I'm using the compression cal. on C-speed.com web site to check the compression of my motor has anybody used it?? how accurate is it??

 

I think its just a general estimate, we used it to figure out some stuff on my friends motor, GSR head with p30 pistons, head was just kissed a little bit but we were coming up with 11.6:1 cr, dont know how accurate it is though but the car is pretty quick.

 

The very first sticky thread in the All Motor forum has 14 pages worth of info related to this topic. It takes a while to read, but by the end, you should be more knowledgeable on the topic. Took me a while to read it, but well worth it. Even if you dont understand it all, at least you will find better, more specific questions to ask.

https://honda-tech.com/zerothread?id=717928

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blacksihatch &raquo;</TD></TR><TR><TD CLASS="quote">I'm using the compression cal. on C-speed.com web site to check the compression of my motor has anybody used it?? how accurate is it?? </TD></TR></TABLE>

Use this site...it's more acurate

http://www.zealautowerks.com/

 

thanks....im just trying to get some idea

 

ive check with both c-speed and zeal comp. calculators and one of them has to be way off. i have a gsr block with ctr std. bore pistons, b16 head and a 2 layer gasket. using c-speed = 12.08:1 comp. ratio
using zeal = 13.1 comp. ratio
we're talking more than an entire point of compression difference in the same setup!!!
sure their both accurate when you enter the stock components of and engine, but when you start changing pistons, heads,and gaskets, they are waaayyy off from eachother! i used to use c-speed, but i'm not sure i would trust either of these now,they are just way too different from eachother. we're not talking about a .02-.04 difference, its more than an entire point? how could you really trust which one is more accurate??

 

yes, im a lil bit confused too. i have +5cc dome pistons at 81.5mm in my b18c1, and zealblablabla said i had 11.33, and c speed said i had 11.21, but imiport builders told me that it would be 11.5-11.7. hmmmmmm.....

 

There must of been someting you were doing wrong because both sites were the same the one thing that was diff that I liked about the zealautowerks was the calculation for a milled head....but i rec otherwise the same results...check it again you may get the same results as I

 

yeah its cool that you can factor in a milled head or decked block but i rechecked and its still an entire piont different than the c-speed calculator.
b18c1 block
b18c1 crank
b18c1 rods
pct pistons
b16a head
2 layer gasket
no mill
no decking

zeal=13.1 c/r c-speed= 12.0 c/r
you can check for yourself but im pretty sure i did it right.

 

Both Zeal and C-Speed are prefectly good calculators as long as the information you put in them is correct. C-speed is off on the compression height of the type-r pistons, which zeal is right on. I think zeal may be slightly off on the deck heights, but good luck finding the real numbers. Zeal should get you within .2 of the real static compression, good enough for me.

 

Hmmmmmmmm that pretty F'd up but I do agree with Bunger ....not only because of the comment but Zeal does narrow down more of the options that your motor may have and the .2 diff is very close so good enough for myself .........the readings I get using the calculator Zeal 11.3:1 and C-speed 11.0:1 with the .3 diff maybe I wont feel very much but Im leaning more to the Zeal 11.3:1 and if it off .2 that makes it 11.1:1 NO BIG THANG BUT A CHICKEN ****.....