I have a set of skunk2 stg2 cams that im using on my b16a, i also have itr valvesprings, retainers and aem adjustable cam gears.
I will be using a comptech h/gasket (.027") and itr pistons on b16 rods.

What will be a safe limit?

I know the itr revs to 8700rpm stock, but the s2s2 cams have a more aggresive profile which i presume will put more stress on the springs and retainers.

Basically, i want to run the highest/safest revs poss (without pointlessly over-reving) whilst getting full potential of my build.

thanks
ste

 

What rod bolts are you using?

 

Well i was gonna use stock rod bolts.....but i can get some arp ones if its worth it?

limiter with stock =
limiter with arp bolts =

????

thanks

 

You will definitely want the ARP bolts instead of the stock ones. ITR springs and retainers are not going to be even close to sufficient to handle the lift of those cams. They are pathetic...I wouldn't even run them with ITR cams. Until you swap those out for proper springs, don't touch the redline. Even worse, your compression is going to be lower than if you had used B16 pistons and it will still be too low for those cams. You are overcamming the engine in pretty much every possible way.

Oh, and the ITR redlines at 8400 rpm, not 8700.

 

The compression will be lower than a stock b16?? even with the highercomp h/gasket and itr pistons???

I thought itr or ctr pistons in a b16 increased the compression???
Thats why alot of people fit them?

So what valvesprings are good enough then? are the omni ones anygood?

My two friends have stock itr's, and theres both limit at 8700rpm, are the ukdm ones differant then??

What compression would i need to work with those cams then?

 

Just found this table, this sound about right then?

Block Head Compression with ITR / CTR pistons
B18C1/5 B18C1 ITR= 11.36:1 / CTR = 12.04:1
B16A B16A ITR = 10.19:1 / CTR = 10.80:1
B18C B16A ITR = 11.11:1 / CTR = 11.75:1

 

ITR pistons will drop the compression ratio in a B16A, they increase it in B18 motors. CTR pistons will increase it the C/R in your setup by only a few points. Your numbers are right in that table and it shows that the ITR pistons drop the compression since the stock compression is 10.4:1.

I am using Supertech springs for my build. Skunk2 is also a decent choice. I haven't had great experiences with other Omni stuff, so I would avoid them.

I'm not sure if the UKDM ones are different but I know the USDM and JDM variants redline at 8400 rpm.

I would say anything in the 11.5:1 or higher range would work well with those cams.

 

Ok thanks for the help, ill try and find some b16a or b16b pistons to use at very least.

How much can i skim the head to raise the comp? i have a cometic head gasket too (.027") to help raise the comp abit.

Ill have a look for those supertech springs as ive not seen them in the uk before.
Unfortunatley im on a slim budget with this build......im just rebuilding it with the cheapest/best parts i can get my hand on as im desperate for the car to be back on the road (daily driver) it was a turbo build gone wrong

 

what would the c/r be with b18c4 pistons?

 

I wouldn't deck the head. That is just me, though. I just find it wasteful to trash a head like that. It is also going to screw with your timing, so do it at your own risk.

Supertech are readily available in the states. I know there are plenty of h-t vendors selling them.

Should have stuck with the turbo setup instead of opening a whole new can of worms...

Same as with ITR pistons.