Valve cover/Cylinder head weirdness

[Schurkey]

1. Best guess on your cylinder heads is that they're the Corvette heads that got developed into the "ZZ" style, as would be installed on the "ZZZ" through "ZZ4" crate engines. They're fine entry-level cylinder heads.

2. It's not the rocker studs that are the problem, it's the extra-tall rocker nuts. Get shorter nuts and use the centerbolt covers, or

3. They're aluminum, it'll drill easy--IF (big IF) there's enough metal around the hole to go oversize. "I" would install Heli-Coils in those holes and never have to worry about stripping them out again--but that assumes there's enough metal to do that. I'm thinking that since the castings were not intended to have holes there...things are not going to be easy.

4. If at all possible DO NOT USE RTV SILICONE. A real valve cover gasket, stuck to the valve cover with actual gasket sealer would be preferable.

5. Those valve-cover bolt "load spreaders" work, but there are better ones. The good ones are much longer, and have formed ends so they're "springy". GM discontinued them in favor of long ones with plain ends, which are still better than what you have.
The aftermarket still sells the springy ones. These, and a hundred other Chinese knock-offs.
www.summitracing.com/parts/mil-85305

Milodon 85305 Milodon Valve Cover Hold-Down Tabs | Summit Racing

Free Shipping - Milodon Valve Cover Hold-Down Tabs with qualifying orders of $109. Shop Valve Cover Hold-Down Tabs at Summit Racing.

www.summitracing.com

6. I can't tell from the photo if your pushrods are merely polished from contact with the guideplates, or if they're being destroyed by the guideplates. When using pushrod guideplates, the pushrods MUST be hardened--and not many stock Chevy pushrods are hardened, 'cause they're not used with steel guideplates. Lotsa aftermarket pushrods are hardened, though.

 

[Jerryred94silvy]

1. Best guess on your cylinder heads is that they're the Corvette heads that got developed into the "ZZ" style, as would be installed on the "ZZZ" through "ZZ4" crate engines. They're fine entry-level cylinder heads.

2. It's not the rocker studs that are the problem, it's the extra-tall rocker nuts. Get shorter nuts and use the centerbolt covers. Or,

3. They're aluminum, it'll drill easy--IF (big IF) there's enough metal around the hole to go oversize. "I" would install Heli-Coils in those holes and never have to worry about stripping them out again--but that assumes there's enough metal to do that. I'm thinking that since the castings were not intended to have holes there...things are not going to be easy.

4. If at all possible DO NOT USE RTV SILICONE. A real valve cover gasket, stuck to the valve cover with actual gasket sealer would be preferable.

5. Those valve-cover bolt "load spreaders" work, but there are better ones. The good ones are much longer, and have formed ends so they're "springy". GM discontinued them in favor of long ones with plain ends, which are still better than what you have.
The aftermarket still sells the springy ones. These, and a hundred other Chinese knock-offs.
www.summitracing.com/parts/mil-85305

Milodon 85305 Milodon Valve Cover Hold-Down Tabs | Summit Racing

Free Shipping - Milodon Valve Cover Hold-Down Tabs with qualifying orders of $109. Shop Valve Cover Hold-Down Tabs at Summit Racing.

www.summitracing.com

1. Since that sounds the coolest I’m going to tell everyone that’s what my heads are lol

2.This sounds like the best option so far. Would shorter rocker nuts involve disassembling the valve train?

3. The top holes could possibly undergo this operation but the bottom two couldn’t. One side of the hole is impossibly thin already.

4. I will keep this in mind going forward. I was doing the best that my inexperienced highschool self knew to do when I tried sealing this up before

5. I knew there was a term for them lol. I’ve seen the ones you’re talking about and they just by looking at them seem more effective than these.

 

[Schurkey]

1. Since that sounds the coolest I’m going to tell everyone that’s what my heads are lol

It wouldn't be lying.

I don't know if your heads are original 'Vette heads, or over-the-counter "ZZ" heads. The "ZZ" heads were "better", in that the valve springs and such were upgraded over the years. I don't know if the actual castings were any different. Maybe yes, maybe no.

2.Would shorter rocker nuts involve disassembling the valve train?

The only thing that would come off is the nuts. But you'd have to readjust to get correct lifter preload because that adjustment would be lost when the existing nuts were removed.

3. The top holes could possibly undergo this operation but the bottom two couldn’t. One side of the hole is impossibly thin already.

Loctite or Permatex makes a chemical form-a-thread, you'd pour it into the cleaned holes, then re-drill and re-tap. I've never used the stuff. Supposedly strong...I'm kinda suspicious.
www.amazon.com/Form-A-Thread-Stripped-Thread-Repair-Kit/dp/B072XT6GQT/ref=sr_1_3?crid=JCY1WWH9CUY9

xc_hide_links_from_guests_guests_error_hide_media

I edited my previous post...check your pushrods.

 

[Jerryred94silvy]

It wouldn't be lying.

I don't know if your heads are original 'Vette heads, or over-the-counter "ZZ" heads. The "ZZ" heads were "better", in that the valve springs and such were upgraded over the years. I don't know if the actual castings were any different. Maybe yes, maybe no.


The only thing that would come off is the nuts. But you'd have to readjust to get correct lifter preload because that adjustment would be lost when the existing nuts were removed.


Loctite or Permatex makes a chemical form-a-thread, you'd pour it into the cleaned holes, then re-drill and re-tap. I've never used the stuff. Supposedly strong...I'm kinda suspicious.
www.amazon.com/Form-A-Thread-Stripped-Thread-Repair-Kit/dp/B072XT6GQT/ref=sr_1_3?crid=JCY1WWH9CUY9

xc_hide_links_from_guests_guests_error_hide_media

I edited my previous post...check your pushrods.

I’ll experiment around with all those nuts and such (dirty joke here) and see what I can discover.

Also here’s your pushrod answer:

You must be registered for see images attach

I don’t know what any of that means but they are polished so I should be fine (right?)

 

[SNCTMPL]

I’ll experiment around with all those nuts and such (dirty joke here) and see what I can discover.

Also here’s your pushrod answer:

You must be registered for see images attach

I don’t know what any of that means but they are polished so I should be fine (right?)

That’s the connecting rods, not the push rods.

 

[Jerryred94silvy]

That’s the connecting rods, not the push rods.

Oh heck you’re right. *derp*

My build sheet doesn’t say anything about pushrods. I’ll look at them tomorrow to make sure they aren’t destroying themselves

 

[Schurkey]

I’ll experiment around with all those nuts and such (dirty joke here) and see what I can discover.

Also here’s your pushrod answer:

You must be registered for see images attach

I don’t know what any of that means but they are polished so I should be fine (right?)

"Polished" if done correctly (lengthwise on the beam) can be useful. If done incorrectly (across the beam) is a disaster.

Shot peening is an aerospace process--not many places offer the service, it's expensive.
Shot BLASTING is an ordinary parts-cleaning operation done by most machine shops, and has essentially none of the benefits of shot peening. Shot blasting and shot peening are superficially similar in that steel pellets are being bounced off the part to be treated. But the similarity ends there.

Is that telling you that the rods have .001 press-fit, or .001 clearance?

Bores resized is more-likely than bores recentered.

How much do you trust the guy who did this work?

 

[Scooterwrench]

I'm guessing he's stating that the small ends have been honed/reamed for floating wrist pins with a .001" clearance. If so a little loose for my liking.
Run VR-1 20w-50 in it.

 

[Jerryred94silvy]

"Polished" if done correctly (lengthwise on the beam) can be useful. If done incorrectly (across the beam) is a disaster.

Shot peening is an aerospace process--not many places offer the service, it's expensive.
Shot BLASTING is an ordinary parts-cleaning operation done by most machine shops, and has essentially none of the benefits of shot peening. Shot blasting and shot peening are superficially similar in that steel pellets are being bounced off the part to be treated. But the similarity ends there.

Is that telling you that the rods have .001 press-fit, or .001 clearance?

Bores resized is more-likely than bores recentered.

How much do you trust the guy who did this work?

Going off of what we know so far he probably shot blasted them and mixed up the terminology.

No clue on the rod clearance.

I never met the guy who built it. I received it from a gentleman who was a lawyer that traded legal work for the motor. The guy I got it from had it in a ‘69 firebird in front of a 6 speed. It’s never given me any troubles and I’ve driven it from San Antonio to Lubbock and back before and it never missed a beat. It just leaks oil and I can’t get it to stop.

 

[1990Z71Swede]

I think tall centerbolt Valve covers are the way to go here. You are newer going to get those threads to be as good as the General intended for it to seal properly especially after taking them off and on a couple of times. Clean those buggered up holes real good with Brake cleaner and compressed air. Then fill them up with JB weld and file flush after hardening.