Swole's Carnage AGAIN!!!!

boost pressure and spring pressure are a very small part of why a better pushrod is needed. Here is a study I did a while back. No opinions just numbers.

Zach


The following equations are for average cylinder pressure not peak which would be much higher for short moments. At the points in which the pushrods will be affected average is more precise such as exhaust opening. Also for horsepower the equation calls for BHP which is at the flywheel. For this I assume any reading obtained at the rear wheels will have a 16% loss in the driveline. For the equation to see how your cylinder pressure lines up look at the second number whiich is a derivative of the BHP. Also a lot of the trucks I have seen peak at around 2600rpm
792,000xBHP/C.I.x rpm=avg cyl pressure

325hp at crank = 273 at the wheels= 275psi
600 hp at crank=504 at wheels= 509psi.
750=630hp at the wheels=636psi
1000=840hpat the wheels=848psi
1200=1008hp at the wheels=1018 psi

now lets figure load on the pushrod factoring 2.65 sq. in. of valve face surface area

275 hp=273psi x2.65sq in=728lbs +220lbs spring press. X1.34 exh. rocker ratio is 1271lbs.

504hp= 2102 lbs force on pushrod

630= 2553lbs on pushrod

1000=3306 lbs on pushrod

1200= 3909 lbs on pushrod

Now here is where the rubber meets the road. Factory pushods are rated at 1794 lbs, motorsport supply 1982 lbs. Hamilton 3/8" 2064 and Hamilton 7/16" 4035. over 500rearwheel horsepower you at least need the 3/8 .095 wall over 630Rwhp you really need to jump to the 7/16" .120" wall. If you don't the pushrod bends first then opens the valve. It delays the valve opening which reduces spool and power. If you are a low budget street racer you will not notice much difference in spoolup or major power but if you are racing or sled pulling and want to make sure you don't snuff that big charger down the line, use a better pushrod to open the exhaust on time at full power. It will help the chargers stay lit by not retarding the exh opening.
 
Hamilton Cams said:
boost pressure and spring pressure are a very small part of why a better pushrod is needed. Here is a study I did a while back. No opinions just numbers.

Zach


The following equations are for average cylinder pressure not peak which would be much higher for short moments. At the points in which the pushrods will be affected average is more precise such as exhaust opening. Also for horsepower the equation calls for BHP which is at the flywheel. For this I assume any reading obtained at the rear wheels will have a 16% loss in the driveline. For the equation to see how your cylinder pressure lines up look at the second number whiich is a derivative of the BHP. Also a lot of the trucks I have seen peak at around 2600rpm
792,000xBHP/C.I.x rpm=avg cyl pressure

325hp at crank = 273 at the wheels= 275psi
600 hp at crank=504 at wheels= 509psi.
750=630hp at the wheels=636psi
1000=840hpat the wheels=848psi
1200=1008hp at the wheels=1018 psi

now lets figure load on the pushrod factoring 2.65 sq. in. of valve face surface area

275 hp=273psi x2.65sq in=728lbs +220lbs spring press. X1.34 exh. rocker ratio is 1271lbs.

504hp= 2102 lbs force on pushrod

630= 2553lbs on pushrod

1000=3306 lbs on pushrod

1200= 3909 lbs on pushrod

Now here is where the rubber meets the road. Factory pushods are rated at 1794 lbs, motorsport supply 1982 lbs. Hamilton 3/8" 2064 and Hamilton 7/16" 4035. over 500rearwheel horsepower you at least need the 3/8 .095 wall over 630Rwhp you really need to jump to the 7/16" .120" wall. If you don't the pushrod bends first then opens the valve. It delays the valve opening which reduces spool and power. If you are a low budget street racer you will not notice much difference in spoolup or major power but if you are racing or sled pulling and want to make sure you don't snuff that big charger down the line, use a better pushrod to open the exhaust on time at full power. It will help the chargers stay lit by not retarding the exh opening.
Click to expand...



Wow, interesting. Question. The old "boost peaks at XX, but drops to "XX-5psi"... Is that directly related to the push rod flexing?
 
Hamilton Cams said:
boost pressure and spring pressure are a very small part of why a better pushrod is needed. Here is a study I did a while back. No opinions just numbers.

Zach


The following equations are for average cylinder pressure not peak which would be much higher for short moments. At the points in which the pushrods will be affected average is more precise such as exhaust opening. Also for horsepower the equation calls for BHP which is at the flywheel. For this I assume any reading obtained at the rear wheels will have a 16% loss in the driveline. For the equation to see how your cylinder pressure lines up look at the second number whiich is a derivative of the BHP. Also a lot of the trucks I have seen peak at around 2600rpm
792,000xBHP/C.I.x rpm=avg cyl pressure

325hp at crank = 273 at the wheels= 275psi
600 hp at crank=504 at wheels= 509psi.
750=630hp at the wheels=636psi
1000=840hpat the wheels=848psi
1200=1008hp at the wheels=1018 psi

now lets figure load on the pushrod factoring 2.65 sq. in. of valve face surface area

275 hp=273psi x2.65sq in=728lbs +220lbs spring press. X1.34 exh. rocker ratio is 1271lbs.

504hp= 2102 lbs force on pushrod

630= 2553lbs on pushrod

1000=3306 lbs on pushrod

1200= 3909 lbs on pushrod

Now here is where the rubber meets the road. Factory pushods are rated at 1794 lbs, motorsport supply 1982 lbs. Hamilton 3/8" 2064 and Hamilton 7/16" 4035. over 500rearwheel horsepower you at least need the 3/8 .095 wall over 630Rwhp you really need to jump to the 7/16" .120" wall. If you don't the pushrod bends first then opens the valve. It delays the valve opening which reduces spool and power. If you are a low budget street racer you will not notice much difference in spoolup or major power but if you are racing or sled pulling and want to make sure you don't snuff that big charger down the line, use a better pushrod to open the exhaust on time at full power. It will help the chargers stay lit by not retarding the exh opening.
Click to expand...

So really all thats needed is the exhaust side?
 
I don't want to make this thread about pushrods, I am just trying to correct some mis-information.
Jason, I'm not sure exactly what you are asking, also not all engine float at the same points due to the fact there are MANY variables, Boost, cam profile, lash setting, rpm@ a given boost, there is a chance you might have seen float at X rpm but another might have seen it later. You are both right, kind of.

bh 10, not at all. The intakes have a higher rocker ratio so spring pressure is a bigger factor for the intakes. Also I don't have a formula to calculate all of the loads and factors for the intake side. Suffice it to say that the exhausts have much more stress at higher cylinder pressure which is directly related to HP@ X rpm, which is why swole upgraded his exhaust pushrods. I think it is safe to say he is close to 848psi cyinder pressure which is a LOT for a street driven engine.

Back to your regularly sheduled program

Zach
 
Post from my other thread...Just making sure it's seen.

New Information!!!


Ok! I spoke with Joe (I think he's the owner) at PPE.

First off, Very nice guy and gave me plenty of attention to my questions.

He explained more about the fuel controller, how it works, and what happens if it fails....The long and the short of it is this, His explanation basically says that if the box fails, gets broken, has a bad ground, or looses power, that the system is designed to let the TOP pump (supplied with my kit - dmax pump) go to full 100%........Yet the BOTTOM pump gets cut to virtually 0% demanded pressure.....

So, even with a rail cap he stated that there would not be enough pressure to hang an injector that bad and melt down a motor.....After all that he explained, I can see how things work a bit better.

Why and What was exactly wrong with my controller was never exactly explained other than to say "there were just a few things that did not test to specs so we replaced it even with it being over a year old"....This was done as a courtesy to me given that the kit had very few miles on it...

I got to explain again what happened at the track and why Jeff attempted to re-thread the fuel line JUST to get me cranked and off the track....He understood.

SO, if what they say is really correct about the function of the controller, I now find it hard to believe that it was the sole cause to my pressure spike so high to blow the line and melt the motor.....

And additionally, Joe offered to refund the money to my Card for the fuel line and fitting after understanding why it was "over torqued" at the track.

Now even though I am still puzzled about the complete cause of my carnage, I can say that I feel better about the fact that PPE's controller was probably not the sole cause....I guess I will simply just put this behind me now and carry on with my build. Hoping and praying that my luck changes with this one!

Thank you Joe / PPE for putting up with me and taking the time to explain things better for me. Also thank you for being generous enough to refund the fuel line cost!

David Elrod
 
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