SSR getting crazy

[phoenix]

Can a SSR be to high.When you look at some of the cyl heads out there ie.. Pro Topline 12 degree, Mclaren Pro King, IHRA boss Ford.. the SSR is extremely high.

[maxracesoftware]

Can a SSR be to high.When you look at some of the cyl heads out there ie.. Pro Topline 12 degree, Mclaren Pro King, IHRA boss Ford.. the SSR is extremely high.

in most of the Heads you've mentioned is not much of a problem .

Heads that have too much of a "Ski-Jump" shaped Short Turn shape
like a 23 deg SBC that the Floor starts off just a few hundred thousandths
above the Block deck, and rises very quickly into an abrupt
"Ski-Jump" can definetly show HP/TQ losses on the Dyno and down the DragStrip if that "Ski-Jump" is taken too far.

example=>
suppose you Flow Test a Cyl Head , and its nice and stable throughtout
the entire Lift Curve with great CFM flow numbers ,....you then add clay or epoxy on the short turn apex area and see 2 to 4 percent Flow gains on a FlowBench ....but in reality on a Dyno or down the DragStrip, you will see a HP/TQ Loss even though the FlowBench showed you a Flow gain
by making the Ski-Jump taller and more abrupt.

if you would have used a Pitot Velocity probe at the Ski-Jump,
you would have seen you greatly increased the velocity over the
Short Turn apex and are now getting into CHOKE and/or Fuel/Air separation on a live engine, even though the FlowBench numbers increased.

you need just the correct amount of Short Turn apex height and curve
"RELATIVE" to where the Port's Floor height is and the Roof Height and cross-sectional area at the Short Turn.

[phoenix]

Thanks Meaux. The heads I picked were extreme. The port floors on some of those are at least 2 inches from the deck, if not more. Can the port get to high from the deck?

[Darin Morgan]

Can a SSR be to high.When you look at some of the cyl heads out there ie.. Pro Topline 12 degree, Mclaren Pro King, IHRA boss Ford.. the SSR is extremely high.

The answer to your question regarding SSR height is, heck yes it can be to high! Have you ever seen a set of those piece of $hit Mclaren heads ever make any power? NO and you never will unless its an injected alcohol low end TQ engine. Any engine that operates at high engine speeds has to have the proper SSR height or the engine will shut off like a light switch in the upper rpm ranges. Not many professional engine builders even know this but the good cylinder head guys know how to maintain a good port height to valve centerline angle and when people get carried away with there flow benches as in the case of both the Mclaren head and the Pro Top line heads, the power goes down the tubes. The Pro Topline convention BBC heads shut off bad even on mild engines like our 555cid Super series engines. They flow a lot of air on the flow bench but the dynamics are horrible on the running engine. The Ford IHRA Boss is a different matter because the SSR height not that high, it just looks that way.

[phoenix]

Thanks darin. This is a learning process for me. Its information from guys on this forum that really help to educate.

[dbusch]

i have never seen the mclaren head up close. is the short side the entire floor or is it just too much of a 90* turn as it approaches the bowl?

[Guest]

Would flowing the heads at a higher depression show that the short turn is to high?

[cboggs]

Would flowing the heads at a higher depression show that the short turn is to high?

Yes, .. Darin talkas about this a bunch, .. and I've seen it too.
Flow looks good at 28" but at 36" or above the short turn starts to
fall appart, .. I think it's very important to flow at faster air speeds
to find problems.

I've recently found some power on a Ford 4 cylinder buy using
a higher flow depression.

Curtis

[la360]

Excuse my ignornace, but SSR is an abreviation for what exactly? I will probably kick myself when you guys tell me.
AL...

[bill jones]

-ssr means the short side radius or the floor of the port basically from the crest to the valve seat.

[la360]

This is just another term for the ports short turn?
AL...

[maxracesoftware]

-ssr means the short side radius or the floor of the port basically from the crest to the valve seat.

SSR = Short Side Radius

i usually use the abbreviation of STR = Short Turn Radius
for the same referrence
from the Seat Angle -to- Short Turn Apex height on the Port's Floor