340 pump gas stroker tests, guess results for tomorrow?
#2389028
10/17/17 10:57 PM
10/17/17 10:57 PM
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Joined: Aug 2003
Posts: 43,230 Bend,OR USA
Cab_Burge
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I'm engine dyno testing a 4.0 inch stroke 340 motor with a 4.070 bore (EDITED ) and 10.41 to 1 compression ratio with a Quikfuel 830 CFM black carb with down leg boosters. The heads are a set of eddy RPM and a Eddy Performer Air gap intake. All testing was done with Oregon 92 octane non ethanol pump swill bought this morning. We had to fight ignition and carb. issues this morning so we didn't get to make a lot of pulls today We did make two, first one was from 2500 to 5000 RPM and it made 440 HP at 5000 RPM after running it over 30 minutes total time to break in the cam and lifters. We let it cool down so the oil temps were under 150 F and made the next pull from 3000 RPM to 5500 so we could see If the torque and HP curve crossed at 5250 RPM, which it did On that pull it made 447 HP at 5000 RPM and 459 HP at 5200 RPM with 514 Ft. Lbs. torque at 4300 RPM I've seen SB Mopar NHRA legal stocker motors take 6 to 12 pulls before they stop gaining power on the dyno Tomorrow will be a short day testing jetting and timing only, who wants to take a guess at peak torque and peak HP All guesses welcome, no rewards so no favors I'll post the results as soon as I can tomorrow evening so bear with me please.
Last edited by Cab_Burge; 10/18/17 12:19 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: 340 pump gas stroker tests, guess results for tomorrow?
[Re: Twostick]
#2389123
10/18/17 02:22 AM
10/18/17 02:22 AM
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Joined: Aug 2003
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Cab_Burge
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Me thinks 4.0 stroke with a 4.070 bore(EDITED ) = 416 C.I. The last race 471 C.I. BB I built and dyno made 720 HP at 7000 RPM and was still gaining 2 to 5 HP per 100 RPM, the customer swore he would not rev it past 7000 RPM so he had us stop their HP is not hard to make, paying for it can be
Last edited by Cab_Burge; 10/18/17 12:20 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: 340 pump gas stroker tests, guess results for tomorrow?
[Re: Cab_Burge]
#2389130
10/18/17 02:41 AM
10/18/17 02:41 AM
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Joined: Aug 2011
Posts: 2,865 Pattison Texas
CSK
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master
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Pattison Texas
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Cab Check your #'s on bore & stroke
1968 Charger COLD A/C Hilborn EFI 512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim 2020 T/A 392 Stock 11.79 @ 114.5
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Re: 340 pump gas stroker tests, guess results for tomorrow?
[Re: Cab_Burge]
#2389196
10/18/17 10:47 AM
10/18/17 10:47 AM
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Joined: Oct 2003
Posts: 11,684 W. Kentucky
justinp61
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Me thinks 4.0 stroke with a 4.370 bore = 416 C.I. The last race 471 C.I. BB I built and dyno made 720 HP at 7000 RPM and was still gaining 2 to 5 HP per 100 RPM, the customer swore he would not rev it past 7000 RPM so he had us stop their HP is not hard to make, paying for it can be Me thinks if it's a 416 with a 4" stroke the bore is 4.070". I'm guessing the cam is small for a stroker? Was the QF carb rich out of the box? The ones I've messed were pig rich as delivered. Should be a fun driver.
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Re: 340 pump gas stroker tests, guess results for tomorrow?
[Re: Cab_Burge]
#2389277
10/18/17 12:53 PM
10/18/17 12:53 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
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Lincoln Nebraska
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All guesses welcome, no rewards so no favors I'll post the results as soon as I can tomorrow evening so bear with me please. Cab you sound pumped. I'm glad it is (nearly) finished & going well, enjoy it!
live every 24 hour block of time like it's your last day on earth
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Re: 340 pump gas stroker tests, guess results for tomorrow?
[Re: Cab_Burge]
#2389298
10/18/17 01:32 PM
10/18/17 01:32 PM
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Joined: Jan 2003
Posts: 14,506 So. Burlington, Vt.
fast68plymouth
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.....and made the next pull from 3000 RPM to 5500 so we could see If the torque and HP curve crossed at 5250 RPM, which it did..... The curves will always cross at 5252. HP and TQ are exactly the same at 5252 rpm.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: 340 pump gas stroker tests, guess results for tomorrow?
[Re: fast68plymouth]
#2389351
10/18/17 03:30 PM
10/18/17 03:30 PM
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Joined: Dec 2009
Posts: 20,647 in a cattle trailer down by th...
Guitar Jones
Paddle faster! I hear banjo music!
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Paddle faster! I hear banjo music!
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in a cattle trailer down by th...
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.....and made the next pull from 3000 RPM to 5500 so we could see If the torque and HP curve crossed at 5250 RPM, which it did.....
The curves will always cross at 5252. HP and TQ are exactly the same at 5252 rpm. Horsepower is a matter of calculation from torque. To get from pound-feet of torque to horsepower, you need to go through a few conversions. The number 5,252 is the result of lumping several different conversion factors together into one number.
First, 1 horsepower is defined as 550 foot-pounds per second. The units of torque are pound-feet. So to get from torque to horsepower, you need the "per second" term. You get that by multiplying the torque by the engine speed.
But engine speed is normally referred to in revolutions per minute (RPM). Since we want a "per second," we need to convert RPMs to "something per second." The seconds are easy -- we just divide by 60 to get from minutes to seconds. Now what we need is a dimensionless unit for revolutions: a radian. A radian is actually a ratio of the length of an arc divided by the length of a radius, so the units of length cancel out and you're left with a dimensionless measure.
You can think of a revolution as a measurement of an angle. One revolution is 360 degrees of a circle. Since the circumference of a circle is (2 x pi x radius), there are 2-pi radians in a revolution. To convert revolutions per minute to radians per second, you multiply RPM by (2-pi/60), which equals 0.10472 radians per second. This gives us the "per second" we need to calculate horsepower.
Let's put this all together. We need to get to horsepower, which is 550 foot-pounds per second, using torque (pound-feet) and engine speed (RPM). If we divide the 550 foot-pounds by the 0.10472 radians per second (engine speed), we get 550/0.10472, which equals 5,252.
So if you multiply torque (in pound-feet) by engine speed (in RPM) and divide the product by 5,252, RPM is converted to "radians per second" and you can get from torque to horsepower -- from "pound-feet" to "foot-pounds per second."
"Follow me the wise man said, but he walked behind"
'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion. '74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost conversion. 2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
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Re: 340 pump gas stroker tests, guess results for tomorrow?
[Re: Cab_Burge]
#2389375
10/18/17 04:14 PM
10/18/17 04:14 PM
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Joined: Jan 2003
Posts: 14,506 So. Burlington, Vt.
fast68plymouth
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In laymens terms......
HP = (TQ/5252 x rpm)
At any rpm below 5252 the TQ is greater than HP, at any rpm above 5252 the HP is greater than TQ.
As for the question posed at the start of this thread......
I've seen so many dyno results that make no sense to me at all that I rarely bother guessing anymore.
With regards to this thread...... I see plenty of guesses...... But no cam data at all.
I would think there could easily be a 75hp swing between a .460 lift hyd cam vs a .650 lift solid roller cam.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: 340 pump gas stroker tests, guess results for tomorrow?
[Re: fast68plymouth]
#2389523
10/18/17 09:28 PM
10/18/17 09:28 PM
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Joined: Aug 2003
Posts: 43,230 Bend,OR USA
Cab_Burge
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With regards to this thread...... I see plenty of guesses...... But no cam data at all.
I would think there could easily be a 75hp swing between a .460 lift hyd cam vs a .650 lift solid roller cam.
I'm sure your correct on the cam, it is a custom grind Comp Cams with lobe # 5965B on the intake lobes with .364 lobe lift and #5985B H on the exhaust lobes with the same lobe lift ground on 107 LSA and installed on a 104 ATDC intake lobe center. It has 1.6 ratio Harland Sharp aluminum roller rocker arms also UPDATE from today. We made several more pulls with no changes except for the oil and filter change and then tried one size smaller jet on all four corners, the AFR where showing fat(11.3 AFR) from 3500 RPM to 5000 RPM and then getting better to 12.3 AFR above that That change help a little bit also Tried three more degrees of timing, 32 to 35 and that helped a tiny bit. I decided to call it a day after that test due to the motor going into a street car with exhaust and air cleaner, we'll finish the tuning in the car with a wide ban The dyno printer wasn't working so the operator will E mail me copies tonight or in the morning so I have exact information as copied from the dyno information reports instead of relying on my old , feeble memory The weather changed from yesterday to today due to a low pressure front moving in, lower B.P., higher humidity with lower outside air temps. resulting in no big performance gains today
Last edited by Cab_Burge; 10/18/17 09:30 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: 340 pump gas stroker tests, guess results for tomorrow?
[Re: Cab_Burge]
#2389581
10/18/17 10:59 PM
10/18/17 10:59 PM
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Joined: Jan 2003
Posts: 14,506 So. Burlington, Vt.
fast68plymouth
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Okay, so a XE285HL on a 107, with 1.6 rockers.
It seems everyone's dyno is different.......but, If I were dynoing it here.........and assuming it would rev high enough to reach its natural peak before any valvetrain unhappiness sets in.......and has at least 1-3/4" headers........I'd be looking for it to make real close to 500hp with ootb or very mildly reworked(more like "prepped") heads.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: 340 pump gas stroker tests, guess results for tomorrow?
[Re: fast68plymouth]
#2389682
10/19/17 01:59 AM
10/19/17 01:59 AM
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Joined: Aug 2003
Posts: 43,230 Bend,OR USA
Cab_Burge
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It was making peak HP at or under 5300 RPM, which didn't make since to me I should have tried a bigger carb, maybe in the car later The last pump gas 340 stroker motor I built, ( 9 second Phils Cuda W2 motor in 2002 or so) and dyno tested made 514 HP with a BG 850 CFM Speed Demon, 13 more HP with a 1050 Dominator on a adapter on the same intake Bottom line is that I'm hoping this motor tuned well in the customers 1966 Dart GT will put a big old grin on his face at WOT
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: 340 pump gas stroker tests, guess results for tomorrow?
[Re: Cab_Burge]
#2389688
10/19/17 02:27 AM
10/19/17 02:27 AM
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Joined: Jan 2006
Posts: 797 WA
pro451bee
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super stock
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WA
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Bigger carb wont help much .
Last edited by pro451bee; 10/20/17 02:38 AM.
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