2 heads better than 1 - power porting E7TE iron.

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Erland Cox
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by Erland Cox » Mon Nov 26, 2018 11:37 am

David, what is flack?

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Re: 2 heads better than 1 - power porting E7TE iron.

Post by Stan Weiss » Mon Nov 26, 2018 12:34 pm

Erland Cox wrote:
Mon Nov 26, 2018 11:37 am
David, what is flack?

Erland
Erland,

flack
crap, or abuse; excess pressure on oneself; burdens or weight added by unecessary trials or psychological pressures
My teacher gave me flack for talking in class; Why can't you keep the flack light when I'm trying to study?

https://www.urbandictionary.com/define.php?term=flack

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Re: 2 heads better than 1 - power porting E7TE iron.

Post by Erland Cox » Mon Nov 26, 2018 1:48 pm

OK, thank you!

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Re: 2 heads better than 1 - power porting E7TE iron.

Post by MadBill » Mon Nov 26, 2018 9:45 pm

Flack with a 'c' is actually slang for publicity or a publicist, e.g. "He's just a PR flack." In David's reference the word is usually (but not always) spelled flak with no 'c' and originally meant antiaircraft fire as experienced by the aircrew on the receiving end, hence it became slang for taking criticism: "I got a lot of flak re my last post..."

Now back to our regularly scheduled programming... :)

<Edit> OK, now I've looked at Stan's link, but I like my version better...
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by Erland Cox » Tue Nov 27, 2018 11:05 am

FLAK Flugabwehr kanone. Anti aircraft gun.

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Re: 2 heads better than 1 - power porting E7TE iron.

Post by randy331 » Tue Nov 27, 2018 10:16 pm

Erland Cox wrote:
Mon Nov 26, 2018 11:37 am
what is flack?
Erland
On Speed talk, on some threads, flack is,....information, dyno results, experiences, posts. suggestions, that differ from the originator of the thread.
On those threads real world conflicting results aren't welcome.

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Re: 2 heads better than 1 - power porting E7TE iron.

Post by CamKing » Wed Nov 28, 2018 9:26 am

Carnut1 wrote:
Tue Nov 20, 2018 11:59 am
David Vizard wrote:
Tue Nov 20, 2018 11:41 am
Carnut1 wrote:
Tue Nov 20, 2018 10:45 am


Will that be a hft or hyd roller? Thanks, Charlie



Hyd. roller.

Just had a call from Mike - good news - cam will be shipping today.
DV

Nice! I guess 390hp with DV/Charlie E7's with fixed quench and 32 degrees timing. Thanks, Charlie
If it works well, I'll make you a great deal on it.
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by integrale Evo » Wed Nov 28, 2018 10:06 am

Correctly spelt it's 'flak', it was anti-aircraft fire during the war, but has come to mean strong criticism, i.e. receiving something which has been fired at you verbally.
"you must be strong enough to take the flak if things go wrong"
Synonyms: Criticism, censure, disapproval, disapprobation, hostility, complaints; castigation, condemnation, execration, excoriation, vilification, abuse, revilement, lambasting, knocking, panning, slamming, tongue-lashing, a bad press, verbal, slagging off, slagging.

"he has come in for a lot of flak from the press"

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Re: 2 heads better than 1 - power porting E7TE iron.

Post by David Vizard » Sun Dec 02, 2018 12:28 pm

CamKing wrote:
Wed Nov 28, 2018 9:26 am
Carnut1 wrote:
Tue Nov 20, 2018 11:59 am
David Vizard wrote:
Tue Nov 20, 2018 11:41 am





Hyd. roller.

Just had a call from Mike - good news - cam will be shipping today.
DV

Nice! I guess 390hp with DV/Charlie E7's with fixed quench and 32 degrees timing. Thanks, Charlie
If it works well, I'll make you a great deal on it.
Mike, your statement was just about a waste of time other than making a point that I am already well aware of. Damn it man, of course it is going to work just great - consider where it came from!


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Re: 2 heads better than 1 - power porting E7TE iron.

Post by David Vizard » Sun Dec 02, 2018 1:40 pm

We have looked at the difference in output produced by the RBJ Racing 'production ported' E7TE heads and those more extensively modified E7TE's that
Charlie and I did. (page 38 of this thread)

Now lets look at the differences we see on the flow bench.

Take a look at the CFM chart below.

What we see here almost certainly represents twice the man hours to achieve but ---- we have to ask just how much longer would it have taken without the in depth analysis rendered by IOP. Notice the RBJ hed, with it's bigger throat (1.48 Vs 1.4) flowed really well up into the higher lift ranges but was, at what would have been max valve lift for our 260 Mike Jones cam, overtaken by the more modified head.

Remember that basically we are looking at a set of heads that went 50 HP over stock Vs a set that went 70 HP over stock. The question is:- does this look like enough extra airflow to have been able to deliver such a gain???

OK you head specialists let's have your thoughts please before I go on.
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by CamKing » Sun Dec 02, 2018 2:39 pm

David Vizard wrote:
Sun Dec 02, 2018 12:28 pm
CamKing wrote:
Wed Nov 28, 2018 9:26 am

If it works well, I'll make you a great deal on it.
Mike, your statement was just about a waste of time other than making a point that I am already well aware of. Damn it man, of course it is going to work just great - consider where it came from!


DV
I was just trying to make a little cash for Christmas :lol:
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by Erland Cox » Sun Dec 02, 2018 3:42 pm

When I have enough head flow for the combination I have never been able to get more power from a better head.
But then the previous combination was optimized around the old head.
Exhaust manifolds and exhaust duration seem to be very sensitive.
Once I swapped carbs to bigger, then head, then cams and at last the header.
Power had stopped at 220 hp but the header change released the potential of the changed parts with a 20 hp jump to 240 hp.
I guess that 4-1 headers on a V8 are not as touchy as 4-2-1 headers on a 4 cylinder.

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Re: 2 heads better than 1 - power porting E7TE iron.

Post by PRH » Mon Dec 03, 2018 1:03 pm

I don’t know how much difference I’d expect between the two in a combo like that, but it does seem like that particular engine combo(small cubes/small cam, low rpm) would lend itself to the better flowing heads with the smaller bowls and valves, as opposed to something that is severely area limited.

Another armchair quarterback comment........
It seems to me the test that really should have been done with such a mild baseline build would be a set of heads more in line with what would more likely be used in that type of build.
Some of that same castings done up with the 1.84/1.54 valve package and a nice valve job and simple bowl blend.
Somewhat handy with a die grinder.

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Re: 2 heads better than 1 - power porting E7TE iron.

Post by n2xlr8n » Tue Dec 04, 2018 9:59 am

Personally, I found it particularly interesting that the DV/CS heads made that much more with a weenie camshaft.
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by MadBill » Tue Dec 04, 2018 2:21 pm

It's often said that heads that aren't up to the task can be 'crutched' to some extent by more cam duration, so the reverse is likely also true: heads that are ideal for the application don't need as much cam to deliver.
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