do people usually upgrade their pistons when they change their cams? What are benefits of upgrading pistons? And whats a compression that the engine can handle with 91 octane?

 

Not really, you really wanna upgrade pistons if say you wanna get a lower CR for boost or if u wanna build a monster and upgrade to say CTR pistons for higher CR! Up to 12:1 is bout highest you wanna go on 91 octane! IMO

 

When putting in bigger cams you'll get more gains with higher compression. You see when that big cam opens up your compression gets bled out so to compensate you add higher compression pistons.

 

I was gonna ask that, but damn you answered my question before i even asked!

 

so it would be worth it to upgrade my pistons at the same time as upgrading my cams? Labor charges would be too much if i did them separately. Or would it be the same?

 

Uh, it would be a lot more since they have to take out the block and basically do a rebuild job on the bottom end! Where as you go buy some cams and have them installed for say $80 or better yet install them yourself for free. Its only worth putting in some better pistons if you are gonna rebuild the block anyway other than that i say keep yours.

 

ah i see. thanks alot for clearing everything up! So you think i can still make good power with jun cams and valve springs without getting new pistons?

 

You will make some very nice gains with Jun, if you go with stage 3's might i suggest sum Titanium Retainers also!

 

are the June stage 3 cams like the Toda spec B in the sense that they work with ITR valve springs? Does it cost alot to install valve springs?

 

It will cost no more to install valve springs if you're having cams installed anyway.

 

with either of these you wanna upgrade the valve springs & retainers

 

12:1 cr is okay with 91 octane? Anyone running this since the lowered the octane in Ca? A lot of people I know with Cr's of 11.5 using spoon/mugen headgasket swapped it out for an Oe one. Maybe we're just wusses.

 

are the June stage 3 cams like the Toda spec B in the sense that they work with ITR valve springs? Does it cost alot to install valve springs?

To get the valvesprings installed you have to remove the head which is usually around $100 then to get the valve springs in I think its about $50 or 60.

 

Uh, it would be a lot more since they have to take out the block and basically do a rebuild job on the bottom end! Where as you go buy some cams and have them installed for say $80 or better yet install them yourself for free. Its only worth putting in some better pistons if you are gonna rebuild the block anyway other than that i say keep yours.


I heard that you can just cahnge the pistoins from under the block without removing it by taking the oil pan off. Anyone else heard this?

 

The pistons can be changed by taking the head off (easy when doing a cam install) and going from under the car, thru the oil pan.. Taking the block out is only necessary when boring out the cylinder walls or decking the block, etc etc, where machine work is necessary on the block itself.. If u'r gonna be down for a 3-4 weeks, then might as well take out the block to clean up the engine compartment, or maybe just to do it.. Good luck!


[Modified by HKxBlur, 1:05 AM 10/23/2001]

 

That information is FALSE. The ONLY reason Toda EVER recommended ITR valvesprings is 1) they are good for about 8400 rpms and 2) they hadn't started making their own yet.

If you're going to go over 8400 rpms and use Type R valves springs, you're running the risk of blowing your valvetrain b/c the springs will bind. Toda valvesprings are SPECIFICALLY designed for their cams. Don't believe me? http://www.importreview.com/reviews/valvesprings.html Compare the spring rates between the ITR and the Toda. Can you say, "bind?"

 

YOU MUST use JUN Valve springs with there Cams. theres are the only ones designed to not bind. You can use any titanium retainer you want though. JUN cams work best with 11.5:1 compression ratio and up.