[High On Octane]

Hey Everyone!     

I'm not sure if anyone is interested or not, but I'd thought I'd throw this out there.  As most of you know I'm in the middle of building a supercharged 700cc twin.  I got a phone call from R&R Connecting Rods in Illinois today in regards to a quote for producing some custom steel H-Beam connecting rods that will be a direct replacement for the original rods.  Now they are not cheap, but they are field tested to hold over 300hp per rod, WAY beyond what any Enfield will see (as of now  ).  As you know the factory rods are the weakest part on the entire bike and known for breaking and putting holes in engine cases.  And if you have looked into it you also know that the only replacements are OE rods or Hitchcocks forged aluminum rods.  The custom steel H-Beams will end being about the same price as the aluminum Hitchcocks rods for a pair.  The advantage to a steel rod over aluminum is that steel does not fatigue like aluminum does.  Aluminum rods have a stress life and need to be replaced over time depending on riding habits and mileage, where as the steel rods are much stronger and don't fatigue and do not need to be replaced.

The quote I received was $690 for a pair.  I asked if there was any kind of discount for producing more than 2 and he replied that I could get 4 made at a price of $985.  He then explained to me that the more I order in one batch the cheaper they will be as the set up fee for the CNC machine is a good part of the actual cost for small runs.  Either way, if more than 1 pair is produced, the cost would be no more than $500 a pair, which is cheaper than Hitchcocks by the time you factor in exchange rates and shipping.

I'm not looking to make a profit off of anything.  I just thought that as long as I was going to have these made anyways that I would extend to offer out to everyone in case there is anyone in need of rods or looking to upgrade.  I believe there are a couple of different people that are in the middle of builds.

Anyways, just let me know if you're interested.  Cheers!

Scottie J

[Blltrdr]

You should email Hitchcock's and see if there interested in purchasing a few pairs since they are buying up twins all over the planet.

[ace.cafe]

What do they weigh, and what are the rotating and reciprocating masses?

[High On Octane]

I don't know yet Ace, but I will can certainly ask Monday morning.  I know my preliminary phone call with them I was informed that a Honda Civic has a very similar dimension rod as what the 700s require.  Those rods are holding 1500HP on a 4 cylinder for several thousand miles and are still holding together.  I will ask him what the weight is of one of those Civic rods so we can at least get a rough idea of how much they will weigh.  Or maybe their computer will even give a rough estimate as to how much they will weigh.  I'm not sure.  I DO know that like Carillo, R&R also balances their rods within +/- 1g.

You should email Hitchcock's and see if there interested in purchasing a few pairs since they are buying up twins all over the planet.

Maybe I should tease them "I'll trade you a pair of custom 1-off bullet proof steel rods for a 1 piece cylinder."   

Scottie J

[ace.cafe]

I don't know yet Ace, but I will can certainly ask Monday morning.  I know my preliminary phone call with them I was informed that a Honda Civic has a very similar dimension rod as what the 700s require.  Those rods are holding 1500HP on a 4 cylinder for several thousand miles and are still holding together.  I will ask him what the weight is of one of those Civic rods so we can at least get a rough idea of how much they will weigh.  Or maybe their computer will even give a rough estimate as to how much they will weigh.  I'm not sure.  I DO know that like Carillo, R&R also balances their rods within +/- 1g.

Maybe I should tease them "I'll trade you a pair of custom 1-off bullet proof steel rods for a 1 piece cylinder."   

Scottie J

Just for your reference, our Carrillo rods for the Bullet weigh about 365g and have 135g reciprocating mass. They are 6.875" long, center to center.

[High On Octane]

I have the dimensions written down at work.  I want to say they were 6 3/8" center to center but I can't remember at the moment.  I still have the spun rod in the garage.  I'll take a measurement when I go out there in a bit.

"The Garage/Shop.  A Man's Home Away From Home."   

[Blltrdr]

Maybe I should tease them "I'll trade you a pair of custom 1-off bullet proof steel rods for a 1 piece cylinder."   

Scottie J

Does a late model 750 cylinder actually mate up with a 700 case? If so that would be cool.

If it turns out the custom rods are a bit mass-ive for your taste you could have them reprogram the CNC machine to trim it down to a 200 hp rod.

Seriously, I'm not funnin on you!

[High On Octane]

Does a late model 750 cylinder actually mate up with a 700 case? If so that would be cool.

If it turns out the custom rods are a bit mass-ive for your taste you could have them reprogram the CNC machine to trim it down to a 200 hp rod.

Seriously, I'm not funnin on you!

When I first heard of the 1 piece alloy cylinder I personally called Hitchcocks and asked to "speak with to most knowledgeable person in regards to a 700 twin."  After speaking with Richard, he had informed me that they have placed the cylinder on a standard 700 case and all the holes line up, except the head studs need to be replaced with 3/8" studs which I already planned to do, but no one has actually built a 700 motor with that 1 piece cylinder.  I'm taking the honors of being the first to try it.  I will essentially have a Series 1 early Interceptor motor when I am finished.

And that's not a bad idea to have the rods lightened a bit more if they are too heavy.  This motor will never see 600 hp.   

Scottie J

[Blltrdr]

Well Scotty it definitely seems like you are leaving no stone unturned on this engine build. Hope it all comes together as you have envisioned with all your goals being met. I'm sure at this stage of the game, sleep has become a commodity.

Thinking about leaving no stones unturned. Brian Jones would be the only Stone unturned. 

[High On Octane]

Every stone has certainly been flipped over at some point.  LOL  I've been researching this build for over a year now and the research part is pretty much finished.  Now I am in the development stages of the build, which is the painstaking part of the build.  Between money spent and the endless weeks waiting for parts to be developed, it is quite nerve racking.

Scottie J

[High On Octane]

OK.   I spoke with Mike at R&R yesterday to finalize some things before actually putting the order thru for rods.  When I mentioned that the weight of the steel rods were a concern for me he asked what kind of HP I was looking to achieve, so I told him 125HP at 7000-8500 RPMs under about 10psi of boost.  He told me that the steel H-Beams were going to be too heavy and that I was going to have a hard time balancing the crank with them.  He then told me that aluminum I-Beams are going to be the best option for me, as they are lighter and cheaper than steel and will be able to hold up to about 200hp per rod no problem.  I asked about fatigue rate on the aluminum rods and he said that he doesn't of any that have failed.  The rods are also going to be made with ARP 3/8" rod bolts which cost an extra $50 per rod, but will pretty much eliminate any chance of failure in that department.  Mike also informed me that he didn't like how the originals are made and that he will be "Starting over from scratch" in making the new rods.  I told him that would be a good idea because a lot of these twin motors lived short lives after sending a rod through the engine case.

Final pricing for these rods are going to be $475 per pair.  I have one person who has contacted me and will be ordering a set of these rods too.  If you are interested I will need to know soon if you want a pair.  Send me a PM if you like a set.

Scottie J

[Bullet Whisperer]

Hi Scottie,
 Just a heads up - we had some 'unbreakable' alloy conrods specially made in the U.K for our racing Bullets / Clippers a few years ago. Here is one of them not long after we fitted it in our 500 ...

[ace.cafe]

The general rule regarding aluminum rods in severe duty is to replace them regularly before they fail. The higher the stress, the shorter the life. Top fuel guys replace them every weekend, ans sometimes after every run.

They are lighter, but not an awful lot lighter. Our steel H-beam Carrillo rod only weighs 30 grams more than the OEM alloy rod, and the reciprocating mass is the same as the alloy rod. All the extra 30 grams are in the big end mass which is rotating mass, and much less problematic.

So, think about this rod materials decision carefully. Aluminum rods are not a 'one-time buy'. You need to change them out. Steel rods you can leave in for the duration. Like forever.

[High On Octane]

Well damn it!        Uuuugggghhh

[Bullet Whisperer]

Here is an alloy rod from a SII Interceptor 750 engine I rebuilt. There is not much room inside the twins' crankcases for a very 'beefy' big end on the conrods, so steel may be a better bet for what you are doing, Scottie.
 B.W.