test/tune/confussed

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dartman340ta

dartman340ta

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ok lets see where to start 340,40 over 195 psi cyc pressure ,port an bowl work to x heads port match intake ,284-528 528 purple cam 34*total timing ,holley750 72 jets primary 80 jets sec 38 squirter's, msd , plugs gap 45, 391gears posi 904trany 2500 stall trans built buy pro 30 yr mopar trany guy ,it wont spin the tire,s in low gear 185/70/14 . it still a little on the lean side plug reading, but 72 was the largest jet i had at this time ,more on order . driving down the road normal i have a serge.(power valve maybe)oh yeah i do run the good fuel in it 110 .... my thought it should light the tire,s up in 1st with out any problem old 6cyc leafs in rear 6cyc bars in frt an 90/10 shocks .it runs good but not what i expected or im i expecting to much. all in a 68 post car dart need some fuel for thought .......no track time sorry .... it leaves good no tire spin no bog pulls hard through the gears . my thought this car with 185/70/14 should have major hooking problems .s/s springs on the way. it will run better or it will get tore apart an try something diff
 
Are you sure you have full throttle engagement with the gas pedal? You may only be using 3/4 of the linkage. Have someone mash the pedal down and make sure the carb is opening all the the way. Very simple check that makes alot of difference if it's off.


p.s. make sure you leave the kickdown linkage off to make the check then do the same for the kickdown.
 
what rpm range does spec card say.may need more converter. that combo should fry the balonys
 
Man I would think that thing would fry them tires. I just put my 408 thru a little test and had to drive it all the way thru 1st gear. I have to find some traction. I guess your cam is in the right?
 
750 dbl manual sec throttle wfo . cam center lined to specs dont feel bad even has my engine builder friend confused also . very crisps throttle response .... keep them coming.. whats the serge coming from
 
Check to make sure the throttle is opening the carb all the way.
 
The carb is too large IMO. It will kill the low end when you floor it and it opens. Other ideas... too much squirtor and jet IMO, and not enough timing if you're running 110 in it. I would start with a timing curve that has 20° initial, centrifical at 18°, for a total of 38° all in at 2500. For base carb stuff, change the 4150 series double pump to a 3310 750 vaccum secondary. The low stall and mild gear mean the engine is simply falling on it's face until the airflow goes up. Put back in the 31 squirtors and I'd run a 68 jet to start. If you keep the double pump, plug the secondary power valve and jet it at 78. Start with these changes and see what it likes....
 
Years ago a friend had the same problem-no red flags-turned out his cam was ground wrong,was yours degreed?.Even poorly tuned that thing should blow those little tires off-will it power brake?,also what rpm is the engine stalling at while foot braking?-just a few ideas.
 
well the 4150 only carb i have i'll try the rest have to order a power valve plug . the closes speed shop is some 60 mile's from me easier to order online i change my avatar this the car its in love sleepers i also put a couple pic in the photo thing old /6 car put it together in 3 days motor to diff now working bugs out getting better. yes it was degreed in, balanced rotating assembly( machinist's anal about the numbers)been my machinist for 25yrs . ill get it dial in just needed to get in the right direction i think moper got me going there now be a couple days before summit gets me my order
 
With key in the run position, engine off, make sure you have 8 volts at the + side of the coil.

Dual plane or single plane intake?
 
well back again I think i found the issue got the car fatten up got rid of power valve re adjusted valves took it out to the paved highway flog the **** out it converter would not flash . ok try it again nope not happening back to garage pulled trans pan fluid nice an red pink what ever full of metal so the trans goes back we will see what he has to say ......... couple days later .... trans guy calls hey you need a new converter in side of converter junk . just my luck . have to put /6 converter in for now an save some more money
 
I'd think you'd be able to tell if you're slipping the trans or rear or whatever ... it should not be to difficult to be able to know if you're getting good engagement through the drivetrain or not. How hot is the engine running?
 
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