M42 conrods help.

[raivz]

Can someone help me figure out the conrod lenght needed for 8.5:1 compression ratio? original m42 rods are 140mm, and i dont want to change pistons because i've heard that orig. pistons are fine over 300hp.

[Warsteiner]

raivz,

Wouldn't you rather change the head gasket and leave all the internals alone then?

from wazzu70:
.080” = 9.75:1
.098” = 9.34:1
.120” = 8.89:1
.140” = 8.52:1

Cheers,
~Ralph

[raivz]

I dont get it. Compressed headgasket should be .140(3.55600 mm)?

[Warsteiner]

Yes. If you don't change you're bottom end, that is the way to change your compression.


Cheers,
~Ralph

[raivz]

I dont know, maybe stock conrods can't manage with extra power. So i thought maybe lower compression with new conrods. Can someone also giw me a hint what injectors should I choose. Car needs to be 300-350hp and reliable.

Thanks for the info

Raivo Villers

[Darky]

Hi
Standard connecting rods are fine for that purpose.
Just change your head gasket, so much easier.

Cheers

[raivz]

how much stock rods can take? And which Engine managment system ms1 or ms2?
I thought maybe i'll swap m42 cyl.head to m44 cyl.head.

[raivz]

I have two mazdaspeed 3 L3M7 turbos laying around. Both needs a rebuilt kit. And can someone tell me what injectors will fit in m42b18. I think i need 750cc to keep the duty cycle down and allow for some growth.