550 cubic inch bb dyno!

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gregsdart

gregsdart

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I finally got my race motor dyno'd.
4.5043 bore. 4.315 stroke. 2.2 rod bearings 6.86 molner h beams, CP pistons coated by line 2line to make up the overbore of .0043 from 4.5000. Megablock. Charlies SS style pan. Cam is a Jones Cams inverted flank roller with 284/296/114 @ .050 duration. .510 intake lobes .480 exhaust lobes. 1.7 Jesel rockers for .867 intake lift and .816 exhaust lift. .019 in lash .020 ex lash. 15.0 compression.
Heads are 440-1 fully ported with 2.30 intakes, 1.78 exhausts. Heads flow 390 at .900 on the intakes. 3x Indy intake manifold. Rons Terminater alcohol injection , methanol fuel. Headers are 2 1/8 x 30 x4 inch collecters. Dyno headers were 2 1/4 tubes. I was hoping for 880 to 900. So i am pretty happy! We tested with my aircleaner, lost 4 hp. My race 2 1/8 headers lost 1 hp! So the motor should be within 5 hp of dyno numbers in the dart.

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That should rotate the earth, nice torque #'s throughout the curve. :thumbsup:
 
Should go 11's pretty easy.... :)

Nice mill and ought to run nice. Get some laps on it!
 
Thats impressive torque, carries 700 lb feet torque all the way to 7000 rpm. Very good Hp as well.
 
Thanks guys. When i built the headers years ago i read that a straighter exit for ren inchs or so allowed a smaller pipe. Making virtually identical power to the ceramic coated 2 1/4 dyno headers seems to bear that out.
This motor originally made about 860 hp as a 528 with 13.5 compression and an isky rr735 cam with the rest being the same. So adding 22 cubes, a point and a half compression and the skirt coatings really brought all the stars into line IMHO.
This was not so much a calculated change as it was "lets do what we can to up the power some". Offset grinding the crank from 4 .15 to 4.3150, cutting the heads for compression, and coating the pistons for the .0043 bore wear. Putting it on the pump was a good move. My starting tune was supposedly rich by 8 percent.
The tune starting point was .108 main bypass and .038 nozzles. A high speed bypass set to open at peak torque fuel pressure of 50 psi has a .064 bypass. I ended up at a .090 main bypass and power was still climbing the richer i went but i ran out of pills at .090. The BSFC ended at 1.05 roughly from peak torque of 5600 to 7200 peak hp. Two things i never would have known without the dyno session was what it wanted for a high speed bypass and where the power would be. My thinking was way off on both. Timing ended at 34.
 
Hey, congratulations on the new baby !! got any cigars left? :)
 
I'm thinkin 13's.......with four plug wires off.
 
That’s very impressive. Well done. Here’s how my dumb brain works, my first thought was “you’re only 15 psi away from 2000hp”.
 
Some specs i didn't include earlier-
The fuel pump is an 80a-1 and flows 6.48 gpm at 4000 pump rpm(8000 engine rpm) The terminater throttle body flows 2500 cfm and has four 2.5 inch throttle blades.
Plug gap .025 using 5672-9 NGK plugs.
Crank trigger. Stock type distributor with locked advance plate.
I converted the Jesel intake rocker bodys to register against washers rather than snap rings on the 9/16 individual paired rocker shafts which rode against the needle bearing cages. I had suffered many broken needle bearing cages at the bearing on the adjuster side of the .800 offset rockers. The hammering from the side loading of the angled pushrods would beat them to death over time.
 
@gregsdart what did your car run with the old combination? And what do you expect from the new one?
 
TT5 i went 8.779 at 153 mph, 3055 lbs running MT radial 14.5x15x33 slicks, torqueflite, 5500 stall and 4.56 gears. DA was 1600.
I am running bias 10.5x33 hoosiers now which aren't as fast. I hope to see some 8.60s. With Goodyear 2078 15x15x33 the car was slower by .012running a best of 8.88. Trap rpm will probably be close to 7500 rpm as it data logged 7350 at 8.90/150 mph.
I may go to 4.30 gears to drop the trap rpm.
 
Impressive. I bet you exceed your new goal. And with 700+lb/ft from stall to 6800 I bet that engine cares very little what gear is in it.
 
Gear it for whatever rpm you want at the stripe and let it eat.
 
Track results oosted in "550 bb track results!
 
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