Hi Guys,

Sorry if this has been asked before, i did search but i didnt get a solid answer for my questions..

my questions is,
what is the differences between A12 & A14/15 conrods?
Can A12 conrod be use with A14 crankshaft?


Many Thanks.

The can be used on the crank, but the it depends what pistonsand in what block, as the early a12 pistons hav a 17.5mm gudgeon pin, and late a12/14/15 use a 19mm pin, and both early and late a12 use shorter conrods then a14/15's.

So you need the right Pin, crown hight(piston), deck hight(block) and rod length

edit: late a12's may still use 17.5mmpin?

I'm in a middle of gathering some informations for myself,to put the RB20's piston in A14 block..

so far,what i've found that,in A15 block with A15 conrod,the RB piston will exceed 3mm from the top of the deck..

Is it the same scenario if i'm doing that in A14 block?What if i'm using A12 conrod?

Thanks.

A14 has same deck hight as a15 so wont change anything.. as for a12 rod's Im not sue of the differance? but I think (verry questionable) they are 3.5mm shorter witch with a light skim of the block would make them perfect.

You cannot use A12 conrods to replace A14 or A15 conrods. They are shorter. You can use them with an A14 crank if you want to build a hybrid...

How much shorter are they?

Quote:

So 0.46 inches difference

A12 Conrods are 121.5mm length. Early A12 have 17.4mm pins [part # 12100-H1000]. Later A12A rods are the same 121.5mm length but have 19mm pins [12100-H8500].

A14/15 Conrods are 133mm length and have 19mm pins [12100-H7200].

My A14 block has been decked 2.3mm off..so i'm wondering if i'm still able to do the conversions with the block?

i dont think the Rb's piston can be shave 5.3mm the top off..(taking the point from the standard block height with the
A14 conrod)

hmm..i think i cant do the conversion with this decked block