The Official Vortec 454 Info thread

[Schurkey]

What's the point of them? They'd only be needed if you were using a stud-girdle which requires taller rocker covers.

The L29 doesn't have enough valve spring pressure to need stud girdles.

No stud girdles, no taller covers...no need for spacers on the plenum.

IF (big IF) I were upgrading the heads to allow enough RPM to need really-stiff valve springs that needed a stud girdle to stabilize 'em...I wouldn't be using that intake manifold.

 

[rpoL98]

... if you want to convert to adjustable rocker arms, and go with roller rockers while you're at it.

 

[Schurkey]

I ran roller rockers under OEM valve covers when I had L29 heads on my boat. No stud girdle, no tall valve cover needed. Kinda thinking I did need double valve cover gaskets.

I've got roller rockers under OEM "Corvette" aluminum covers on my K1500 5.7L; the same rockers under different "Corvette" aluminum covers on my 'Camino, and roller rockers under OEM stamped-steel covers on the 455 Olds in the Toro. I did have to hole-saw four holes in the baffles of the Olds valve covers, (to clear the tall Polylocks) and on some of these engines I needed double gaskets...but I've forgotten which got double gaskets and which didn't.

Shorter polylocks would eliminate the need for the double gaskets.

"Roller rockers" is not a sufficient reason to need tall covers.

 

[yevgenievich]

Roller rockers with short locks fit with stock valve covers

 

[454cid]

Wasnt there an issue with short poly locks backing off? I'm thinking it was Richard.

 

[someotherguy]

Wasnt there an issue with short poly locks backing off? I'm thinking it was Richard.

Me? Nope.. I never ran full rollers on a 7.4. I did go to adjustable using the Comp Cams stud kit and my first go-round with their hardware was a big disappointment - the lock nuts galled the threads on several studs so instead of being adjustable, they backed the studs out when trying to adjust. Dunno if it was a QC problem with the studs or what. I'm no fastener expert but they looked to me like Stover nuts, which are supposed to be infinitely re-usable, but 2 or 3 damaged the studs on first install.

When I went back into the engine over a year later trying to address valvetrain noise I tried again with that same kit and didn't have problems with the hardware, and went with Comp roller tip rockers which were probably no improvement over stock, I was just trying to get the 200K+ mile originals out of there.

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Dunno why the forum software insists on rotating that picture 90° for me..

Richard

 

[rpoL98]

i threw away the stover nuts from the outset, didn't trust them. Pics are from 10 yrs ago. haven't had to retighten the poly locks, not even once.

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[Carlaisle]

This was posted on the OBS Obsession Facebook page, what do y'all think?
I'm intrigued as to how well it'll come together. I'm definitely going to be paying close attention to this product.

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I designed a set some years back. As two separate L/R pieces I wasn't confident traditional gaskets would adequately seal - and remain sealed - for multiple reasons. A liquid gasket is a potential option, but alignment pins would basically be mandatory with the thickness of some of the dividing port walls. A single piece spacer would be ideal, but the cost would be exorbitant. I'll be interested to see what they produce and what, if any, long term issues arise.

 

[someotherguy]

I designed a set some years back. As two separate L/R pieces I wasn't confident traditional gaskets would adequately seal - and remain sealed - for multiple reasons. A liquid gasket is a potential option, but alignment pins would basically be mandatory with the thickness of some of the dividing port walls. A single piece spacer would be ideal, but the cost would be exorbitant. I'll be interested to see what they produce and what, if any, long term issues arise.

Probably be a pain to design but O-ring 'em on both sides, maybe? EDIT - nevermind, just a quick glance at close proximity of the ports negates that idea.

Richard

 

[Mangonesailor]

nevermind, just a quick glance at close proximity of the ports negates that idea.

Each port doesn't need it's own o-ring. You could mold an o-ring of out of silicone if you wanted that would be just like the gasket made for the plenum. Two acrylic plates (so you can see voids) with the pattern milled out put together, pour it, vacuum chamber it, then separate them.

People make custom stuff out of silicone molds all the time. Shouldn't be too hard as long as the mold faces are nice and flat and it's clamped good. Thing is the investment in such.

The spacer seal recesses could be machined and polished in. You'd need 4 o-rings but totally do-able. Who's going to be able to invest in the R&D for such though is the bigger hold-up.