View Full Version : Maybe some pics of my new head
December 11th, 2007, 03:23 PM
IF (and that's a BIG IF" I have master the pic posting deal, there will be shots of my new PES/Clyde Norwood lump port six cylinder head. I suspect that these pics will raise a lot of questions as to how those smaller (seemingly) ports flow more, but for now, let's just say that the flow bench and the track tell the story. I'll post some shots of the PES intake in a day or so.
Well, I THINK i got it. Let's see what happens
December 11th, 2007, 03:28 PM
The new one has some larger valves I see.
December 11th, 2007, 03:31 PM
Very nice! Yeah those valves are huge compared to the old head.
In the second picture what's the function of that tube and why doesn't the new head have it?
December 11th, 2007, 08:11 PM
OK. Time for some explanation of what you're seeing. The stock head is the one with the strut thru the intake port (kind of rusty looking, as the 292 was stored outside). That is the passage for the head bolt - yep, it runs right thru the Siamesed intake ports. Now, there's three major differences between the stock head and the PES head:
1. As noted, bigger valves. The PES head has 1.94/1.60 instead of 1.7(something)/1.50. It's about all the valve you can put in that combustion chamber. If you look carefully, you'll see that the chamber around the intake on the PES head is relieved to unshroud the bigger valve.
2. The strut is gone on the PES head. A plunge cut is made from the valve cover surface down to the lower deck, and the valve cover surface is tapped for a 1/2" pipe plug, just to keep the oil in. How to bolt the head down? - see below.
3. There's a lump added to the floor of the intake port, incorporating a counterbore for a short Allen head bolt to act as the head bolt in that location. The lump, as you can see, actually makes the port smaller. So why would that be good? The stock head, if you look closely, has virtually a 90 degree turn from the port into the combustion chamber. I'm not sure how well you can see it, but the lump provides a radius for the mixture to follow into the valve area. Bottom line - this provides a SIGNIFICANT increase in flow numbers.
The lump port method was devised by Kay Sissel at Sissel Automotive back in - like - the 70s. He used brazed-in lumps. Kay passed away, but Mike Kirby still makes these heads out there - he took over Sissel's upon Kay's death. There are several other shops who do lumps, including Glen Self, and T6 Racing in Florida. To the best of my knowledge, Clyde Norwood developed the bolt-in lump, a concept later copied by T6. If you look at my head on the deck, you'll see a small hole for the lump retaining bolt.
So bottom line - this about all the head you can put on an inline Chevy. I wish I'd known I was going to get this head before I bought my cam, as I may have a gone a bit conservative for the new setup. I'll put it all together and see how it does.
As I said, I'll get pics of the intake up in a day or two.
December 11th, 2007, 08:19 PM
To the Intake!
December 12th, 2007, 10:18 AM
OK. Here's the intake shots. As with the head, this is just the way I found it, so it needs lots of cleaning, etc. The Clifford is included for reference. Remember, the Clifford is a pretty decent manifold, so the PES is WAY COOL.
December 12th, 2007, 10:49 AM
Wow, that's neat stuff! Thanks for taking the effort to figure out the picture thing.
Looks like the port is not really enlarged noticably on top or the sides.
December 12th, 2007, 12:44 PM
These pictures are awesome. Keep us up to date on your progress. I'll be watching for my own inline build for sure.
Here is a great link if you like Chevy inlines:
December 12th, 2007, 02:13 PM
Thanks for the interest. If anyone is interested, I have a link from a guy in Brazil for a bolt-on turbo set-up. Evidently, these are the SBC of South America, and all kinds of stuff is off-the-shelf down there. The bad part is that the whole website is in Brazilian Portuguese, but I could sorta figure it out, just knowing what the pics of the parts were.
December 14th, 2007, 11:47 AM
Dan, what are you plannin on running the head and intake on?
December 14th, 2007, 03:22 PM
An old 454 I found. Oops - wrong universe!
I have a '78 Camaro LSR car with a (currently) bone stock 250 six. To begin, I'll bolt the head, intake, 600 Holley, and headers on the stock shortblock. Should be about a 9:1 or 9.5:1 motor. More later, as funds allow. I have a Delta cam with 221IN, 235EX, @0.050, .537 IN, .575EX.. Notice that intake and exhaust specs are WAY different - this is in response to the characteristics of the head.
I think this will be an interesting project.
December 14th, 2007, 04:27 PM
Curious...did the 78 come with the integral head engine? or was that a later thing?
December 14th, 2007, 07:33 PM
Dan put the damn head on the motor and stop playing with it :D
December 14th, 2007, 08:47 PM
Jim - Yeah, it has the damn integral head. You can't do squat with it. Thus started my search for some kind of improved head. Just got lucky to find the PES head.
Terry - I'm working on it! Gotta get the F150 out of the way first - if I could just get caught up on the doctor's visits. I'll have it ready for the April meet, even if I have to pull the Ford out and let it sit some more (hope to have it done, though). I also need to decide how much if any freshening the head needs. It needs to work all season.
December 15th, 2007, 08:53 AM
we're out in the shop using the robot club's CAD computer to talk about 6 cyl chevys. Just got done fixing some minor issues with the carb on Steve's bitchin camaro, and getting ready to go get some new rear tires for it...
anyways, about those Brazilian turbo guys...
December 15th, 2007, 12:11 PM
How many is a Brazillion?
Yeah, I lost the bookmark, but one of the forum guys found it and PM'd it , so I have it back on my header. I haven't spent much time looking into it, but has anyone found a translator - seems like there must be one somewhere on the internet.
I LOVE to have one of those sitting in the shop and ready to go on when I want to run Blown.
December 15th, 2007, 03:48 PM
December 15th, 2007, 03:59 PM
Thanks, Dave. I was hoping to translate the whole website, and this translator has a limit of 150 words (for free). If I was serious about buying at this time, I'd spend for the translation, but I'll wait for now.
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