Manley vs. Ferrea Valves on High Port SOHC

[jayb]

For you SOHC guys, here are some flow numbers to consider when purchasing a set of valves.  The Ferrea valves have a big advantage in weight over the Manleys, but they don't flow anywhere near as well:





Also FYI, with Comp 943 springs (240 on the seat, 600 over the nose), and using the Manley valves, the valvetrain is stable up to 8000 RPM, based on Bill Conley's spintron tests.  The valvetrain would undoubtedly be stable at higher engine speeds with the Ferrea valves, which are about 20% lighter than the Manleys, but you are giving up port flow to get there.  Since 8000 RPM is about the limit with my stroker motors, I'm sticking with the Manleys for future builds.

[machoneman]

That's cool Jay, even though I'd need to win the big Lotto to do a cammer....LOL!

But, a side-by-side pic is worth a thousand words......suspect one is a pretty much a flat head and the other is a tulip.

Good guess?

[jayb]

No, and that's the funny thing.  The valves are very similar.  On the exhaust side, they are nearly identical except for the margins around the edge of the head; here the Ferreas are rounded, while the Manleys are square.  On the intake side, the Manley have a backside angle of 7 degrees if I recall correctly, and the Ferreas are a little flatter than that, and also the margin on the edge of the head of the Manleys is wider than the Ferreas.  The Ferrea intakes also have this weird convex shape to the cylinder side of the valve head.  Here's a couple of photos, with the Manleys in the center and the Ferreas on the outside:





I'm at a loss to explain the difference in performance, but it is very substantial.  Looks like its back to the Manleys for me...

[Chad D]

How much does the cylinder-side convex shape affect chamber volume?

[hotrodfeguy]

I can see the intake valve not working, the F intake valve looks like a table its so flat. And that would disrupt flow. But the F exhaust has me completely miffed One almost has to play with cutting down old valves on a lathe IE. playing with the shapes in a flow bench to see what works and what does not.

[machoneman]

Thanks for the pics. Can't say I've ever seen a similar convex-headed valve before on any engine.  But hey, we all know that valve angles, backcuts, and even the shape of valves can and does affect airflow a bunch. Too bad that most mere mortals must rely upon others to guide them as flow benches and multiple tests are mostly out of our league.

 

[e philpott]

Jay , was you able to figure out your coolant leak issue in the cammer head ??

intersting on the valves , my brother and I were just discussing the diff between Ferrea vs Manley for his project , looks like he's going Manley

[jayb]

How much does the cylinder-side convex shape affect chamber volume?

I don't know for sure, but it is a fairly small area, and the convex portion looks exaggerated in the pictures.  I would say less than 1cc, but that is a guess - Jay

[jayb]

I can see the intake valve not working, the F intake valve looks like a table its so flat. And that would disrupt flow. But the F exhaust has me completely miffed One almost has to play with cutting down old valves on a lathe IE. playing with the shapes in a flow bench to see what works and what does not.

Again I think the picture exaggerates the difference somewhat, but the Ferreas are definitely flatter.  When I did my flow studies on different valves for the SOHC heads several years ago, I tried a 20 degree tulip style valve on the intake, and it was also way down on flow compared to the valve shown.  So if the flat Ferrea valve is a problem, going the other way to more tulip is also a problem.

[jayb]

Jay , was you able to figure out your coolant leak issue in the cammer head ??

intersting on the valves , my brother and I were just discussing the diff between Ferrea vs Manley for his project , looks like he's going Manley

The coolant leak on the SOHC heads was porosity in the castings.  Funny that my first pair had no problems with this, but the second pair had it really bad.  Supposedly they were cast in the same batch.

Your brother is building an SOHC?  If not, I would be reluctant to draw conclusions about Manley vs. Ferrea based on this data.  Different engines and different valve styles will certainly give different results, and there may well be some cases where the Ferreas are better.

[Barry_R]

Valve shapes are very, very significant on flow.  We had one customer here who demanded we use his already owned set of valves in a set of new CNC ported heads.  After we did the heads for him he flowed them at a shop local to him (no idea about their equipment, intent, or capability).  The flow he got did not match our numbers by a large percentage and he decided to return the heads for a refund because we were so bad at this porting stuff - he kept his valves.  We got them back, installed our normal valves, and they flowed just fine & went onto an engine that made nearly 800 HP.

If you're guys welded on the heads before porting it's possible to pull debris/mold release/sand/crap from the water jacket side of the casting into the molten port wall weld even though it's still plenty thick enough and passed pressure check before the welding was done.  Not that I would know anything about that...

[jayb]

Thanks for the comments Barry.  The one thing that I'm really not sure about is how good the correlation is between flow bench numbers and power production in a case like this.  It begs for a dyno test, where you run the two valve types back to back and see what happens to the power.  Maybe one of those future projects.

On the heads, they weren't welded before the leaks were discovered, so they were obviously porous from the start.  Its very strange, since the other pair of these heads, purchased at the same time, didn't have this problem.

[cammerfe]

I have a very freely admitted bias AGAINST Manley since I equate Manley with chibrolay. And, much more important, I have had very good relations with Ferrea over the years.

Might I suggest that you relay your flow information to Ferrea? Since this forum is, without doubt, THE place for technical information regarding the Cammer engine, I'd believe that they would be anxious to work with you to create a superior product.

Just a thought!

KS

[jayb]

Just to add a little more data on this subject, my friend Kevin (thatdarncat on this forum) recently had a set of SOHC heads done with a minor bowl cleanup on the heads and a valve job.  He also had purchased the Ferrea valves for the SOHC, and was able to get flow data for both the Ferrea valves and also the Manley valves that I had previously used.  Here again the same difference showed up in the flow numbers between the two valves; see the charts below.  I have to say that it is nothing short of amazing to me that just a change in valves will have this kind of a major change in flow.  It really speaks to the importance of the valve and the valve job in generating the best flow numbers.

This weekend I'm pulling the 577" SOHC back out of my Shelby clone, for some dyno development work, before I put it back in and start running it at the track this summer.  I think the first thing I'll be doing is pulling the heads and replacing the Ferrea valves with Manleys...

[babybolt]

What is the diameter on these valves?  It would be interesting to scan them or make a fixture to adapt the backface of the valves to your cam digitizer.