

[steelcomp]

the 427sbc thread I believe was in the 117 arena........Just do a search.....Pretty commonplace.

Thanks...I've got that one. I'm having a little "dispute" with someone who insists that it's virtually impossible to achieve 100%VE with a NA motor, and I wanted several examples to show him.
Aren't Pro Stocks in the 120%+ range?? and Super Stocks right there as well?
Thanks, anyone else?

[ClassKing]

I've had lots of my efficient street engines show 100 to 103% But 120? I think you need boost for that....
Would like to hear from Darrin on this.

[SWR]

Most sportsbike engines these days are higher than 105 as stock...

[flyin ryan]

personally i've never had an engine under 100%. i don't think your pal has much to dispute. the best v/e engine i've done is a s.b. mopar 461 cube single four barrel 94 octane pump gas deal that was solid in the 120's & tickled 127%. all of my really good engine's are in the low 120's, somewhere in the 1-teen's is nothing to sneeze though i am curious as to what the pro-stocker's are at these day's, or even if it's a number they pay any kind of attention to. good or bad it's a number i watch.

[67RS502]

My 502 was around 104VE from what I remember, its been a few yrs.
What do you guys think, a wimpy street motor makin over 100 doesnt seem that hard?

[backpurge]

I did a LS1 408 stroker with a mild cam that had 105%, and that was on the dyno. Might have the datalog of the run if you're interested.

[beth]

How does a dyno know how much intake volume is trapped in the cylinder verses how much is passed through the chamber into the exhaust?

[maxracesoftware]

How does a dyno know how much intake volume is trapped in the cylinder verses how much is passed through the chamber into the exhaust?

if Combo is wrong,
the old Chrysler SS Hemi can waste 20 or so percent out of Exhaust

Trapped Ve% is the Measured CFM minus the Ring BlowBy CFM , minus the CFM
lost during the OverLap Period, then divided by the theoretical CFM

Theoretical CFM @ 100 % Ve = CID * RPM * .000289352

TrappedVe = ( MeasuredCFM - ( BlowbyCFM + OverLapCFM )) / TheoreticalCFM


the CFM lost to Ring Seal should only represent a tiny portion
of measured Ve..the majority lost would be during OverLap.

if you can't "tune-out" the BSAC's to a lower more normal reading and
if Ve + BSAC's are abnormally high to you, its an indication of wasted Air
the BSFC's will also be slightly higher as well.

[Joe Mendelis]

How does a dyno know how much intake volume is trapped in the cylinder verses how much is passed through the chamber into the exhaust?

It doesn't. You can use a meter, but they aren't that accurate.

[70MC]

I had my 434 sbc dynoed, it is NA, and was 113-115 for most of the pull with a high of 120 at one point. You can look at the dyno sheet and specs here http://www.knights-rule.com/cgi/gallery/v/members/70mc/

[steelcomp]

Thanks guys...I think the guy gets the point. Some pretty nice sounding motors, there.

[Dbeck002]

Does anyone know what the VE of an indy car would be? Supposedly it should be astronomical since they rev high, cant they take advantage of the RPMs?

[Mark Workman]

Does anyone know what the VE of an indy car would be? Supposedly it should be astronomical since they rev high, cant they take advantage of the RPMs?

Not necessarily. For a given displacement, 120%VE at 10,000 rpm will have much higher BHP numbers than 120%VE at 6000rpm, even though the torque numbers would be identical. I think friction losses would make the higher rpm example actually show less torque on the dyno, but the force pushing on the top of each piston would be the same.