Will these valves work in my heads?
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How about going with 2.07's or 2.072's and keeping the stock exhaust valves stock? What's a good brand to go with? I am planning on swapping my intake out and changing my head gaskets for thinner ones to help bump up my compression a little. When I do this I wanted to at least have the bigger intake valves installed and some bowl blending and if I can I want to get my heads cc'd. That way I know exactly what im working with. Also I will check my deck height at this point. And yes for those of you reading this post that have answered many other questions for me this is the motor I just rebuilt. I can't stand not knowing what my actual compression is 
. Does any one how much it might cost to have heads cc'd?
Thanks, Mike
. Does any one how much it might cost to have heads cc'd? Thanks, Mike
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Joined: Mar 2008
Posts: 1,012
From: Phx, AZ
I found some 2.11 intake and 1.66 exhaust valves. Will these fit in my #6 heads?
First off, those are Pontiac valve sizes, the intakes have a 30 degree seat, also. They will be about .100" taller, or more. Some come in at 4.875" OAL, some 4.975" OAL.
THAT means you will need an adjustable valve train, and longer pushrods, and someone to set spring height correctly.
They also use a Chevy sized .342-.343"" guide (an Oldsmobile needs a .344-.345 guide) so you will need to install new guides. That alone will be $125.
Open the bowl for the larger valve will be necessary too, and to re-cut all the seats for a fresh valve job.
Check with local shops, on prices. Depending on what your castings need, I think it may cost $400 or more to make them work.
I think you will be happier with an Oldsmobile 2 inch intake/ 1.56 exhaust for a 350 powered street car.
JMO
Jim
Last edited by Warhead; Feb 11, 2011 at 03:22 PM.
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Posts: 8,485
From: Central Fl
Hey Jim,
You're right on most everything but I've seen those very same valves in different stem sizes, as low as .341. And on the plus side the longer stem allows for a better choice of springs.
But I also agree with you to stay with "Olds" sizes. At the very least he can always go as big as 2.07/1.68, more than a enough for a typical small block.
You're right on most everything but I've seen those very same valves in different stem sizes, as low as .341. And on the plus side the longer stem allows for a better choice of springs.
But I also agree with you to stay with "Olds" sizes. At the very least he can always go as big as 2.07/1.68, more than a enough for a typical small block.
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Joined: Mar 2008
Posts: 1,012
From: Phx, AZ
Hey Jim,
You're right on most everything but I've seen those very same valves in different stem sizes, as low as .341. And on the plus side the longer stem allows for a better choice of springs.
But I also agree with you to stay with "Olds" sizes. At the very least he can always go as big as 2.07/1.68, more than a enough for a typical small block.
You're right on most everything but I've seen those very same valves in different stem sizes, as low as .341. And on the plus side the longer stem allows for a better choice of springs.
But I also agree with you to stay with "Olds" sizes. At the very least he can always go as big as 2.07/1.68, more than a enough for a typical small block.
We're both right.
If he needs a taller installed height, it is a viable alternative to get some room for big springs, but that is more for a high rpm racing application.
Jim
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Joined: Nov 2008
Posts: 8,485
From: Central Fl
Not to be ****, but more for high lift which doesn't necessarily mean high rpm. Sometimes you can benefit from higher lift without the extra duration, depends on the total package.
Registered User
Joined: Nov 2008
Posts: 8,485
From: Central Fl
2.072 are fine. CC them yourself, not hard to do. Drill a hole in a piece of plexiglass plate, a pet syringe and some windsheild washer fluid. Use grease to seal the plate, fill the chamber with fluid and check your total volume. I normally grind on the sides to further unshroud the valves but don't go too near the gasket area. Chances are unless they've been hacked on the 2 heads and all the chambers won't be that far off.
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Joined: Mar 2008
Posts: 1,012
From: Phx, AZ
Valve lifts of up to .600" can be dealt with offset keepers/retainers, and commercially available springs, without the need for a taller valves on early heads like his.
I was referring to extreme heavy spring pressure-physically taller springs-necessary to obtain spring rates that would be double, even triple normal parameters. Yes, tall valves can ease packaging in high lift application, but we are deviating from his situation.
I'd rather he go with the 2.0 intake valves for a street only car. JMO
CC'ing is inexpensive. Mark explained it well. Any grinding in the chambers for equalizing.
Find out how much the valve job, and bowl work is going to cost, first.
New large valves, and their depths will change CC's.
JMO
Jim
Last edited by Warhead; Feb 13, 2011 at 07:01 AM.
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From: Central Fl
[quote=joesw31;252692]
Please explain why this makes a difference? Are you suggesting that all rollers high lift? The answer is no.
Not to say this is the case in your application but just an fyi, if the bowl area below the seat isn't blended correctly velocity and flow will be lost, causing less than desirable results when going to larger valves.
While there is case to be argued for the smaller valves, I'd be hard pressed to believe that no one has ever successfully adapted the Edelbrock heads for example, which have 2.07/1.68 valves sizes, to a street SBO.
MARK-
Valve lifts of up to .600" can be dealt with offset keepers/retainers, and commercially available springs, without the need for a taller valves on early heads like his.
I was referring to extreme heavy spring pressure-physically taller springs-necessary to obtain spring rates that would be double, even triple normal parameters. Yes, tall valves can ease packaging in high lift application, but we are deviating from his situation.
I'd rather he go with the 2.0 intake valves for a street only car. JMO
CC'ing is inexpensive. Mark explained it well. Any grinding in the chambers for equalizing.
Find out how much the valve job, and bowl work is going to cost, first.
New large valves, and their depths will change CC's.
I tried the larger valve size 2.07 and the 1.710 in a set of w-31 heads, and I was not happy with the valve size as it moved my rpm curve way up. Unless its a full race car I don't recommend it. WARHEAD hit it right on the spot! The 2.0 intake with the 1.6 exhaust works great. Just get the heads cc'd and a mild port job.
The number 6 heads have deep seats and a installed height of 1.850 is easily obtained. Comp cams has keepers as mentioned to give you more installed height. Unless the person will be running a roller camshaft, the mentioned installed should be ok. JMO
Valve lifts of up to .600" can be dealt with offset keepers/retainers, and commercially available springs, without the need for a taller valves on early heads like his.
I was referring to extreme heavy spring pressure-physically taller springs-necessary to obtain spring rates that would be double, even triple normal parameters. Yes, tall valves can ease packaging in high lift application, but we are deviating from his situation.
I'd rather he go with the 2.0 intake valves for a street only car. JMO
CC'ing is inexpensive. Mark explained it well. Any grinding in the chambers for equalizing.
Find out how much the valve job, and bowl work is going to cost, first.
New large valves, and their depths will change CC's.
I tried the larger valve size 2.07 and the 1.710 in a set of w-31 heads, and I was not happy with the valve size as it moved my rpm curve way up. Unless its a full race car I don't recommend it. WARHEAD hit it right on the spot! The 2.0 intake with the 1.6 exhaust works great. Just get the heads cc'd and a mild port job.
The number 6 heads have deep seats and a installed height of 1.850 is easily obtained. Comp cams has keepers as mentioned to give you more installed height. Unless the person will be running a roller camshaft, the mentioned installed should be ok. JMO
Not to say this is the case in your application but just an fyi, if the bowl area below the seat isn't blended correctly velocity and flow will be lost, causing less than desirable results when going to larger valves.
While there is case to be argued for the smaller valves, I'd be hard pressed to believe that no one has ever successfully adapted the Edelbrock heads for example, which have 2.07/1.68 valves sizes, to a street SBO.
Last edited by cutlassefi; Feb 13, 2011 at 09:10 AM.
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From: Phx, AZ
I'll be the first to admit running BBO heads on a SBO.
I definitely saw a change in the power curve, by a bunch. Much of that can be attributed to the larger port volume, so just 2.07 will have less effect than BB heads.
Fine for me, others-not so sure.
I don't recommend the 2.07's in 350 SBO heads, for most people (403 is a different story). I'm always more conservative on other peoples parts.
Just me
I'm sure Mike will have his say.
Jim
I definitely saw a change in the power curve, by a bunch. Much of that can be attributed to the larger port volume, so just 2.07 will have less effect than BB heads.
Fine for me, others-not so sure.
I don't recommend the 2.07's in 350 SBO heads, for most people (403 is a different story). I'm always more conservative on other peoples parts.
Just me
I'm sure Mike will have his say.
Jim
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