Muddywaters

Come to find out...my missing oil is due to the builder left out the valve guide seals on the intake valves. He says he always leaves out the exhaust seals and if he thinks the engine is going to be run hard, he also leaves out the intake valve guide seals... His reasoning is...to simply get more oil to the guides. I am losing approx. one quart every 800 miles or so. It is not effecting my plugs but is putting a film on the back of the car. Q. Is this a common practice? Thanks in advance! Muddy

...Roger...

I've never heard of it.

Little Mouse

If you have original size 1.250 single valve springs and guides that
have not been cut for pc oil seals use a viton seal that locks over
the guide, don't let them talk you into just throwing on an umbrella
oil seal. if you have dual springs you will need to cut the guides
for pc seals. www.competitionproducts.com , for viton seal
that locks onto stock guides 11/32 valve stem part # S-5325

Muddywaters

DWncchs, Little Mouse: Thanks heaps for the reply...so, you've both never heard... of even leaving the seals off the exhaust side? This shop is starting to scare me. The guy that does the heads for the builder has worked in this shop for umteen years and has raced for many years.

Little Mouse: Whats the probem with the Umbrella seals? The springs are duel...so to cut the guide, does the heads need to be removed? Thanks Muddy

SIXFOOTER

I never heard of that either, even when I was runnin circle track in east texas. The problem with the umbrella seals is they tend to come off.

Muddywaters

Sixfooter, Little Mouse: Thanks again for your inputs Little mouse... I'm pretty sure I am all stock here, I know the springs are the same springs before the build (builder told me he tested them and they were fine??), and they are a duel springs. I do not know if they are the original springs... I'm guessing they are. I do know there was a rebuild at 80K, I had it rebuilt at 133K. Having said that, what would you advise? Muddy

Muddywaters

Thanks a ton for the info... I think your latter advise is the way to go... I'm wondering now, (just curious) if the LT-1's used the single coil or the duel? Or if someone decided to up grade to the duel at one point in time. In my situation #matching engine and only taking her up to 5000 anyway, the single spring would be more than fine and fitted with the push on viton oil seals. I'll call Isky tomorrow! Thanks!!! Muddy

I'm just wondering why the builder did not do this in the first place, as I sort of left it to him... to do what ever he need to do to make this engine right!!!! Sounds to me...by everyones input...that, running without seals is kind of nuts!!!!

Little Mouse

Muddywaters all of the factory cars from hydraulic cammed cars
to the soilid lifter cars used a 1.250 single spring, I put 36,000
miles on my 69 Z/28 from the day it was new tell I traded it for
a 72 vette, ran the living **** out of it everywhere I went, the
single springs were still on it when I got rid of it. it had a soilid
cam with a little more duration and lift then an Lt1 cam, Chevy
use to sell a slightly stiffer single spring ment to work with there
off road cams with even more duration and 492/512 lift. don't no
if they are still availible now, but around four yrs ago a good friend
of mine with an all original 70 LTI bought a new set of the off road
cam springs at friendly chevrolet in Dallas TX, more then likely the
chevy springs are really made by someone like crane cams.

norvalwilhelm

No I have heard of it. In fact my new Brodix fully assembled heads came WITHOUT exhaust valve seals. I wanted to install them but my long time speed shop said NO. They regularly leave the exhuast off and sometimes the intake too.
I do run them on the intake but they convinced me to leave the exhuast off just like Brodix intended.

L88Plus

Umbrellas tend to crack and break, they're little help - a lot like the "O" rings that were popluar for awhile. Stay away from Teflon, they sometimes do too good of a job and let no oil down the stem. Best I've found are Viton rubber, they stay flexible and last. The decision about whether or not to run them also has to take into account the clearance - if it's right-on, a lot of folks leave 'em off of the exhausts but run 'em on the intakes. If they're sloppy, run 'em on both. My .02

cardo0

Racers can run without seals because they don't care if the eng uses a quart each race - but the vlv guides will stay well lubricated.

Sometimes the intake guide can get a little dry from using "umbrella " seals with the original splash guards on top of the spring (under the retainer). And u don't want to remove that splash gaurd once the spring hieght is adjusted/set. But u may not have the stock splash guard installed. Nothing wrong with "umbrella" seals if they fit. But it seems some umbrella seals interfear with some springs. BTW mine are working fine but have little run time so far. Don't mistake your double springs for a single spring with a "dampner" coil inside the single spring.

What can you do? Well simplist fix is install the stock little O-rings back in vlv stem groove on both the intake & exhaust vlvs. O-ring seals are known for puffing blue exh on eng start. Or install umbrella seals and take the chance to see if they get bit by the springs. But both these seals can be installed with the heads on. Now i believe GM has some PC seals that can be installed over the stock guide boss but i have not used them so cannot confirm this - check with your dealer or a "sharp" NAPA parts man.

Hope this helps ya.
cardo0

...Roger...

Interesting....guess I need to get out more.
Norval would this be more for racing engines and maybe not such a good idea for street motors? I can see at high RPMs the plugs wouldnt be effected much but I would think stop and start on the street could foul some plugs.I think I remember you mainly cruise how much oil do you use and have you had any fouling issues?