Cylinder head Q Options

[village idiot]

Are they side specific? What I mean is, I see in the rocker boxes there's a number cast in the middle. One has a "1" and the other has a "2". Reason I ask is I just had new guides installed as well as the seats/valves resurfaced as well as the head sealing surface.

Now after installing the heads and trying to set the valves, I've had to back the adjusters waaay off just to get the rocker shaft/rockers back on. This doesn't seem normal to me, and I double checked to make sure the pushrods are seated correctly in the lifters. Am I missing something here?

Help! I want to put this car back together and enjoy it!

[ejm]

Heads can be fitted to either side. If you need the threaded hole for the CHT make sure it's on the correct side.

Installing the rockers on cyl's that have open valves will cause the problem you describe. Back the adjuster off a couple of turns and put the engine at TDC for the cyl your installing the rockers on. The you can seat the rocker assy and torque the nuts without putting stess on the studs.

You should be checking CR and rocker geometry esp. since the heads have been cut.

[village idiot]

Thanks for your reply Ed!

How would I correct the geometry if it's off?

I've put the motor to TDC for the cylinder that I was installing the rockers on but I had to back the adjuster off all the way.

I'll check again, hopefully I was just losing my mind yesterday.

Thanks again

[brer]

did you check your deck height and compression?

if its high, you may be able to compensate using shims under the barrels.
This can help correct changes in geometry due to flycutting.


Were the heads flycut? how much?
Were they valve jobbed? did they install new seats?

both of these operations can effect the height of your valve stem, and the amount of adjustment you have left on your rocker adjuster.


I wouldn't try to set the geometry until you know your compression is where you want it.

Then its a function of cutting pushrods and shimming rockers, but not as simple as that. (IMG:style_emoticons/default/biggrin.gif)

[village idiot]

Heads were just given a cleanup cut according to the machinist so I don't really think they took much off.

Seats were not replaced, but were ground and the old valves were good so those were resurfaced as well.

Here's a pic. One of the things that concerned me when picking them up was the groove they put just outside of the valve. Any ideas why they did that?

Just for the record, I'll never go back to those clowns for anything.
(IMG:http://i183.photobucket.com/albums/x198/pencilnek/914034.jpg)

[McMark]

There are a lot of checks you can do right now to optimize your engine. The closer you can get to having each cylinder having identical stats, the better/smoother it will run.

CCing the heads is a good idea, measuring deck height is a good idea, etc.

Or you can put it together as is and it will probably run fine. It just depends on how long you want spend building it and what you want to get out of this motor.

[village idiot]

Right now i just want to get it back on the road. There's a '76 911S for sale near me for 1k and I figure I can use the 2.7 later on in my teener as well as the brakes.