Don Terrill’s Speed-Talk

Can you use water jackets as an intake port?

After yet another depressing flow bench session on these E5AE smogger 351w heads, it was decided that the 1.78” intake valve is just too small. These 2.125” valves should fix that. There’s about .030” between the 2.125” intake and 1.45” exhaust valves. I figure a 46* I/e split on the cam should be about right.

travis wrote: ↑Sun Sep 08, 2019 7:34 pm D832E6C0-2C93-4F16-B431-A01B879A10AF.jpeg


Can you use water jackets as an intake port?

Wankel engines need the insides of the rotors cooled, which is usually done with stonkin' big oil coolers half the size of the water radiator. Sachs air-cooled Wankels used for lawnmowers (!) drew the intake air through the rotor for cooling. I always wondered how that even worked at all...

Can you use water jackets as an intake port?

Isn't that what they mean by Water to Air inner-cooler?

One way to check how efficient a given amount of port area is in any Head is to keep in mind that a ideal perfectly streamlined orfice of 1sq inch will flow like 142 cfm at a 28" test pressure.

In a perfectly perpendicular idealized port a 1.780" valve with its 2.396" square inch of area should flow well over 300 cfm@28" depression.

We have a long way to go, lol!

Yes, you certainly can use a water jacket as an intake port as long as you are willing to use the intake port as a water jacket

mag2555 wrote: ↑Mon Sep 09, 2019 6:53 am One way to check how efficient a given amount of port area is in any Head is to keep in mind that a ideal perfectly streamlined orfice of 1sq inch will flow like 142 cfm at a 28" test pressure.

In a perfectly perpendicular idealized port a 1.780" valve with its 2.396" square inch of area should flow well over 300 cfm@28" depression.

We have a long way to go, lol!

I’m at 176 cfm@.500” lift...a long, long ways from 300+

Are those heads anything like E7's? The 1.84 valves worked out pretty well in a set of those I ported. I lowered the Apex of the intake SSR around .080" and smoothed out the radius from there. That was worth over 10cfm. I ended up with those heads going 214 at .600" lift. Not monster numbers, but made good torque on the truck they went on.

I’d do the 1.84 intakes with some minor blending....... and take the added area under the curve you get from the larger curtain area.

I got to give you credit You tried hard. The only way to learn is to try. Some are just too wimmpy

Tried way too hard more like

These are very similar to the E7TE heads, except with a 69-70cc chamber. Supposedly with a .040” flat mill they end up around 62cc like a E7TE.

I had already done a bowl blend/cleanup on the intake ports and the same plus ground out some of the smog hump out of the exhaust and ended up with 167/126 cfm I/e at .500”...roughly 13/20 cfm better than a stock E7TE. Then I reshaped the guides, cleaned up the ports a lot better, a tiny bit more off the short turn, widened on the cylinder wall side around the guides, raised the roof around the apex of the short turn, and took out all the smog hump out of the exhaust. All together easily 4+ hours of work (going slow though being cautious) for anywhere from 7-11 cfm gain between .200” and .500” lift. Intake still peaked at .500”, exhaust pretty much peaked at .500” only gaining 1-2 cfm at various points above that.
What is interesting is that I may have done too good of a job on the intake ports relative to what they flow. Port speed at any point from the flange to the apex of the short turn was only between 260 and 271 fps, only speeding up at the short turn on the common wall side to 375 fps...still 270-ish on the cylinder wall side of the apex. I was much more conservative on the short turn on these than on my D0OE’s. I think these things are crying for some bigger valves and laying the short turn back a little more. They are nice and quiet at all lift points, so that’s something I guess.

4 hours per head, or per pair of heads?

If it’s per head, is the rest of the engine package going to be able to take advantage of that work?

The eternal question; does CFM really matter to power output?

As relating to the question " does CFM relate to power" someone has bumped up an older thread recently that has some incredible discussions going on relating to that very topic. The thread is titled " do hemi head ports go into sonic choke" or something close to that. Maxracesoftware articulates some very interesting examples he has experienced relating to how an engine responded to different flow characteristics from two different sets of heads.
Some very informative and well written discussions in that thread. That thread is bumped back up to the first page, check it out if you have not already done so. Well worth anyone's time.

I just read it...definitely some excellent info there! Makes me think that maybe I should just trim that one fast point a bit and call these heads done.

travis wrote: ↑Wed Sep 11, 2019 2:43 am I just read it...definitely some excellent info there! Makes me think that maybe I should just trim that one fast point a bit and call these heads done.

Yes some good info, I just wish it had detailed pictures and instructions... it would make my adventure less scary.
BTW I ended up ordering some of that high dollar Tetrachloroethylene for my epoxy test, now I just need some sulfuric acid.

Here is the Sonic Choke link for those interested.
viewtopic.php?f=1&t=840