STD heads and Shovel intake ports

[texasbobber]

Description: I thought I might as well get em with shovel intake ports since they seal easier and should be easier to port

Since I'm planning to get some STD PAN heads here shortly I thought I might as well get em with shovel intake ports since they seal easier and should be easier to port.
Any opinions would be welcome.
BobberTex

[sleeper]

BobberTex-

Yea, I'd choose STD's "Band-style" Pan heads...
They do make the EX ports have either a 3 bolt exhaust, Means new pipes. Or stock style spigot.
(your choice there.)

As far as 'porting' I do believe they are already using shovel-size valves, & were flow-benched during design.
Bigger is not always better. I'd leave their R&D work alone.. Bolt 'em on..
Just my 2 cents..

[texasbobber]

Billy,
Thanks for the reply. Does STD's "Band-style" Pan heads use a shovel intake manifold then?
I'll take your advice and leave they're R&D alone.
BobberTex

[Cotten]

Chubble manifolds easier to seal???

You gotta be kidding.

....Cotten

[daveyb]

ah yes, this is the subject i always get bashed on by my shovel riding friends. just about everybody disagrees with me on this, but i don't see what the big deal is about sealing an old fashioned pan spigot exhaust. i always just make sure that the port is not responsible for supporting the pipe itself. a couple of carefully positioned support brackets should do all the work of keeping the pipe in place. a good quality clamp helps too, for sealing only. once i figured this out i was able to throw away my silly beer can gaskets (an ancient fix). meanwhile, my friends have 10 lbs of goo globbed all over their exhaust flanges.

[caschnd1]

I think Cotton was referring to that statement that it was easier to seal the Shovel intake manifold. I've never had trouble sealing the o-ring manifold on my panhead, so I'm not sure that a shovel manifold could be any easier.

The key seems to be to not be in a hurry and make sure that everything aligns well and that you get the o-rings properly placed before you put on the clamp. That's what works for me anyway.

-Craig

[kell]

This is elementary but bears repeating: put the manifold on and align it before you torque down the heads.

[texasbobber]

What I meant by easier to seal is with Shovel intakes you can easily get a 2-piece style clamp on the intake ports, and that cannot be done with ease on the Pan oem intake. I have found the 2-pc style clamp easier to get a good seal. I know that there are differing opinions on that however.
Also you don't have fuel pooling in the manifold when its on the kickstand like you have with oem Pan intakes. Not a major problem but its there.
Besides, wouldn't STD heads that use shovel intake valves flow better with shovel style intake ports? Well ported Shovel heads flow pretty good.
BobberTex

[King]

The STD heads are essentially Shovelheads in valving and porting. A friend who knows a lot about porting etc. was quite impressed when he looked at mine recently. I think that STD did their homework quite well.

I have the Pan type spigots and the O ring intake all of which work well.

King

[daveyb]

"INTAKE" sheez i gotta read stuff a little more carefully. i apologize for my idiotic post above.

[caschnd1]

Kell,

That's a real good point about aligning the heads and intake before torquing the heads. The first time someone showed me that trick was one of the forehead slapping moments. Simple trick to really improve the likelyhood of your intake sealing.

Daveyb, I figured you were just waiting for the second pot of coffee to finish brewing. ;D And your post wasn't idiotic.

-Craig

[Cotten]

Let us start off by dismissing all of the horror stories and bad reputation tagged upon o-ring conversions on early Pans. The vast majority of them were horribly botched with problems not associated with the difference between chubbles and Pans.

So with '55 to '65 in mind, Pans have the advantage of parallel faces upon the heads which hold the manifold so it can only flop up and down in one plane. Chubbles can float in all directions, and they do.

Besides requiring three hands to install a chubble manifold (sticking a hammer handle down its throat to hold it firmly against the heads will help), the o-rings (or bands) do little to center or support the manifold. Pans will sit there patiently for inspection with nothing but the o-rings to support them.

It is rare that the original carb support upon a Pan needs massaging. However, once the subtle 'sweet spot' where a chubble manifold will seal is found (by pressuretesting), you will probably have to fabricate a support from scratch to meet it exactly without bind or tweak. And it helps to add an extra to the aircleaner, as the eccentric mass wants to shake off at different harmonics.
The parallel head support of Pans dampens vibration in the fore-and-aft plane, at least.

Consider also the quality of seals.
Nearly all O-rings are Buna-n, which swells in nasty fuels, but doesn't disintegrate. But bands are quite varied in quality and composition. I have a bag of the best left over (James) that are all slightly too big, and wrinkle when tightened up. Cheapo repops are often either gas-soluble, or too small and eventually split.
(Don't count on the Factory to ever supply a quality part for an obsolete model.)

Y-manifolds certainly have a flow advantage, no contest.

Two-piece clamps?? Eeeeuuu.
Gas will pool in either chubbles or Pans equally, although the late bands let it seep into the rubber better.

In the end you must never leave sealing either design to "chance". Just pressuretest while installing, and eliminate the variable.

...Cotten

[1950bobber]

Hey Cotten....What is a "chubble"???? Sorry, I wasn't born yesterday but your terminology baffles me!!!
jim in Seattle "1950 Bobber"

[panhead]

That is Cottenspeak for Shovels

[Cotten]

Sorry for the confusion, but I live too close to Chicawgo, and some of it rubs off.

Chubbles were followed by da evoz and then came da twinkies, none of which matter if you've got a Pan.

....Cotten