Bbc hp est

Old 10-01-2012, 05:06 PM
  #21  
ejm
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dual disc clutch around 4000 4500 ease into it four speed im gonna give a link to video
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Old 10-01-2012, 05:08 PM
  #22  
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http://www.youtube.com/watch?v=W8EthyUDKZk&feature=plcp
this is the video not the best quality!
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Old 10-02-2012, 04:48 AM
  #23  
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Just guessing, but I think I'd lock out the advance and start at about 36, based on the comp ratio and combustion chamber size . . If he's got the right MSD smart box, he might leave at around 38 and bump it down to 34 or so at the end of the pull.

I'd think, because of the demand on the engine and the increasing weight of the sled as he gets into the run, you'd want to increase torque at the end of the run. It's kind of inverted way of racing. We gain momentum as we increase the run time, he's trying to get all the momentum at the start and needs brute torque to end the run. I think. ejm, correct me if I'm wrong . .

But it's still just a SWAG because I don't know the type of fuel (maybe I missed it here) or the kind of air he's running in . . . either . .


On th' HP thing . . Not being a wiseass here, We're getting mid 9.20's @ 150 with an iron '67 Camaro (582 BBC & 2800#) at 4850' msl (8700' corrected) and we don't know, or care . . Because it really doesn't matter, well, at least unless you're ordering a new converter . . (Tongue in cheek there)

The race track is the most honest dyno ever created! . .
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Old 10-02-2012, 07:06 AM
  #24  
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Road kill you are exactly right if u think I should lock it I will no prob
110 oct msd 6al pro billet dist
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Old 10-02-2012, 09:25 AM
  #25  
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Not enough timeing, 38-39 total, and leaveing too soft, at least 5-5500, what kind of rpm's are you seeing at the end of the pull?
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Old 10-02-2012, 09:43 AM
  #26  
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first pull on this motor not really wanting to turn more than7500 but it pulled it all the way down at the end
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Old 10-02-2012, 04:19 PM
  #27  
hotrod1994
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defiantly more timming
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Old 10-03-2012, 04:34 AM
  #28  
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Originally Posted by ejm
first pull on this motor not really wanting to turn more than7500 but it pulled it all the way down at the end
Based on what I know about "Truck Pulling", which is almost exactly nothing, I'm gonna say you're pretty close to doing what you wanted to do . . Based on the video and the quoted post. Looks like tuning is what you're after . .

On the timing thing. Locking out your mechanical advance and running a set timing number is to maintain a specific ignition tme when you narrow the power band and run the engine within a specific parameter . . If you need a specific timing curve, again, I'd recommend a MSD 735A (If I remember the model number correctly) where you can adjust your timing curves up and down during a run . . and they're exact.

If your EGT is above about 1250, y'might fatten it up a little and definitely, if you choose to bump the timing you should fatten it up. (Advance leans the engine out)

On the glowing headers . . back in the day, if you had a Fuel car with Zoomies, when the glow was down to where the curl started, it was "just Right", as the baby bear said . . . any farther out and you were either heating the engine too long or it was too lean . . . What's your engine temp when you get to the end of the run?

Dunno about leaving harder. I've found with our car, we can leave a lot softer (4750plus/minus) and get really hard leaves that're a lot easier on drive lines than the old 5500 rpm launches. And we "Throttle into" the launch rather than hammer the driveline and tires . . (1.35 60' times) and we use all the tire with no spin, even on late day or greasy track conditions . . But we're drag racing, not pulling . . There's a difference, I'm sure . .

And we're still 'spearmintin' so I'm certainly not the last word . .
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Old 10-03-2012, 05:25 AM
  #29  
ejm
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Well only one more pull next weekend. It got up to 220 which I didn't care for the carb came off of a 509 originally so I figure it wouldn't be lean. But if you say advancing would lean it out wouldn't that glow the headers then?
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Old 10-03-2012, 07:25 AM
  #30  
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For sure on rejetting the carb, with advanced timeing, but you still need to keep the rpm up on the leave as not to lug the engine, it's not like drag racing, in that the load gets heavier as you move away from the starting line, ease into it as always, but at a higher rpm, bout 75ft out drop the hammer. :wink:
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