XXO "specialty head" ?

[Unkl Ian]

For an OHV inline motor in XXO, "specialty" heads are legal, eg  Wayne 12 port.

How far does the legal definition of "specialty" stretch ?

Can later OHV heads be adapted to a legal block ?

Or are we limited to "period correct" aftermarket heads ?

Thanks
Ian

[Buickguy3]

Ian,
We've been trying to adapt a head to the old Buick straight 8 for years. Still looking. It's legal to adapt any head to your engine, as long as the camshaft remains in the block. No OHC heads. It's spelled out pretty clearly in the rulebook. What combination are you looking at? Doug

[Unkl Ian]

Looking at a '50s IH OHV 6 cyl for XO.

XXO sounds like more fun, and more money.
Thanks for the clarification.


What is the hold up on the Buick motor ?
I'm assuming you want to use 2 V8 heads ?
Somewhere, I have a link that lists the bore spacing for various motors.

[Unkl Ian]

We've been trying to adapt a head to the old Buick straight 8 for years. Still looking.

Maybe this will help:
http://victorylibrary.com/mopar/m-table-c.htm

[Buickguy3]

Ian,
Thanks for the link. May be helpful in the search. Who knows, maybe 4 cyl. of two I-6 heads. Two 4 cyl. heads. Thanks, Doug

[rebelce]

I may be in left field here but it is my understanding that the original headbolt pattern must be in there somewhere. One can't just redrill the block and slap on any head.

[Buickguy3]

Rebelce,
What I've done in the past, is use allen setscrews and put Locktite sealant on the threads and re drill and tap new holes. If you're lucky, you won't run into half of one of the old holes and have to weld it shut and drill and tap a new one. Same type of treatment of water passages. That's the kind of fun Hot Rodders have. And it makes them think and smile. 

[Stan Back]

Reminds me of my '54 Plymouth street rod.  It's on a '87 El Camino chassis.

I'm asked if "it bolts on?"

Well -- I didn't weld it on (but it sure wasn't a direct bolt-on with the 354" hemi).

[rebelce]

I'm familiar with the adaptation portion of the process.  Here's a link to the engine we're using now.

http://www.customdesignperformance.com/leo/leo.html

 I think it's one thing to have a specialty head, quite another, to have a specialty block.  When you change the headbolt pattern, you have created another engine and that may pose problems with legality. In the past, it's been OK to add headbolts but not change the original pattern.    Not that I wouldn't love to slap a couple of wacked 18 degree heads on my Jimmy.  Dan, JD, Rich  where are you?

[Buickguy3]

Beautiful work!!!!!!!!!! Sorry, I didn't mean to belittle your knowledge of the subject. When does it show up on the Salt? Killer setup. Doug

[RichFox]

When I put the "Y" block head on the Plymouth, 8 of the head bolts came "close enough". Two I drilled into the deck and eventually that was where the block failed. But it made a lot of passes at El Mirage and Bonneville first. Because of the varing bore spacing on vintage engines (wider where there are main bearings) no late model head will be perfect. But aluminum heads lend themselves to welding so much better that iron, cutting heads into groups of 2 seems right. Murrays use a plate to bolt the late Ford head on their B block. Holes I didn't use I put cast iron pipe plugs in as they are eaiser to surface than Allen set screws. I plugged all the water holes and ran water rear to front in the head then front to rear in the block. Made my own copper head gasket without water holes. Ran the oil through one of the valve cover studs into the rocker shaft.

[rebelce]

I wish I could claim their work, I get to play on it after it's done.  I'm doing a Dugan aluminum block for the car now. Unfortunately, we fill the block for drag racing and lord knows what class it would fall into.

Rich, are you saying we could fill all the holes and redrill the deck for any head we want?    I don't think so, but then again you've been pushing the envelope a long time.

                        Armond Orr

[RichFox]

The V4 rules are more liberal than XXO, but I do believe you can drill for and run any rocker arm head. Of course the Dugan block will not fly in XXO

[panic]

Save time: just assume that anything I say is wrong.

[rebelce]

Changing the headbolt pattern really changes the game.  Compare a Skinner 12 port Jimmy head with a Falconer head from one of their V-12's. We're talking 400+ CFM with an excellent discharge coefficient. Now that vintage classes can run sophisticated ignition systems (which is great, even without a computer) we could lose the spirit of the very word "Vintage". Why not weld in a few main bearing webs while we're at it, I mean, nothing in the rules, right!