Worse combustion chamber design ever? Saveable?

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oliver

oliver

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Yes, they are brand x. And... Wow. Worse shrouding I have ever seen. Would unshrouding the intake valve help or hurt this cyl head? I guess they were shooting for some type of swirl and quench but what the hell were they thinking? That wall is right up against the valve and is close to .200" not only that but the spark plug boss impinges on the flow as well. Bust out the carbides or round file this junk?

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I can see from here why everyone who builds sb fords slings the heads and gets something aftermarket now....
 
Probably a pretty efficient head for a stock application.
 
But not much different than most performance heads. Here's a Edelbrock.

edelbrock-1.jpg


edelbrock-2.jpg
 
at least those valves have a fighting chance! The fords are in a bucket...
 
That poor spark plug angle and depth is just the way it has to be on those heads...need enough of a boss to hold them. Makes you appreciate a well though out design from the start.
 
It may not be as bad as you think. Pressure recovery (reducing exit loss) is a big deal, and blowing out the chamber wall out can kill it.

Move the chamber wall .040 and send it. If you do that and it kills some flow, who cares? Flow isn’t everything when all you do is look at bulk flow through the port.
 
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thesiren74 said:
Ford?
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Yes, and these are original to a so called 'HO' motor with factory flat tops, roller cam, and 4bbl. Saaaaad.

Garrett Ellison said:
I can see from here why everyone who builds sb fords slings the heads and gets something aftermarket now....
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Yep. They are all pretty much garbage. Sad to see a stock 4" bore and 3" stroke motor stop making power at 4200 rpms.

toolmanmike said:
Probably a pretty efficient head for a stock application.
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I agree with that. If you like to shift at 4500

Demonracer said:
That's about all they are good for "stock" application.
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They weren't even good for that.

toolmanmike said:
But not much different than most performance heads. Here's a Edelbrock.

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Their combustion chambers are pretty similar. Hmm, gives me something to go off of. Maybe I'll grind 10-20 lbs of iron off of each head. :p

yellow rose said:
It may not be as bad as you think. Pressure recovery (educing exit loss) is a big deal, and blowing out the chamber wall out can kill it.

Move the chamber wall .040 and send it. If you do that and it kills some flow, who cares? Flow isn’t everything when all you do is look at bulk flow through the port.
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I think I may try. I'm going to try my handy work on one chamber when I have some time and post a pic. The valves are exceptionally small at 1.78/1.45. definately not worth changing that I wouldn't think.
 
teringer said:
have you flowed the head? mopar 302 heads look just as bad!
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I don't have a bench, not do I know anyone that has one. Maybe I'll diy a bench. Do the 302 heads have the valves sunk into the chambers almost .200"?

Edit: maybe that's why they called it the 302 head because they copied a ford 302 head :lol:
 
oliver said:
I don't have a bench, not do I know anyone that has one. Maybe I'll diy a bench. Do the 302 heads have the valves sunk into the chambers almost .200"?

Edit: maybe that's why they called it the 302 head because they copied a ford 302 head :lol:
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:rofl: No just the last 3 numbers of the casting number.

302Castings019_zpse479835b.jpg
 
Edelbrock, Magnum, and #302 from top to bottom

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IMO valve shrouding is a term thrown around way too much so people can sound like they know what they're talkin about. In 99% of the cases, any "valve shrouding" you think might be goin on doesn't amount to a hill of beans.
 
RustyRatRod said:
IMO valve shrouding is a term thrown around way too much so people can sound like they know what they're talkin about. In 99% of the cases, any "valve shrouding" you think might be goin on doesn't amount to a hill of beans.
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I agree with that, but I can attest that this type of blockage of the intake charge because the valve has a literal wall around 75% of the valve will kill higher rpm flow. It's great for low end torque. I used to do alot of relieving on flat heads where the valve is obstructed 100% until .150 lift. After you relieve, you gain a ton up top.
 
oliver said:
I agree with that, but I can attest that this type of blockage of the intake charge because the valve has a literal wall around 75% of the valve will kill higher rpm flow. It's great for low end torque. I used to do alot of relieving on flat heads where the valve is obstructed 100% until .150 lift. After you relieve, you gain a ton up top.
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So post up your flow bench comparison.
 
RustyRatRod said:
IMO valve shrouding is a term thrown around way too much so people can sound like they know what they're talkin about. In 99% of the cases, any "valve shrouding" you think might be goin on doesn't amount to a hill of beans.
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You’re not wrong. Blowing that chamber wall out away front the valve almost always looks good on a flow bench, but you have to do the best you can to control the air everywhere from the air cleaner to the end of the exhaust.

How many times has it been said it’s all about shape, and it is, but too many guys live and die by their flow numbers. That’s why you see so many HUGE exhaust ports that are just power killers.
 
RustyRatRod said:
IMO valve shrouding is a term thrown around way too much so people can sound like they know what they're talkin about. In 99% of the cases, any "valve shrouding" you think might be goin on doesn't amount to a hill of beans.
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Yea, but it is easy to visualize the air flowing into the combustion chamber having to bounce off that close vertical combustion chamber wall and causing a restriction. At the same pressure more air will flow through a 2 inch hole than through a 1/2 inch hole.
And I have seen flow improvements on my flow bench when the valve shrouding was relieved.
Two more things, 1) when working to improve port flow, there is almost no place easier to work and with less risk than the combustion chamber wall next to the valve, just leave room for the head gasket seal.
2) one of the critical set up characteristics when doing flow bench work is duplicating the cylinder diameter of the block that the head being tested will run on. Blow the cylinder diameter out larger and flow values go up. That is evidence that valve shrouding has an effect.
 
oliver said:
Yes, they are brand x. And... Wow. Worse shrouding I have ever seen. Would unshrouding the intake valve help or hurt this cyl head? I guess they were shooting for some type of swirl and quench but what the hell were they thinking? That wall is right up against the valve and is close to .200" not only that but the spark plug boss impinges on the flow as well. Bust out the carbides or round file this junk?

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Typical of a factory closed chamber head.
 
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