Just wonderign what kind of compression ratio (roughly) I'd be looking at with a straig swap from the CTR block to a B20 block. I know I'd need a main girdle and of course I'd be swapping the R oil and water pumps. Pistons stay in their respective blocks however. Because I don't feel like buying new pistons. Wondering if it would be worthwhile....I'm getting really fed up with my B16B's lack of low end grunt. Wish I had boght an ITR instead.

 

I know that some motor guru can answer this for me easily.

 

If it's a B20Z block the compression would be roughly 10.03:1, if it was the B20B, it would only be about 9.15:1, stock head gasket, no milling or decking.

 

Thanks alot man. Hmm, I guess a B20Z with a thin HG would be a decnet setup then. Hopefully the lowered CR wouldn't make the CTR cams unhappy.

 

Could the bigger displacement help compensate for the lower compression?

...maybe??

 

Just finished, building my B20vtec. B20B block and type R head, compression ratio on the dial was 210 lbs/ft. Stock B20B pistons w/ new rings and head NOT milled. Duno how you convert that to ratio...

 

Why do you think you need a main girdle?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ChampWht &raquo;</TD></TR><TR><TD CLASS="quote">Just finished, building my B20vtec. B20B block and type R head, compression ratio on the dial was 210 lbs/ft. Stock B20B pistons w/ new rings and head NOT milled. Duno how you convert that to ratio...</TD></TR></TABLE>

There is no conversion to figure out what the comp ratio is from a psi reading. You have to calculate it out using measurements and volumes. Try going to this site if you want to calculate it:

http://www.c-speedracing.com/h...c.php

 

if you do a b20z block you need to get your pistons machined for vavle clearnce. ITS A MUST! or you could just retard your timing and not rev past 6 grand and youll be fine, actually just dont hit vtec and youll be ok..

 

you can also do this with a dremel.. theres a few people on HT that have done this and had good luck, i didnt!