12 HP Through Longer Rods And HC Pistons

[Dr. Curve]

It's nice to see that some of the advances in "Hot Rod" engine development over the past 20 years will be made available to us R1100S owners. A bit of head work, plus some new pistons, plus some new and longer rods, plus a few other small bits, and for 3000. dollars one can add 12 real world HP in a way that really counts. CC Products (California) is soon to offer the parts and the machine services to us all. For now you must take a look at the new issue of Cycle World to gleen out more information on this new development.

Long Rod tech has been around for awhile and started as a Stock Car tuning trick that would help maintain compression at higher RPMs. The higher the RLR (rod length ratio) in a engine, the longer the piston stays near TDC. By staying near TDC for a longer ammount of crank movement (time) the combustion pressures develop more before the piston get too far down.

I built the first LR BMW airhead that I have ever heard of in 1986. CC products would later build some airhead race bikes for Daytona and private use. It is wonderful that they are going to make a Long Rod kit available to S owners. I, for one, and others perhaps, have put off building a LR R1100S engine because of the expense of not only pistons and rods, but mostly I was unsure how much of a increase in ratio could be gained. The stock pistons already carry their pins quite high and after checking it looked to me that I could only go from a 1.77 which is standard to a modest 1.92 which is not really that high. (stock airhead ratio is 1.91 however) Still I could get this 1.92 by adding 11 mm of rod length while still not needing a "behind the ring wrist pins" location which can be a problem to install and maintain. Tempting, but never done.

Well it looks as if Chris and CC has arrived at some type of longer rod ratio that works. I am thrilled and will try and purchase one of the kits right away. We should all get in touch with him and put some money down so that CC can get this project in full gear and in turn we will make sure that some real R1100S "sleepers" are out prowling the roads. Lets get some money out his way.

I have never forgot how much more power my original LR airhead made than it had ever made before, although it already had lots of good tricks. Boosting the RLR and Piston Compression at the same time can really put some serious torque and HP on the ground. Best,

[Supermag]

Dr. Curve:
So were up to around 100 HP and still weighing in around 525 pounds.
Hmmm.
Lost my S had it on the trailer and it got knocked off and totaled.
Ended up with a GXS-R1000 A little suspension work and a pipe, power is not a issue........its wild.

[Joe]

Originally posted by Dr. Curve
It's nice to see that some of the advances in "Hot Rod" engine development over the past 20 years will be made available to us R1100S owners. A bit of head work, plus some new pistons, plus some new and longer rods, plus a few other small bits, and for 3000. dollars one can add 12 real world HP in a way that really counts. CC Products (California) is soon to offer the parts and the machine services to us all. For now you must take a look at the new issue of Cycle World to gleen out more information on this new development.
,

Hi Jim

Your about a month late on this info ( Talked To Chris At SanJose .........Piston kit )

Is the cost worth it ??

I'm approximating cost

Full exhaust system..........$1000

Intake Snorkel..................$325

set of cams.......................$600

little head work................$500

piston & Rod kit................$1200?

BBP 6 setting chip.............$350

fluids & gaskets & labor....$800

We get a total of .............$4775

Now if we want to go to bigger valves and bigger throttle bodies add a lot more.
I don't know the actual cost of Chris's labor or long rod kit.

[ckcarr]

Where's old Cliff when we need him?

[Rattus]

I miss Cliff!!

[Chris Eastburn]

Supermag, that whole bike off of the trailer thing is beautiful! I can't give my S away.

The gixxer is a proper motorcycle will you ever go back? Give me a 954 to go with my 9R, that's all I need.

I installed the stock exhaust back on my S and guess what, it's just as fast as it was with the $1200.00 Staintune. Geez if only I'd have dropped another $350.00 for a chip. Oh well.

EAST

[Dr. Curve]

Sorry I missed the month ago post. I am still excited that a kit of some kind is coming our way and hope to support CC in this effort. Your assessment of price is very high. How do you come to those figures?

That seems to be way too much money. Most anybody can do their heads locally if they simply need to increase the valve size by one MM. You can even go up one mm in size without changing the stock seat if you want to. The stock exhaust system is ripe for modification at much less outlay of cash than you mentioned. The piston and rod are really all you need. The rod is made to your specs and the piston is cut from blank which is much easier now that they are almost flat. Cams can have their backs shaved down some so that lift is increased and regrinds are a lot less expensive than new ones. I think CC products will be able to offer a basic LR Kit for under 2800. that would include two rods, two pistons, two sets of rings, one set of rod bearings, and one EPROM. Full installation instructions would detail assembly of course and a S owner could run this in their otherwise fully stock R1100S.

There are other solutions to power that have not been addressed here, at least recently. One is a simple rod swap whereby the owner exchanges their stock rods for aftermarket units that are .050 of a inch longer (eye to eye) than stock. The now removed heads are cut slightly deeper (.040), in the squish band area only, and all is reassembled. The stock pistons are now closer to the slightly reshaped head. This increase in compression alone would yield 4 to 5 HP. A easy job for under 1200 dollars excluding labor. Best,

[Joe]

Originally posted by Dr. Curve
Sorry I missed the month ago post. I am still excited that a kit of some kind is coming our way and hope to support CC in this effort. Your assessment of price is very high. How do you come to those figures?

I'm talking the average BMW owner is just going to hand it over to his shop and tell them this is what I want........expect a $5k invoice.

I didn't think they were regrinding these cams because of press fitted lobes being a problem.

[pdonnell]

Joe,
I believe your assessment on price is spot on. I sincerely doubt there are sufficient wrench heads out there prepared for this type of labor. Having said that demand would be light. I think for the money it would be better spent for a "true" sports bike. (Or another sport/tourer) with the appropriate horsepower outta the box. The kit, cams, head work, labor....that amount of cash (over $3000) is a bit ridiculous. But what do I know?

[lennie]

I know Chris does a great job with his development at CC Products and I have the utmost respect for what he does but I need some questions answered.

.

1. Is Chris making the claims ?

2. If not are they embelished at some point ?

3. Do the claims start with a stock bike and then add the pipe and everything else or does it start with a modified bike eg pipe, intake etc ?

4. Can someone who intends to do this, please go and do a proper before and after dyno test and document it correctly to prove the doomsayers wrong ?

With all care not to offend anyone, I would just like to see all the talk proved.

[Dr. Curve]

Cycle World is making the claim based on their rear wheel reading dyno. Starting with a totally stock bike............just adding the HC pistons (12.5 to 1) the longer rods (132 mm eye to eye) with no other mods is going to offer 8HP or so to the rear wheel. Pipes, cams, intake, lightened valve train, increased line pressure, and now (thanks to BMW) a update to twin plugs will add even more HP to the total packet. Lets all hope this rod and piston kit becomes available right away.

Increasing the RLR over stock will decrease torque down low just slightly but will increase it up top and offer more peak HP. A proven mod that is just expensive and requires a engine tear down, or at least from the crank out.

If we can get a solid 108 HP to the rear wheel on our hot rod street bikes that should be enough to trounce most anything in the real road world. Best,

[Joe]

I with you Lennie what point are they starting at.
We know we can get 94-95rwhp with a chip/pipe/combo. Are we going to get 10-12hp more for $3k then it's still a good deal. If we make a total of 100rwhp thats only a 5hp increase over a pipe and chip for a $3k outlay...........not a good deal .

If anybody has the Cycleworld article please scan it in.

[MoDog]

Originally posted by Chris Eastburn
Supermag, that whole bike off of the trailer thing is beautiful! I can't give my S away.
EAST

Gawd...I was thinking the same thing...

[smallj]

I bought the 12 to 1 pistons from SJ a while back, I wanted to do a good dyno before I had them installed but the harley shops in the area were booked till the end of november (yeah right...) so it did not happen. So much for science...

So the bike is up at Bobs BMW in Maryland having the pistons installed, pistons and rods balanced, valves ground, and whatever else you techie folks do to engines when they are in peices. I am guessing the whole thing will run me about $900 for labor on top of the $630 for the pistons. will it be worth it? sure, the money is already gone so it's no use crying about it now. I will be sure to get a good after dyno on the bike when it's done.

should have the bike back shortly after thanksgiving, a few hundred miles to break it in and I will be off and running...

[Joe]

Smallj

Could you list what HP related Mods and cost your "S" has before the added $1500 piston mod.

[pdonnell]

smallj,
I would be more curious about how the overall rideability of the S is improved by all the grounding and balancing of the motor.
.
Let us know ASAP once you get the bike back and put some miles on it. Very curious indeed.....

[smallj]

Currently the bike has the following Mods:

SJ Powerfilter (Big KNN)
Lennies InDuct
BBPowerchip (stage 2 or 3 depending on air temp)
Staintune

I was very happy with the bike and ordered the pistons on a whim, I figured $600 is not that big of deal, when I found out how labor intensive all the other things that 'should' happen when they are installed cost, I about choked. Oh well, it's only money, and this is my baby.

Right now I am enjoying the F650ST that Bobs loaned me while the bike is in the shop. I am very impressed by the amount of fun I am having on the 650, good bike. I sure do miss the heated handgrips and manners of the S on the highway though.

I'll be posting a storm to be sure when I get the bike back. Performance for the money, the Powerfilter and Induct can't be beat.

[roger albert]

Hi,

Other than me having just a laser cat-elim instead of the full staintune, that sounds just like my configuration.

I hope you wait a pretty fair amount of time (bare minimum 1000 miles) to Dyno it. New, unseated rings will rob a couple HP and aren't a fair comparison (yeah, I know we're not getting a before and after anyway, but it would at least be good to compare the various other dyno runs out their that were done with broken in engines, to your dyno run)

Any idea of new piston mass vs old piston mass?
I.e. besides getting the balancing, are you getting a reduction
in mass which would also reduce the rocking couple? Just curious.

Roger

[smallj]

I do not know the mass difference in the pistons, the shop boys were also going to port them so presumably they will weigh a bit less but I can't give you any hard figures. the pistons came from SJ BMW, they (Chris if I am not mistaken) may be able to shed a bit of light on the weight "out of the box"

While a before dyno would have been nice, with my configuration there are enough dynos out there that we can pretty much guess that I was making somewhere around 90 hp and 80-something in the ft-lbs department.

As far as numbers are concerned, I'm with Brad, they mean little, seat of the pants is where it counts.

[Dr. Curve]

Just curious. Did the piston set from SJBMW come with its own rings, wrist pin, and clips? With rings, pin, and clips those pistons will weight about 450 grams each. Should be good for 4 HP and possibly 5. Best,