New cylinder head question: Max Lift vs Actual Lift?

[Zero Signal]

I am about to order my cam and rockers from Summit and noticed that the max lift listed for the Brodix ST5.0R head is .575". The total lift with 1.6 rockers on the Comp XE274HR cam is .555/.565. Now the allowable coil bind clearance is (correct me if I'm remembering wrong) about .060". So the question is: is the .575" listed for the heads an absolute maximum or does it take into account the allowable coil bind clearance?


Also, does anyone think it would be worth shelling out the extra $80 for Comp Pro-Magnum Rockers over the plain old Crane Energizers or Harland Sharps?

 

[blksn955.o]

I would call a brodix tech line and double check with them to see what they speck the springs out to.

I have seen a few motors use HS rockers and have liked every set, all make a good rocker.

 

[mo_dingo]

You are getting a really big cam man!! Sweetness.

But you are pretty damn close to the max line, regardless of coil bind. Maybe you should think about better springs. They will probably be less prone to valve float in the future. Don't you think???

 

[Nagash01WS6]

NORMALLY, max lift includes coil bind.

Call and see what kind of springs those heads use, you may be better off going with a bare head and buying everything seperately.

 

[BlackVert]

don't fear the cam! what intake are you going with?

i'm also pretty sure the max lits takes the coil bind clearance into account.

i ended up with pro magnum rockers. stock height valve covers fit over them, at least they do on mine. but the valve cover risers on the afr's may be higher than the brodix risers.

you might be able to score some used pro-magnums over on corral.

 

[Killercanary]

NORMALLY, max lift includes coil bind.

Call and see what kind of springs those heads use, you may be better off going with a bare head and buying everything seperately.

I agree.

 

[Zero Signal]

Thanks for the input. Yeah I'm going to call Brodix and find out. My assumption was that they do include the coil bind, but I've long since learned my lessons about making assumptions like that.

The springs that come with the Brodix heads are 125lb/325lb seat/open which I think should be enough for alittle over 6000rpm or so. I will look into what my builder thinks of doing a bare head build. The cheapest valves he uses are still pretty expensive so I have a feeling it will run up the cost quite a bit. Not to mention any valve job, valve guides, bowl work etc. etc. that bare heads may require.

For the intake, I'm going to have to run with the tubular GT40 untill I can afford a new one. I will probably sell it for what I payed and move to a Typhoon, RPM2, TFS R or TFS R Box type short runner intake. Untill then it will still definitely be a torque monster.