Valve Seals!

[Erik the Awful]

I was looking into building my engine a few years back, and I targeted >.500" lift as a goal. I was looking at buying the cutters to drop the spring pocket. Then I stumbled on the combo on an F-body forum. Vortec heads with LS2 valvesprings and Comp Cams 787 retainers install with about a 10% increase in seat pressure and no machining. You also gain the benefits of beehive valvesprings.

I assembled it a couple years ago, so I don't remember the installed height. I was nowhere near coil bind. The roller on the rocker is centered on the valvestem.

The whole reason for the seat cutter is to give clearance for the valve seal. The 787 retainers are a fair bit shorter than the factory retainers, giving you the clearance without cutting.

In all fairness, I don't have a lot of road miles on this yet. I pulled it back out of my Suburban for a ticking sound - a .030" hole in the oil galley plug behind the timing chain fixed that. It's now in my Stepside, and if I could get the TBI running decent I'd happily give long-term results. That said, I'm pretty sold on switching over to a Holley Sniper.

 

[PANHEAD]

I am not the one that introduced panhead into the discussion.that is just my site name .I misunderstood the 305 useage and I appoligize for that I do believe redneckgeriatric brought panhead into the truck text

 

[cngodfather]

i have installed them on a bunch of engines that spun a lot of rpm and pushed head temps. not an issue, what is the supposed reason not to run them on exhaust side? im curious.

I heard that the exhaust valve needs to be lubricated more. I think it had something to do with heat.

 

[Redneckgeriatric]

I heard that the exhaust valve needs to be lubricated more. I think it had something to do with heat.

more than what? if you lubricate "more", what will become of the additional oil? it will destroy the guide and allow more lubrication which destroys more. again, cast guides are the way of the dinosaur. a good thing you can do is contact AV&V. they are in canada and got their act together on all things valve related. i have used a ton of their 7mm stuff with titanium and beehives. makes for a reliable super light valvetrain. it doesnt come with accolades or a sticker, or a fake dyno chart. its just real stuff.

 

[Redneckgeriatric]

I was looking into building my engine a few years back, and I targeted >.500" lift as a goal. I was looking at buying the cutters to drop the spring pocket. Then I stumbled on the combo on an F-body forum. Vortec heads with LS2 valvesprings and Comp Cams 787 retainers install with about a 10% increase in seat pressure and no machining. You also gain the benefits of beehive valvesprings.

that is a great benefit. so, if ima reading right, you put the heads together blindly, based on a combo declared to work on an internet forum? its possible the magic dust settled on such a combo, but you really dont know where you stand as far as blueprinting or reliability.

I assembled it a couple years ago, so I don't remember the installed height. I was nowhere near coil bind. The roller on the rocker is centered on the valvestem.

so you are at light lift, and heavy spring pressure? a spring compressed more is usually a spring with higher pressure at the nose. will it fail early? break due to hormonics?

The whole reason for the seat cutter is to give clearance for the valve seal. The 787 retainers are a fair bit shorter than the factory retainers, giving you the clearance without cutting.

shorter retainers , hmm. again, that is something measured with the test spring in place. im assuming a different angle for the locks? this would allow the valve stem to appear longer ? so what we know is spring pressure(s) are all over the place, and may be too light to pull the valve closes at speed, or too heavy and slap the face on the seat and ruin the flow at he seat. any flow work would be for S&G. another thing that could happen is the valve head tearing off the stem.....catastrophic.
i hope it all fell into place and works great. maybe the magic freee formula works for the masses and doesnt cost anyone a blown engine or death/injury. something you will never know without a teardown and come back up with the blueprint. maybe find someone with a spinatron to see where the failure point is. ?

In all fairness, I don't have a lot of road miles on this yet. I pulled it back out of my Suburban for a ticking sound - a .030" hole in the oil galley plug behind the timing chain fixed that. It's now in my Stepside, and if I could get the TBI running decent I'd happily give long-term results. That said, I'm pretty sold on switching over to a Holley Sniper.

 

[PANHEAD]

once again I am sorry for sharing my opinion on the 305. this is a fantastic site. I will continue using it but I will keep my opion to myself if it offends youall

 

[PlayingWithTBI]

That's cool, sharing your opinion is fine, we all have one. Let's just try to keep it civil. We all like to kid each other from time to time.

 

[Erik the Awful]

redneckgeriatric, I hesitate to respond, because we're clogging up someone else's question, but you're talking to me like I'm a moron.

I didn't find one post by a guy doing the spring swap, I found several, with some reporting a decent amount of years and mileage on it. It ain't rocket science.

The installed height is the same. The difference in retainer height is under the keepers. The keepers have the same angle as stock, but I bought new keepers just because I know dropping a valve is catastrophic. Spring pressures are all over the place? No, they're about 10% stiffer than stock, which is what I want. I don't need doubled springs with crazy seat pressure, and the beehive means better valve control at higher rpm.

I'm no internet car newb posting random crap. If this combo ends catastrophically, rest assured I'll post pics and a diagnosis.

 

[evilunclegrimace]

more than what? if you lubricate "more", what will become of the additional oil? it will destroy the guide and allow more lubrication which destroys more. again, cast guides are the way of the dinosaur. a good thing you can do is contact AV&V. they are in canada and got their act together on all things valve related. i have used a ton of their 7mm stuff with titanium and beehives. makes for a reliable super light valvetrain. it doesnt come with accolades or a sticker, or a fake dyno chart. its just real stuff.

1) More than the intake valve guide.
2) it will cool the valve stem and guide, we are not talking about excessive amounts of oil.
3) the majority of GMT 400 factory engines in with cast iron heads have cast guides.
4) After market heads are a different circumstance.
Would you care to explain how keeping a valve guide lubricated destroys it?

 

[nokia]

HI guys . this discussion is right for my issue. I think the engine 350 V8 1990 on my Silverado have valve seals broken. some spark plugs (specially # 8 ) become encrusted and wet by oil . I believe to buy this set :Engine Valve Stem Seal Set-VIN: 6 Mahle S S45779. it is for exhaust valve . can I also install on intake valve ? or is better get seals for exhaust and intake proper? I'm live in italy and i need to buy i right parts . thanks