Some "Dynomite" Heads!

[Paul Workman]

If y'all are interested...I'll be happy to share w/ you where the "quicksand" is and how you might avoid having to pay big bucks to a welder when you have an "oops" moment...

Course, going it alone has it's own mystery and the excitement of "discovery" awaits; something to be said for that, I recon! Well...just a thought

P.

[Locobob]

Originally Posted by Paul Workman

If y'all are interested...I'll be happy to share w/ you where the "quicksand" is and how you might avoid having to pay big bucks to a welder when you have an "oops" moment...

Course, going it alone has it's own mystery and the excitement of "discovery" awaits; something to be said for that, I recon! Well...just a thought

P.

Do you have a diagram or something Paul, that would certainly be helpful to see.

[LGAFF]

if I recall Jerry has some heads that are scrap.....do what Mercury MArine did, section the heads to find the weak spots.....would be cool for an article for HOB or video clip.

Just a thought

[A26B]

I'm gonna cut those heads up in single cylinder chunks, with the cam cover installed, have 'em signed by Bob Hall, Pete P., and some other famous members and sell 'em for about a zillion bucks each so I can retire.

Seriously, it takes quite a few sections to see everything that is of concern for full boogie head porting.

[Paul Workman]

Sectioning the LT5 heads...Sounds like a winter project coming on!

I have a friend of mine that sends stuff out to a head repair outfit - that often sections heads (not LT5 heads) to make repairs. I'll see about sectioning mine and keep y'all posted. Also, I might need to borrow a stock (un-touched) head to take some measurements from, and or maybe make a reference casting from. (I'll attempt to locate the approximate location of oil and water, relative to the stock ID. The actual dimensions of say my ports are the "intellectual property" of Pete, Bob G's and Marc Hs. I'll just say they are big, and as Marc H said once, "80% of the risk (of perforating the runner) is in the last 20% of the cutting.

In the mean time, I'll get some measurements and do a diagram and post it, for anyone interested.

P.

[Pete]

Originally Posted by A26B

I'm gonna cut those heads up in single cylinder chunks, with the cam cover installed, have 'em signed by Bob Hall, Pete P., and some other famous members and sell 'em for about a zillion bucks each so I can retire.

Seriously, it takes quite a few sections to see everything that is of concern for full boogie head porting.

Thanks for the compliment Jerry,i'll start cutting my heads to sell for zillions

LocoBob i see your having some fun,very nice work

There will be some fast Z's at BG next year (5 months)

Pete

[Locobob]

Originally Posted by Pete

Thanks for the compliment Jerry,i'll start cutting my heads to sell for zillions

LocoBob i see your having some fun,very nice work

There will be some fast Z's at BG next year (5 months)

Pete

Thanks Pete, wish I could do BG this year but its not in the cards, be fun to see what you FBI boys have been busy cooking up.

[Locobob]

Doing a little clean up in the bowl area with a sanding drum.

Here you can still see some of the casting imperfections.


The unworked (grey area) to the side of the valve guide sticks out a good bit and forces an abrupt change in air direction just before the throat. I will be taking a good bit of this off and doing a lot of blending here. It is more pronounced on the primary side do to the angle of the port where as the secondary has a straighter shot "as cast".


Another angle on this


Looking down the primary you can see the "J" shape of the port near the bottom.

[tomtom72]

okay, dumb Q's from the penut gallery.

The Bowl is the area ( space ) starting the back side of the valve seat and going back up the head port(?) toward the I/H port(?)? The guide sticks into the bowl and into the air flow causing not good things?

To "blend a Bowl" is to get rid of the rough casting finish, fix the protruding part of the guide, and some how 'straighten out' the air flow path from the I/H to the back side of the valve?

I'm sorry to ask so many Q's. Thanks Bob.


grasshopper

[Locobob]

Originally Posted by tomtom72

okay, dumb Q's from the penut gallery.

The Bowl is the area ( space ) starting the back side of the valve seat and going back up the head port(?) toward the I/H port(?)? The guide sticks into the bowl and into the air flow causing not good things?

To "blend a Bowl" is to get rid of the rough casting finish, fix the protruding part of the guide, and some how 'straighten out' the air flow path from the I/H to the back side of the valve?

I'm sorry to ask so many Q's. Thanks Bob.


grasshopper

The bowl is basically the area above the valve seat extending upstream to about where the valve guide boss is.
Not much you can do about the valve guide, you can trim it up a little and maybe contour it some. A few have cut it short but frankly I'm not sure that is a good idea, could lead to durability issues.
The valve guide boss can be reduced in size and blended - by blending I mean smoothed and shaped.
Straightening airflow is a key goal in most cases, it is not really possible in the bowl however. The air has to turn at the valve so basically you want to bias the port so that the air can make a gentle turn toward the center of the combustion chamber.