[Donovan]

Fun! Thank you for sharing your experience on this.

[67gtospud]

Subscribed! This is pretty cool!

[phil400]

This really is cool, I love the thought behind it, its so true anyone can make big power with aftermarket heads, but a really fast car with cast iron heads is untouchable, man I wish I had pontiac guru's like you guys closer to me, the knowledge of the pontiac on this board is awesome.

[GOAT WHORE]

Originally Posted by phil400

This really is cool, I love the thought behind it, its so true anyone can make big power with aftermarket heads, but a really fast car with cast iron heads is untouchable, man I wish I had pontiac guru's like you guys closer to me, the knowledge of the pontiac on this board is awesome.

Phil, don't be afraid to ship an engine to Paul. I did and will do it again!
Check out my thread where Paul documents all his work.
http://forums.maxperformanceinc.com/...715125&page=10

[68azbird]

413 CI IDPHTTFMF

[gtofreek]

I just got home from working on this head again.

First, I reamed the intake valve guide and installed an 8mm guide liner. Then I cut the intake seat for 2.08" late model 6.1L Hemi intake valve. This valve has a flatter angle[10° versus the 12° Ferrea Pontiac valve. This valve also has a .3125" stem. And, most importantly, it weighs 56 grams[2 ounces] lighter than the Pontiac valve! That's means a lot if I'm going to try to spin this thing. In brief testing in a set of open chamber heads, this valve out-flowed the Ferrea by quite a bit. I then throated the bowl to match the seat cutter. Below are flow numbers for what it did with just a valve job, and this valve. This time I flowed it with a Ferrea 1.77 exhaust valve, with a 44° face and a 30° back cut. I used a radius seat cutter with a .060" wide seat. Unfortunately, because of how big Pontiac made these bowls, I couldn't get much of a radius cut under the seat. My plans with the actual heads I use is to neck down the seat insert I.D. from stock 1.625" to 1.562. This will allow me to get a little more radius on it. When I open up the small valve heads to a 1.77, they have a 1.530" throat, and they flow considerably better than the factory big valve heads. That's with a .100" smaller throat! This is because of the radius cutter making a nice radiused venturi for the air to flow into the port, instead of having to make an abrupt[45° to 90°] turn like a factory head.

The intake seat was cut 45°, and .040" wide and the valve has a 30° back cut.

No porting or chamber mods. just valve job and valves.

_______Intake____Exhaust____gain/loss
.100"=__73_______64________-12/+7
.150"=__108______88________-13/+8
.200"=__142______109_______-11/+10
.250"=__172______126_______-6/+10
.300"=__200______138_______+1/+7
.350"=__214______149_______+13/+6
.400"=__220______160_______+14/+8
.450"=__218______168_______+9/+5
.500"=__221______173_______+9/+5
.550"=__222______178_______+8/+5
.600"=__223______182_______+8/+4
.650"=__226______186_______+9/+4
.700"=__226______189_______+8/+3
.750"=__228______191_______+9/+2
.800"=__229______193_______+9/

__________________________=+55/+84

Average gain/loss =____________+4/+6 per lift point.

[gtofreek]

Then I did a quick port job on it. Concentrated more on the intake than the exhaust at this point. Basically just blended the exhaust bowl and cleaned up the casting. Still no chamber mods, that will have to come later. Made the entry match a RAIV gasket[Fel-Pro # 1233]. Here are those results.

_______Intake____Exhaust____gain/loss
.100"=__72_______64________-1/0
.150"=__106______88________-2/0
.200"=__140______108_______-2/-1
.250"=__171______127_______-1/+1
.300"=__200______140_______0/+2
.350"=__224______150_______+10/+1
.400"=__245______164_______+25/+4
.450"=__253______171_______+35/+3
.500"=__230______177_______+9/+4
.550"=__231______183_______+9/+5
.600"=__232______187_______+9/+5
.650"=__234______194_______+8/+8
.700"=__236______197_______+10/+8
.750"=__238______202_______+10/+11
.800"=__238______205_______+9/+12

Net gain or loss =____________+128/+63

Average gain/loss =__________+8.5/+4 CFM per lift point. Average gain from .350" up =___+13.4/+6.1 per lift point.

As you can see, over .450" lift it went super sonic. I need to work some more on it to fix that. I will do that after I re-work the combustion chamber.

[gtofreek]

[gtofreek]

[gtofreek]

This is spark plug to deck height after decking.



This is what the plug to deck depth was before decking.

[gtofreek]

The actual intake valve I will use will be 2.08" x 5.165" for a 5.7L Late model Hemi. It's basically identical to this one, except longer. This is a stock 6.1 hemi valve, and is 4.9something inch's long. Too short for my needs.

[GOAT WHORE]

Paul, do you care to guess what these heads will flow when your done, or what they need to flow to meet your goals, or both?
Also, do you like to look at area under the curve numbers?

[hurryinhoosier62]

Impressive numbers, Paul. I'll be following this one.

[gtofreek]

Originally Posted by GOAT WHORE

Paul, do you care to guess what these heads will flow when your done, or what they need to flow to meet your goals, or both?
Also, do you like to look at area under the curve numbers?

I don't know yet, but am hoping for 275-280 to meet my goals. The air speed is intense. It's too much for the port at this point.

As for the average numbers, I base that on the cam being used. If it were a small hydraulic, flat tappet cam, then at TDC, the valve is barely open, so flow numbers in the .100"-.300" lift range mean a lot, and I would stick with a 30° seat for that use. When talking larger solid roller cams, like I am using, the ramps are much faster, and with Harold's cams, the valve is going to be open .175"-.250" or more at TDC, so low lift number are not so important, and in some cases better, as not as much going to go out the exhaust during overlap. I look more at .250" and up numbers. Especially .250"-.500".

The air flow was super smooth[manometer had no bobbling going on] until it turned over. It started making big gains until that point. Need to get that worked out. I have a few ideas. Also, I think the exhaust would be a lot better with a real header on it, because right now, the only way I could get a pipe on it, was to point it off to the side. The exhaust is trying to exit the head, going downward, then has to make a sudden right turn. That can't be good for it. I'll do the real heads with a header, and the flow plate fixture that will clear it.

[hurryinhoosier62]

What I find remarkable, Paul, is the increase in flow numbers with BASIC port mods. Angle milling .100 off the intake side of the deck is something I would have never thought to perform to increase intake flow. I've always heard the 670 heads were good, but I never thought BASIC port mods could increase flow that much. Bravo!!

[pont406]

Im in the process of building a 414 ci short block, 70 400 block, filled to inch below water pump holes, 4 bolt main, billet caps, ARP studs, 4.190 bore, GM 3.75 cast crank, BBC rod journals, 6.635 Eagle rods, Ross custom spec pistons, going to put my mildly ported 96 D ports on it, have a Custom ground Lunati cam, 488/498 lift 230/239@50,114 LC with either modded stock intake I have, (Jim Hand style) or RPM, Qjet or Demon for my 66 Lemans Street /Strip car.

[Formulajones]

There isn't much out there that I like better than a high strung engine with a 4 gear behind it. Especially with a rear gear that will rotate the earth Reminds me of UMTR back East. I like torque as much as the next guy but a combo like this really has alot of fun factor. Can't wait to see this one done.

[rexs73gto]

Paul when I said you could use the Alum. head I wasn't saying the 670 wasn't a good head but only if you were trying to make big power you could use the Alum. head & you would start where you are just getting to with the iron heads. I appalud your effort for the iron heads , but to make the big power the Alum. heads are good just for that. If going the cheap route is the way your going , go for it & I hope you get what you want , so far you have great results so far. Keep up the good work.

[68azbird]

Depends what you consider big power. Haven't seen any aluminum head factory block stock crank engines that were all that impressive.

[gtofreek]

Originally Posted by rexs73gto

Paul when I said you could use the Alum. head I wasn't saying the 670 wasn't a good head but only if you were trying to make big power you could use the Alum. head & you would start where you are just getting to with the iron heads. I appalud your effort for the iron heads , but to make the big power the Alum. heads are good just for that. If going the cheap route is the way your going , go for it & I hope you get what you want , so far you have great results so far. Keep up the good work.

It's cool. I didn't take it like you were saying 670's were bad. There are advantages to iron heads though. For one, the ports are much smaller than the E-heads, and if I can get these flowing 275-280, the velocity will more than make up for the lack of flow. The smaller port will accelerate my car faster also. So even with less flow, on a 400, it could be much quicker.

One thing about me, is I don't follow trends or fads. I do my own thing. I like to be different. Now if I had to pay someone $2000 to make these heads work good, then forget, I would buy some aluminum heads. But I don't, I have these heads, as well as many others. I even have a set of #62's that I have already installed guides, intake, and exhaust seats, and started porting. I could finish them and use them for this build, and would have a lot less work to do, but I feel they are not a good candidate for what I want to do. If I was building a 500 HP street engine, then they would be fine. For this build, I really need to push the envelope. These 670 heads not only had the best flowing intake port under .400" lift of any Pontiac head, but they have the closed chamber too! To me that is a plus because that will allow me to reshape it the way I think it needs to be. Can't do that with the 62's. I also have a good intake port to start with. I think this engine will surprise people for what an iron headed 400 can do. Lot's more work to do though, at this point, so we'll just have to wait and see.

Plus, I'm not trying to build this engine cheaply, just for the least amount of money possible[inexpensively]. What people may not understand is I have a wife who cannot work, and a lot of bills, so I have to save a few bucks here, and a few bucks there. Takes time. I've already waited 17 years to drive this car, I'll be damned if I wait another 17 because of expensive parts. Plus, I still have a tranny, and rear-end to build, plus paint supplies to buy. Have to cut frills out, and get down to business, and get only what I really need.