I have a gsr block with no head so i got my hands on a si head complete for free.. now i heard different thing about this but i really wanna know will i see better gains with the si head? i heard with the si head you will have better flow and something else.. but i was thinking too i also have some gsr cams and i was wondering if i put the gsr cam in on the si head will it gain more.. you know how everybody take the gsr engine and gsr head and adds itr cam or ctr cams.. so i was thinking if they got gains from the itr and ctr cams then i should see gains from the gsr cams rite.. someone hit me up please.. thanks

 

think u lose compression w a b16 head...so u'd want ITR pistons and stuff...it does flow better....but i'm not sure what would happen to performance...i too would like to know

 

anybody ???

 

ITR/CTR cams have a higher duration and lift than SI or GS-R cams.

To be exact, the stock GS-R cam or any B-series Cams (except ITR/CTR) have 230 degrees of intake duration with 10.6mm of lift. The exhaust cams are 227 degrees of duration and 9,4mm lift. These cams all have about 17 degrees of overlap.


Now the 2000-2001 ITR cams have 240 degrees of intake duration with 11.5mm of lift while the exhaust sports 235 degrees of duration and 10.5mm of lift. The ITR cams also have 25 degree overlap. CTR's have 3 degrees more than the ITR's intake cam. The exhaust cams are the same.

As you can see, the Type-R cams are MUCH better and aggresive than the Si or GS-R cams. That's why you will see gains. I'm not sure about swapping in GS-R cams with an Si head... You'll maybe gain lik 4-5hp? Not sure.

 

With all the online resources I've read, you lose compression, but the gains in flow outweighs the compression loss. Leave the SI cams in there, they're not noticeably different from the GS-R cams.

 

ok what about the hp with the si head will i gain or drop i know it has better flow... thanks for the info really but can you just put it in english... lol j/k

 

but i have the gsr cam just laying here. if i put them in will i see like 4 hp if any?? i dont care as long as i dont lose hp.. anybody else

 

Plain simple english without Car terms:


The b16 head flows a bit better. GS-R and Si cams are about the same. Therefore, you won't see a noticeable gain. Maybe up on top.

GS-R/Si cams and ITR/CTR cams have a big difference, hence if you get ITR cams, you will see good gains.

 

I also heard that if you drop GS-R cams in a B16a, you can feel the difference in vtec.

 

why does the b16 head flow better then the gsr head?

 

The combustion chambers are a tad larger which allows for a better design on the ports. But, since the chambers are larger that also lowers the compression ratio. A thinner headgasket with the B16 head will gain back the coupla tenths of a point of CR compared to the GSR.

Regardless, the differences are minimal until you get into really high-output applications.