Im slowly piecing my b20 vtec turbo together.

block is assembled, forged goodies etc etc etc...

I have a GSR head that I built for a customer years ago I just bought back- at that time I installed ITR springs in it for him. He bought them used. No idea on milage. I know this guy, and he maybe hit vtec twice a week in the car.

The first thing I will do once I disassemble is check spring pressures to make sure they are ok at installed height, and fully open.

It will be on stock GSR or B16 cams.
I will not be spinning the engine over 8500- so i don't feel TI retainers would be a benefit here, nor will I be forcing more than 14lbs into this engine. (added force on the springs, not hp)

My question is, what is the standard limit ITR springs will work to?

I think as long as the pressures check out they would be more than enough on this build. Anyone agree or disagree? and why?

I don't think this build will ever see a big turbo, much cfm or psi... so i don't think i need to over build it in anticipation for that.

I will be replacing the valves.

 

Here is food for thought.....

How much additional spring pressure is needed to close a valve at 1lb vs 10lbs? (Just to give easy round numbers)

Think about WHEN a valve closes.

 

A stock cam needs no more than stock springs if you're keeping a similar redline. Springs are for aftermarket cams, 10k redlines, and misshifts. If anything, stiffer springs will make you loose some power, since it takes more power to open the valves. It may be marginal, but it's there.

FYI the engine builders I know don't waste time with Ti retainers. They stick to steel since it doesn't wear out.

 

 

use the k20a2 retainers if you have the engine apart still. you can get them for like 40 bucks for 16 right from honda and appear to be used with great success.

you do have to remember as was previously said that you are also closing the valve against the boost pressure. i would just use those itr springs with the k20 retainers and gsr cams. i know the itr springs are good for just about up to 8700, and have seen them float valves at 9000. when i had my car with itr springs, gsr cams and ti retainers dyno tuned we set the limiter at 8700 and never had 1 issue. im still using those springs today in another build, 6 years later

 

I know the psi adds pressure to the valve- just looking for feedback on whether or not ITR springs will be enough for this mild setup.

 

I use tool steel retainers, while they last much longer than titanium pieces, eventually they too will wear out. I also use super tech springs, both of which I can you a price the almost equals they fell off the truck lol

But springs are needed under the following situations

1. You put aftermarket cams in
2. You plan on revving the motor high than stock springs can take
3. You run such high boost pressures that it causes valve closing/sealing issues because the extra boost pushes against the valve head and effectively lowers the valvespring rate.

 

I doubt there is anyone who has a "chart" which indicates how much CFM turbo / cam lift = seat pressure spring required.


IMHO (for Bvtec motor), if your going for anything over 400whp or reving past 8200rpms, I would change out to stiffer valvesprings. It's cheap insurance that you won't bend a valve if you over rev during mis-shift, or drop a valve take out the entire engine.

I have always recommended to countless others to get Rocket Motorsport valvesprings.
They are only $155-160ish shipped. They are designed to work with stock seats & retainers. They are 86lbs seat pressure @ 0.832". We've used them on bvtec with pro2 consistanly to +9000 with zero issues & on turbo setups with +600whp no issues.

ITR will be fine. I hope your not paying more than $70-80 for them. Also make sure you know how to identify them.


I personally use the RSX type S "flat" retainers which work with Bvtec valve & keepers.

It's about bang for buck & piece of mind.
I'm sure you could use stock valvesprings to 500whp but not worth risking your engine on $155 insurance.


B16 & RMS (left)
IIRC stock gsr/b16 are like 40lbs & ITR are 50-55lbs seat pressure.

 

Stock Type R or GS-R is fine for mild builds. only when you start to go for specific camshafts do the requirements change. 8400-8500rpms is about the limit. But for mild builds like that, you won't see power past 7800rpms on average anyway, so don't overthink this.

 

thank you gentlemen.

This will be a conservative build to say the least.
I ran TI retainers on a N/A build that was a 10k rpms h22. But i was going for high rpm useable power, it was a hilly road running car. and a blast to drive. But i know i don't need TI for this junk im doing now. LOL


Im not paying a dime for the "itr" springs. They came with a lvtec i bought off an old customer in need of some cash- i had built the motor years ago, he wrecked the car yanked the drivetrain and it sat.... and sat... and sat.... i know valve springs sitting in the compressed position for a while can be harmful to them too, so I will check the spring rates.


"shodan" - you don't think i will see power above 7800?
thats a bold statement, I know you have experience in this field, but you don't even know my setup, all i posted is b20- and gsr head with stock cams.
I could have a huge turbo that wont make any power till 5500, for all anyone knows. LOL
Im just f-n with you, ur right the cams most likely wont allow high rpm power.

 

NICEEEE free itr springs.
Q: when you say "compressed" you simply mean they are installed on the head?
if so, then you have nothing to worry about.

Form what i've seen on turbo bvtec setups using gsr cams, 7400-7600rpms is when the powerband tends to flat-line. i have a few saved on my computer, doesn't matter if i look for 300-500whp setups.

 

by compressed, i mean at some to full lift. I didn't pay attention to which ones they were when i pulled it apart... so i may end up tossing them out and starting with something new. we will see. but ill have all the springs checked for installed height pressure and find what they should be at full lift too.

 

You are right, valve springs can have some "memory" and storage on an assembled engine is never ideal. Its best to turn the engine on a regular basis to keep the springs from staying in one place too long. We all know the oem springs are pretty damn reliable, but I personally think its foolish to run them for forced induction. Having to worry about a certain rpm not to exceed or random guesses on where the acceptable level of valvetrain stability is.

I did a type r motor with a new oem complete head, and piston and rod bottom end. Made 400 wheel at 14-15lbs on a 30r. Great motor. at 10,000 miles the owners friend upped the rev limit to 9k (I did not know) and we were at the drag strip. At the burnout box I heard the engine shutoff and knew something bad happened. The intake valve broke off, and this could have easily been avoided with an inexpensive and easy to swap set of springs. I have also seen several people miss a shift and bend or break the valves all the hell. Not worth it, even if you are a cheapskate.

 

that was the yellow hatch right? i remember seeing it at the valley before. it sucks that happened to you guys but i have to say thats one of the reasons i learned that you dont want to go to 9000 on stock itr valvetrain.

 

Yep, right on..it was the yellow hatch.