First dyno run...yesss....could it be my cam....oh noes....

[SeeMy355]

I'm interested to know what the machine shop did to your heads to run with that cam. The cam lifts are .488 and .510. The valve guide seal will be pinched between the retainer and guide if valve lift exceeds 0.470 inches and it's not suggested to run anything with more than a .460 lift. Also what valve springs are you running?

This is my main dilemma...

I had my engine spec'd before I started this project, but when the machine shop shaved my double hump heads, he gave me these vortec heads that he machined. I'm not sure of the springs, I just know that he has a relationship with my uncle who assembled my engine and my uncle told him what kind of cam I was running...

I knew that issue with the heads would come back to screw me...

 

[pontiacgp]

if you check ebay you should find new valve springs from ZZ4 engine vortec heads. Those engines are being bought and upgraded to use at the strip. As far as the heads they rework the aluminum head and replace the valve springs It's a cheap build for those guys.

 

[SeeMy355]

if you check ebay you should find new valve springs from ZZ4 engine vortec heads. Those engines are being bought and upgraded to use at the strip. As far as the heads they rework the aluminum head and replace the valve springs It's a cheap build for those guys.

Off the top of your head, do you know if those heads will be compatible with my cam?

 

[JESSE]

dyno

i also think your carb is to small... step up to a 750 mechical secondary.

i have stock vortech's on my engine and a small cam...vortech's are great low budget heads, but they have limits.....

their best flow is between 400 and 500 lift..thats the key to making horse power!!!

i use a super victor single plane intake and 750 carb and the car drives great on the street and strip...jesse

 

[pontiacgp]

if you check ebay you should find new valve springs from ZZ4 engine vortec heads. Those engines are being bought and upgraded to use at the strip. As far as the heads they rework the aluminum head and replace the valve springs It's a cheap build for those guys.

Off the top of your head, do you know if those heads will be compatible with my cam?

the .488 intake is borderline but the exhaust lift is .510 which is over the limits unless the head has been modified so I would say no. But then I don't know what the machinist did to the heads to say the heads are compatible with the cam...

 

[JESSE]

dyno

he most likley cut down the the guides so you can use old style springs... and a higher lift cam
anything over 500 lift is a waste....jesse

 

[SeeMy355]

Still gathering advice...

So would you guys recommend I swap the cam (I know it would be cheaper) or the heads?

 

[patmckinneyracing]

You also may have too much torque converter for your set up. 3000 is a little high for a street car and your valve train could be the other cause too. That's why I went with a 442 lift cam instead of going larger because once you go with say the cam you have, your bound to run into problems. I would go get a second opinion from another mechanic cause it sounds like your running into too many problems with your current mechanic.

 

[JESSE]

dyno

theres nothing wrong with your heads as long as the machinist didn't mess with the valves...

i also run a b&m 3000 stall ...if you goal is to have a serious street car imo it's a must....jesse

 

[pontiacgp]

another thing it is a good idea to use the recommended valve springs for a cam