2.5L Rocket Stroker Engine Kit with 6 Speed Transmission (R&D)

[ruzzle]

One thing that concerns me (Tho' the blown Engines don't seam to have a problem) is that the Big End Journals are not that large, they are a heap smaller than the Trident ones, and that's only a small Engine.
Just what is the longevity of a bored and stroked Rocket going to be ?
Again how do the Blown Engines last ?

Surely this is ultimately a factor of power output? This thread seems to be talking sub-300 HP.... and there are any number of 300 HP R3's out there which apparently survive.

 

[Neville Lush]

Hi Ruzzle

 

[Claviger]

Interesting thought on how three different 300hp motors, NA, Turbo, and SC would apply torque to the crank.

It would definitely see different loading between the three, and the NA motor may be the worst on it.

Hmm things to ponder...

 

[Neville Lush]

Turbo would tax the crank the most normally, as the low end torque is increased dramatically.

 

[Claviger]

I should say, there is one significant technical challenge remaining which I haven't looked into yet.

The crank ladder and windage tray. When I put my engine back together I'll be sure to measure the clearance between all that stuff and see what needs modification (or not) to accommodate a crank increase.

I made an error earlier when I said 5 or 6 millimeters is what i'd limit the increase to, that was just increased throw, so stroke increase would be double, at 10mm. With a known 4mm available in the piston to move the pin up, you'll end up with an 8mm increase using stock rods (my preferred option) resulting in a 2488cc displacement. Close enough to call it a 2.5 and 8.4% increase in displaced volume.

4mm won't hang the piston skirt out of the bottom of the liner very far, it will easily clear the side of the case that's closest to the rod bolt as it rotates and I'll check on the crank ladder and windage tray soon.

Suddenly it seems a lot more compelling than a 5% increase.

Using the 2488cc for me it would be something along the lines of:
201lbft Peak
268whp Peak

 

[Dr.D]

Ah the big boy brains at play. The stuff of dreams.

 

[warp9.9]

One thing that concerns me (Tho' the blown Engines don't seam to have a problem) is that the Big End Journals are not that large, they are a heap smaller than the Trident ones, and that's only a small Engine.
Just what is the longevity of a bored and stroked Rocket going to be ?
Again how do the Blown Engines last ?

Was the Trident crank forged?

 

[Paul Bryant]

Was the Trident crank forged?

En16B Hardened and tempered Stamping one piece.

 

[warp9.9]

En16B Hardened and tempered Stamping one piece.

Ok a low alloy steel utilizing chromium and molybdenum as strenthening agents. Not bad say equivalent to a SAE4140 or 4150 steal. Now for the bonus question. What is the rocket crankshaft made of.

I wish I was back home to have access to my cookbook

 

[Claviger]

Adamantium