Carrillo rod types?
 

I am currently choosing rods for an engine build, And i’ve gone through the CP Carrillo catalogues but there appears to be two types of pro-H rods available for the FA20 engine

AFA20-1HS-5090B6M
Or
AFA20-1HS-5090B6W

I cannot see what the difference is between the two rods from the CP spec sheet, anyone on here that can confirm what the difference is?

From looking at retailers and per the spec sheet both appear to be available with CARR bolts which I initially thought was the difference.

I’ve emailed CP tech team but they’ve not replied back to me yet so though the forum gurus were worth a try!

I would suspect compression ratio...

Rods don't select compression ration, the pistons do. OP on different part sites I can't spot a difference. I'm going to assume the difference will be that one is an older revision. Not sure though!

Ah, yes. You are correct, I guess I really didn't think that one through. :bonk:

Do you know who probably knows? Carrillo...

If they would only reply to my e-mail....

Well, their online catalogue lists a small difference between the two...

https://cp-carrillo-catalog.cld.bz/C...og/105/#zoom=z

Basically, the 'M' designation are slightly heavier. What this means in terms of strength, you'll have to ask them.

So Carrillo actually came back to me just now, turns out their online spec sheet is incorrect

“The part ending in W has WMC bolts and the part ending in M has CARR bolts.”

Hence the weight difference.

Mystery solved :-)

Thanks all for the replies.