Hitech stage 2 cams on a PI swap

lordgufi · Oct 2, 2009

Ok so ive called bart and recieved the " your going to have problems unless you A notch pistons B cut valves or C get manley valves "

Ive taken the Cut valves approach. I'm just wanting to hear from any one else that had this done how much they had them cut. ive currently read that .040 is all i need but at the same time if it isn't i dont want to waste my time/money.

DropTopPony · Oct 2, 2009

Look up Tbuck07 threads on his Hitech cam install.

lordgufi · Oct 2, 2009

Talked to him already. did more research and had the shop cutting my valves call hitech.

.080 has to come off the face of the stock valves to make it work.

Willis_98GT · Oct 3, 2009

lordgufi said:
Talked to him already. did more research and had the shop cutting my valves call hitech.

.080 has to come off the face of the stock valves to make it work.

are you 100% positive that you have to cut on stock pi heads? with the npi bottom?

cant you just degree

lordgufi · Oct 3, 2009

i'm not cutting the heads. that would cause more problems. I'm cutting the intake valves .080 off the face ( the part that sticks into the cylinders )

i'm also going to be degreeing the cams so i wont have any issues anyway. if you degree the cams with the clearances stock you will have the cams so far off from center line you may as well rev the motor to 3k and quit

Willis_98GT · Oct 3, 2009

lordgufi said:
i'm not cutting the heads. that would cause more problems. I'm cutting the intake valves .080 off the face ( the part that sticks into the cylinders )

i'm also going to be degreeing the cams so i wont have any issues anyway. if you degree the cams with the clearances stock you will have the cams so far off from center line you may as well rev the motor to 3k and quit

but valve interferance will occur if the cams are degreed or not correct?

lordgufi · Oct 3, 2009

if i didn't get the valves cut yes if i want the cams degree'd properly. because of the duration on the stage 2's.

if i wanted i could install these cams and degree them to not hit but it would push the powerband way off to the left or right of the RPM range which is pointless

Lift isn't what causes these to hit the pistons its the duration. more specificly 5-10* after TDC.

Willis_98GT · Oct 3, 2009

lordgufi said:
if i didn't get the valves cut yes if i want the cams degree'd properly. because of the duration on the stage 2's.

if i wanted i could install these cams and degree them to not hit but it would push the powerband way off to the left or right of the RPM range which is pointless

Lift isn't what causes these to hit the pistons its the duration. more specificly 5-10* after TDC.

seems like i'll have to do some more homework on these then.

lordgufi · Oct 3, 2009

the problem is the fact that we dont have some of the same equipment that the PI block does.

I have not been able to confirm what that is just yet but. this info is Directly from Bart ( owner ) of Hitech motorsports.

Willis_98GT · Oct 3, 2009

lordgufi said:
the problem is the fact that we dont have some of the same equipment that the PI block does.

I have not been able to confirm what that is just yet but. this info is Directly from Bart ( owner ) of Hitech motorsports.

Piston dish is the difference

and valve design

lordgufi · Oct 3, 2009

ah thats right. thank you.

dish differences and the fact that the Pi valves have a lip on them for some Weird reason.

Willis_98GT · Oct 4, 2009

i guess im still noob to the valves and whatnot, i still dont understand why its going to have contact, i mean i know i can degree these cams not to "hit" but it was mentioned that i wont get the full power of the cams?

Tbuck07 · Oct 5, 2009

Thats right Will. I dont get it either..but for some reason Bart at Hitech said degreeing was a bad idea on these cams. Dont ask me..not sure why.

I would get as much clearance as you can, and make sure you do the cam swap correctly. Spending 80 bucks to have the valves machined correctly is so worth it.

I didnt do that, and machined them myself. I regret that to this day. My car runs fine, has almost 1600 miles on it, but has noisy valvetrain. So it makes me cringe..wish I had a smooth sounding engine.

Willis_98GT · Oct 5, 2009

Glad to hear its running good bro. I haven't heard from you

lordgufi · Oct 5, 2009

when you degree a cam away from the spot that perfectly goes with it for combustion, you change when the valves open in correlation to where the piston is. so you could have air coming in earlier or later than designed. which will move your power band up or down.

if you retard the cams back behind where they are designed to be, you will lose power in the areas that it was supposed to be there.

DropTopPony · Oct 5, 2009

Tbuck07 said:
Thats right Will. I dont get it either..but for some reason Bart at Hitech said degreeing was a bad idea on these cams. Dont ask me..not sure why.

I would get as much clearance as you can, and make sure you do the cam swap correctly. Spending 80 bucks to have the valves machined correctly is so worth it.

I didnt do that, and machined them myself. I regret that to this day. My car runs fine, has almost 1600 miles on it, but has noisy valvetrain. So it makes me cringe..wish I had a smooth sounding engine.

I was thinking of you last night

not in that way... A friend was explaining an issue he had with his cams and it was just like yours. Made the car sound like a diesel etc in the valve trane. Turns out the base circles on the cams themselves were off and that caused everything to be off. I wonder if your cams were just made wrong?