Will these valves work in my heads?
February 10th, 2011, 07:40 PM
#2
Registered User
Join Date: Mar 2008
Posts: 3,841
With significant machine work in the chambers, yes. However, they are "too big" except for maximum all out racing. The factory used 2" intakes only on the W31, and those same 2" intakes on 425 and 455 engines too.
February 10th, 2011, 08:27 PM
#3
Registered User
Thread Starter
Join Date: Mar 2010
Posts: 106
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
February 11th, 2011, 03:15 PM
#4
Registered User
Join Date: Mar 2008
Location: Phx, AZ
Posts: 1,012
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; February 11th, 2011 at 03:22 PM.
February 11th, 2011, 04:09 PM
#5
Registered User
Join Date: Nov 2008
Location: Central Fl
Posts: 7,822
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.
February 11th, 2011, 05:00 PM
#6
Registered User
Join Date: Mar 2008
Location: Phx, AZ
Posts: 1,012
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
February 11th, 2011, 07:55 PM
#7
Registered User
Join Date: Nov 2008
Location: Central Fl
Posts: 7,822
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.
February 13th, 2011, 06:40 AM
#9
Registered User
Join Date: Nov 2008
Location: Central Fl
Posts: 7,822
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.
February 13th, 2011, 06:56 AM
#10
Registered User
Join Date: Mar 2008
Location: Phx, AZ
Posts: 1,012
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; February 13th, 2011 at 07:01 AM.
February 13th, 2011, 08:42 AM
#11
Registered User
Join Date: Nov 2008
Location: Central Fl
Posts: 7,822
[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; February 13th, 2011 at 09:10 AM.
February 13th, 2011, 09:39 AM
#12
Registered User
Join Date: Mar 2008
Location: Phx, AZ
Posts: 1,012
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
Thread
Thread Starter
Forum
Replies
Last Post
Seff
Small Blocks
3
September 21st, 2013 08:45 AM
import extermination
Small Blocks
14
November 29th, 2011 09:05 AM
MDchanic
Parts Wanted
0
April 23rd, 2011 07:15 AM
