Wow,, where were these a few years ago, when they informed me 2" was the smallest pistons they could make
I might be wrong, but I think these guys fabricate what they need, in small quantities. If we ask them for a set, it will probably cost a huge amount.
$500 USD, bare, EACH discouraged me (5 years ago), but it appears someone had handed over enough moolah to cover setup costs now,,,,,
You'd need to see a pic of the underside to tell but I'd suspect they've found a source for the right size forgings. It's very unusual for pistons to be completely CNC'd from solid, usually they're finished off from a forged blank. Wouldn't surprise me if more piston suppliers have this small size available now. They often buy in from the same forging company.
Nothing listed in Carillos partsbooks. Half tempted to call, but at the same time I've already spent money on new pistons that will suit my needs.
John Nunan would be the man to talk to @ C.P Carrillo, you might mention the Aussy who wanted some MC19 forged pistons made, I sent him a sample, he sent it to Germany, they sent it back to the USA, John sent it to Woosner, they scared me off the idea.
The rods mentioned in this document don't appear to be the same as what is listed in the Honda service manual e.g. 13mm gudgeon pin is standard and 16 listed in this document. I guessing these were custom dimensions that you specified.
These numbers for the rods look much more like ones that I have been researching for 600's - they're 115.5mm long for a start and that big end spec of 33mm seems large, same as those I've been researching for 600's Something is amiss... Would the CBR250RR take a 1.75mm overbore? I know it's a lot, but if so, that would put these pistons in the running https://www.daytonaindonesia.com/product-detail/jupiter-z1-50.25-blank-head/26
That's OK, weren't saying that you had, @maelstrom just pointed out to me that the rods in the invoice weren't CBR250RR Rods, and now that I think on it, more than likely that invoice was to show the cost of custom Carrillo, so we probably misunderstood - apologies
Oh no,,,,, It all started with a postie bike, and ended with just a postie bike kick start lever.. The bottom end is an early 70's Honda XL100, a new cylinder location was added to enable a lay down type engine, the original cylinder location was welded shut. It has stock Honda crankshaft & crank pin, yamaha 'rod & slipper bigend bearings, the stock oil pump was routed via a home made pressure regulator the "extra" oil lubes the gearbox & top end once the regulator maintains 70 psi. Big end oiling is via a braided steel oil line fed into the crank end using some ultra high pressure stainless tube, Mark1 feeder was a .22 caliber rifle barrel, but that snapped off during it's 1st run on the salt, lucky I felt it nipping up, and saved the crank from damage The head , barrel & piston is from a '93 fzr 600, capacity is 161cc, the fzr cams were shortened, and #3 lobes turned down & used as support with out rigger bushes , o/h gear lube is fed thru the Y shaped alloy support. Gates HTD 20 belt & pulleys were used to drive the cams, a commodore idler pulley takes out the belt slack. After trying many unsuccessful carby styles, the humble Mikuni Tm32 was used to feed methanol It held MF-175 record in Oz for a few years, @ 87 mph I beefed it up internally & bored it to take an R6 piston , bumping the capacity up to 174CC, the use of a custom Carrillo 'rod gave it a c/r of 16/1, it has not fired since the upgrades,,
As soon as I saw that pic I was interested. Been trying to contact them but had no reply. Really want to lower my compression a bit for my turbo 250....oh need to update my efi thread...
Well had a chat. Still around 500 a piston and close to that per rod. So...think I will just stick with what I have.
I'd rather destroy a few sets of China's best while finding that elusive "tune" There's 2 ways of reducing your C/R Akeizm, you could try this :- Or, get a 3mm MLC head gasket made, which also requires modification to the cam drive "cassette", involving cutting the tabs, & rewelding them to take up the slack moving the head away from the cylinder will create. https://gasketsolutions.com.au/ Tiny