im trying to see if fiat 128 rods will fit without tearing down my block just yet.anyone have the BE Bore and BE\PE width of the stock aeries con-rod. the fiat 128 has a 45.52mm rod journal diameter and company like crower and manley have them on shelf. rather then ordering custom rods for 1-2k.

the con rod i want to fit has the following specs
c to c BE bore BE width pin dia
5.060 1.914 1.000 0.866

so if the Base width will fit the aseries. all i would need is to make these work on an a12 is to a source a motorcycle piston with a 22.5mm compression height and 22mm pin have have a custom one made as i am trying to build a high rpm\boost engine i will need a forged piston anyways

A series runs a 48mm journal
Are you offset grinding for stoke ?

A12 rods are 121.5mm c/c
A14/15 are 133mm

From memory the BE width is 24.18mm which I think converts to .951 so you'd have to mill the rods to fit the crank journal. A while back I was mixing matching and finally came to the conclusion it would be easier to just order custom rods becuase the machine work needed cost almost half the price of custom so I thought might as well spend the money and just get custom rods.

i thought Aseries have a 50mm main and a 45mm rod journal size?

A12 Main bearing journal diameter, 49.964 mm to 49.957 mm [1.9671" to 1.9668"]
A12 Crankpin journal diameter, 44.947 mm to 44.961 mm [1.7706" to 1.7701"]

so i did some digging Pauter P/N NIS-190-480-1364F for custom rods specs are:
C-C BE BEW SE SEW
5.3700" 136.40mm|1.8901" 48.01mm| 0.9520" 24.18mm| 0.7480" 19.00mm |0.9000" 22.86mm

i also took a look at some crower rods. i got a set of their fiat 128 rods on clearance for $150. i have access to a machine shop with a surface grinder fitted with a magnetic chuck that i plan on using for this project. so 1.00"-0.9520"=.048"=1.2192mm surface grinding ~.6mm on each side seems very possible. i am currently contacting various piston company(ross,wiseco,CP) to see if a 22.5mm compression height and 22mm pin is even possible. i think with a piston that size i may have to experiment with a 2 ring piston.

from what i know a longer rod and shorter pistons will allow me to rev faster by increasing rod to stroke ratio and allow me to run lighter pistons with a shorter skirt.

are there any down sides to using a longer rod and shorter piston? the only one i can think of is possible increased cylinder ware.

There are lots MC pistons with 19-22mm pin heights but no idea how a 22mm pin would effect that.

I gave thought to a long rod motor as well for all of the performance advantages you noted but at the power levels I'm likely to net (110-120whp)it wouldn't be worth the extra effort.

So your engine makes 120hp. Your competitor -- who made the extra effort and went with a longer rod/stroke ratio -- is making 121hp. Who will win the race?

136.40mm rods are longer than the stock A15 rods. The resulting ROD/STROKE RATIO:
1.663

This is better than the stock A15 ratio of:
1.622

But nowhere near the idea of a "long rod/stroke ratio" which for naturally-aspirated wedge heads should be somewhere around 1.7 to 1.8. So it's doubtful these 136.40 mm rods will enable even the 1% difference.

Maybe spend the time & effort on custom pistons which can give 3% hp increase even at stock bore size or 10% with 79mm overbore pistons -- if your racing class allows that much displacement. With custom pistons you can get a shorter skirt and lighter weight even with stock rods

Dave, Dave, Dave, my competitors will need a lot more than 1-3hp to beat me...…...I'm currently getting past people with 20-30hp more. LOL

I get the point but for amateur racing, unless you're at national events, it's seldom someone with a few ponies more. You're usually better served to use a solid known solution than trying to reinvent the wheel.

I have a few sets of "longer" A13/14/15 H-beam Carillo rods. Stock center to center length is 133mm. I have some 135; 136 and 137mm length. I'm asking $500/set of 4 Carillo rods. I even have a set of 141mm. Peter

thatsabloody bargain pjz

Peter, just wondering do you have any knife edged
and balanced A14 or A15 cranks atm?

The rods Peter has would be quite the deal; there are a whole host of production pistons in 76-79mm bore with 23-27mm pin heights. The ability to use off the shelf pistons is a huge benefit.