[Formulajones]

Originally Posted by gtofreek

Now if I had to pay someone $2000 to make these heads work good, then forget, I would buy some aluminum heads.

That's hitting the nail on the head right there. When you have skills and machines available to you, it makes all the difference. You can make a very strong iron headed engine with any make/model, if you want to pay someone to spend the time to work on them. That's why people jump on the modern aluminum head band wagon because the cost of working 45 year old iron heads like Paul is doing here could wind up being double the cost. Not cost effective for us that pay for the work unless you're a class racer.

Paul has a huge advantage here, and it's nice to see someone spend the time with antique parts to make power, the old school way. I have no doubt it will make the power he's looking for.

[gtofreek]

I was just thinking, I've had this car for exactly 1/3 of my life! Damn, it's time to get it running!

[71 T/A]

Originally Posted by Formulajones

That's hitting the nail on the head right there. When you have skills and machines available to you, it makes all the difference. You can make a very strong iron headed engine with any make/model, if you want to pay someone to spend the time to work on them. That's why people jump on the modern aluminum head band wagon because the cost of working 45 year old iron heads like Paul is doing here could wind up being double the cost. Not cost effective for us that pay for the work unless you're a class racer.

Paul has a huge advantage here, and it's nice to see someone spend the time with antique parts to make power, the old school way. I have no doubt it will make the power he's looking for.

Uh.... no. It is cheaper by like a $1,000 to pay SD Performance to port your iron heads to flow real close to out of the box E-heads and KREs. Those heads cost about $2,500-$2600 while porting a set of iron ones will be around $1400-$1500.

I know. I did it. Now if you want even more power, then you go with the aluminum heads.

[Formulajones]

Originally Posted by 71 T/A

Uh.... no. It is cheaper by like a $1,000 to pay SD Performance to port your iron heads to flow real close to out of the box E-heads and KREs. Those heads cost about $2,500-$2600 while porting a set of iron ones will be around $1400-$1500.

I know. I did it. Now if you want even more power, then you go with the aluminum heads.

Nope, not what I was talking about. I didn't mean "simply porting iron heads." When you get into the fancy stuff like angle milling (which requires intake milling) and getting into things like changing valve angles and all that fancy stuff, reshaping combustion chambers and welding up cast iron, that's how you make big power with stock stuff. It's not cheap by any means. Most of that stuff is already designed and cast in the aluminum offerings you buy.
Appears to me Paul is going above and beyond a "simple" port job here to extract anything he can out of a stock casting. Aluminum heads don't necessarily mean "more power" when you get into the details like this unless you are buying something that you simply can't do with an iron head, like wide ports for example.

[gtofreek]

Plus, why, would I as an engine builder/machinist/cylinder head guy, EVER consider sending my stuff to someone else to do? Wouldn't say much for my confidence. I don't have anything against Dave, but, noway I would send my own stuff to anyone.

[Formulajones]

You sound like me Just the kind of guy I like to work with. Mike was right.

By the way, I'll have to send you a PM. I'll be bringing down at least 2 engines, and now possibly 3, here in the near future.

[gtofreek]

Cool! I'll keep an eye out for it.

[geeteeohguy]

Paul definitely gets my thumbs up. Excellent thread. Educational and inspiring!! Thanks for the thread!

[rexs73gto]

I don't know where you guys are getting your prices??? The E-heads I bought cost right at $ 1600.00 with the tax, I had a set of 4X heads done by a good shop that I have a lot of work done & there good. I had the heads cut , a complete valve job, all new set Installed screw in studs All new springs & 10* keepers & then had the intake & exhaust ports cleaned up a bit. Not a complete port job & that work cost me right at $ 1300.00. Now I bought the Alum. heads for the price of some avg. machine work for some iron heads, ... If I would have just bought the Alum. heads I would have been money ahead, but I stayed with the iron heads because it was my 64K mile 73 Trans Am & didn't want to lose the correct heads. If I would have been able Like paul to do all the work myself with all the machines to use I might have stayed with my iron # 48 heads to. If your going just for dollars then depending on what your doing is your decider. If you have the machines then of coruse the iron heads are going to cost less but you'll have only YOUR labor, those of us who don't have the machines & knowalage to do all the proper stuff then we buy the HP & guys like Paul will build the HP if able. That goes back to my first post I used the Alum. heads cause I don't have the mahines or the knowalage to do this amount of work but Pauls doing a great job.

[gtofreek]

I agree with you 100%. If I have a customer with some iron heads, wanting me to completely port them, I most certainly recommend an after market head, because I tell them up front, it will cost about as much to do the iron heads than buying aluminum, and the aluminum will generally have more power potential. If they still want the iron heads, then I do them, but at least they know where they stand.

I agree my case is much different as I don't have to pay for any of this work. Just parts. Lucky me!

[Formulajones]

Paul,
I'm told you guys used to have a dyno in there?? Is that not the case now?

Any chance we'll get to see a clip of this thing zing on the dyno?

[gtofreek]

We're working on a new one right now. Damn straight you will see footage of it on the dyno! What kind of a thread maker would I be without doing that?

[68azbird]

No happy dynos

[gtofreek]

I believe my pistons will be here today!

[Doug1]

Very cool thread Paul. I'm in the boat with a lot of others in that I just had to suck it up and buy performance for my Pontiac. I went all in with a IA2 with aluminum heads to keep it "all Pontiac". Now that I have been there and done that, I realize that my engine is more of a resto-mod, like my car, than a true Pontiac motor, since virtually nothing on it was actually designed by Pontiac. I'm fine with that since I resto-mod my cars and therefore a resto-mod engine is in line with the rest of the car.

Love what you are doing. You're taking the actual factory parts and making them work to get what you want. It's cool to watch someone do it like the old masters. The vast majority of us hobbyist are more "assemblers" rather than builders. We take what others figure out and apply it to put our cars together. You'll have a sense of accomplishment that money can't buy when you finish it. What you are doing is HARD. Very impressive.

[Doug]

Acknowledging that I have no particular knowledge of flow bench testing, I have these observations (and questions).

When Pete McCarthy did his head flow comparisons in the April-June 1991 issues of High Performance Pontiac I plotted the flow test results for several of the most popular heads. McCarthy’s test results are shown at this website: http://www.wallaceracing.com/ultimatehead.htm

McCarthy’s testing was done using a Meriam Instruments 400cfm flow bench testing at 12 inches of water. (The magazine read that the testing was done at 12 inches of mercury but a “correction” paragraph in the June issue clarified that 12 inches of water instead of 12 inches of mercury was used. This “correction” paragraph is not shown in the website copy of the article.)

Paul’s testing apparently was done with a Superflow SF 600 flow bench rated at 500cfm@36” water and 600cfm@20” water. I don’t recall Paul mentioning at what rating (inches water) he tested at.

As Paul indicates, his initial set of flow numbers for his 670 head came from flowing a “bone stock port (#2 cyl) with stock valves“. McCarthy’s numbers for a stock 670 came from testing two ports, one interior and one end. There was only slight differences between McCarthy’s inner and end port numbers.

Without paying attention as to what brands/flow rates/etc. of the flow benchs were, I decided to plot Paul’s numbers on my chart graphs. In doing so, I was immediately struck by the fact that Paul’s numbers for a stock 670 head were substantially greater than McCarthy’s numbers for a stock 670 head, with Paul’s ranging 30% to 40% higher in mid-to-upper lift ranges. Comparisons of Paul’s and McCarthy’s numbers are:

670 Heads- Air Flow Test Comparisons
INTAKE
0.100 0.200 0.300 0.400 0.500 0.600 LIFT
82 149 193 208 212 214 CFM -Paul
73 130 148 155 161 163 CFM-McCarthy
12.33% 14.62% 30.41% 34.19% 31.68% 31.29% percent greater flow by Paul

EXHAUST
0.100 0.200 0.300 0.400 0.500 0.600 LIFT
54 98 130 157 171 181 CFM -Paul
39 76 100 117 122 129 CFM -McCarthy
38.46% 28.95% 30.00% 34.19% 40.16% 40.31% percent greater flow by Paul

What is more noticeable is that Paul’s numbers for a stock 670 substantially exceeded McCarthy’s flow numbers for stock 614’s, 722’s, 63 Super Duty, and greatly exceeded McCarthy’s numbers for stock 16 and 48 D-ports and 96 round ports. Ironically, McCarthy’s 670 was the worst of any of these heads.

So, when one sees a set of head flow readings, how does one “compare” them with readings from tests done by others? Is there a “conversion factor” of the different “inches of water” numbers? Is there a “standard “inches water” testing number? Generally speaking, when a head is flowed at a given “inches of water” on one machine, should one expect flow numbers to be comparable to flow numbers at the same “inches of water” on another machine?

No doubt both Paul and McCarthy have the same expertise and used apparatus and machinery of comparable accuracies. Obviously, there apparently is some sort of apples and oranges situation with Paul’s numbers and McCarthy’s numbers. However, in McCarty’s testing of numerous different heads, they are indeed “apple to apple” comparisons of those heads that indicate the stock 670 head is one of the worst flowing relative to other stock performance heads. This would suggest that similar efforts of porting these other heads would yield proportionally higher flows than the 670’s. Of course, there is an upper limit and point of diminishing returns in all that cannot be exceeded.

Like the website article of McCarthy’s tests cautions: “Take these air flow readings with a grain of salt. The ratings may not be comparable to flow ratings from another flow bench. Calibrations,set-up,etc. may be different than other flow benches also. I think the main purpose would be the air flow comparison between the different heads.”

I admire Paul’s do-it-yourself efforts and it is being done in the true spirit of “hot-rodding”. I’m sure he takes great pride and satisfaction in his efforts, deservedly so!

[Stan Weiss]

I have seen those flow tests numbers a number of times and they along with the depression they were tested at do not add up. If we use 12" water for McCarthy's numbers and convert then to 28" water I get.

.1 111.51
.2 198.58
.3 226.07
.4 236.77
.5 245.93
.6 248.99

If we use 15" water for McCarthy's numbers and convert then to 28" water I get.

.1 99.74
.2 177.61
.3 202.21
.4 211.77
.5 219.97
.6 222.70

Stan

[gtofreek]

I flow at 28" of water, which is why there is a big discrepancy between my numbers and Pete's.

[Donovan]

nothing looks better on this forum than fresh machined parts....

[gtofreek]

I got my pistons today. They are CP's Bullet line of forged piston. They have a compression height of 1.630". Made for a 6.700" BBC rod. The pin is BBC .990" x 2.500". Weighs 128 grams. Piston weighs 540 grams, compared to over 600 for stock or around 600 for the Icons 400 piston. It utilizes .073" wire locks which are not only lighter than Spiral-locks, but also stronger, and way less likely to beat out. Pretty much impossible to beat wire locks out. The rings are 1.5mm x 1.5mm x 3mm. They are a steel gas nitrided top ring. Here are some pics before I start working on them.