91phoenix

iTrader: (5)

Measured valve stem guides on vortec heads I just bought for my 91 bird. They measure as .520 +/- .002. What are my options. I measured some .550 seals and they measured .535 id. Could some .530 work or would they not be tight enough. The info I have says min would be .525. These vortec heads are really beginning to aggravate me.

skinny z

Are these over the counter Vortecs that you're looking to put new valve stem seals on?

sofakingdom

iTrader: (1)

Sounds like some machinist was asleep at the switch.

The 2 standard aftermarket sizes are .530" and .500". In Comp, they're part # 510 & 503 respectively. I don't know offhand of any .520" seals, myself. You can cut em down yerself with a hand drill and their part #s 4716 (cutter for .500") and 4732 (arbor for 11/32"). That's about $175 of toolage but might be cheeeeper than paying some dork to screw em up some more.

skinny z

I've never used these (or ordered any Alex parts) but they might fit the bill.
Range: .520"- .565".

https://alexsparts.com/11-32-x-520-5...ght-vss-408-8/

91phoenix

iTrader: (5)

The heads are gm heads. I have a stock set of machined heads, 906 and a set of factory 062 heads. The 906 heads are the issue. The 062 heads are good except for one valve stem guide. One had been rebuilt by GM, I believe, and they machined valve stem guides to .500 and then sleeved them back to stock. One of the sleeves broke off. I know I can get .500 x 11/32 seals easy. I guess I will have to buy a set of .500 seals to fix that one and later get the tools to fix the pair of 906 heads. I much appreciate the info.

91phoenix

iTrader: (5)

I did find those Alex Spring seals. Just little leary of using one of a kind parts.

skinny z

If your guides measure .520", the Alex seals might do the trick. I think Trick Flow also carries them.

sofakingdom

iTrader: (1)

I'd be concerned that they might not stay put on the guide, at/below their absolute bare minimum "spec". If they fit tighter to the valve than the guide they'll just turn themselves into "umbrellas". USELESS.

I suppose you could twist some safety wire around them REAL TIGHT to help clamp them on there though.

All that said, I've never used Alex's parts; and given that their claim to fame is the "ghetto grind" on retainers for Vortec heads, I'm not inclined to put alot of faith in their level of engineering overall. Butt hay, to each their own, if it works it works. Whether it's good advice to someone else is an open question; but if it works FOR YOU, then ... it works FOR YOU anyway.

And of course, Alex is hardly FelPro, Comp, Mahle, etc. Who knows who actually makes their parts. I doubt Alex has a foundry for retainers, a rubber/plastic molding plant for seals, etc. I've been in the business of making parts long enough to know that it's NOT CHEEEEEEP, and if the parts don't cost much, then there's usually a reason. Several REALLY GOOD reasons usually, actually.

skinny z

Exactly this ^^^.
As stated:
The "ghetto" thing has always kind of bugged me. Not to mention grinding on a part that should have a specific heat treat, etc.
That said, he does source those parts from somewhere. It's our job now not to find information but to sift through it all and discern what's ***** and what's Shinola.

91phoenix

iTrader: (5)

I have gotten two heads together finally. For the Alex Springs parts I ordered the spring kit for these vortec heads. Because of the problems with the heads I know more about their parts. Their seals are slightly shorter in the actual valve stem seal area. The spring caps are slightly raised in the center around the keepers at the bottom. The keepers are interchangeable with stock keepers. With the first head the clearances are barely good for a .525 valve lift.
The second head was a mess. From GM the valve stem seal area all had sleeves. One was broken. One gave me a measured .440 valve clearance. Took it apart and looked and measured. It was a little over 1/8 inch taller than the sleeve. Carefully ground it down to top of sleeve and touched center to make sure no inside burs. Used small grinding stone and beveled outside. Looked at my Felpro valve stem seals and both packages are the same part number but are different in overall side height. Used the shorter one and got to over .580 valve lift clearance with the alex springs.
The other pair will have the guides cut down tp .500. I will check all heights and correct any issues. This will allow at least .550 lift with extra for clearance.