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Old 01-18-2012, 08:55 AM
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mighty demon.BC carb ?

Ok i got a.489 BBC with.8-71 TBS blower got 2x.750 blower carbs also from TBS. Just got motor.fired up i had no vacuum lines hook up to the carbs
these carbs are boost ref power vavles.i found the nipple that pulls vac.through the vavle are these suposed.to be tied together.into the back of the blower manifold?

With no vac lines.hooked.up..shouldnt it run rich.?.which i think it is
would this.make my headders glow.red at.about 2000/2500 rpms?

This is my first blower carbed engine.

And for my trans. Mod valve.run it.to a full vac source off the base plate...did i need.to tee.them together on both carbs to the mod vavle..thanks

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Old 01-18-2012, 05:30 PM
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Thanks.real helpfull

whay about this.eze idle.adjustment ?

I thought like you.said.that.boost pressure.would be pushed back on the.power V.

Or.would it be better to take.the nipple.fittn on the boost ref port .back to the base plate full vac source.would.thay work ?

Ans same.with.trans mod.V. Cause the.carbs.base.plate.or not pressured.by boost

im going to post up so pics.soon from my home pc..not.sure.how.to do them from cell.and can see and type.better.to without all the.peroids
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Old 01-18-2012, 06:55 PM
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ok heres my 68 chevelle i need help on pic 1



pic 2


pic 3


pic 4


pic 5


pic 6
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Old 01-19-2012, 08:44 AM
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Cam is a comp cam blower grind
255/262 @.050. Lift is .652 on both. On a 114 lash is .020 .
O got.dart.pro1s rect.port 345 cc intake.runners

is.that a big cam.and heads .thanks man u been big help can i call you still dont fully still dont understand pm.me.with.# of.you dont mind thanks Gary
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Old 01-21-2012, 01:24 AM
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Okay so my pic #5 the nipple.goes.to the.vacumm andbboost to the.bottom.of the intake.below.the.blower.correct
so when i fired.up my car.wirhout.rhe.ref.nipple.hooked uo the.power valve.so open or.closed.?.. I think.the.boost ref. Carbs.it.dont.get.a.vac.signal.to the.power.valve.so it.would.run rich correct my.plug are.black.
So of.i hookthem up the.nipple.the.the.boost.ref. It will get vac.closing the.power valve.then when it.gets.boost.it.willpush.the.power.valvw.open to get more.fuel correct?
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Old 01-21-2012, 01:32 AM
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In pic.#3.the.big.plig at the rear.of the.cars.am going.to run it to the.vac mod. Valve.correct?

i need.to lock oit the.dost.like.you said ?.is that to much.i thought more.like.22/26.with.pump gas i might.have less boost then planned on .i as.set.up for 12%ud.but.that.was.with.srock iron heads.i got.345.cc.ingake.runners now.TBS.I might.noy see 8psi.bit less pulleys.are.59 /58 upper and.52/54 lower cant rember.but.of i only.see.say 5/6 psi .i will the.swap the.pullehs.and.od.ot.13.5.% i thinllk.

Let me know.if.am.rigth.or not.thanks
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Old 01-21-2012, 09:49 AM
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What is the static compression ratio?
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Old 01-21-2012, 02:09 PM
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Quote:
Originally Posted by cobalt327
What is the static compression ratio?
8.2to 1 compression flat.top srp's blower piston.heads.are.cced.at.122cc .010 in the hole.not.sure on head gasket thickness .042 ? Flat tops have -3cc
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Old 01-22-2012, 07:39 PM
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What should.this.car.run in the quarter mile. Has.3.50 gears with.dlocker 10 stall speed
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Old 01-22-2012, 08:50 PM
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That CR is fine, my concern was that it may have been on the high side for running any real boost. No idea on the times, though. I'd imagine traction will be a problem. What's a "10 stall speed"?
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Old 01-23-2012, 03:13 AM
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The.transmission converter is.a.3800.stall speed.with.3.50 gearrs.with.Detroit locked.for.the.street .hopen for.some.low.10's.at least.got.32x17.50x15 mt et street dot slicks
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Old 01-23-2012, 05:43 AM
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Quote:
Originally Posted by 2fox
The.transmission converter is.a.3800.stall speed.with.3.50 gearrs.with.Detroit locked.for.the.street .hopen for.some.low.10's.at least.got.32x17.50x15 mt et street dot slicks
I may be wrong, but that's an awful lot of stall for a blown BBC, IMHO. But that's really not your question. Best thing I could suggest is get the tune to a safe point and start track testing to dial it in unless you can buy some dyno time.

Quarter mile trap speed and ET along w/the other vehicle specs (mainly weight) is as good an indicator of real world HP as most anything. You have enough motor to run your numbers- the question comes down to chassis set up and traction.
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Old 01-26-2012, 10:16 PM
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I been haven that tci conv.with many different combos over the years combo before a ws build was a 580 14.6 bbc dart block.then decided to build a pump gas motor.at that time a had 4.11's with a spool.
I thought with A3.50 gear withvthe 10 inch converter would work together Good?
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Old 01-26-2012, 10:32 PM
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Update

Quote:
Originally Posted by 2fox
Ok i got a.489 BBC with.8-71 TBS blower got 2x.750 blower carbs also from TBS. Just got motor.fired up i had no vacuum lines hook up to the carbs
these carbs are boost ref power vavles.i found the nipple that pulls vac.through the vavle are these suposed.to be tied together.into the back of the blower manifold?

With no vac lines.hooked.up..shouldnt it run rich.?.which i think it is
would this.make my headders glow.red at.about 2000/2500 rpms?

This is my first blower carbed engine.

And for my trans. Mod valve.run it.to a full vac source off the base plate...did i need.to tee.them together on both carbs to the mod vavle..thanks
ok update.....got car running smooier but headders are stll.glown red.temp redingwith my gun reads 780 °goes higher but my gun dont go that high but thats with motor just revedup at 3000 and holding it steadt for 30 seconds..also tryed timing set at 8 btdc idle eith total.of 28 °max.idled smooth....them i set dist at 28° at idle motorsurged bad

it seem to back fire seen flame shoot out of drivers side pipe i pulled the plugs and that side all look.black..could this be because i dont have the vac. Lines run to the bottom of the intake to pick up vac and boost ..maybe lran cause boost is not opening not given it more fuel? Comp checked the drivers side sence plugs where out 130 psi remenber 8.2/1 ad the ca specs above...anyideas ?


Thanks scared to run it anymore 12% under driven with 93gas 2summit elect.pumps Bigger than the 110 holley blue pumps 2#8's out the two tsnk fittings fuel filters first then pumps.the y'sinto a#10 line up front to a mallory reg. Then #6's to the carbs
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Old 01-26-2012, 11:36 PM
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I been haven that tci conv.with many different combos over the years combo before a ws build was a 580 14.6 bbc dart block.then decided to build a pump gas motor.at that time a had 4.11's with a spool.
I thought with A3.50 gear withvthe 10 inch converter would work together Good?
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