GSR head on B20B JDM high comp motor.
 

I have been looking around and find just as many post saying you cant run a gsr head on a B20B high comp as I find ones that say you can.

Is any one on here able to tell me for sure if they have ran a B18C1 head on a B20Z/B20B high comp block?

The bottom will be all stock, I want to run the GSR head for the quench pads and higher compression. I was told that the only way possible to run it on a b20z/b20b high comp block is to cut valve reliefs into the pistons as the valves will hit the piston on Vtec engagement.

I'm a little iffy about cutting on a piston since I can not do it in a precise fashion and would be eye balling it.

I have heard lots of people say they have ran a GSR head with no problems but as I have come to learn alot of people get confused when they talk about B20's

Re: GSR head on B20B JDM high comp motor.
 

i think you should be fine as long as your still running the stock cams.

Re: GSR head on B20B JDM high comp motor.
 

Anyone else?

Re: GSR head on B20B JDM high comp motor.
 

i run gsr cams with a b16 head on a stock b20b. has 20k miles no problems. the way i understand it is that clearance issues are more common with the z block not the b. you could always clay bar the motor, it must be locked in vtec for the readings to mean anything. there are some very helpful b20 vtec articles, just takes some time to find and get through them.

Re: GSR head on B20B JDM high comp motor.
 

I had a B20b with a gsr head and the valves hit the pistons with a 3 layer headgasket. B16 heads dont have that problem even with ctr cams

Re: GSR head on B20B JDM high comp motor.
 

my buddy ran into clearance issues on a b20z with b16 head(stock cams).you could also get a set of rs machine pistons with the correct valve reliefs. i have also heard the work and doesn't work stories. measure the running clearance and choose your option that you think will work best for you.

Re: GSR head on B20B JDM high comp motor.
 

Could it be most problems come from cam degree? Because so many people have such difference experience? For every person that says their b16/gsr head works I hear it doesn't work.
I also read if you degree the cams the gsr works just fine..

Re: GSR head on B20B JDM high comp motor.
 

that should be considered, but you will need to use degree wheels to find out where to set everything. you will also still need to measure your running clearance. you can guess and check but measuring is the correct way to build a motor. i run stock cam gears on a 100% stock b20b from h motors, b16 head, and gsr cams. its been one of my favorite DD engines. it currently has 20k on it 2 years later. mine was one of the lucky ones, no huge set backs, just measured valve to piston with clay. i used 10mm hardened steel rod(cut to length of the two vtec pins plus .0080in in each assembly)from a pump shop to hold the rockers in vtec. it was on the tight side but i only rev to 7,600. hope you go through with your build, i believe they are great engines for the price. under 1k invested in mine.

Re: GSR head on B20B JDM high comp motor.
 

Would decreeing the cams effect the over all engine Performance though in a negative way?

Re: GSR head on B20B JDM high comp motor.
 

retarding or decreasing timing moves the power band higher into the revs and advancing or increasing will mover the power band lower into the revs.

Re: GSR head on B20B JDM high comp motor.
 

Thats what I was thinking, thanks for the post.
Well,
I guess I'm pretty much stuck at clay'ing the motor and head combo and seeing what clearence I have.

Am I wrong in thinking that Advancing timing at the cam will increase chances of P2V interference.

Thanks

Re: GSR head on B20B JDM high comp motor.
 

retard the timing for more clearance. you can also measure clearance with a dial gauge. use soft springs from a hardware store and use the dial gauge to measure how far you can push the valve open with your hand(motor must be at tdc on the cylinder being tested). with the tested cylinder at tdc and the cam holding the intake valve all the way open, use your hand and see if you can push the valve open any farther. this extra distance is your clearance.but claying will allow you to see if the valves are hitting out side of the b20's valve reliefs on the piston. if there is no clearance at all, you need to come up with a plan(new pistons, cutting the pistons, or if retarding timing will give you enough room). to simulate retarded timing, move the crank a degree at a time past tdc and remeasure valve clearance. make sure to turn the crank in the same direction as it would when running to test for retarded timing clearance.

Re: GSR head on B20B JDM high comp motor.
 

Thank you for all the help. Seems I'm on the same page with you. The only thin left is cutting valve reliefs. A friend of mine said I should just use a dremel and open the reliefs up for the valves. I just feel this could lead to disaster, have you had experience doing this and did it work?
I was trying to avoid pulling the engine apart as i didn't want to have to do machining.
I'm wanting the gsr head as it seems to complement the b20 bottom end better in my mind.

Re: GSR head on B20B JDM high comp motor.
 

I'm about to be doing the same on my Integra. Was wondering how your engine came out and what kind of power is it putting out?