FE Power Tunnel Port Cylinder Heads

[blykins]

Flow numbers and valve details for the exhaust side of the SE head are shown in the link below:

https://fepower.net/simplemachinesforum/index.php?topic=7336.0

Also, no reason that the tunnel ports I'm making wouldn't flow in the 360 cfm range with some porting.  But my info for stock tunnel port heads is that they flow around 330 cfm, and that is what I'd expect mine to do.

I saw where it was said stock Tunnel Ports flow in the  320 to 330 range, and  the ported version in the link I provided in my previous post was ported but had a raised floor to reach the 360 cfm, and I don't think the ports were made larger to achieve that flow.

It showed 360 cfm was reached with a 2,250" valve, I wonder how much more can be achieved with a 2.300" valve, and room restraints may require a 1.675" exh valve, with still 240 cfm @ .600" without porting. I am using the .600" range for my self, I would run a cam around .600 to .650" lift for the street.

Going to a bigger valve doesn't always guarantee that you will see benefits.  Sometimes you don't.  The port and throat have to be in line with the valve size and there has to be no issue with valve shrouding, which means that you really need an aftermarket block to take full advantage of a 2.300" valve or bigger.  A 2.250" intake valve will support well over 700 hp. 

[1968galaxie]

One must also remember that the tunnel port has an intake which reduces the actual flow the cylinder sees.
The push rod tube (even when modified) has a significant effect on true flow numbers.
375 cfm without an intake and 330 or less with intake attached.

[blykins]

375 cfm without an intake and 330 or less with intake attached.

Source?

[frnkeore]

The intake tube, is not in the intake port of the head. Test head flow, w/o the intake attached, is the only way to test it.Therefore it becomes a intake porting issue.

If the port in the intake, is widened and contoured, at the tube, much of that problem should be mitigated.

[1968galaxie]

Source?

Seriously?
You haven't flowed a TP intake with a TP head?
At least make a meaningful measurement with a push rod tube in  your radius plate.

[blykins]

Have you?   Or are you quoting someone?

[jayb]

All tunnel port intakes have the port widened at the pushrod tube.  My intake adapters do that also.  Jon Kaase says that the tunnel port is the only head that actually picks up flow with the intake attached.  Haven't flowed one myself, but I respect Kaase's opinion.

[blykins]

I will tell you that I don't build a ton of Tunnel Ports, probably 6-7 total.  They're just not in high demand and a lot of guys want to hang onto the original parts. 

I will also tell you that in all of the FE's I've ever built, including engines with TFS heads, ported TFS heads, CNC ported Edelbrocks, etc., etc.. the engines that have made the most hp/ci were Tunnel Port headed engines. 

This 1x4 TP intake, modified by Joe Craine, averaged 490cfm between all 8 runners.   I'd be willing to listen to some arguments about how the Tunnel Port heads are at a detriment because of the tubes in the intake, but that would be about the extent of my involvement.  I think I even made the same comment years ago, but my outlook has changed.

[1968galaxie]

I NEVER said the TP head was a detrimental head. Of course they made - and still make impressive power.

I don't build engines as a profession. However, all of my personal builds have had the intakes as well as the heads flow tested together. Testing a head alone, as well as testing an intake by itself can be very misleading. The entire intake tract
is important. A intake with a lousy approach angle will not show up on a flow test of the manifold itself - however, with the head attached - yikes!

Even my turbocharged 86 Escort had the head flow tested with and without intake during development.
Same for the FE and same with the 503" 385 series 800hp build.

It does help that my brother does cylinder head work and has a SF600 to test theories.

[Joe-JDC]

That intake manifold also has the floors filled to match the epoxy in the heads and still manages to flow 490 cfm average.   I have been a proponent of porting any intake manifold to flow at least 110% of the head flow, and for performance usage, I try to get the flow up to 120-125% of the head flow.  When bolted together, the heads don't normally drop in flow this way as a result.  I have flowed hundreds of heads with intake manifolds over the last 29 years to verify the process.  I also work very hard at balancing each runner's flow so that each cylinder makes close to the same power and torque.  Makes the carburetion easier to jet, also.  Joe-JDC

[blykins]

Apropos to the discussion about Tunnel Port tubes, the SBF street Tunnel Port heads also do very well for themselves despite having the tubes.  They're in the heads on a SBF though. 



This was on a 312ci SBF with just a 221° @ .050" hydraulic roller camshaft and 9.9:1 compression.  Very respectable!

[Katz427]

In a time ,probably late 70's, I ran some tests on the effects of various size and shape tubes,  on the airflow, and fuel atomization.  Of course, the diameter of the tube, and too some extent, shape, affected CFM. But what got the attention of the engineer, was  how fuel atomization was changed down stream of the tube.  One reason I like Jay's raised  intake port, with no pushrod tube. Of course  this testing was steady state, airflow in a pretty much straight port, and not a true tunnelport head.

[1968galaxie]

One can certainly make decent power with a push rod in the middle of a port.
Ford tried it (reasonably successful in NASCAR) as well as TP302  in trans am.
The Boss 302 head turned out better.
Ford in the late 80's tried a TP 351 head again, limited success.

I love Fords, but some ideas come and go and newer better cylinder heads evolved.
TP type engines are very cool dinosaurs. Wish I could afford one.

[1967 XR7 GT]

Flow numbers and valve details for the exhaust side of the SE head are shown in the link below:

https://fepower.net/simplemachinesforum/index.php?topic=7336.0

Also, no reason that the tunnel ports I'm making wouldn't flow in the 360 cfm range with some porting.  But my info for stock tunnel port heads is that they flow around 330 cfm, and that is what I'd expect mine to do.

I saw where it was said stock Tunnel Ports flow in the  320 to 330 range, and  the ported version in the link I provided in my previous post was ported but had a raised floor to reach the 360 cfm, and I don't think the ports were made larger to achieve that flow.

It showed 360 cfm was reached with a 2,250" valve, I wonder how much more can be achieved with a 2.300" valve, and room restraints may require a 1.675" exh valve, with still 240 cfm @ .600" without porting. I am using the .600" range for my self, I would run a cam around .600 to .650" lift for the street.

Going to a bigger valve doesn't always guarantee that you will see benefits.  Sometimes you don't.  The port and throat have to be in line with the valve size and there has to be no issue with valve shrouding, which means that you really need an aftermarket block to take full advantage of a 2.300" valve or bigger.  A 2.250" intake valve will support well over 700 hp.

Hi Brent

I remember one of your Tunnel Port builds, maybe the first one, you talked about your porter made the int port smaller by raising the floor and getting better cfm, so assuming your using the same guy on all the TP builds, since he has experience porting TP's. A question to him, would a 2.300" valve increase cfm ?  A porter would have a sense about such things, like if a larger valve could flow more or not in that port?

I found some numbers for a TP int port and they were 2.2" x 2.31" but don't know if their correct.

And Jay mentioned the chambers were designed for 4.250" bore, so a 2.300  x 1.675 giving .050" larger Int and a .075" smaller exh should fit.

The exh already supports 240 cfm @ .600 lift with a 1.675" valve, without porting.

The chambers are of a modern design but not exactly the same as FE Power Cylinder Heads chambers.

[blykins]

Richard,

I've used two head porters in the past for Tunnel Port builds.  Neither of them have ever suggested using a larger valve.  I think that's because of two reasons:  1.  Not enough room.  2.  A 2.250" valve will support *a lot* of horsepower. 

Here's a picture of a Tunnel Port chamber with a 2.250"/1.750" valve pair. 



The seats are already butted up against each far enough that you don't end up with two true complete circles. 

In addition to all of that, an engine needs a given volume to make a specified horsepower.  We have to watch about making things too big as a big valve/big port can make for a lazy engine if everything below the head is not sized to match it.