BIG VALVE BIG PORT TYPE 4 BUS HEAD Options

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(IMG:style_emoticons/default/WTF.gif) Exhaust side

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More of a streetable version (IMG:style_emoticons/default/WTF.gif)

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Exhaust (IMG:style_emoticons/default/WTF.gif)

[spare time toys]

Is that the same head manufacture Jake is using in his head that he is showing in his head thread? I see both have the AMC cast into them. (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)

[Joe Ricard]

Best aas I can recall the other casting is the square port design.

BTW whats the hole in the side of the exhaust port for? smog pump?

[ChrisFoley]

The only thing these heads and Jake's heads have in common is the AMC castings. Both use their square port bus heads as a starting point.
I don't see any value at all in using the heads shown here in a 914. There are no exhaust systems available to fit them for starters.
I make stub pipes for my exhaust systems that mate up to the square ports - no need to make them round and create additional problems with pushrod tubes etc.
... and what's the deal with the "special mini side exhaust ports" It just looks like they went through the wall by over-enlarging the port to me... not a good thing!

[Jake Raby]

Too much welding! All that welding has adverse effects on the integrity of the head, especially if it wasn't properly pre heated before the process.

They have filled all the passages that allow air to pass close by the exhaust ports!

The exhaust ports are the hottest part of the head and the area that MUST attain airflow unless you want cracked ports.

I seriously doubt those are good for anything other than a drag race engine- say good bye to a flat torque curve!

Before jumping the gun to Titanium parts understand that they have negative effects including a valve job that will only last 1000 miles unless you use some new, very high tech coatings on the faces of the valves. This is VERY expensive!


There is more to a 914 engine than just making power!

Hang around a flow bench with a fellow like Len and see just what it takes to get an 80% head with the proper flow values at the most critical points of valve lift and see why headwork costs so much.

All that weld work and they didn't relocate the plug- Must have never witnessed the same dyno results that Len and I have!

[Mark Henry]

Much rather have Jakes/Len's heads.

see them here:

http://www.914world.com/bbs2/index.php?act...=ST&f=2&t=23423

[Bleyseng]

Dyno? Flowbench? We don't need no stinkin Flowbench!
Its look cool thats all that matters!

Geoff

[pete-stevers]

Now i know who Jake is... (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)
darn cool site/ great ideas for fours
steve

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[Bleyseng]

Thanks for sharing the pics of the heads, we are a bunch of doubting Thomas's when it comes to making real power with these. Giant ports aren't always the answer as port velocities slow waay down resulting in poor air/exhaust flow. Same holds true to huge valves. BTDT years ago. 8000 rpms is great but what about hp the rest of the rpm range?

Geoff

[ChrisFoley]

QUOTE (V6914 @ Jan 14 2005, 06:21 AM)

For starters, your header system, will fit them (IMG:http://www.914world.com/bbs2/html/emoticons/aktion035.gif)

I understand that all I would have to do is make special stub pipes for my header to fit, but as Geoff says the port velocities would be a big problem. There's just no need to go there IMO.
My 1 3/4" header will easily support an engine with 225+ peak hp using smaller ports than the ones pictured.
As far as dimpling the stub pipes goes, I already dimple the 1 5/8" square port stubs on one side.

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