tru-blue 442

I am breaking down some old G's I have for another build, and came across this.
Talk about having hell to compress these bad boys. Has anyone ever seen the inside spring installed with the double spring valve spring. It also has 4 washers,
3 I believe are shims. It has been a long time since I have pulled any down and
my memory is a little fuzzy to say the least. Seems the large flat washer and
double spring is what I remember when pulling these type heads down.
Here are a few pics.

TripDeuces

That's aftermarket stuff. Looks like bronze valve guides too.

brownbomber77

YA..... I've never seen shims on factory heads and guide inserts like that. You sure those are original?

tru-blue 442

Not original, I can tell the have been off before. There is what looks
like Felpro head gasket material left on them. So is there supposed to
be any washers, or do the springs just set against the head?

Oldsmaniac

I have a similar setup on a set of G heads without damper spring, not factory and the heads originally had valve rotators so shims are needed for install height and pressure.

joe_padavano

These heads came from the factory with the heavy valve rotators, so the thick washer and shims are needed to get the correct installed spring height when you delete the rotators with aftermarket double springs like these.

tru-blue 442

So the heavy rotators are the factory double spring correct?
Pretty sure this head is destined for the scrap pile, damn.

joe_padavano

The rotators were used with the factory single spring and inner damper, not double springs.

tru-blue 442

So these are the correct rotator springs and should be used
with the large flat washer? Also, not one valve umbrella in the mix.
Thanks for the responses Joe.

joe_padavano

Sorry, I guess I'm not being clear. The factory springs used with the rotators would have been the outer coil spring and the flat damper ONLY. The springs in your photo show an outer coil, inner coil, and damper. Those appear to be aftermarket springs. The added thickness of the inner coil precludes the use of the rotator, thus the shims and washers are needed to make up the thickness when the conventional thinner retainers are used. Also, since the rotators are much heavier than retainers, they are often deleted to raise allowable RPM.

joe_padavano

Ah, your photo didn't come through originally. Yes, these appear to be original springs.

tru-blue 442

Thank you sir, got it. Do you think the added spring pressure is
what attributed to the cracked part of the head?

joe_padavano

Where's the crack? My inclination is that they did not contribute, depending on where the crack is located, but I'll defer to the more hard-core racers here.

Octania

I am not seeing any reason to scrap these heads yet.

Though, I head that the price of steel is so high that when Iron Man heard about it, he almost scrapped his pants.

:-)

tru-blue 442

Post # 7. Can you see it left of the little screwdriver? It is almost
all the way around. I could knock the piece off with a hammer tap.

tru-blue 442

That's pretty funny Chris.

Oldsmaniac

I am pretty sure that broken part can be repaired, there were no valve stem seals because there was no room for them with the dual springs...

tru-blue 442

^^^ Thanks, that does explain the no umbrellas on the stems.

joe_padavano

Besides, what's a little oil smoke on a race motor?

Oldsmaniac

Repair?

tru-blue 442

Interesting tool. What is that, some sort of gauge?

Oldsmaniac

That is valve stem height checker pictured by 67cutlassfreak. I grabbed the picture from another thread...

tru-blue 442

Nice. I have never seen one.

80 Rocket

That head can be easily repaired. When you go with a full bronze replacement guide, that old cast iron guide boss is eliminated anyways so you are good.

tru-blue 442

Thanks 80, good to know. Do the just drill out the bosses and install
the bronze guides to look like the photo that Oldsmaniac posted?

80 Rocket

Yes, I didn't realize Oldsmaniac posted a photo. The OD of the replacement guide is slightly less then the cast iron guide boss. The cast iron guide boss should be completely eliminated though, because it would be very prone to cracking with so little material left for support.

tru-blue 442

I see. Thank you again. I really enjoy learning about this sort of thing.
CO & all her members rock!

Octania

I saw the crack, yes
machinists replace guides all the time
usually by the time they get 'er reamed out to fit the guide insert there is little or nothing left of the original guide anyhow.

TripDeuces

There are plenty of valve seals that fit those aftermarket springs. Why they weren't installed is a puzzle. Viton comes to mind. They are small diameter and press right onto the guide. Unlike umbrella seals they don't ride up and down with the valve.
As stated that cracked guide can just be replaced with bronze ones. No need to scrap those heads.

TripDeuces

A word on those shims. There are special spring retainers that are made to sit deeper on the valve stem thus taking up the distance that was originally for the valve rotator and restoring valve spring height. There was no need for all those shims if the machinist had done his job right.