18º 434 SBC Dyno Results

[Orr89rocz]

How fast will a 500HP 4cyl run in a 1400lb car? Lets run that by the calculators.

They rarely et well if fwd but mph wise they scoot lol

Your combo will come around give it some passes and play with tire size

[Stan Weiss]

He said / she said .... blah blah blah

Bring em on up and we'll see what they run on the same day in the same conditions and weigh em on the same scales.

Chad, How fast will a 500HP 4cyl run in a 1400lb car? Lets run that by the calculators.

Rick

Using the same CF of 1.12109 (BP=27.72 T=79 H=55 DRY DA=4514) and guessing at the HP / torque curve and everything else about the vehicle.

60 Foot ET = 1.1575
330 Foot ET = 3.3559
1/8 Mile ET = 5.2901
1/8 Mile MPH = 127.0259
1000 Foot ET = 6.9674
1/4 Mile ET = 8.3999
1/4 Mile MPH = 157.2004


Stan

[Rick360]

Just an update to this engine project ...
Found an issue with trans that is fixed and made it to the local track for test-n-tune in another miserable muggy evening with better results.

Car is otherwise the same as last outing.
No engine or tuning changes
same 4.33 gear, same 17x33.5x16 tires and same 1750lb weight
Still running the 1050 carb which made about 850hp (about 15hp less than the 1350carb best dyno pull that I posted).

60' = 1.080
330' = 3.112
660' =4.866 @ 139.75
air had HPCF=1.127 which was the same as previous run.

I bought a 4.71 gear to try sometime this year when time allows. I think twith these over sized tires it will help and I will probably get a 1350 to get to the full HP as dynoed.

Rick

[woody b]

Good improvement. As a bracket racer I personally wouldn't worry about the big tires. You maybe wouldn't have made a good pass during a test and tune with smaller tires. It would probably be faster with smaller tires, but not as consistent on marginal tracks. I've never had a dragster......but I've made a bunch of money bracket racing on marginal tracks. I suppose my 2300 pound 355 cubic inch vega was over tired with 14X32's but I ran 5.80's and 5.90's all over the South. (and a few places up North too)

I suspect smaller tires may be easier on parts, especially if they shake on the burnout. I doubt the 4.71 gear will be any faster, with the right converter, but might be easier on the converter and trans. I ran within 5 hundredths 1/8 mile with a 5.13, 4.88 and 4.56. Again, 355 cubes, 2300 pounds. I know the 18 degree stuff likes RPM, but that's where my "right converter" statement comes in.

[Rick360]

I doubt the 4.71 gear will be any faster, with the right converter, but might be easier on the converter and trans. I ran within 5 hundredths 1/8 mile with a 5.13, 4.88 and 4.56. Again, 355 cubes, 2300 pounds. I know the 18 degree stuff likes RPM, but that's where my "right converter" statement comes in.

I will be surprised if the 4.71 isn't at least a little quicker especially when the air isn't good. My converter is a Coan that stalls 6600-6700. I will have to stay with a big tire or buy different wheels since they don't make any small tires for 16" wheels. I didn't even see any 16" tire from Goodyear that wasn't bead lock.

With great air like standard conditions (HPCF=1.000) my Density program shows the 4.86 run would be 4.66. I doubt those conditions will happen for me but 4.70's should happen.

Rick

[randy331]

Just think what your ET would be "IF" your engine really made 865 HP !!

Randy

[woody b]

The calculator from John Wallace's web site (thanks John) shows 742 horsepower for 139.75 mph @ 1750 pounds. With the HPCF of 1.127 that's 836 horsepower, if my math is correct. Engine made 850 corrected on the dyno with the smaller carb that's on the car. We know smaller tires would be faster. (I think the bigger tires are better for bracket racing) I suspect very few bracket cars ET within 14 horsepower of their dyno numbers. Am I missing something?

[steve316]

There is no doubt it will run 4.70's with the 4:71 gear . At a well prepared track with good air it will most likely run a 4:68 or 4:69. Good Job Steve

[Rick360]

Just to update this thread if anyone still interested in this engine project, here's a couple of runs made this year ...

I did not get a bigger carb yet so I finished the year with the same 1050 carb. Same big tires and no other changes to car except changing 4.33 gear to 4.71 for the final TnT run shown below.

At a bracket race in September with the 4.33 gear still in the car it ran this. (actually 4 runs in a row at 4.81x) Track prep was pretty good. Quite a few large tire cars racing.

HPCF = 1.089
60' 1.067
330' 3.083
660' 4.811
MPH 141.42

At the same track in November with pretty good weather conditions for a Test and Tune event after changing to a 4.71 gear. Track prep was good at starting line but traction was not good down track. Spinning and moving around from a couple hundred feet out to 1/8 mile to the point of being a bit of a scary ride. The mph being about the same as the race day run above even though the air was quite a bit better.

HPCF = 1.033
60' 1.038
330' 3.038
660' 4.765
MPH 141.29

No more racing this year. Maybe more dyno testing this Winter. We'll see if I can fit that in with the other projects I am trying to finish.

Rick

[steve316]

In those track conditions I would say that was getting it done.

[randy331]

Maybe more dyno testing this Winter.

What changes would you make this time around ?

1.038 60' is getting it done !

Randy

[zums]

Good numbers, also good feeling of accomplishment knowing you did all the hand porting yourself, i didnt look through all the notes but did you get your best numbers with the Comp Cam
Tom

[Strange Magic]

Nice passes. What tires?

y Strange Magic » Wed Jun 10, 2015 9:00 am

4.79-4.83 @4500 DA 142-143mph and these are conservative figures for a small block 870hp@1750 pds

You are making around 790-805 for real power.
strangemagicperformance.com
Strange Magic Camshaft Technologies
Decisions on parts and advise should not be based on how much money a company can pour into marketing. This is a common mis-conception in the industry.

[Rick360]

Maybe more dyno testing this Winter.

What changes would you make this time around ?

1.038 60' is getting it done !

Randy

I may buy a custom Braswell carb for it and then tune it on dyno. Maybe rockers if I can find some exhaust rockers with more ratio. I have another set for these heads that take a different stand that have more ratio on intake and exhaust.

Suggestions?

Rick

[Rick360]

Good numbers, also good feeling of accomplishment knowing you did all the hand porting yourself, i didnt look through all the notes but did you get your best numbers with the Comp Cam
Tom

Thanks Tom ...
Yes it's a COMP CAM spec'd by me.

COMP CAM 273/288 - 112LSA .800"/.688" with 1.7/1.6 Jesel rockers
Intake lobe is a 1812 RX Drag Race lobe and Exhaust is 1480 High Torque Exhaust lobe.

I like COMP CAMS cause you can see all the lobes and what family it's from with a description about that group of lobes as well as all the specs like Major Intensity, lift at TDC, Duration at .050 and .200, all listed right there in the catalog. Best thing is they have ALWAYS measured right on what they say on the card. Good Stuff.

Rick