351C High port plates.

[tauruck]

I'm born on May 1st so that tells you I'm Taurus, stubborn, calm until pushed but loyal to the extreme. I'm a Cleveland lover, big admirer of Jack Roush and I won't part with my 351C stuff. Two motors is not a collection but the second one is what I call the big one. I have a set of 4v heads with the small combustion chambers. Being a die hard I decided that I was going to do my own High port plates. As most of you know these Boss style heads are great but because the motors were fitted in smaller vehicles the exhaust port takes a sharp turn downward to facilitate the installation of the exhaust. The shock tower was very close and the story goes that the dogleg in the exhaust port hurt power, The solution was to mill a section of the head and install port plates that would raise the port and eliminate the dogleg freeing up some power. I followed what I read and if it's good enough for Jack Roush then...
         The pics tell the story. I still have seven ports and spark plug recesses to do. I could have sent the job to a shop to be done on CNC but this is personal and it keeps the mind working. All the information came from Ford Performance written by Pat Ganahl. I don't have a mill so I took the heads to my engineer Geraldo and showed him what I wanted. He milled the heads, cleaned up the Aluminum plates and drilled them. ARP sells a set of longer studs that are used on that side of the head. There is an area in the exhaust port at the top that needs to be contoured to get rid of a bump that's still there even after milling. It's recommended to finish up with a D shaped port but I figured that with the turbo thing it won't make a difference. I did the port and plug recess on the drill press and semi finished them. These parts have been gathering all the sanding dust from doing the bodywork but I've promised to do one port and recess a week.

[tauruck]

The inlet side. Show me any other 350ci motor that left the factory with ports that size.

[tauruck]

As it stands right now.

[tauruck]

This is what it should look like when done. I photoshopped it to get an idea.

[kiwi belly tank]

That's a lot of work there Mate, sounds like a crime of passion.
Back in the 80's when I was still in Aus, I built a bunch of Cleveland's for customers. The thing's were like flies down there, they were everywhere.
I built a turbo'd 302C with a blow through Dominator & closed chamber heads for a hydro but it really fell on it's face on the top end. After a lot of changes I finally put a set of open chamber heads on it & it came alive. I believe the chamber was shrouding the valves & killing the flow. If you're running a 351 or longer crank, that problem might come up pretty early. The 302 was going away at 5k with closed chambers but I had to run more prop with the open chambers to keep it down closer to 6.
This is basically an FYI for what you might run into.
  Sid.
 

[tauruck]

Thanks Kiwi. We do a mod on the chambers. It's unshrouding that area and putting a generous radius all around. The sharp edge adds to detonation problems so we get rid of it. I won't be taking the race motor past 6500. I've had to get all new internals for this one because I was going to build a pro stock clone of the Jack Roush motors that went up to 11,000RPM. I've got a cam, pistons, manifold and lots of other stuff I can't use now. Love is blind as they say. My buddy who taught me all I know on these motors built a F150 with a long wheelbase and looked like a 4x4. It wasn't much more than a slightly modded motor and the truck did 14s on the drag strip. We'll see what happens with this one I guess. Those open chamber 4V heads never made it to South Africa and I think they'd be perfect for turbo applications. This is a can of worms. We're going to run on Ethanol too. Steep learning curve.

[zenndog]

That is great work. Thanks for posting!

This modification to Cleveland heads is what inspired my experiments with the Stude head. Rich was explaining the mod to me and showing me a Pontiac head he had milled the same way, all the while my Stude engine was sitting there and I was wondering why it wouldn't help a Stude head.

Also the fellows on this forum who remade the intake ports on their Buick inline 8 and that whole story.

[SPARKY]

302 Jimmys anyone 

[tauruck]

Hey Zenndog, I used to drive a 57 Transtar. I don't remember what mill it had. Your mod took much more than commitment. The Ford heads are much simpler.