i'm building a cr calculator for b-series components (so we can FINALLY be rid of the "what cr would i have with this block, this head, these pistons, etc") and the only figure i'm missing is the displacement cc's for a gsr piston.. does anyone have this?? please.. you will be doing EVERYONE a favor.. not just me!

 

Mr Bojangles,
It's about time you got yourself on this board.
How the hell have you been? How's the car?

James

 

1797cc

 

eeeeerrttt....

compression height cc of the piston.

if nobody knows... and has a spare GSR piston, i can machine some plexi and cc it eventually, like, on winter break or so...

D

 

I always thought that it was 0 cc's (flat dome piston), but i guess not, I'll try to find out because i would really like this calculator also. I'm tired of busting the formula out everytime I need to do a particular compression. Good luck finding it.

 

hehe.. yeah, i've been here for about a month now.. first couple days i was already getting **** for only having 4 posts.. apparently no posts on this board= no knowledge.. sheesh..

i've been good.. car's runnin great.. just gotta reset the idle but otherwise it's good.. pullin real hard.. what about you? still sellin tha beast or what?

 

yep, i'm tired of having to the math too.. that's partially why i'm doing it. to save myself some time with the calculations, but also i think tons of people would get alot of use outta it.. time for me to make a contribution to this community of ours ya know..

 

well i still haven't found the cc's so if you could do that i'd appreciate it.. if i do find the cc's first i'll let you know.. **** and i just threw out a spare gsr piston a couple weeks ago.. arrrrggg!

 

OK, based on the B18C1's 10:1 CR, 41.6cc combustion chamber volume and 449.34cc cylinder volume (1797.36/4) I come up with an approximate 7.5cc void in the B18C1 piston.

449.34cc + 41.6cc = 490.94cc (this is the cylinder volume + combustion chamber volume.)

490.94/(41.6 + 7.5) = 9.999.

 

**Grabbing his head to try and stop the spinning**

James

 

you taking into account the ~ 0.050 of space created by the head gasket, i don't think you are.

anyway, i just talked to jeff (FAST94GSR), he has a spare GSR piston (and he's local to me), so, i'll try and find some thick *** plexi in our shop, CNC a nice bore in it and go from there... no promises, but i'll give it an effort when i get some time.

D


[Modified by D, 4:35 PM 10/25/2001]

 

Let's not go there........Lately I've been dealing with Fastlane trying to get them to warranty the work on my clutch. Looks like it's a no win situation though. Never going back there again.

James

 

Crap! You're right, I forgot about that.

A head gasket thickness of .05cm will add 2.576cc to the combustion chamber volume.

So...

449.34cc cylinder volume, 44.1764cc combustion chamber volume (41.6 + 2.5764)

combined volume of 493.5164cc

divided by combustion chamber volume of 44.1764cc you get 11.171. Still too high, so there is a void that needs to be accounted for. 10:1 is pretty easy to estimate, and just by looking 5cc makes a good place to start. Adding 5cc to combustion chamber volume you get...

493.5164cc / (44.1764cc + 5cc) = 10.04.

So if the factory head gasket is .5mm thick, a 5cc void in the B18C1 piston is probably a pretty close estimate.

 

Is the USDM Type R piston a P73?

Victor Penner

 

yes.

D I got the pistons here when you need em.

 

p73-ao (us)
p73-00 (jdm)

 

hmmm.. that's weird. i've done my own formula and i get around the same as you.. i get approx. -5.0375cc's for them.. that's strange considering us itr's are
-3.64cc's and jdm itr's are -5.96cc's.. so that means a gsr dome sits right in between these? i think not.. unless of course my cc's for these two itr pistons are incorrect! hey d, don't suppose you've cc'd the gsr's yet?

oh, a couple things on your formula mkultra.. headgaskets are actually .030" compressed which equals .762mm (.07cm) and i dunno whether you were taking into account deck clearance or not (didn't look like you were) but you need to in order to get truly accurate measurements..

ok, so anyone else know what the deal is??