[Tom Vaught]

I have to agree with Neighbors Complaint, I have used a lot of Ferrea over the years, know the owners, spent time at their shop in Florida, currently have a set of Ferrea valves in a ported Edelbrock set of heads done by Keith Wilson.

My heads use 1.71" diameter Exhaust Valves and flow 260 cfm at .600 lift thru the exhaust ports. That is at 25" water test pressure. No need for 1.77" valves in most heads, even under boost conditions.

Tom V.

[Will]

Originally Posted by PAUL K

So how much power is lost by using a RAIV tulip valve?

You know darned well it's impossible to answer that question with a hard number. It will be combination dependent.

The bottom line - do the tuliped valves hurt flow? Yes they do, particularly at lower lifts. If you have two heads that are basically identical but one flows less than the other at lower lifts, which is going to make more (or less) power over the RPM range?

[PAUL K]

Originally Posted by Will

You know darned well it's impossible to answer that question with a hard number. It will be combination dependent.

The bottom line - do the tuliped valves hurt flow? Yes they do, particularly at lower lifts. If you have two heads that are basically identical but one flows less than the other at lower lifts, which is going to make more (or less) power over the RPM range?

Not sure that is why I asked. I believe the answer could be found if enough effort was applied. A tuliped valve will pick up exhaust flow considerably compared to a flat valve nine times out of ten. We tested a tuliped valve compared to a flat valve and found nothing. So I'm certainly not convinced there is going to be a big difference if the same test was done on the intake side.

Do you think a tuliped valve would flow worse on a wet flow bench compared to a flat valve?

[77 TRASHCAN]

Are titanium valves supposed to be used with a specific type of valve guide material? Bronze maybe?

[PAUL K]

Originally Posted by racegto65

I've run RA4 length valves in iron heads for years for the better valve spring installed height.
The op also said they were Titanium and I have never seen a Titanium valve with a tulip face
Just my 2cents

Hah.... Now you have. Lol

Valve on the left is titanium and the one on the right is a factory RAIV. The back sides are close but the front aren't nearly as deep which helps with the compression. Some of the aftermarket valves modeled after the RAIV's are bricks.... If I remember correctly they were around fifteen grams heavier than the factory valves.

[NeighborsComplaint]

Originally Posted by 77 TRASHCAN

Are titanium valves supposed to be used with a specific type of valve guide material? Bronze maybe?

Bronze guides are recommended. Bronze guide liners will work in a pinch but will not dissipate the heat transferred by the titanium valve as well.

[slowbird]

A whole of CFM is king in this thread when it comes to making power.
Flow benches can lie. An engine is nothing like a flow bench.
At what rpm is there a steady 28" being pulled for a couple seconds??
What is the fuel doing on a flow bench?
I have personally see flow loss lead to power gains. So cfm on a flow bench doesn't always lead to power gains or power losses

[Skip Fix]

When I got my bare SR 614s in '88 few valve choices. C&A had SS replacements made my SI like factory tuliped and heavy . Ended up using D port SS SpeedPro V3923 exhausts and flat V1825 intakes and picked up flow.

Also one day flowed a buddy's 614 with factory valves then swapped in his HO heads flat valves and picked up flow, and lost it with the RAIV tulip in the HO heads. All these heads had 30 degree intake seats.

[steve25]

The fact is that if a loss in Intake air flow makes for any amount of better upper rpm power ,that is then telling you the simple fact that with your motors combo of Cam, CID and level of rpm that the minimum port area in your Intake tract is not enough due to the velocity in that local area being too much.

[slowbird]

Originally Posted by steve25

The fact is that if a loss in Intake air flow makes for any amount of better upper rpm power ,that is then telling you the simple fact that with your motors combo of Cam, CID and level of rpm that the minimum port area in your Intake tract is not enough due to the velocity in that local area being too much.

So cfm is king and more cfm has to translate to more power?

[Skip Fix]

Not if the combination is not right , but you have to have a minimum flow of X to make Y horsepower. IF you are below that you can't make the power. That is not saying the car/chassis can not be optimized to go faster with less HP.

[PAUL K]

Lots of opinion, little first hand knowledge and not much participant discussion going on here.

A few years ago we pulled a good running well tuned single plane manifold off a 446 cid engine and replaced it with another single plane manifold that flowed 30 cfm more. The car picked up nothing!

So now we have a FACT ..... Increased cfm doesn't translate to guaranteed power!

[PAUL K]

I have another fact;

A thousand horsepower engine will not pick up or loose 30-40 horsepower by switching to a tuliped intake valve.

Amazingly it might pick up 30-40 horsepower by changing from a steel valve to a titanium valve and the power gain would come with zero change of CFM in the intake tract.


I'm not sure if that is one fact or two facts but the fact of the matter is the facts are starting to pile up.

[NeighborsComplaint]

Originally Posted by Will

You know darned well it's impossible to answer that question with a hard number. It will be combination dependent.

The bottom line - do the tuliped valves hurt flow? Yes they do, particularly at lower lifts. If you have two heads that are basically identical but one flows less than the other at lower lifts, which is going to make more (or less) power over the RPM range?

Seems like a reasonable back to back test of the same port on a flow bench would do.

Net and average CFM gain/loss would be indicators of a HP gain/loss.

[Skip Fix]

Fact -my RAIV headed 400 picked up 2mph and .2 with smaller headers who would have thought. Also did the same additional increases with a reverse split cam the heads flowed 85% E/I ratio and if flipped the bench on suction the exhaust flowed 90% of the backwards! The motor with the initial cam (288/296 UD) dynoed identical HP and TQ numbers with an HO intake a Torker and a Torker II. At the track with a bigger solid cam the Torker KILLED bottom end that I could not tune out but picked up 2 mph on the top end.


Also would not have thought my step 1 3/4-1 7/8 headers with just a short 1 3/4 tube the same size as an E head exhaust port would have lost 30 HP on my buddies 461 Dave Bisshop ported E head 461!
So yes you can have less flow and make more power. I think Jim Hand showed that with his combination-but lots more guys able to make the HP to run 11s,10s with more flow and an Eddy head that they could with iron D port heads. I would be way too many variables unless you flowed then dynoed a set of heads with flat valves, then put in tuliped.

If I had the tuliped titanium valves I'd use them.

[steve25]

Hi Paul!

I would very much love it if you could go into more detail about that manifold swap without any performance gain story that you posted here about please?

In peticular if the manifold you swapped on had more port runner area on average per runner then the Intake that was being run before on the motor?

Let me relay a similar end result story that I had with a buddy of mines 408 cid SB Mopar that was running in the top of the 9s in the 1/4 at the time.

I had ported his Brodix heads up to a 315 cfm@28" flow level and cleaned up / port matched his Mopar performance Intake a few years before and now, as we all do wanted more power.


I took a look at his heads again and it seemed that I could pick him up more Intake flow if I could get a bigger valve in the motor, but that could not be done without making a bad cylinder shrouding situation take place.

In then looking at his intake manifold which had a huge runner expansion rate I found that with clay I could neck the runner down and pick up 30 to 35 cfm, all in the same lift range his Cam was providing.

I then broke out my Tub of epoxie and made the changes.

That next weekend at the track with no less better air then what he had the last time the car ran he lost darn near a full second in ET.

This is proof positive that too much port velocity created by a combo of unneeded air flow and not enough minimum port area is a guarantee disaster, just like on the opposite side of the coin where you have too much port area and not enough average port velocity that the motor wants in the power band it's built to run in!

In terms of header size needed just concider this tid bit.
The Butlers 446 cid 1200 hp twin turbo , 8000 plus rpm motor makes that 1200 hp thru 2" headers!!
Why you folks making well under that hp level think you need 2 1/4" tubes is beyond me?

[Tom Vaught]

Travis Q and I agreed on that Header Diameter for the 446 engine (2" header is actually
smaller than 2" as all exhaust pipe is measured by the outside diameter not the INSIDE DIAMETER). Most headers are .060" wall thickness and two walls opposite of each other for the actual area so Butlers exhaust plumbing was actually a 1-7/8" flow diameter per pipe.

Tom V.

[racegto65]

Originally Posted by PAUL K

Hah.... Now you have. Lol

Valve on the left is titanium and the one on the right is a factory RAIV. The back sides are close but the front aren't nearly as deep which helps with the compression. Some of the aftermarket valves modeled after the RAIV's are bricks.... If I remember correctly they were around fifteen grams heavier than the factory valves.

The one on the left looks like stainless from the picture and even if it is titanium I don't consider that a "tulip" face. Just my 2¢

[Tom Vaught]

Originally Posted by PAUL K

Hah.... Now you have. Lol

Valve on the left is titanium and the one on the right is a factory RAIV. The back sides are close but the front aren't nearly as deep which helps with the compression. Some of the aftermarket valves modeled after the RAIV's are bricks.... If I remember correctly they were around fifteen grams heavier than the factory valves.

After seeing the RA-IV disaster (Valve head came off a race car engine) I personally would never put one of those "2 piece" manufactured valves in any engine I would ever own. Might be ok on a show car driven on and off a trailer but not on a engine that is raced, street or track.

Tom V.

[PAUL K]

Originally Posted by Skip Fix

Fact -my RAIV headed 400 picked up 2mph and .2 with smaller headers who would have thought. Also did the same additional increases with a reverse split cam the heads flowed 85% E/I ratio and if flipped the bench on suction the exhaust flowed 90% of the backwards! The motor with the initial cam (288/296 UD) dynoed identical HP and TQ numbers with an HO intake a Torker and a Torker II. At the track with a bigger solid cam the Torker KILLED bottom end that I could not tune out but picked up 2 mph on the top end.


Also would not have thought my step 1 3/4-1 7/8 headers with just a short 1 3/4 tube the same size as an E head exhaust port would have lost 30 HP on my buddies 461 Dave Bisshop ported E head 461!
So yes you can have less flow and make more power. I think Jim Hand showed that with his combination-but lots more guys able to make the HP to run 11s,10s with more flow and an Eddy head that they could with iron D port heads. I would be way too many variables unless you flowed then dynoed a set of heads with flat valves, then put in tuliped.

If I had the tuliped titanium valves I'd use them.

No matter how you look at it the facts are piling up in this thread

Since no one else will share their opinion, do you think a tuliped valve would flow better on a wet flow bench than a flat back valve at higher lifts?