b18c-93

i have a b16a1 in my 93 integra i was wondering if i could put the ctr cams in with my stock springs with stock computer

SpeedracerS4

yes it'll work with your stock valvetrain, just dont rev it pass 8k

hybrider

you`ll be fine, just done raise that redline, cuz revvin past 8k wont be that fun in the end

rice_classic

Why? is it because of the valve springs?? if you did an ITR valve train on a b16a with the ctr cams could you rev past 8k?

hybrider

well if you do plan to raise the redline itr outters would be just what ya need and maybe some stiffer inners, and you should be more than ok to rev past 8k so your ITR cams can peak out.

JD_B18CDX

Another thing to consider is compression ratio.
If ctr engine has a much higher comp ratio than your integra, bigger flowing cams (like the ctr) MIGHT not work as expected on your engine.
Bigger cams will have more valve overlap and will loose some cyl presure on an engine not designed to work with it. Higher comp engines compensate for this by having high comp ratio.

Your engine will run.... just MIGHT (not saying it wont work) not work as expected.

Just some thought.

rice_classic

Ok.. so that spawns another question. Since the CTR intake cam is slightly more aggressive than the ITR intake and it is designed for the CTR engine would it be better to have the ITR intake and exhaust cams or the CTR Intake and the ITR exhaust with all ITR springs?? Or should I leave the original b16a intake springs in because I've heard they are a bit stiffer than the ITR intake springs?? If someone could clear the air on this one I would be most grateful

SpeedracerS4

whoever told you that its on crack! type r have stiffer valve springs compare to b16

hybrider

Speedracer,

B16CRX

The only difference is the intake cam. The exhaust cams are identical. And, I believe it is only a 3 degree difference on the intake cams. So there would not be that much of a difference between the two.

ITR springs are deffinately stiffer than the B16A. If you want to get the cams and rev high, I would also get the springs and retainers with them. Of course thats just my opinion of how I would want to do it. Do it all at once the first time so you don't have to worry about it.

JD_B18CDX

I think you are missing the point. I'll try to clarify.

Valve overlap is when both intake and exhaust valves are open at the same time. You want this overlap because at higher revs, the inertia of the intake and exhaust gasses helps the engine breathe. The intake pulse pushing the air in the intake manifold toward the cyls and the exhaust pulse pulling air out of the cyl.
This will only happen when if the gasses are moving fast enough like when the engine is screaming at 5000-8000 rpms.

On a simple engine........(no vtec, no variable valve timing etc)
Normally, you want a certain amount of presure in the cylinders to get good torques and HP. Less aggressive cams will create good cyl pres with an engine with a moderate compression ratio ( say 9.8:1) because they do not have much valve overlap.
At low rpms, extended time the intake valve is open actually make you loose cyl presure because piston is already on its way to compression stroke and intake valve is still open. Well.... this pushes the intake gases out the cylinders again. At high rpms, the gases are moving fast enough that it gives then engine a "longer" intake stroke (sucking air and fuel) by letting the inertia of the intake gasses "ram" itself inside the cylinders.

Now for your example.......
If you try to put an aggressive cam (say a ctr or itr) on an engine not built for it, the valve overlap on the cams would make ur engine idle roughly and loose drivability at low rpms because

1. Engine does not pull enough vacum to atomize the air fuel mixture (remember intake stroke is being cancelled by the upward movement of the piston during compression stroke because intake valve still open)
2. Not enough cyl presure during power stroke because not much air fuel was burned therefore making less power and torque.


Bottom line is you cant just slap on an aggressive cam to an engine that does not have a comp ratio to match it. You loose overall drivability and there is a chance you might actually loose HPs at higher rpms.

I hope this info helps.
It would suck to get all hyped about a new toy only to find out its not working as expected.

>would it be better to have the ITR intake and exhaust cams or the CTR Intake >and the ITR exhaust with all ITR springs??


[Modified by johnd, 8:36 AM 2/19/2002]

HKxBlur

this is so very true as a rule and you've got the explanation down pat, however in this case it's not an issue.. It'll work absolutely fine and as expected with the lower compression motor.. Depending on year/model there's a 0.6-0.4:1 ratio difference between the A1 and the B, but there's been plenty of guys quite happy with the setup.. I recommend NOT using the stock springs, although they will work fine, but I personally don't like to half-*** stuff, that's all.. The stock springs will work under 8k just fine, but i still recommend cheap itr springs..


[Modified by HKxBlur, 1:38 PM 2/19/2002]

rice_classic

JohnD and HKxBlur: thank you so much for the explanations!! When people respond in such a manner I learn a great deal and it makes me very glad I asked the question.. I am going to do a b16a1 with ITR Springs and retainers and a CTR/ITR (whatever's cheaper)intake cam and ITR exhaust cam..

Without your response I NEVER would have taken CR into consideration when upgrading cams. Maybe I can find someone with an ITR intake manifold with springs and cams as a package!!!! Either way.. thank you much!


[Modified by rice_classic, 1:21 AM 2/20/2002]

Chris_

Good thread. I also have a b16 and am looking at similar setups. Since CR may be an issue, would it also be beneficial to throw some CTR pistons into the b16 block (to bump up the CR)? Also, how high could i rev with the ITR valvesprings (8400 rpms)? What aftermarket valvesprings would allow for a higher redline (but still be safe)?

nfn15037

Good points, but ITR or CTR cams are really fairly mild. The small lobe isnt big enough to worry about idle problems(kinda the whole reason we have VTEC), so no worries about that. Also, on a motor that has 10:1 compression, these cams will be fine, again, they are really pretty mild cams. The USDM ITR only has 10.6:1. Just some food for thought.

HyperREV

i've heard that as well actually.. dont R's have lighter valves as well, requiring a softer spring?

nfn15037

That is wrong. The valves are a couple grams lighter, this coupled with the stiffer springs allow the ITR to rev to 8400 in the US and the JDM ones revlimiter isnt till close to 9k. The ITR valvesprings also have an ovel cross section to prevent binding. The Realtime Type Rs rev to 9200 on completely stock ITR valvetrsin, try that with B16 valvesprings.

GokuSSJ4

get ctr intake and itr exhaust (every bit counts for N/A)
use itr intake outters (all around) and portflow inners ) if you plan to rev high !

hybrider

wow some great information, anyone want to archive this one?

crxfactor1991

how high do you plan on revving with your stock teg computer?

the computer wont let you see the sweet spot on the ctr cams, so in essence, your valvesprings will be fine

nfn15037

Portflow inners with ITR outers can rev to 9200, and they are not super stiff like toda or JUNs so they wont have to be replaced as often