92smokin blacky

So i was readin the local classifieds the other day and Freedom diesel had a page with a bunch of stuff they have and they showed a stroker kit for a 5.9 cummins and said double your torque, make it equivilent to a 7.1!!! It said call for more info and pricing. I was kinda curious about this. I've never seen this, I was wonderin if anyone has done it or knows any more about it?

ebteckx

I want to know this too!!!!

wannadiesel

What I want to know is how they are going to double your torque by adding 10% to your displacement. That would be a neat trick.

dzl_damon

sounding like a snake oil type claim!

Strokin is cool though and does help, especially in gassers. IDK about diesels though. In Gassers they sometimes increase compression ratio at the same time which helps. But in a diesel, we sometimes need to decrease it since our boost pressures make up for it, and we'll break things otherwise. So the displacement is really the one big thing that would help.

I guess I can see where a torque claim would come from. Torque= Force X Moment Arm (length of lever you are pushing on) By increasing the stroke, you are making a crank shaft that has a greater swing (Moment Arm). So if your Force is the same (which most likely, it will increase a little as you have more displacement to boot), you torque will subsequentially increase too. I'm not forseeing DOUBLEING the torque though, as Wanna said.

Riflemanusmc

If one looks at bore vs. stroke on the bigger engines. The STROKE is more than the bore... Its just a diesel thing, thats all. Big bore short stroke is great for a gas burner, not diesel. darn near all of big diesels are small bore, big stroke. Thats where the torque comes from.

14racing

In any engine when you stroke it and still use the same heads its gonna raise the compression. Maybe not much but it will raise it. Clearance volume will be the same but the total swept volume will be more. Hence swept volume vs. clearance volume gives you your compression ratio.

wannadiesel

I'm sure the pistons included in the kit will compensate for the compression increase.

Riflemanusmc

Swept volume would have been taken into acount of the kit, OR should have been. Don't forget gents. Its a DIESEL not a gas burner. They are dealing with a flat head that has a known cc/volume of valve recession. ALL 6bt's/bta's valves are reccesed. The dish in the piston is where all the action happens, not a combustion chamber in a head that uses gasoline...The dish in the piston IS the combustion chamber..

BC847

Don't forget relocation of the wrist-pins when stroking.

Riflemanusmc

Uh, yea. Ring pack and center to center length on the rods IF they are not factory.......Nobody knows so far what the "KIT" is. Its IS going to be over stroked...

92smokin blacky

I might call them one of these days and see what they have to say about it and maybe get a price...$

Crossy's son

Ford 302 Engines (speed density engines at least) had a huge bore and tiny stroke and thats what made them so gutless when it came to torque.

I'm pretty sure diesels have a smaller bore, big stroke. = torque

dzl_damon

I'll give you an answer: A lot! Lots off good things you can do to your Cummins with the money I bet.

smoking

Actua;;y the ford 302's 4" bore and 3" strole is a great combo. The heads were the downfall. Compare them to the longer stroke chevy 305??? I pull with alot of guys that stroke their tractors up to 4 inches, without a head, fuel and fire they are worthless. Just my .02

ttcfan4476

the chevy 305 was small bore with big stroke 3.48" the same as the 350 but with 8.75:1 cpr it was guttless in tq and hp. the cummins is 4.02 bore x 4.72 stroke so the stroke is more than the bore but commpression ratio helps alot to 17.5:1 just my .02