BBC thoughts

General engine tech -- Drag Racing to Circle Track

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MadBill
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Re: BBC thoughts

Post by MadBill » Sun Apr 29, 2018 10:05 pm

If you can get enough hands in play, you might be able to ease the tips of toothpicks (the machined cylindrical kind) into at least the primary idle air bleeds and see if the meter shows richer as it should or reads suddenly lean as it comes out of lean misfire.
Felix, qui potuit rerum cognscere causas.

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Re: BBC thoughts

Post by af2 » Sun Apr 29, 2018 10:53 pm

Never used a AFR gauge. But lotts of TR and CR 2x4's jets at 70ish and depending on cam the PV has to be inline. The best set up I had for the street on a small block was 2 4412's
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Re: BBC thoughts

Post by prairiehotrodder » Sun Apr 29, 2018 11:21 pm

whats a inline PV ?
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Re: BBC thoughts

Post by prairiehotrodder » Tue May 08, 2018 10:32 am

So I purchased an AEM failsafe AFR gage that does data logging. It monitors AFR, Vacuum and RPM and logs it all. Hopefully this should be a better tuning aid and also prevent me from hitting the guard rail while watching the gage! Hopefully the plan is to get to the track on May 25 for the test and tune. I'm looking forward to seeing what this new Erson cam and the tunnel ram setup has done for me. As a side note my local track just switched from NHRA to IHRA. Not sure on what that's gonna do to the rules but i'm told I won't need to have my cage certified until I reach 9.0 where NHRA was 9.99.
Brian
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Re: BBC thoughts

Post by cjperformance » Tue May 08, 2018 6:05 pm

prairiehotrodder wrote:
Tue May 08, 2018 10:32 am
So I purchased an AEM failsafe AFR gage that does data logging. It monitors AFR, Vacuum and RPM and logs it all. Hopefully this should be a better tuning aid and also prevent me from hitting the guard rail while watching the gage! Hopefully the plan is to get to the track on May 25 for the test and tune. I'm looking forward to seeing what this new Erson cam and the tunnel ram setup has done for me. As a side note my local track just switched from NHRA to IHRA. Not sure on what that's gonna do to the rules but i'm told I won't need to have my cage certified until I reach 9.0 where NHRA was 9.99.
Brian
Isnt that the way, often all the extra gauges etc just provide more distraction ! #-o
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Re: BBC thoughts

Post by prairiehotrodder » Sat May 26, 2018 11:23 pm

prairiehotrodder wrote:
Fri Oct 20, 2017 12:30 pm
With the t-ram i understand that each barrel of a carb feeds a intake runner and intake valve. This should mean that the butterflies on the carbs open equally (not progressively) and have the jetting squared. Is this line of reasoning true?

Also - statsystems, the only part of what you said that i didn't agree with is it costing 3 times as much. I'm sure you are right and i don't doubt that you know what you are talking about. My cam may well not be optimum and dedicated t-ram carbs i'm sure would have been better. They couldn't have been worse! This time on this cam i'm gonna try what I think is best and see what the results are. Maybe i'll be disappointed but i'll show the results good or bad.
Well here is the truth on this deal for anyone that cares. I went way slower. Down on power. Should have listened. May swap my old Lunati cam back in. Don't know what else to do. The tunnel ram runs and drives ok and seems to be responsive to my tuning at the track.
Brian
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Re: BBC thoughts

Post by F-BIRD'88 » Sun May 27, 2018 12:21 am

Get the carbs right first. There is nothing wrong with the cam.

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Re: BBC thoughts

Post by F-BIRD'88 » Sun May 27, 2018 12:31 am

Too bad Joe Sherman is no longer with us. He is a old hand at this. He could help you withit (thru PM)

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Re: BBC thoughts

Post by F-BIRD'88 » Sun May 27, 2018 12:37 am

Inspect the valve train and ignition system for a fault first too. Look for a bisted valve spring coil or a ignition fault . Winter storage ias hard on ignition. (corrosion) clean all ground points.

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Re: BBC thoughts

Post by prairiehotrodder » Thu May 31, 2018 10:50 am

distributor cap was bad, not sure if that was my problem. I didn't misfire, just tested bad with my ohmmeter.

Picture of my car from Saturday :

http://www.pbase.com/nitroimage/image/167571567
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Re: BBC thoughts

Post by prairiehotrodder » Sun Jun 03, 2018 9:32 pm

is two -6 fuel lines enough to feed a tunnel ram with two 4 barrel carbs ? The motor is a 540 BBC making about 800 hp give or take.
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Re: BBC thoughts

Post by F-BIRD'88 » Sun Jun 03, 2018 11:35 pm

Is this the same pump and line as last year, other than adding a T and 4 -6 lines to the 2 carbs now? Should be enough. Are there any brass filters in the fuel inlet fittings of the new carbs?
If so, remove, as your big filter at the back of the car is fine.

You have 4 needle seats doing the flow job of just 2 of a single carb.
So unless there is a restriction in your new added 2x4 plumbing, the net system flow is increased, now.
if the engine was starving for fuel flow now, it would show up on the AFR gauge (and or data log) as going lean(er) in the top end of the track. (last 200-300 ft)


Pump wiring (grounds)(relays) needs to be checked for voltage drop.
Winter storage is hell on electrical connections and ground points.

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