cam and spring swap

[johnmc]

this is to the heavy motor guys. I am planing on changing the cam in my motor I also will be changing the springs. in there a intake spring and exhaust spring. and do i need the exhaust rotators ? this is not going to be a street motor.
I see after some head jobs they shim the spring and why?

 

[dirtroadoutlaw]

The shims are to get the spring to install at the correct compressed height as indicated by the manufacturer suggestions. You really need the proper tools for head setup. Don't second guess anything unless you're one of those that likes broken and/or dropped valves.

The rotator probably isn't going to fit the spring anymore anyhow. They only reduce the likelihood of a bent valve by a tiny bit. Deleting them requires some thick spring shims. I think I'll just buy heads already assembled my next go around. I got effed over a while back dealing with this & WP heads would have been WAY cheaper in the long run.

 

[johnmc]

i hear you I have done my own valve jobs before and I had axcess to the mechine shop. but I was wouldering if i could just do a spring swap with a good running set of heads. I have a set of 2.02 heads cast cammel hump heads wanted to run a large cam . with out valve float at 6,800 rpm

 

[Manbearpig]

Eek don't run Comp 918s

 

[johnmc]

the class i want to run cant run alum.heads

 

[crazy4offroad]

You need to look into Vortec heads. Bolt on 40 horsepower, outflow 2.02s in stock form. Cast iron so legal to run in stock class, at least around here they are. You're more limited on cam lift though, 0.465" or so max I believe.

 

[dirtroadoutlaw]

You need to look into Vortec heads. Bolt on 40 horsepower, outflow 2.02s in stock form. Cast iron so legal to run in stock class, at least around here they are. You're more limited on cam lift though, 0.465" or so max I believe.

Yeah you can even massage on those a little & get a little more lift & flow

 

[crazy4offroad]

About the most I would do is clean up the runners. Holding the throttle at 5k+ rpms in a bog going nowhere fast could easily overheat Vortec heads if they're ported too much.

 

[johnmc]

thanks guys I guess i will sell the camel humper heads and look for a set of vortec . Do you have a year of head truck or car that was the best? I think i was reading about vortec head flowing good.

 

[crazy4offroad]

Here's my sticky on the subject at the top of the page in this section lol...
http://www.gmsquarebody.com/forum/showthread.php?t=1594

 

[johnmc]

Here's my sticky on the subject at the top of the page in this section lol...
http://www.gmsquarebody.com/forum/showthread.php?t=1594

Great link looks like those heads are a little better for the budget. think i would add bee hive springs and roller rockers. with cam lift not over .500 I was thinking of a holly 750 would also like to add a shot of nos to it . its just a mud truck . I will need a intake any sugestions ?

 

[crazy4offroad]

I was gonna go with an Edelbrock Performer RPM air gap made for Vortec heads. The rpm range starts at 1500 instead of idle for the plain Performer but with an auto trans 1500 would be fine. The cool thing about the Vortecs is they make power without a lot of lift. I had spent a lot of time looking at cams trying to make my mind up what would be best and I'm liking the Crower Beast ( http://www.jegs.com/i/Crower/258/00904/10002/-1?parentProductId=962950 ). If your rules state you have to pull a minimum amount of vacuum (17" of vac @ 1,000 rpms here) then you have a mess to wade through trying to figure out where that skating edge is. Too much overlap and you find yourself in the next class up. NOS isn't legal for street class here but I guess you could take out the bottle for street class runs if you wanted. IIRC you got caught up in a tire size rule that threw you into another class and if that's the case you should build for the class limits of that tire size. I wanted to build mine for street class since there's no tire size limit (bigger tires dont really make you faster) but still have some driveability to run the hills when not racing.