anyone using bronze valve guides without seals (o-ring or umbrella) ? the shop i had check these heads out recamended i not use em because they have seen a LOT of them seize up due to no lubrication especially with such a close tolerance between the guide and valve. if it means a little puff-o-smoke at start up thats fine with me. just don't want what i have now. an oil guzzler http://www.chevelles.com/forum/rolleyes.gif

oh sb 441 heads

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John Krenn
1970 malibu SS look-a-like well kinda
350/200-4r (soon to be 383)

Ft.Worth, Tx

Chev-hell, yeah I went round with this last year. I;m not convinced. My heads have no seals on the exhausts. This is where the heat could in fact seize a valve and where, other than startup, you wouldn;t have a oil intake problem.

My engine moves oil. I suspects it's the ring seal and not the lack of seals. I run a compression test as soon as the weather clears up here.

My bud 509Camaro also ran no seals on the exhaust and his fresh mill moves oil too.

I'm not convinced. I'd like to hear from more experinced engine builders on this one. As an addendum, in a big block, if the oiling system is good in stock form, why would I choose to run restrictors just because I use roller rockers. Seems to me the restrictors would exacerbate the siezing problem.

Hate to answer your qusetion with a question, but I'm hoping overs chime in with some experienced answers.

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Chaas
Gold #62/ACES
67 SS396/L88

just to make sure too i mean NO seals intake or exhaust

There is no reason I know of to not run the O-rings.However it is not uncommon to run with no umbrella seals on the exaust valves on "High Performance" engines wherein the oil is checked regularly.
I do not recommend the Posi-lok type of seal for any application, as I have seen enough valve guides eaten plum up on heads that have them.

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Harley
69 461 El Camino Nitrous Model, 69 Chevelle coupe
70 El Camino,71 SS Camaro
79 Corvette
Kerrville,Tx.
A Camel is a Horse designed by a commitee

Chev,
We put seals on everything unless a customer absolutely insists otherwise. We generally use a factory type positive seal on the intake, and a small plastic umbrella on the exhaust. On Fords and real late model Chevy's we put the positive seals on intake and exhaust, thats the way they come from the factory. Bronze guides are actually less likely to have a problem with valves siezing, due to the lubricating properties of the bronze. Most aftermarket heads (Edelbrock, Brodix, AFR etc) have bronze guides and come with positive seals on intake and exhaust. You can also go with the Teflon type seals, but I personally do not think they do as good a job as the factory rubber type seal. I think the Teflon ones are too hard and tend to get little grooves in them, whereas the factory rubber seals conform to the valve better.
I have heard of shops having problems with bronze guides when used with real cheap stock valves but we have done it and not had any problems. We lube the valves with a good assembly lube, I think initial fire up is where half the problems start. If you are using any type of stainless valves, you should not have a problem. Also,
we don't use any tighter clearances just because of the bronze guides.
These are just my opinions, and what has worked for us. If your machine shop is building the entire motor, and warrantying it, go with what they say. Personally, I like to keep oil out of the combustion chambers.
Hope this helps,

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Bill Koustenis
Advanced Automotive Machine
Waldorf Md

1971 Heavy Chevy - original owner
Team Chevelle #100

[This message has been edited by BillK (edited 02-19-2000).]

bill thanks these were within 1/1000 of the valve is this close or normal???? i have good stainless valves that's why i don't want to stick em in the piston. ya think i should just run the little o-rings on the intake?? only take a sec to put on.

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John Krenn
1970 malibu SS look-a-like well kinda
350/200-4r (soon to be 383)

Ft.Worth, Tx

Bill thnx, I'm with you John, tired of the "smoking gun".

John,
.001 is about as tight as I would run them, but I would still put good seals on them. You did not mention what heads you are using. I think if you have assembled them with a good moly based assembly grease, and use a good oil (Mobil 1 is my preferrence) you will not have a problem. Absolutely, at least put the o-rings on, there is enough oil floating around in the heads without funneling more down through the retainer. I you are scared of the positive seals, get two sets of the small plastic umbrella seals that are used on the exhaust valves on late model 305's in trucks. They will still allow plenty of oil to keep from having problems, and will fit inside almost any valve spring.


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Bill Koustenis
Advanced Automotive Machine
Waldorf Md

1971 Heavy Chevy - original owner
Team Chevelle #100

My iron BBC #049 heads were purchased used with about 1 weekend of time on them in a twin turbo boat. They have Manley Stainless 2.19 & 1.88 valves, all bronze guides and PC seals on both intake and exhaust. They have been all cc'd and flowed, chambers are smooth, and ports are just lightly cleaned up. All the valves are numbered to each cylinder. They had not been cleaned when I bought them. They show NO signs of oil in the combustion chambers. I know that a high quality, reputable shop did the work. I don't think I'll have any problem with them. The only thing that I have to do, is change the valve springs as they have double springs with dampers. They have the nice hardened spring seats also. I will run a mild solid cam, so I don't need the high spring pressures. I figure it had a big roller cam in the turboed boat. I need the solid lifter ticking to go with my 396 emblems and 427 engine. Yes, its an original L78 car, and I'll tell how it's a stock 396! LOL http://www.chevelles.com/forum/rolleyes.gif
Rick
'68 SS 427
'66 Yenko

I'm still stuck on oil restrictors if you;re running roller rockers. I've read over an over that the BBC has an excellent oiling system. Why mess with it?

Rick I saw your post on the cam seection. Acutally went over to compcams website to see the specs, but their site is not so good. I'm really, realy pleased with my crane grind ( F304-2 ) but think it has a bit too much duration for your compression. Hope the cam choice works out well.

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Chaas
Gold #62/ACES
67 SS396/L88

Gene,

Oil restricters can only be used with true roller rockers and solid cams(roller or flat tappet). There are two trains of thought on this. I subscribe to the first idea, especially since I run an 8-quart oil pan.
Oil around the valve springs is what keeps them cool. If you run the car on the street quite a bit, which I know you do, I would not run them. It could prematurely wear the springs due to heat.
The other train of thought is that all of the oil in the motor will go to the top since the lifters(solid) don't use any oil. and there will not be anything in the pan to pump to the main and rod journals. This should obviously only happen at high RPM. Chevy ran solid lifter cams and never put them in and never had problems? The only time I would consider running restrictors is with a car that only sees the strip. The springs aren't run that long without cooling in this situation. I would put some seals on the guides and forget about the restrictors.
When I ran my old motor without seals on the exhaust(I did use the O-ring) it used about 1-quart of oil per oil change(3000 miles) Prior to doing this it did not use any oil.

Good Luck,

Jason Gore
AKA DragRacer
jgchevelle@aol.com

I'd like to thank everyone for the great info. that they have. This is a great site!
Gene> I'll post those cam specs. back at my post on the cam question.
Rick

so what im being told is Use the o-rings. it just scares the hell outa me since that shop advised me not to. But i guess it couldn't hurt that bad w/ a few o rings that just keep the oil from running down the valve i would think it gets pleanty of oil otherwise

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John Krenn
1970 malibu SS look-a-like well kinda
350/200-4r (soon to be 383)

Ft.Worth, Tx