How important is it?????

[allmotorcivic26]

ive put together an all motor project, nothin too crazy because its my daily driver too..i have a jdm b18c1 in my civic SI and ive went with crower 403s, s2 retainers,springs,cam gears, itr pistons so my compression is around 11:1.. and im runnin 310cc injectors...the basic bolt ons also, blox i/m, dc headers, magna flow exhaust..but my questions are, would it be smart to up grade the valves or are the stock valves ok?? if not, and suggestions??and also the fuel pump, its still stock, should i replace that too or will it be fine with my setup?? and any suggestions there too. thanks

[CapnToll]

Bigger fuel pump wouldn't hurt. You don't need anything like the Walbro 255lph, max like 190lph. If you plan on running the 310s at 85-90%, something bigger than stock wouldn't hurt.

Stock valves are fine unless you are trying to squeeze the most compression out of this thing as you possibly can without stroking it. That, or you want the negligible weight savings of the lighter valves.

You could see up to a 20whp increase in some areas of the powerband if you switch to a HyTech (or quality knock-off like Rage) 2.5'' Collector Header. Make sure the exhaust is 2.5" as well with hi-flow cat or testpipe, and your intake is 3".

How are you tuned? What's your AFR at?

[allmotorcivic26]

Originally Posted by CapnToll

Bigger fuel pump wouldn't hurt. You don't need anything like the Walbro 255lph, max like 190lph. If you plan on running the 310s at 85-90%, something bigger than stock wouldn't hurt.

Stock valves are fine unless you are trying to squeeze the most compression out of this thing as you possibly can without stroking it. That, or you want the negligible weight savings of the lighter valves.

You could see up to a 20whp increase in some areas of the powerband if you switch to a HyTech (or quality knock-off like Rage) 2.5'' Collector Header. Make sure the exhaust is 2.5" as well with hi-flow cat or testpipe, and your intake is 3".

How are you tuned? What's your AFR at?

yeah my tuner said i should go with hytech and a bigger intake and PP aslo..im not exactly sure what the afr is but i know he tuned it on crome pro.. he put in forged srp pistons so the compression ratio is around 11:1 but i have another question for you..is it normal for it to cause piston slap with those pistons? because it does it but only between about 1k and 3k rpms..but it runs real good though but im sure he does know what hes talking about because he is well known out here in CT.. i just dont want anything to get messed up..

[CapnToll]

Uh, as far as piston slap....As long as your pistons are the correct bore for your cylinders, and all your piston rings are up to par, you should be fine. If those specs are fine, then maybe your cylinder walls are warped? They can become warped from running too rich for too long (Cyl Wall wash, i.e. unburnt fuel gets trapped between the piston rings, and finally explodes pushing out against the cylinder wall), or not enough lube.

Anyways, you shouldn't see piston slap if you or your builder has done your/their homework and checked clearances. So if everything is good on that front, it could be one of the issuse I mentioned.

Look into getting the Edelbrock Performer X Intake Manifold for more power. Already on this forum and honda-tech, it has proven to make more power than ITBs...and in a nicer powerband with better tunability.

EDIT: I would also recommend investing in a nice wideband AFR gauge so you can always monitor your AFR. This way, if your Air/Fuels get wonky, you'll know before you blow something up.

Did your rods have to be modified to fit your new pistons? Could be issues there with the rod sliding on the wrist pin.