One Connecting Rod Shorter (Nap z20s engine)

[Hondanx250]

Hey Guys, So you guys helped me out on my Headbolt! Thanks very much!!!

 

So i ran into another problem. One of my connecting rods is shorter(Number 3) It was in the engine and running fine. My question is should i use it or Find the correct Connecting rod? Would it toss the engine off balance? I was reading that the L20B Engines are the same lower end parts. Would a l20b Connecting rod work?

Does anyone have a extra laying around? Or How i can find the part number? (Tired searching with no reveal)

 

 

Thanks!!

 

 

[datzenmike]

You have three Z20E rods 12100-N8500 152.5mm and one L20B rod 12100-U6000 149.5mm. Look at the numbers on the side of the rods.

 

Your pistons will look like this... or at least the three with the longer rods.

 

The number 3 may have this or a stock L20B dished piston. (can't see that as it would be obvious something is different) Either way the number three is going to have a much lower compression than the other three. This is an incredible ooops.

[Hondanx250]

Would it be alright to stick the l20b Connecting rod back in? The pistons look like the one in the picture.

 

 

Thanks for the help!!!

[ggzilla]

Yea, if it ran before. But it will run smoother and with more power if you put the correct rod & piston in.

[datzenmike]

Your compression on the long rods is 9.941. Because the rod is so short the piston does not go all the way to the top of the block surface and is 3mm short. This 3mm translates out to an extra 17ccs of added volume to the combustion chamber lowering the compression on the #3 to  6.88!!!!

 

I would very much recommend getting the 152.5mm rod from a Z20E or Z20S motor. It probably vibrates from the uneven rod weight and lack of efficiency with the low compression cylinder.

[laotsu]

I'll be damned if I don't have a set of long rods for sale...