[NHRASuperStock455SD]

Chris I will call you and I will surely investigate this. Let me do some research before calling you. One thing I do need to clarify. If you look at the spark plug location in the picture below off the Dart website, this was what I was talking about for our plug location. My observation from your picture was that you had the plug exiting at the apex of the casting divide whereby incoming fuel charge would not be shielded. (I know it was a very small picture.) Could you explain further?

Here is the link: http://www.dartheads.com/products/cy...num-heads.html

[Mo]

How about the big block platinum head? It looks different from the small block.

[blaktopr]

Here are a pic and links Lynn.
Quote
"PLATINUMOne result of Dart's wet flow bench investigations was a major combustion chamber redesign for the Pro 1 Platinum-series heads. The spark plug is now located as high as possible within the chamber, promoting more-efficient combustion. "The flame only has to travel one way," says Dart's Tony McAfee, "rather than both up and down." The long side of the chamber (arrow) has also been redesigned to further unshroud the intake valve... "

http://www.dragracingonline.com/tech...wetflow-1.html

[NHRASuperStock455SD]

Originally Posted by blaktopr

Lynn, I left a message on your phone. Putting the plug on the exhaust side of the "ridge" may land it right in the middle of a vortex created when the liquid passes over that "ridge". Low pressure created from the speed of the mixture passing over that ridge combined with the "higher pressure" at the surface of the dome behind the ridge has it comming back to "flank" the air at the peak of the ridge. Now you have a swirl of denser fuel at the plug. This would probably call for a little more spark lead than with no vortex at the plug.

Check out what happens behind your side view mirror of a car or truck. If still want some more info, take a look at the new Dart Platinum heads. Or give me a call back. Thanks.

There was no message, my number is below

Lynn McCarty
317-839-8378
317-504-4410
[email protected]

[NHRASuperStock455SD]

Originally Posted by NHRASuperStock455SD

To add to this information, it our opinion that a dish piston would be better than CNCing the combustion chamber. This is by virtue of quench phenomena. A dish piston will keep the combustion charge away from the cool side of the cylinder, and we get to keep the heart shaped combustion chamber which is more %CE to boot.

I know not all will want to buy new pistons, but it is something to think about if you have that option.

Lynn

That is reverse dome technically not dish piston.

Lynn

[Jim Robertson]

Lynn,
Significant effort. Thanks for spending your resources so we all can benefit. Great looking piece that should open some eyes. Continue down the path of casting quality and machining accuracy. The legend lives on. I will be purchasing a set...or more.

Jim
www.racev8s.com

[JC455]

All I can say is WOW!!

[NHRASuperStock455SD]

Thanks John!

I have just contracted to do a short intake to fit under the hoods of stock cars. The intakes we are doing will look similar to these.

[Region Warrior]

Interesting runners on the 3rd pic.

[Tom Vaught]

Typical Ford Intake, Mike. Did not take people long to figure out the very short center runners were not happy on the old Ford stuff. Having the runners on 2 levels is not an issue either.

Tom Vaught

[cgeise]

I believe those are pictures of the Profiler intakes - the hitman on the right - the new Edelbrock for spread port Chev looks a lot like it - only shorter and seems to work very well

[BVR421]

Any chance these will work on a real Pontiac? ie: 4.120-4.25 bore?
or will the valves be a little too large

[NHRASuperStock455SD]

Originally Posted by BVR421

Any chance these will work on a real Pontiac? ie: 4.120-4.25 bore?
or will the valves be a little too large

They will work on a stock Pontiac block, my build up for dyno purposes is a stock 455 block 0.30 over, eagle crank and rods, stud mounted rockers, very typical street RA-V crate motor. Will give you updates as it goes together.

Just like the original RA-V it will work on a regular Pontiac OEM block with the obvious changes for a RA-V. Most people should be able to swap piston holes, and of course you always check valve clearance on any motor right?

Lynn

[NHRASuperStock455SD]

Originally Posted by Tom Vaught

Typical Ford Intake, Mike. Did not take people long to figure out the very short center runners were not happy on the old Ford stuff. Having the runners on 2 levels is not an issue either.

Tom Vaught

Very true,

In fact when Bernie Knudsen threw the Tunnel Port project guys under the bus, the Pontiac Racing guys hired them! So we are just picking up from all that great work and millions of dollars the Ford Racing team did and never got to finish. From what I hear Ford was completely committed to the Tunnel Port design. However, Bernie was the GM of Chevrolet Motor division and hired by Ford and all the BBC engineering team was brought over, thus the splayed valve 429 engine was born.

On the longer runner intakes we extend the plenum front and back. Therefore looking on the outside, it looks like the runner are much longer, however the plenum extensions provide for a very close intake runner length and a bigger plenum. I will try to get a picture.

Lynn

[Dragncar]

Whats the most reliable power Ford got out of a Tunnel Port engine? It seems like the bottom ends of the FEs were a problem.
A guy at our track just blew up a 427 side oiler with some factory looking aluminum heads heads. It ran 9.30s in a Mustang. He has a SOHC 427 also but it is just too valuable to race. There is a lot in common with the Pontiac and the FE, 4 head bolts and inline valves. But I think Pontiac has passed it up in reliable power.
I like any idea of finishing what Pontiac had going. All the new parts is just way cool.
You have to have some sort of love for the Pontiac engine to do what Lynn has done, thanks.
BTW, BBCs still idle like a can full of rocks.
Another guy at out track just blew up his 454. He has had 3 engines in the same time period I have had my 455 running the same low 11 times like me in the same car. Only I do it with pump gas and he race gas. Freaking unreliable Pontiacs, rod chuckers!!

[ponjohn]

Blacktopr mentions that the plug will be shrouded by the "bump" in the chamber.

How do you know if the cylinder head is going to fill CW or CCW?

John

[Tom Vaught]

Originally Posted by Dragncar

Whats the most reliable power Ford got out of a Tunnel Port engine? It seems like the bottom ends of the FEs were a problem.

SOHC Engines would make about 800 hp

Tunnel Ports were in the 720 hp range but detuned at LeMans for the 24 hr deal. Ford ran dyno tests at 7000 rpm for 48 hrs continous at about 600 hp level (less load on dyno) and did not have any failures. You could probably run at Tunnel Port at 650 HP for 24 hrs and have it live.

The guy who blew up a side-oiler engine did not know how to build a Ford Tunnel Port Engine.

Tom Vaught

[marks73ta]

Just a thought/question. I use the TRW SD455 forged single trough pistons. Would the head change to the RAV configuration require changing the pistons if I'm using the single trough valve relief? Or are the valve angles different enough to still require a piston change? Would be nice for me if they would then swap. Mark l

[NHRASuperStock455SD]

Originally Posted by Tom Vaught

SOHC Engines would make about 800 hp

Tunnel Ports were in the 720 hp range but detuned at LeMans for the 24 hr deal. Ford ran dyno tests at 7000 rpm for 48 hrs continuous at about 600 hp level (less load on dyno) and did not have any failures. You could probably run at Tunnel Port at 650 HP for 24 hrs and have it live.

The guy who blew up a side-oiler engine did not know how to build a Ford Tunnel Port Engine.

Tom Vaught

Tom,

This must have been in the 60's? I know as early as 1978 we were getting 860HP, but that was much later. We also had sheet metal intakes, titanium 2.25 valves, twin dominators, in a drag race configuration.

What do you think with today's technology Ford would be getting out of those same castings? I know it is hard, but please speculate. I would say with the standard castings....that is, then with raised port configuration?

I know we have found just 20HP since then with oil chemistry and another 20HP with just fuel. Everything back then was too big and too heavy. I know this was NASCAR stuff, so I am not 100% familiar with the level of that early technology in NASCAR. I know Widmer came into the scene and changed a few things?

Lynn McCarty
[email protected]

[blaktopr]

Originally Posted by ponjohn

Blacktopr mentions that the plug will be shrouded by the "bump" in the chamber.

How do you know if the cylinder head is going to fill CW or CCW?

John

John, alot of it depends how the port is shaped. One person's "work" can be different from another. This includes how well the mixture exits the valve depending what is happening upstream. But the air/fuel exits "out" away from the valve. So if it was concentric (no swirl) it will still travel over that ridge. Port bias and valve shrouding lead to the direction you ask. With that, the direction goes from the intake side to the exhaust side, so it can be either direction. To have the charge go in the opposite direction would mean a stronger short side flow over the long side. Looking at newer chambers, you can see the valve/chamber configuration working toward a more even and contolled exit out of the valve. But remember, the charge will still travel away from the valve riding over the ridge. It follows the same situation as the bed of a truck. Throw a plastic bag in there, and go for a ride down the highway and watch what it does.
Here is a pic of a Pro Stock head's chamber done in flourecent dye. Look at the vortex behind the plug away from the valve. That is what happens when air/fuel passes over a ridge or obstruction. Then take a look at one of my vids.http://www.youtube.com/watch?v=MHO0CwIOceY
This is just a cast #62. But note the similarities.