Dyno numbers are in!

[evilmopar]

Update: Got the heavy car to the track last sunday and did some laps. This winter i swaped the Trickflow singleplane intake to a tunnelram and dual Brawler 950 race carb... And got a new set of 29,5" slicks. It went 10.80@124 and a 1.50-60-Foot. Still bone stock body and interior. Stock rear suspension except for SS leafsprings. Next on my list is to chang the rear shocks and get the carbs tuned better and test the nitrous... Still have a bad knock and i´ve had that for a number of years. It follows the rpm, it haven´t been worse or better.. Had it with the old engine as well and i´ve torn that engine apart 3-4 times without fining anything wrong. This new one made no knocks on the dyno but first startup in the car... My guess is the the transmission, i know nothing about it, bought it as a "running shell" but i changed the valvebody, billet servos, bolt in sprag and a custom 10" Converter.

 

[B3RE]

Hey guys! I just finished my 440/500 build and ran it on the dyno.. But i was a bit dissapointed, it stopped making power to early, sure got some nice tq numbers but the rpm are to low, i was hoping it to be happy for atleast 1000rpm more, but it died off. So i need your experts to give me some clues of what could be wrong with my build.. Here are my specs to start with...

.055 over 440 with 440source 4,15 stroker kit
11.6 CR
Untouched TF 240 heads
Brawler race 950 cfm 4150 carb
TF Trackheat intake
Crane ductile iron 1.6 rockers
PAC 1.46" springs. 120lbs seatpressure @1.9" Installheight, 394lbs Open
Howards Solid flat-tappet .657/.661 (with 1.6) 260/264 @.050, LSA 108, ICA 104
MSD Probillet dissy 32degrees full ignition.. Tried 36 but made more power with less


And here are my dyno sheets
View attachment 1106677 View attachment 1106678

This could be a problem. Trick Flow specifically states that their heads are to be used with a roller rocker. The stand/shaft position is way too high for a stock style non-roller rocker. That will make the opening, and closing, velocity very high at the seat which leads to valve bounce. Valve bounce limits rpm.

 

[Nxcoupe]

I just ordered a new set of springs, My thought was maybe start of valvefloat, Howards recommend a spring that has 140 seat pressure and 420lbs springrate.

Nevermind, didn't realize this was a year old thread.

 

[evilmopar]

This could be a problem. Trick Flow specifically states that their heads are to be used with a roller rocker. The stand/shaft position is way too high for a stock style non-roller rocker. That will make the opening, and closing, velocity very high at the seat which leads to valve bounce. Valve bounce limits rpm.

I do run the crane adjustable rockers, i don´t see why the opening velocity should be higher with a non rollertip compared to a rollertip, if i use the same ratio on both rockers. Could you please explain in more detail?

 

[B3RE]

I do run the crane adjustable rockers, i don´t see why the opening velocity should be higher with a non rollertip compared to a rollertip, if i use the same ratio on both rockers. Could you please explain in more detail?

It doesn't matter that they are adjustable. Mopar had adjustable rockers on slant sixes up to Hemi's. The roller tip makes the difference and gives the effect on geometry as if the head has a longer valve. A longer valve means the shaft has to be raised. Trick Flow insists on a roller rocker because they have raised the stands. Edelbrock, and others, say you can use a stock rocker because they haven't raised the stands. If you put stock (non-roller) rockers on a Trick Flow head, the shaft is too high and increases velocity at the seat. If you put a roller rocker on an Edelbrock, or other similar head, the shaft is too low and will increase the velocity at high lift. Either way is bad because it changes the intended velocities, and other information, ground into the cam lobe and induces valvetrain instability.

Honestly, if it wasn't important, Trick Flow wouldn't have included the roller rocker requirement in their instructions. It would be a waste of paper and ink.

 

[evilmopar]

It doesn't matter that they are adjustable. Mopar had adjustable rockers on slant sixes up to Hemi's. The roller tip makes the difference and gives the effect on geometry as if the head has a longer valve. A longer valve means the shaft has to be raised. Trick Flow insists on a roller rocker because they have raised the stands. Edelbrock, and others, say you can use a stock rocker because they haven't raised the stands. If you put stock (non-roller) rockers on a Trick Flow head, the shaft is too high and increases velocity at the seat. If you put a roller rocker on an Edelbrock, or other similar head, the shaft is too low and will increase the velocity at high lift. Either way is bad because it changes the intended velocities, and other information, ground into the cam lobe and induces valvetrain instability.

Honestly, if it wasn't important, Trick Flow wouldn't have included the roller rocker requirement in their instructions. It would be a waste of paper and ink.

Thank you for explaining Now it makes sense

 

[B3RE]

Thank you for explaining Now it makes sense

You're welcome, friend!

 

[440rb]

611fwhp@3900@line, 29.5"/4.10 =

60 Foot E.T. :​	1.50​	Seconds​
1/8 Mile E.T. :​	6.82​	Seconds​
1/8 Mile Trap Speed :​	99.70​	MPH​
1/4 Mile E.T. :​	10.80​	Seconds​
1/4 Mile Trap Speed :​	124​	MPH​
1/4 Mile Trap RPM :​	5,796​	RPM+slip​

 

[Rev. Mopar]

Two cents worth from a Stock Eliminator and Super Gas sort of guy. BE VERY CAREFUL "PORTING THE HELL" OUT OF THE HEADS. You can very easily ruin port velocity when doing so, you don't want them to stall out and think they need even more. We have a .060 over 383 in our stock eliminator car, running a tiny AFB carb, .431 lift cam, and all the stock stuff to be legal. Dyno yielded 450.28 HP at 5400 and 474.1 ft.lb torque at 4800. Torque held above 460 right up to 5400 but at 5500 things dropped of significantly. In our class we cannot (really) port our heads (915's with stock 1.60 exhaust valves), and we have to also run the cast iron intake.

If it is carburetion you need, call ATM in Bowling Green, KY and ask about one of their 1050 cfm 4150 carbs. They also have 4500's up to almost 1700 cfm. Marvin Benoit, former owner of Quick Fuel Technology is their consultant. His daughter operates the business.

Hope that helps just a wee tad. I guess what I am saying is: Don't go ape crap on the heads - seek flow rate without sacrificing velocity or you might end up with heads that work about as good as a 351 Cleveland 4 barrel head worked on that small and low compression of an engine.

Best of luck, Rev. Mopar

 

[biomedtechguy]

We have a .060 over 383 in our stock eliminator car, running a tiny AFB carb, .431 lift cam, and all the stock stuff to be legal. Dyno yielded 450.28 HP at 5400 and 474.1 ft.lb torque at 4800. Torque held above 460 right up to 5400

I love to hear about strong 383s.
I'd like them to get more love!