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Re: Dyno testing tomorrow, what will it make?
[Re: Cab_Burge]
#1633007
06/15/14 05:32 PM
06/15/14 05:32 PM
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Joined: Feb 2005
Posts: 5,221
Branson, Mo.
joedust451
super gas
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super gas
Joined: Feb 2005
Posts: 5,221
Branson, Mo.
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Quote:
I have another 3.90 stroke 440 block pump gas motor I will test next month, if the money allows that  On this one the RPM intake probally limits the peak HP RPM, I looked at the sheets the dyno operator sent me, there hard to read by E mail or Photo Bucket  It looks like the motor made 506 HP at around 5700 RPM and 570 Ft. lbs at a RPM I can't read, I'm guessing between 4000 to 4500 RPM   As far as the jetting on the 4781-2( the second carb. tested) I had 78 in the front with a 6.5 power valve and 86 in the rear with no power valve and no other mods. I'm aware of or did other than having the choke blade removed. On the first Carb, 4781-7 I did open up the H.S. bleeds to right at .028 or .031, CRS  It ended up with 76 jets in the front and 74 in the back with power valves in both metering blocks like stock  I think thats the jetting and H.S. bleed sizes, CRS again  It really suprised me when the earlier carb did better with stock jetting than the later carb. did I guess that is why we test I will switch manifolds on the next motor, take off the RPM and put on a either a Mopar M1 single plane or my old favorite, the Weiand Team G single plane   I'm hoping to get some printed copies of those results soon so I can read all the data instead of parts of it All in all it was a good day, nothing broke and it made 40 more HP than it started out with BTW, making the AFR leaner did reduce the torque but it improved the HP, at the track by using a wide ban gets the same results  Leaner is faster than richer. We don't race dyno ,do we My old M.W.stocker out ran the other cars in the same class that had hot spark plugs and a rich mixtture Test, test and test some more, the spark plug and time slip is your freind 
Most DPers 4150 series come with .031" on the HSBs, Using a smaller HSB like .028" will allow a smaller jet. I read an article once on tricks to do with larger carbs & dog-leg boosters to help signal, They make a stepped dog-leg booster that helps strengthen the signal down low without sacrificing flow.
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Re: Dyno testing tomorrow, what will it make?
[Re: joedust451]
#1633008
06/15/14 10:51 PM
06/15/14 10:51 PM
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Joined: Aug 2003
Posts: 43,223
Bend,OR USA
Cab_Burge
OP
I Win
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OP
I Win
Joined: Aug 2003
Posts: 43,223
Bend,OR USA
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I forgot to add the weather was horrible that day, it was raining outside, the B.P. in the dyno room was reading 26.35 most of the day and the humidity in the dyno room was 34 %, air temps where cool, under 65 F. The dyno operator pointed out that the correction factor was 118 % during the tests, he said had not seen it that bad before I've always used that dyno in the cold of winter, not intentionally, but that was when I could get the motors on it. It would be at or under 32F with a high pressure cold front blowing through I had ran into similar weather conditions down in Ontario,CA on Vrbansic Brothers DTS dyno once, it was raining outside and the motor on the dyno was down on power(by 20 to 50 HP) compared to other motors I had built using very similar parts and build specs. with better weather The customer is happy so I shouldn't be crying, should I
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Dyno testing tomorrow, what will it make?
[Re: Cab_Burge]
#1633009
06/15/14 11:57 PM
06/15/14 11:57 PM
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Joined: Feb 2008
Posts: 715
Central TEXAS!!!!
sr4440
super stock
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super stock
Joined: Feb 2008
Posts: 715
Central TEXAS!!!!
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I hate to say this but if the weather is raining I will tell my customers that we should wait because the info won't be of much use.
The J607 standard that everyone uses (including me) is pretty good until you get more then 10% off of "standard" then the number start to get really skewed.
Joe
Without Data, you’re just another guy with an opinion.
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Re: Dyno testing tomorrow, what will it make?
[Re: sr4440]
#1633010
06/16/14 01:10 AM
06/16/14 01:10 AM
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Joined: May 2003
Posts: 6,566
Downtown Roebuck Ont
Twostick
Still wishing...
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Still wishing...
Joined: May 2003
Posts: 6,566
Downtown Roebuck Ont
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I'm not sure how similar you would consider my build given the extra stroke.
4.15 stroke RB 493 9:1 (8.97:1 actual IIRC) E-heads M1 108 lsa MP509 with 1.7 rockers 900 CFM Holley TBI.
Mine did at least 500 ft/lbs from 2000 to 5000 and peaked at 600 ft/lbs @ 4000 500 HP at 5000 and then it fell off a cliff.
Elevation at my machinist's is 300' +/- and he has a stingy Stuska dyno.
Heads are OOTB with a real valve job.
Kevin
Last edited by Twostick; 06/16/14 01:15 AM.
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Re: Dyno testing tomorrow, what will it make?
[Re: Cab_Burge]
#1633011
06/16/14 03:16 PM
06/16/14 03:16 PM
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Joined: Feb 2005
Posts: 5,221
Branson, Mo.
joedust451
super gas
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super gas
Joined: Feb 2005
Posts: 5,221
Branson, Mo.
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Quote:
I forgot to add the weather was horrible that day, it was raining outside, the B.P. in the dyno room was reading 26.35 most of the day and the humidity in the dyno room was 34 %, air temps where cool, under 65 F. The dyno operator pointed out that the correction factor was 118 % during the tests, he said had not seen it that bad before I've always used that dyno in the cold of winter, not intentionally, but that was when I could get the motors on it. It would be at or under 32F with a high pressure cold front blowing through I had ran into similar weather conditions down in Ontario,CA on Vrbansic Brothers DTS dyno once, it was raining outside and the motor on the dyno was down on power(by 20 to 50 HP) compared to other motors I had built using very similar parts and build specs. with better weather The customer is happy so I shouldn't be crying, should I
Yeah BP was horrible at 26 no doubt, That would explain it wanting less jet. If the customer is happy, thats what counts
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