515 BBC Build/Straub/Foxwell

[GuysMonteSS]

that's a big hydraulic roller!

The question is.......is it big enough?

Is this built to take full advantage of a vacuum pump ??
Guy

[Newold1]

My guess is based on the fact the original engine was down about 5% on power from hard usage and the new changes will add about 130hp. That puts the new number at about 915HP in my "guess-o- meter"
The camshaft will be the big determiner. A little bigger solid roller would probably yield about 940HP depending on fuel. I sure that anything in the nines will call for a beer! Best of luck!

[dtrubey]

Everyone involved was pretty happy. This was the last pull with everything cooled off and on MS109. Looks to me like with more jet, it would have gone over 900 without a problem.

[Newold1]

Based on those A/F's I think if they had been around 12.75 to 13.0 my guess-o-meter guess of 915HP might have been spot on. Nice work! Get those jets out so you don't burn that motha down!

[dtrubey]

Based on those A/F's I think if they had been around 12.75 to 13.0 my guess-o-meter guess of 915HP might have been spot on. Nice work! Get those jets out so you don't burn that motha down!

I think you'd be the winner! It was dyno'd in Colorado Springs and will race at Woodburn in Oregon, so it will be rejetted for sure!

[vortecpro]

Based on those A/F's I think if they had been around 12.75 to 13.0 my guess-o-meter guess of 915HP might have been spot on. Nice work! Get those jets out so you don't burn that motha down!

I think you'd be the winner! It was dyno'd in Colorado Springs and will race at Woodburn in Oregon, so it will be rejetted for sure!

My 1150 test dominator was tuned for max power. The owners carb a 1050 dominator was running in the 13.5 range and was down on power quite a bit, my air turbine was calibrated by SF, but I'm not sure its perfectly accurate, all that matters is I know where the engines run the best on my setup and I'm sure I got every thing there was to get. 740s HP to 890 right around 150 HP gain on the same dyno. Car should run 147 MPH @ 3600 pounds.

[Keith Morganstein]

Based on those A/F's I think if they had been around 12.75 to 13.0 my guess-o-meter guess of 915HP might have been spot on. Nice work! Get those jets out so you don't burn that motha down!

Foxwell and Straub work together a lot. Vortecpro (Mark) is known for expert machining, assembly and tuning.
I doubt anything was left on the table regarding tune-up/power. (Regardless of what the a/f metering indicated)
Very nice combo.

[dtrubey]

Based on those A/F's I think if they had been around 12.75 to 13.0 my guess-o-meter guess of 915HP might have been spot on. Nice work! Get those jets out so you don't burn that motha down!

I think you'd be the winner! It was dyno'd in Colorado Springs and will race at Woodburn in Oregon, so it will be rejetted for sure!

My 1150 test dominator was tuned for max power. The owners carb a 1050 dominator was running in the 13.5 range and was down on power quite a bit, my air turbine was calibrated by SF, but I'm not sure its perfectly accurate, all that matters is I know where the engines run the best on my setup and I'm sure I got every thing there was to get. 740s HP to 890 right around 150 HP gain on the same dyno. Car should run 147 MPH @ 3600 pounds.

Mark, as my wife reminds me.... no matter what I say, it comes out wrong. I didn't mean that you left anything on the table. I meant that it will for sure make over 900hp at Woodburn and a 29.90 baro.

Now, does the AFR read different at altitude? The old motor at Woodburn ran best about 13.0. I know it'll be more about going richer until it slows down instead of the gauge. But need to know where to start. The old motor and carb loved fuel.

[Old as Dirt]

Congrats.. turned out very nice.. I guessed 840HP @ 6250.. made more up higher, but was right there at that RPM level.. Seems VortecPro exceeded expectations again..

[dtrubey]

.

[Wolfplace]

Dal
Disregard what the hat A/F reads on the dyno, any dyno. Do not get wrapped up in the fallacy of a perfect A/F number when it comes to power.
It is almost useless to anyone but the person that knows the dyno on a sweep test due to the way the information is gathered
You are reading air in pretty much real time but you are measuring fuel that is replacing the fuel in the bowl not what is being mixed with the air
Lambda is a different deal but even then I use the numbers to pick a direction not as a set in stone power number
Your last sentence says it all,,, you jet for power or MPH not a magical number

[dtrubey]

Dal
Disregard what the hat A/F reads on the dyno, any dyno. Do not get wrapped up in the fallacy of a perfect A/F number when it comes to power.
It is almost useless to anyone but the person that knows the dyno on a sweep test due to the way the information is gathered
You are reading air in pretty much real time but you are measuring fuel that is replacing the fuel in the bowl not what is being mixed with the air
Lambda is a different deal but even then I use the numbers to pick a direction not as a set in stone power number
Your last sentence says it all,,, you jet for power or MPH not a magical number

Thanks Mike. I know Mark knows his stuff for sure and certainly wasn't trying to say he didn't do his job. Also, I don't know crap about the dyno sensors and just assumed it's an O2 sensor that we use in the collector only. I know those are bogus too. Thanks for the explanation.

[MadBill]

The fuel flow and B.S.A.C. data on the dyno printout strongly suggests that measured fuel and air flow were used for AFR nunbers.

[bob460]

What ever happened with this build?

[vortecpro]

What ever happened with this build?

The car went on to run 9.04 @ 148 @ 3580 NA 10 inch tire. The owner died of cancer, the car was given to his friend, the friend ran the car for a few years, and now the engine is back at Straubs for a rebuild/new engine.