Attention: TDR Forum Junkies I have long been a proponent of a Drag racing engines ability to Rev-Gain , the definition of this is to accelerate at a given RPM’s per second . some engines like to do this and diesels inherently don’t. The diesel responds dramatically to efforts to make it work that way, guess because it has so far to go that it makes it up in leaps and bounds.
I believe that a pulling motor is way over fueled , and will make power , but this power in not applicable to accelerating a drag racing vehicle down the track. IMO the added duration of big pumps only adds fuel to the end of the combustion cycle , and this contributes to the incomplete combustion process. While this may make a small amount of additional power , it is near the point of demising returns. The better way is to put more fuel in at the right time and better atomize this fuel.
Any engine has the point in degrees , or thousands down the hole where you need to make peak cylinder pressure , and this point is the same at any given RPM , that is specify the need to lead more and more timing as a motor revs up, to achieve that peak point , if you achieve that pressure to soon , by loading the motor down low , or with to much timing for that given RPM you create pressure spikes where nothing will hold the pressure in , something has to give , and its usually the head gasket , I believe that most head sealing procedures are nothing more then trying to fix a incorrect tune up.
You can also speed up flame front propagation with different additives , or by better atomizing the injected fuel and this also reduces the amount of lead or timing required to make everything happen at precisely the right time.
The 1400 hp puller is a fact , talked the guy that uses his special dyno to pull these big motors , but the motors are not accelerated , and sometimes pulled down the RPM scale . the reason is that is the way a puller runs the motor so you must dyno in real world conditions. On the SF901 I use we run a program for NASCAR engines where the motor is accelerated and decelerated for hours looking to find the little link that will make more power at the end of the race where everything is wearing down. On a drag racing power plant , you must run the motor the way it is intended also , meaning at a given rev-gain . this takes a lot of power and the big numbers away as the motor is chasing the dyno. The tune up for running this way is designed to give maximum hp at that acceleration rate, in Pro Stock , or any other maximum effort motor program , we would have different timing curves for each gear , if a timing curve was used when the motor was not accelerating at the race designed for that given curve you would find the ring lands lifted
I talked to Scott Bentz and one of the reason, I believe he kinked out a head gasket was going in to lock up way to low a RPM and unit loading the motor , causing a pressure spike that nothing will hold it. I think that it is easer to hold in cylinder pressure in a drag motor , but the tune up is less forgiving on fuel curve , to much fuel and the motor gets last , to little and the Egt’s go way up, my motor has stupid Egt’s and is totally cleaned up. But this motor will rev and pull, on a few lapsI have left it in 3rd to see what the motor will do up around 5000+ RPM’s , the truck was still pulling . 32 G’s in the traps at 5400
In conclusion , I am not going to give any more of the small deals away , but will be talking in genialities , and basis engine design and assembly .
I believe that a pulling motor is way over fueled , and will make power , but this power in not applicable to accelerating a drag racing vehicle down the track. IMO the added duration of big pumps only adds fuel to the end of the combustion cycle , and this contributes to the incomplete combustion process. While this may make a small amount of additional power , it is near the point of demising returns. The better way is to put more fuel in at the right time and better atomize this fuel.
Any engine has the point in degrees , or thousands down the hole where you need to make peak cylinder pressure , and this point is the same at any given RPM , that is specify the need to lead more and more timing as a motor revs up, to achieve that peak point , if you achieve that pressure to soon , by loading the motor down low , or with to much timing for that given RPM you create pressure spikes where nothing will hold the pressure in , something has to give , and its usually the head gasket , I believe that most head sealing procedures are nothing more then trying to fix a incorrect tune up.
You can also speed up flame front propagation with different additives , or by better atomizing the injected fuel and this also reduces the amount of lead or timing required to make everything happen at precisely the right time.
The 1400 hp puller is a fact , talked the guy that uses his special dyno to pull these big motors , but the motors are not accelerated , and sometimes pulled down the RPM scale . the reason is that is the way a puller runs the motor so you must dyno in real world conditions. On the SF901 I use we run a program for NASCAR engines where the motor is accelerated and decelerated for hours looking to find the little link that will make more power at the end of the race where everything is wearing down. On a drag racing power plant , you must run the motor the way it is intended also , meaning at a given rev-gain . this takes a lot of power and the big numbers away as the motor is chasing the dyno. The tune up for running this way is designed to give maximum hp at that acceleration rate, in Pro Stock , or any other maximum effort motor program , we would have different timing curves for each gear , if a timing curve was used when the motor was not accelerating at the race designed for that given curve you would find the ring lands lifted
I talked to Scott Bentz and one of the reason, I believe he kinked out a head gasket was going in to lock up way to low a RPM and unit loading the motor , causing a pressure spike that nothing will hold it. I think that it is easer to hold in cylinder pressure in a drag motor , but the tune up is less forgiving on fuel curve , to much fuel and the motor gets last , to little and the Egt’s go way up, my motor has stupid Egt’s and is totally cleaned up. But this motor will rev and pull, on a few lapsI have left it in 3rd to see what the motor will do up around 5000+ RPM’s , the truck was still pulling . 32 G’s in the traps at 5400
In conclusion , I am not going to give any more of the small deals away , but will be talking in genialities , and basis engine design and assembly .
