Head cutaway pics - where are they?

[MerkXRTurbo]

Hey guys, sorry if this is posted in the wrong section, but a few years ago I came across a website that showed a pair of SHO heads cut down the center of the port, along with flow numbers at various lifts, but I can no longer find it. Anyone know what I'm talking about? Is it stilll on the net?

 

[1993MTXSHO]

I have them but they are on my computer at home, if no one posts, shoot me a pm this weekend to remind me and I can post them up for ya

 

[MerkXRTurbo]

That would be awesome. Do you have the flow bench numbers that were with it?

 

[92sho16]

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[Phoenix]

Aint that thing beautiful or what?

 

[MerkXRTurbo]

Yes sir it is indeed. It just shows that there's not a lot of factory imperfections to be improved upon within the ports (without removing a lot of material and losing velocity in the process), which I've found out already as I'm in the process of reworking my heads right now. Pretty much I'm just smoothing out the rough surface of the ports left over from casting (is that a sand cast???), and then I'll be polishing it to a nice surface. By the looks of it, the place that needs to be taken care of the most is the valve shrouding in the combustion chambers. Besides unshrouding, the chambers are getting a nice polish themselves, to help fight detonation causing hot spots under big boost. :woo-hoo:

 

[Phoenix]

Yup , nothing much to do cept some gasket match and some polishing.

I didnt go with the valve area (kinda tricky) but I did this , opened up the chamber a tad on the edges. I donno what gains on this , cause when I did the re-build I slammed everything in one shot so I cant tell what mod does what HP.

 

[MerkXRTurbo]

That's similar to where I'm starting with the chambers, but I'm doing a full polish on them.

 

[NovaSS]

Here is the complete story with pics on cutting up the sho heads , both v6 and v8

http://www.dccarcare.com/shoclub/membersonly/shoheads/shoheads.htm

 

[NovaSS]

That's similar to where I'm starting with the chambers, but I'm doing a full polish on them.

After the block is at its final bore diameter install the head on the bare block and scribe the outline on the the bottom of the head. How open up the area around the valves "wall side" to this line, you will end up with a clover leaf pattern.

Do a google search for valve unshrouding.

 

[MerkXRTurbo]

I was thinking more along the lines of opening it up all around to the size of the bore, not just around the valves for the 4 leaf clover pattern. Any kind of lip what-so-ever seems like it would be a point of flow disruption. Here's a quick MS-Paint to draw out my theory:

 

[NovaSS]

DO NOT open it around the entire bore!

Do a google search for "quench area" and you will see why this area is needed is a gasoline fueled engine.

 

[MerkXRTurbo]

I've studied quite a bit of head porting and had not come across that phenomenon. Thanks for the info.

 

[NovaSS]

I've studied quite a bit of head porting and had not come across that phenomenon. Thanks for the info.

Its pretty neat and it works, I built the big block in my Nova with a very tight quench. It runs 11.0 -1 on the street on 93 octain and NO detonation or preignition.

 

[victorymike18]

Here is the complete story with pics on cutting up the sho heads , both v6 and v8

http://www.dccarcare.com/shoclub/membersonly/shoheads/shoheads.htm

Excellent article! Thanks so much for posting that. :thankyou:

Any Chance you have a link to Part 3 of that article?

 

[MerkXRTurbo]

Here is the complete story with pics on cutting up the sho heads , both v6 and v8

http://www.dccarcare.com/shoclub/membersonly/shoheads/shoheads.htm

BTW, this is the link I was looking for. I'm bookmarking that! Thanks!

 

[victorymike18]

So, it appears that the V6 heads are very well designed. The intake port is at an excellent angle, but it looks like both the intake and exhuast ports could benefit from some slight work to smooth the castings.

The V8 head adds a few engineering tweaks, yet I find it odd that there was not a substantial Hp increase by comparison...

Once I get the heads off my motor, I will be doing a mild port and polish to the entire port, and some very conservative work to the combustion chamber. A common mistake that people make is to try and re-engineer the ports when they go in there.