Ok, I've now read all three pages of the link you sent, Stang, and sure appreciate you having sent it. But, did you get the feeling I'm just like Steve, the OP? I sure did - paralysis by analysis. That's me.

Anyway, those are exactly the pistons I hope to be buying. I say "hope" since I've had to ask the guy to hold them, at his asking price, until this afternoon since my grandtwins are to arrive here any minute. Unfortunately, they'll have to leave mid-afternoon, so I can go get the pistons then.

And, I do see the advantage of them in both CR but also quench area, which is the more significant thing. (I've read about quench for quite some time but now I think I may almost understand it.) At least I'll have an option when I get to that point, which should be soon.

About gaskets, I'm going back with the standard Felpro gasket that I used on the previous engine. I pulled one of those off and the metal surrounding the bore measured .050 - .052". But, most of the posts on that thread say the standard gasket gives .040". Not that it is that significant, but do the ones I'm using compress to .040 and spring back to .050ish when pulled? Just curious.

 

Got the pistons. They look good and have never been mounted, much less used. For $75 I think they were a good buy, and the guy threw in a new C4 flex plate 'cause he was wanting rid of the stuff. I'm assuming the guy was right that a C4 takes a different flex plate than a C6, but will look as I have a couple of them.

Now I just have to get the heads flow tested and get cracking on cc'ing the heads and other pertinent volumes. Will get back with y'all when I get more info.

 

Congratulations on all your progress, Gary.
That was a lucky deal.
Hope those pistons work out for you.

 

Jim - A bit premature on the "progress" compliment. I sit here humbled & disappointed. For the most part what I've done with all the effort heretofore has been for naught. However, please don't take that as lack of appreciation for all the help I've gotten. More, it is yet-another reminder to myself to do my homework before rather than after acting.

Ok, why all the angst? Because I had the heads flow-tested yesterday. Here's the results: (Sorry for the small size. Guess I need education.)


As you can see, I didn't do any good on the intake to speak of. In fact, when the guy performing the test (Eric) backcut the stock valves at 33 degrees the low-lift flow was better than all my porting and valve work - although, as he pointed out before we ran the test, backcutting gains down low and gives up at the top end.

On the exhaust it looks like I did some good. However, most of that is at high lift, and my cam doesn't quite get to .500" so the stuff above that is of no value.

In order to compare my numbers to others I've put them in the following table along with some from Desktop Dyno (DD), CamQuest (CQ), and some I found on the internet - smogger, goingbroke, and Thumper. It should be noted that Thumper sells his ported E7TE heads for $595/pair. And, it should also be noted that I've left the .600 and .700 lift info out of the "printout" of the table to make it fit the page better since my cam doesn't lift that high.


As you can see, both applications assume a lot more flow from a stock head than these heads give. And, if you pick either of the "improved" head selections in the programs you get an even more inflated expectation. Also, there are some out there that know a lot more about porting than I do.

So, what's it all mean? Eric, who just got back from the Amsoil Engine Masters competition and placed 6th, said my engine should put out 311 HP and 386 ft-lbs of torque. Since I don't have a dyno available to find that out, the best I can do on that is to run the numbers through the two dyno applications I have - Desktop Dyno 2000 and Comp Cams' CamQuest6. Here's a table that shows horsepower and torque, both peak and average, for the engine as I'm building it with various head/valve combos.

So, what are the observations? I'm not sure as I'm still trying to wrap my head around the results. What are yours?????
?
?
?
?

 

OK, what did I say? You'uns have been quick to come back before, but not this time so it must have been something I said. Or, the volume of what I said? Or the plaintive way I said it?

Well, I'm calming down a bit and now realize I need some advice, so here I am asking for your wisdom. I think I have it down to a few questions. But, first I need to reiterate my goal, maybe more for myself than you. Goal: Increase torque at low end of operating range, as well as increase fuel mileage.

Given that, here are my questions:

1. Have I gone far enough? This isn't an effort to achieve the goal at any cost, as it really has been intended to be a budget build. And, I need to keep in mind this is but one component in the overall scheme.
2. If not, what next?
   1. Modify these heads or valves more?
   2. Get different stock heads and bolt them on as-delivered? If so, which ones?
   3. Get different stock heads and clean them up but not spend the time truly porting them? Which heads?
   4. Go to aftermarket heads? Which ones?

Toward an answer to questions 2.3 - 2.5, I put a WTB on craigslist as well as a search agent via CraigsPro, just to help me make a descision based on cost, if not benefit. I've gotten one response back for a pair of Holley System Max heads ready to go for $600. However, a bit of googling tells me these heads are fraught with problems as they changed the geometry of the valve train and it didn't work - it wears out the valve guides in short order.

Anyway, please let me know your thoughts. I'm forming some myself but don't want to bias you with my own.

And, btw, thinking through it enough to do this post has been helpful in and of itself. So, you are helping already!

 

Would it be helpful to determined what went wrong/failed in your first attempt to port these heads before you move forward? I mean, the "easy" solution would be to just buy a set of Thumpers. I'm not sure if they would survive a cost analysis, but it would certainly be easier.

True aftermarket heads would always be beyond a "budget build", reworked heads like the Thumpers are closer, but DIY heads make the mark. So keeping to the goal of this project, and hoping that you succeed so that I can copy your work, why did your attempt at a DIY fail (not perform as expected)?

Inquiring minds want to know....

 

Gary, head porting used to be PFM, mostly trial and error. Years ago in Hot Rod Magazine someone built an inexpensive home flow bench that used a vacuum cleaner to pull the air through. I don't remember all the details as to how he measured the flow. Something like that so you could see changes as you worked might be an idea.

 

Ha ha, I actually had to go look that up. LMAO, that 's great! (and also true)

 

You guys are going in exactly the same direction my nephew, the mechanical engineer/hot-rodder, went: What is wrong with the head, and could you build a rudimentary flow bench to find out?

I started down that path, at least mentally, thinking I could go back to Eric and get his thoughts re what was wrong. And, David Vizard outlines how to use a shop vac to build a flow bench, including a way to calibrate it to get back to what Eric got.

But then I read the results a guy posted re his quest to get >200 CFM from the intake side of E7's. He went through a bunch of steps (I'm thinking 39 steps, but maybe that was just a movie), documenting each with flow bench results awa diagrams and descriptions, with some of the steps actually reducing the flow. In the end he got excellent flow with those heads but basically made them look like GT40's.

At that point I stepped back and questioned my goal(s) and came to the conclusion ...... oops, there I go prejudicing your thinking.

PLEASE don't take my response as criticism. More, it is intended to be thanks to you for responding and encouragement to others to follow suit. There are no wrong answers, but the more answers/responses the more help there is for me to think through this.

EDIT: Forgot about the PFM comment, but I'll confess I, too, had to look it up. And, unfortunately, from where I sit it appears to be true. However, "the big boys" seem to have figured out the reasons things work or don't.

 

Amazon.com: Engine Airflow HP1537: A Practical Guide to Airflow Theory, Parts Testing, Flow Bench Testing and Analyzing Data to Increase Performance for Any Street or Racing Engine (9781557885371): Harold Bettes: Books

not sure if you have seen or read this book before, but it might help. it has alot of theory in it and alot of math, but its a good thing, by far the most in depth that I have seen. I bought it on kindle and liked it enough to buy the hard copy. there is even some math for building your own flow bench.

in it he talks about using pitot tubes, flow *****, and flow wands to find separation. the latter of which could probably be used with nothing more than a shop vac sucking on your head.

my question for you: how consistent are the runners from port to port?

I agree that a little more flow would be good, and no the results were not what you were hoping for. but if you are aiming for mileage I wouldn't get too caught up in how much they flow, but in how well they flow, and that each port flows the same (not sure how close the stock ports are to each other, but im guessing that its the same as the rest of a factory engine: sucks). I think you should be thinking more along the lines of blueprinting than going huge for power.

(didn't try to rant or preach BTW, I admit that the only thing I have tried porting was a briggs and stratton. just trying to toss in my .02)

 

Hadn't seen that, but I do appreciate the link as it will now arrive on Friday. (One of the advantages/downfalls of being a Prime member - sooooo easy to order.) I'll read it ASAP.

I can't answer your question re each cylinder since all I did was to test one cylinder on a stock head and my ported head. The intent there was to see if I'm made improvement. Having said that, Eric did take readings at 9 places in each intake port via a pitot tube, and I didn't get off with that info. Maybe I should get it to find out more.

So, one approach would be to do whatever I'm going to do, with whatever head and/or valves, and go back to Eric to flow all cylinders with an eye to not only flow but consistency. And, btw, in that last sentence is another variable I forgot to put in my list of options/questions in today's first post: Do more work w/the valves in light of what Eric showed me. Wish I was good enough to somehow extrapolate or interpolate such that I can guestimate what Eric's back-cut valves would do in my ported head. Would it give more down-low flow awa decent flow up high?

But, you are kinda/sorta thinking like I am starting to - if I'm in this for mileage and torque ...... There I go leading the witness.

As for preaching, in what way? Seriously, everything you said was constructive and not at all like preaching or ranting. And, btw, was the B&S a Model N? No, couldn't be, surely it was much later. I'm giving away my age, but I will say I spotted one of those 50' away in the museum across the street from the Dover Mile one day while waiting on the race to start.

 

I guess I may have to look for that when I get home. My porting work has been primarily on the exhaust side as most Ford heads are really bad in that area, worse once the Thermactor systems started. I used to try to find 65 289 4V heads to drop on 302s, big improvement! I'm glad everyone got a chuckle out of my PFM remark. I may later try some work on my F3TZ 460 heads for project 468.3 (.040 460). I would really like to be able to build a ram intake for it similar to the late BB french engines (it circles around to get the needed length).

BTW, I am old enough to remember B&S A,N,ZZ etc. I have an Onan generator that is old enough it has a postal zone in the address (Onan division of Studebaker corporation) and a 1946 Evinrude 2hp outboard.

 

There is a big block guy in Tacoma Washington who offers port templates and tutorial online for a fee.
Re in"Car"nation High Performance, BBF information / porting index

I wonder if this sort of information isn't available elsewhere for Windsor engines?

 

All this is way over my head. Especially since Pulse Frequency Modulation is a method of representing an anolog signal. And here we are dealing in flow which i suppose could be measured anoalogicaly, but there is where I fall short as I am usualyy ill-logically inclined.

 

Herb - Google "what does PFM mean". I did. Ain't pulse frequency modulation for the "hip". Just us old electronics types.

All - You seem to be thinking I should go down the "port s'more" path, either reworking these heads or maybe some different ones that flow reasonably "out of the box". While I'm not saying no to that, what about what Stang said some time ago: "If torque is all you are after, stop where you are." Or, maybe put Eric's 33 degree backcut on all the valves and "stop where I am"?

I don't want to get so engrossed with each alligator that I forget the object of this exercise was to drain the swamp. IOW, for what I started to do have I gotten "there" as far as the heads are concerned?