Max rpm our 7.3's can effectively turn

[golfer]

Whoaaaaaaaaa 10miles?! Wtf did he have going on w/ that motor to create so much interference?

poor assembly...clearances not measured.

he had too little piston to valve (head, LOL!) clearance...too much piston protrusion...

probably used standard deck height pistons, and the machine shop took too much off the block, without addressing the piston protrusion...

could be a goofy combination of rod length, std height pistons, block surfacing...but at the end of the day...the pistons plain and simple...stuck 'up' too far...

about 40thou too far at least.

 

[85_305]

poor assembly...clearances not measured.

he had too little piston to valve (head, LOL!) clearance...too much piston protrusion...

probably used standard deck height pistons, and the machine shop took too much off the block, without addressing the piston protrusion...

could be a goofy combination of rod length, std height pistons, block surfacing...but at the end of the day...the pistons plain and simple...stuck 'up' too far...

about 40thou too far at least.

So this scenario is more of a 'poor machine shop job' than it is 'stock pistons slapping the valves'...
Still an interesting scenario..

 

[ChattyCathy]

Exacly...I kinda wanna see that video.....LOL

Watch any video of that piece of **** wop dragster and wa la.

 

[golfer]

So this scenario is more of a 'poor machine shop job' than it is 'stock pistons slapping the valves'...
Still an interesting scenario..

I wouldn't blame the machine shop..unless THEY were the ones that assembled the engine.

100% assembly error, for assuming anything.

forget about the valve marks on the pistons...

the pistons left imprints on the head...that has nothing to do with rpm...(unless you want to get into oil clearances, low oil pressure, etc, etc)

chit was just assembled and obviously not measured...or measured by one without a lick of experience.

 

[under pressure]

Whoaaaaaaaaa 10miles?! Wtf did he have going on w/ that motor to create so much interference?

a little boost and high rpm on week stock valve Springs can do that to a stock motor.

 

[85_305]

I wouldn't blame the machine shop..unless THEY were the ones that assembled the engine.

100% assembly error, for assuming anything.

forget about the valve marks on the pistons...

the pistons left imprints on the head...that has nothing to do with rpm...(unless you want to get into oil clearances, low oil pressure, etc, etc)

chit was just assembled and obviously not measured...or measured by one without a lick of experience.

Yes I should have said assembler, but I had assumed the machine shop was also the assembling shop.

a little boost and high rpm on week stock valve Springs can do that to a stock motor.

Which brings me back to, whats considered high rpm on a 7.3 w/ basic mods and boltons? With springs/pushrods and without them?

 

[kluttzstroker]

I would say about 4200 is the safe bet

 

[golfer]

Which brings me back to, whats considered high rpm on a 7.3 w/ basic mods and boltons? With springs/pushrods and without them?

...this is like asking if this color is "too blue"...

too blue for what?

 

[85_305]

Whats considered an rpm on both a bone stock valvetrain 7.3, and a mildly upgraded valvetrain 7.3 (springs n pushrods), that can create a somehow dangerous situation within the motor.

 

[jaybuller]

Ill try and re word it for ya.....
Is 3500 rpms safe to run up to with all stock parts no supporting mods?
Is 4000 rpms safe ect......
Or do people float valves at those rpms with stock springs? That's the only thing I would worry about in a factory 7.3

 

[golfer]

I'm out......

 

[under pressure]

Unless air supply, hpo, nozzle and tuning are on the same page, pushing to 4000 will not make any advantageous gains.

RPMs will come naturally with making power.

 

[bad12jr]

My 220000 mile stock internal engine floats valves at 3600. That's it that's all it will do. I have built a lot of racing kart motors that float valves intentionally. I would say there are marks in my pistons. Its simply physics. If you can't comprehend it after all that has been said then your not going too.

Sent from my x2 chillin in the middle of no where

 

[85_305]

Ill try and re word it for ya.....
Is 3500 rpms safe to run up to with all stock parts no supporting mods?
Is 4000 rpms safe ect......
Or do people float valves at those rpms with stock springs? That's the only thing I would worry about in a factory 7.3

Yes exactly thank you

Unless air supply, hpo, nozzle and tuning are on the same page, pushing to 4000 will not make any advantageous gains.

RPMs will come naturally with making power.

So the guys making 1,000whp on their 7.3s... what kinda rpm's are they running to?

My 220000 mile stock internal engine floats valves at 3600. That's it that's all it will do. I have built a lot of racing kart motors that float valves intentionally. I would say there are marks in my pistons. Its simply physics. If you can't comprehend it after all that has been said then your not going too.

Sent from my x2 chillin in the middle of no where

I understand physics, but I'm not seeing the response I'm looking for. Perhaps I'm wording it poorly, look at jaybullers interpretation. How do you know you float valves @ 3600rpms?

 

[under pressure]

Realistically, i d guess you have to take a peak in there ?

 

[Hotrodtractor]

Whats considered an rpm on both a bone stock valvetrain 7.3, and a mildly upgraded valvetrain 7.3 (springs n pushrods), that can create a somehow dangerous situation within the motor.

Starting it. Anything more than just sitting there is dangerous. If you want nothing to break - don't move it from where it sits.

You have no idea the status of old worn out springs, bearings, initial tolerances the motor was set up for.

OEM piston protrusion is from 0.010 to 0.031" When you figure in a crushed gasket thickness of 0.062" (off the top of my head - don't use without checking) - then you have anywhere from 0.031-0.052" of piston to head clearance. That right there alone without anything else will effect how many RPMs you can spin.

There are too many variables to give you a concrete answer - that is exactly what Dave was trying to tell you. Oh - and its dark blue - definitely dark blue.

 

[85_305]

I'm confused on why the 7.3 is so much more different than any other motor produced?

Why can you take a 12v cummins that spins 2100rpms from the factory and spin 4-5k rpms w/ a simple GSK and springs.

Why can I take my 4k rpm 1.9tdi and make it spin 6k rpms with ease?

Why can a 6.0 powerstroke spin 4k-4500rpms w/ ease...

yet we cant give a straight answer on how many rpm's can spin? I realize that injection methods have a large part in this... but that cant be the ONLY reason why a 7.3 cant spin rpm's like the other motors?

Not trying to be dooshy, I just dont think I'm really getting my question out there properly.

 

[under pressure]

1000 hp, couldnt tell ya, those are few and far between....

However... If the motor can handle it, along with the best of everything, you can make all your power at 2500 rpm if thats what its tuned for.

I believe lowdowns 603 hp was made at 2700 rpm. By 3500 rpm it was making less than 550.

 

[Hotrodtractor]

I'm confused on why the 7.3 is so much more different than any other motor produced?

Why can you take a 12v cummins that spins 2100rpms from the factory and spin 4-5k rpms w/ a simple GSK and springs.

Why can I take my 4k rpm 1.9tdi and make it spin 6k rpms with ease?

Why can a 6.0 powerstroke spin 4k-4500rpms w/ ease...

yet we cant give a straight answer on how many rpm's can spin? I realize that injection methods have a large part in this... but that cant be the ONLY reason why a 7.3 cant spin rpm's like the other motors?

Not trying to be dooshy, I just dont think I'm really getting my question out there properly.

Because we are trying to give you knowledge and advice that comes from the real world from the consequences of "Just slapping in some GSK and springs" and letting it hit 6K and blah blah blah.

You want to spin RPMs and do it SAFELY - your words not mine. If you just want to spin RPMs - then go have at it with what you have. Enjoy. If you want to do it SAFELY - then comprehend.

 

[85_305]

interesting! Why the hell are the powerbands so early?? Is it the nature of the fueling characteristics of these engines and setups???