Just a basic question. Would there be a difference in performance if i were to A. install a higher compression piston (type r, p30, etc) or B. raise compression by use of thinner head gasket, flat faced valves?

Are the pistons making more power or is it the higher compression? What is the correlation?

Also, a completely off topic second question. If i replace my brake lines with oem brake lines (i have no idea how old the ones i have are, as i bought my car with 120k+ miles) is it going to make a difference, or am i okay leaving the older brake lines on the car?

 

it all depends on whats going on in the CC.
the compression makes most of the power, but the shape of the piston has a lot to do with it also. a flat top piston is ideal because there are no obstructions for the flame front to navigate.
so i guess to answer your question. it would be much cheaper, easier, and better to do valves and HG.

good luck.

 

thats the kind of info i was looking for. this isnt for a build im doing or anything, its just something i was thinking about. If anyone has any more or better information please chime in, id love to hear more, im still learning about this engine stuff

 

Not to dumb it down, but anytime you replace air space in the chamber with metal, you'll get a static compression increase. Flat valves will do it, higher piston domes do it, thinner HG will do it too.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dfoxengr &raquo;</TD></TR><TR><TD CLASS="quote"> a flat top piston is ideal because there are no obstructions for the flame front to navigate.

</TD></TR></TABLE>
.....which is why CTR pistons are not such a good choice to raise compression. The dome has a "funny" shape which hinders good flame front propagation.


And if your OEM lines aren't dry rotted or cracked or leaking, I wouldn't bother replacing them.

 

i would recommend "four stroke performance tuning", author:bell

 

thanks for the recommendation, wish i could find it for cheaper than 18$ on amazon, anyone have a used copy they wanna send my way?

 

dude thats cheap, lol.

 

do you think trader joes pays me good? definitely not

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by clem kevin &raquo;</TD></TR><TR><TD CLASS="quote">thanks for the recommendation</TD></TR></TABLE>

x2

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by King V &raquo;</TD></TR><TR><TD CLASS="quote">.....which is why CTR pistons are not such a good choice to raise compression. The dome has a "funny" shape which hinders good flame front propagation.</TD></TR></TABLE>

I should add that, although this could be a factor, it is not as big of a problem on a Honda as many people make it out to be. Much of the bad stuff that you hear about domed pistons comes from old school (and even new school) two valve domestic V8 guys. Those engines tend to have large cylinder bores and spark plugs that are off to one side (the exhaust side) of the cylinder. Because of this, the flame actually has to travel ACROSS the (long) combustion chamber, and any kind of dome will tend to slow/block it. But Honda engines have MUCH smaller cylinder bores AND centrally located spark plugs (typically exactly above the dome itself). So the flame has MUCH less distance to travel, and radiates outward from the center. For this reason, it can go pretty much everywhere unimpeded. So domes are MUCH less detrimental. After all, Honda uses them with no problem in such high compression motors as the JDM ITR and CTR.

 

Agreed. Plus you could argue the swirl/tumble that is present in the chamber hinders detonation, and being that it is a Type R engine, maybe they did it that way on purpose so race teams/ weekend track guys had more room for possible tuning errors or fueling mistakes.