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

I'm missing something here, crank angle is a function of time, BDC to BDC is one revolution, at a given rpm, it would be the same time interval for both curves, how can it be fatter all the way? More time at dwell would have to be less time somewhere else? Not sure what I'm missing here, something obviously.
 
Never mind, I got it, time is fixed, no reason lines would cross. Rate of acceleration just changes.

Thus force exerted on the big end of the rod, small end of the rod, and wrist pin decreases.

The rocket rod ratio is at the bottom end of what’s generally considered a “motor sports” ratio, so it likes to spin.
 
Oh, and your R&D would have to include an understated badge of some sort akin to the letters on Mercedes and BMWs that give a clue to the vehicles salient characteristics.

You sir, need to move closer to me, like next door, so we can combine our powers and form Captain Rocket 3!!

I'm too exhaust to consume technical stuff atm, 1200 miles on my sportbike, all twistie roads, has absolutely wiped me out, but, I'll revisit soon!

I have done some research along exactly these lines already and sources some shops that have confirmed they're both able and willing to take some of the work on.

Oh I LOVE your idea Joesmoe, to have a performance enhancement shop for Rockets along the lines of M, Alpina for BMWs and AMG, Brabus for Mercedes, etc, and a little badge for the bike to show it's been force-fed steroids :D
You'd have guys sticking the badges on to try fool people too like they do with M and AMG badges

But I'm afraid in order to be an M or an AMG, you'd have to be strongly affiliated with Triumph themselves.. better chance of being an Alpina or Brabus though!

Clav, what shops have you been in contact with? Could add them to the list for when pricing quotation time comes
Also would you like to be the guinea pig road bike :D



This is exactly what I did with my old Trident.
Stroke was increased by 12mm, bore by 4mm.
I drew up all the parts and assembled them in the Auto C.A.D. before cutting any steel/Alloy.
I created a 3D model of the Piston and Combustion chamber (not including the valves or valve seats) so as to determine the Volume for the Compression ratio.
I designed it at 10.0-1, when I built the Engine I had to skim .010" off the head to raise the comp to the designed 10.0-1.
I used flat top pistons and had to shorten the block by 1.8MM (this being a longer Block to accommodate the longer stroke)

Engine 1.jpg

Ooh fantastic, you've done this job before. Your knowledge and help would be great to have Paul. What cc did you end up with, 1000?



I have confirmation that we can get longer rods from Carrillo rods. They're not cheap, but, they've already designed them, and can provide great pistons to match!

I've a heap of sketches and calculations done, and right now I'm actually looking at going with shorter rods would you believe
 
Shorter rods would seem obvious - greater swept area with higher volume and compression ration while helping to preserve valve clearance.
 
Ok it’s morning and I’m not exhausted, some thoughts:

Short rods would be a double whammy on RPM capability. By shortening them you’re increasing the forces exerted on the whole assembly. The stroker could be done using stock rods and revised pistons (I think).

The crank has the rotational room in the block to be stroked some, but no more than about 8mm until you’ll need the clearance the case slightly to make room for the rod big end and bolt.

At BDC, the piston skirt on my CP pistons comes out of the liner about 1.5mm. The bottom of the liners have a chamfer on the to ensure that the unsupported are slides back in easily. Hanging the skirt out of the bottom a bit is NOT the end of the world, LS motor guys do it all the time. The best thing to do would be getting longer liners increased in length equal to the increase in stroke.

Falicon out of Florida will do crank work for us. I spoke with them about stroking or destroking the motor and basically he said if it’s a one piece crank you can’t do it properly. The welding on the journals warps the cranks and renders it unusable. I don’t know if our cranks is one piece or not...

I firmly believe more than an 8mm stroke increase is not possible max, but because of clearances, would not even try for more than about 5.

It would be 101.6x99.3 bore/stroke, = 2415 cc, or, 5.2% more displacement.

Regarding RPM a 2415 motor would have 26.48 m/s mean piston speed at 8,000, a 2294 motor has 26.404 m/s at 8400.

- 7700 rpm on the stroker would be very similar to piston speeds of a 2294 at 8000.

- I would set redline to 7800, but, I also disagree with the 9000 limit in the first place.

All things being equal it should gain roughly between 5 and 7 percent torque across the board. Considering the cost, I can only assume fully built motor owners would be interested, because more power can be had cheaper from top end work.

As an example though, on my motor using pump gas:
Peak torque would rise to ~ 196lbft
Peak power would rise to ~262whp

Multiply by 1.055 or so to come up with MR12 numbers and you can see how this will get you to new levels previously not reached.

All that said, I believe 260-270 can be done on pump gas without stroking.
 
I agree with all of this so why would one want to spend a heap of coin for a marginal gain.

Well it's like this;
It's not so much about the actual gain in power.
I can see where Arto is going here, he already has the Carpenter Engine with a hair dryer attached, so why would he want more ?
Because he can !

This is exactly where I was at back in my Trident days, I would sit there and stare at the Engine (usually after I had blown it to bits) and think about just how much more, or what else could I do to this Engine.

Below is one of the development projects after I'd blown the modified stock Block, I decided to cast my own Block.

20180720_073033.jpg
 
Anyone fancy a 2500cc Rocket Stroker Engine Kit?

And/or a 6 speed Rocket transmission?


That is the vision.


Step 1: Build an R&D testing engine from spare parts to run on a bench


This is the construction of the R&D Test engine, which will be used to facilitate & test engine enhancements such as above. It's made from spare parts I've accumulated over the years,, e.g. block fro an 06 Classic, head from a 2010 Roadster, throttles from a silver engine 06 Classic, clocks from a 2013 Roadster, ECU from another 2013, and so on.

Been planning this for a few years now, in fact @warp9.9 may recall some conversations from 2010/11 (before I even had a Rocket) where I was picking his brain about possibility of stroking the engine, and some other stuff.



Original plan was;

upload_2018-7-17_22-56-53.png



Had the spare engine since 2012.. as its first job, it was used to facilitate Carpenterizing my daily driver.
Have been gathering the other spares since to run the R&D engine.

Anyway I did 1 & 2, even though i had the spare engine since 2012 I kinda skipped 3 & 4 and went straight to 5 (except changed mind to supercharger instead of turbo for a few reasons).

I see a lot of folk who would like a 2.5L, 6th gear in their bike (me being one), but nobody has done anything on it afaik.

It's going to be an expensive venture, it will take a LOT of time.
I'm prepared to go through with it just so I can have it, and if anyone else wants a kit too (once R&D is complete and the kit is proven and solid / after I've done the guinea pig duties..) that would also be welcome.


The plan would be to have multiple trims of the kit available too - you could go for same materials that are in the stock engine, you could go for high end/light/stronger metal if you're a power maniac, you could go for low compression ratio (8:1) if you want to go boost, or you could go for high compression ratio (~12:1), same goes for the tranny, you can go basic material or full on high end indestructible material.

I don't know if the 6 speed is possible in this block - we will see. Might have to go another route that's thinking outside the box :)

On Roadsters at least the GPS has a 6th gear position already on it. I found this 6th gear the time my GPS went faulty. Getting 6 gear maps made from Dynojet for map-by-gear ain't a problem.


But I believe it is entirely achievable to move up to 2.5L... that's not much to ask.
i hope it can all be done just with stroker crank, rods etc. But if we also need to bore out the cylinders and fit thinner liners made from stronger metal and fill them with different pistons.. well so be it.

The Rocket cylinders are 765cc each, with a diameter of 101.6mm and stroke of 94.3mm (an oversquare motor). If we increase stroke length (that's what she said) to 101.6mm to be perfectly square, the engine CC will rise to 2,472cc (or 2.5L :D).

If we go all the way to 2499cc, stroke length would need to be 102.7mm, an undersquare motor.

Reckon there will be a downside to the stroker though - higher piston speed for the same revs as stock engine. This might limit us in terms of top engine speed - the 9000rpm redline mightn't work, might need to limit to 8, 7 or even 6k rpm. But the torque increase/lower down and increased fuel economy might be worth it for some..

Thinking the kit would look like:
> Stroker crank
> Matching balancer shaft
> Journals, bolts, wrist pin circlips etc etc
> Stroker conrods
> TuneBoy & TuneECU maps
> OEM-looking 2500cc badges to replace the 2300cc ones
> Pistons if needed



Step 2: Get R&D engine running

Almost there, got a couple of faults to fix;

upload_2018-7-17_23-10-53.png



Step 3: Measure up engine & transmission internals

Step 4: Design new components

Step 5: Get new components made

Step 6: Install & trial new components......


Anywho, been dying to get stuck into this for years,,,, so here I go :)


I too have been looking into spare engine blocks and a displacement increase After examing components and speaking to knowledgeable engine builders these are my thoughts;

The cheapest way to get more torque/power is increase volumetric efficiency fooling the engine into behaving larger than it is but this is complicated and filled with trial and dyno testing Not cheap or easy
The cheapest way to increase the displacement in this engine is to increase the bore The cylinder liners once pressed out of the block are a sophisticated alloy with ribbing and a hard wearing coating They are thick .These could be easily replaced with a suitable thinner custom solid sleeve of larger internal bore .LA sleeve company will do custom sleeves
If more bore was desired the block would need to be bored 2 or 3 mm to enable yet larger sleeves
Doing the above could potentially give an engine with 3 to 5 mm more bore
A few problems have to be dealt with .
First of all cylinders like these do not have the longevity of the original hard slippery material of the stock engine
Secondly the pistons would have to be specifically designed and built with a piston company that could keep piston weight identical to the originals by short wrist pins judicious weight milling design and material
The above would minimize changing the original R3 excellent balance and design of the crank rods and counterbalancers Vibration problems would be minimal if any.The crank rods and counterbalancing is complicated and changing any of these components would be tricky costly and limited to small displacement increases anyway compared to the bore option
Thirdly though the bore can be easily increased the seal of the bore with the head area might have to be redesigned slightly or o -ringed to seal perfectly
I had the heads on my stock engine flow tested and the results were basically excellent They can support a lot of horsepower in stock form and dont seem to need much porting to increase flow Flow rises in proportion to valve lift linearly to .450 lift and beyond
To accomodate a larger engine larger titanium valves and mild throat blending would be the route to follow if modest valve lift were to be retained
properly done this approach is the right one for 1)size of increase(2.7 litres possible)
2)ease cost and complexity
3)ultimate HP potential of engines.Increasing displacement doing bore increase is usually near double that of stroke increases

this engine doesnt need 6 gears
More gears in the same space would compromise the beef just to make space and a weaker trannie
The more torque you have the less gears you need
What about a lower differential final ratio This could give you relaxed top gear engine revs and the increased displacement would make even a taller gear effortless
 
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