496 BBC Build
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496 BBC Build
I built this 496 with a Eagle crank and rods and this crank was heavy! After the typical remachining of the rods and crank they went into the engine, you could feel the mass of the crank while turning it, will this hurt power? The customer supplied the crank and rods, I really don't like to use parts I'am not familiar with considering what goes into one of these builds. I ended up with 12.1 compression, GM production iron heads, 268/278 @ .050 roller .730/.715 lift on a 108. Intake is a Victor Jr with a 1000 CFM AED 4150. Moroso pan with 6.3 quarts. I will test this engine Saturday and will share the results.
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cjperformance
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Re: 496 BBC Build
Nice work, ultra neat.
I like the wooden carb spacer, aside from the benefit they just look cool !
As for the heavier crank, i dont think it will greatly affect peak numbers but yes it will affect 60' when max rpm rise rate is being used, as for shift recovery the extra crank weight may help on the shift due to its inertia but hurt recovery as it wont want to accelerate as fast so will it cancel its pros/cons out?? A "crank swap only" back to back would be interesting on the dyno and on the strip!
I like the wooden carb spacer, aside from the benefit they just look cool !
As for the heavier crank, i dont think it will greatly affect peak numbers but yes it will affect 60' when max rpm rise rate is being used, as for shift recovery the extra crank weight may help on the shift due to its inertia but hurt recovery as it wont want to accelerate as fast so will it cancel its pros/cons out?? A "crank swap only" back to back would be interesting on the dyno and on the strip!
Craig.
Re: 496 BBC Build
I am curious as to what all you "touched" during the build. Did you cut the counter weights, go with bigger lifter diameter, port the heads and intake? You always put up great numbers that show well on the track so I don't question the numbers. Just curious as to how far off my stuff should be.
Paul
Paul
"It's a fine line between clever and stupid." David St. Hubbins
Re: 496 BBC Build
We did regrind the crank journals because at Std it was unacceptable and the stroke and index was set, it varied .006 as delivered, the counterweights were not modified. The heads and intake are ported. Lifter diameter is .842 with a solid Morel lifter. A real basic build, although the crank weight does worry me, I don't think were going to have any record power here. Actually the oil pan was modified extensively.
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Re: 496 BBC Build
The final dyno test.
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Re: 496 BBC Build
Great Job Mark- I take it this isn't a oval head build? What fuel do you like to use with 12:1?vortecpro wrote:The final dyno test.
Pete Graves
CPMotorworks,Inc.
Custom Engine Machining
Cylinder Head Fixture for Vertical / Surfacing Mills since 2008
CPMotorworks,Inc.
Custom Engine Machining
Cylinder Head Fixture for Vertical / Surfacing Mills since 2008
Re: 496 BBC Build
How heavy was the crank compared to other brands? Any concerns with the cross drilled oiling?
Fantastic numbers.
Fantastic numbers.
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stokerboats
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Re: 496 BBC Build
Mark, you always seem to impress and I don't impress easily. Any info on cylinder heads and combo is appricated! Thanks, Charlie
Servedio Cylinder Head Development
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Re: 496 BBC Build
What was your BSFC at peak HP? What was your atmospheric correction factor for that run?
Competition Fuel Systems Birch Run,MI. www.compfuelsystems.com/index.html 520-241-2787
Re: 496 BBC Build
Let me answer your questionsNormS wrote:What was your BSFC at peak HP? What was your atmospheric correction factor for that run?
SF 600 Wyndyn software
Dyno altitude 6400 feet
DA 8412
Baro 23.72
Vapor pressure .15
Hum 23%
Air temp in dyno 66 degrees
STP correction factor @ peak 1.277
SAE correction factor @ peak 1.227
BSFC @ peak .488
Measured HP @ 6800 RPM 573.6
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Re: 496 BBC Build
GM 049 fully ported, 2.250 Manley severe duty valves, Tullipped 1.880 exhaust valve. Fully ported Victor Jr intake, 1000 CFM AED carb.Carnut1 wrote:Mark, you always seem to impress and I don't impress easily. Any info on cylinder heads and combo is appricated! Thanks, Charlie
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Re: 496 BBC Build
I didn't weigh the crank, but its probably around 2 pounds heavier than what I normally run. It was not cross drilled. The engine felt a little lazy compared to normal.Orr89rocz wrote:How heavy was the crank compared to other brands? Any concerns with the cross drilled oiling?
Fantastic numbers.
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Re: 496 BBC Build
Thanks, GM 049 head, we used VP C-12 gas.cpmotors wrote:Great Job Mark- I take it this isn't a oval head build? What fuel do you like to use with 12:1?vortecpro wrote:The final dyno test.
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