Additional port work (finally completed)

[Mike T]

The motor is out right now and it seems that each time it comes apart I end up porting the heads a little more.

I've did a couple of unconventional things to the heads in the past so I really don't mind experimenting on them. The main difference is the shape of the combustion chamber....this was done in attempt to unshroud the valves as much as possible and to eliminate as many hot spots as possible.

After doing this the big concern was how the quench area would respond but there would be no way to know until it was run. I did the exhaust ports and a very minimal amount on the intake side the first time around.
The motor ended up making 450 to the ground on straight 93 octane so I'm willing to spend a little more time in the ports to see what improvement if any can be made.

This is just an experiment so don't do this to your heads because I really don't know what may be the potential down side may be yet.

 

[PSID6]

What is your final chamber cc's?

 

[TURBOELKY]

have them put on a flow bench and see what you have there. I have stock head flow numbers at the shop for reference if you wanted them.

 

[fastblackracing]

Current trends in the higher horsepower power adder engines is moving away from quench areas for the most part.
This is not being done for improved airflow but for other reasons.
Reasoning that this eliminates detonation prone areas from the chambers, opening up tuning windows and allowing more power adder.
This is referred to as "chamber softening". basically turning the chambers into a inverted dish...similar to a hemi type chamber
but with the valves at the wrong places..Here is a pic that shows it pretty well.

 

[TURBOTIMMER]

The motor is out right now and it seems that each time it comes apart I end up porting the heads a little more.

I've did a couple of unconventional things to the heads in the past so I really don't mind experimenting on them. The main difference is the shape of the combustion chamber....this was done in attempt to unshroud the valves as much as possible and to eliminate as many hot spots as possible.

After doing this the big concern was how the quench area would respond but there would be no way to know until it was run. I did the exhaust ports and a very minimal amount on the intake side the first time around.
The motor ended up making 450 to the ground on straight 93 octane so I'm willing to spend a little more time in the ports to see what improvement if any can be made.

This is just an experiment so don't do this to your heads because I really don't know what may be the potential down side may be yet.


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I love threads like this. Please keep the pics and updates coming. Some people don't realize how far you can go with iron heads.

 

[PSID6]

Current trends in the higher horsepower power adder engines is moving away from quench areas for the most part.
This is not being done for improved airflow but for other reasons.
Reasoning that this eliminates detonation prone areas from the chambers, opening up tuning windows and allowing more power adder.
This is referred to as "chamber softening". basically turning the chambers into a inverted dish...similar to a hemi type chamber
but with the valves at the wrong places..Here is a pic that shows it pretty well.

I've never seen chamber softening to that extent! That's why I asked about cc's in the other post. Seems to me that it would totally kill your compression ratio with the amount of material removed. But hey, if you can make more power why not.

 

[TURBOELKY]

I've never seen chamber softening to that extent! That's why I asked about cc's in the other post. Seems to me that it would totally kill your compression ratio with the amount of material removed. But hey, if you can make more power why not.

I guess if you were going to do so, do it before a fresh build for proper piston purchase. Pretty extreme pic shown though!

 

[fastblackracing]

I guess if you were going to do so, do it before a fresh build for proper piston purchase. Pretty extreme pic shown though!

I guess if you were going to do so, do it before a fresh build for proper piston purchase. Pretty extreme pic shown though!

Theres plenty of it going on out there....we just tend to stay in our own little turbo 6 world..
You get the compression back easy enough you just spec out the dish for less cc's or even end up with a flat top piston down in the hole a bit....
I think there is something to be learned from this.
More boost, More timing, less detonation=more power.
600 + hp N2o for the nitrous guys and the turbo guys running 40+# boost is happening more and more.
Around here you cant even play hard if you cant run 9.5 or faster....in 5 years it will be 8.90 or better.
The 2 faster ones run 7.70-8 ohs..makes it hard to keep up.

 

[Mike T]

What is your final chamber cc's?

I did the chambers many years ago but I'm almost certain they ended up around 53cc or about 5cc over stock. The valves and a surface cut made up some of the ccs.

BTW thanks for my new alarm clock.......

 

[Mike T]

Current trends in the higher horsepower power adder engines is moving away from quench areas for the most part.
This is not being done for improved airflow but for other reasons.
Reasoning that this eliminates detonation prone areas from the chambers, opening up tuning windows and allowing more power adder.
This is referred to as "chamber softening". basically turning the chambers into a inverted dish...similar to a hemi type chamber
but with the valves at the wrong places..Here is a pic that shows it pretty well.

It has probably been about 8 years since I did this to my heads.....I read a article on the hemi and tried to emulate the shape. Didn't intend on going as far as I did but it was too late after the first chamber was shape and I had to make the other 5 match the first one.

 

[Mike T]

have them put on a flow bench and see what you have there. I have stock head flow numbers at the shop for reference if you wanted them.

I would be very interested in how well they flow....my next dilemma is do I remove the exhaust guide boss that extends into the exhaust port or not.
Champion completely removes this but I'm a little concerned about how short this makes the guide.

 

[Convertedfromv8]

Looks good I'll have to try this

 

[TURBOTIMMER]

I would be very interested in how well they flow....my next dilemma is do I remove the exhaust guide boss that extends into the exhaust port or not.
Champion completely removes this but I'm a little concerned about how short this makes the guide.

Friend of mine did that on a set he ported. He said the guides were completely wiped out at just a couple thousand miles (though, knowing how he drives, they were hard miles). Doesn't champion put bronze guides in their iron heads?

 

[Mike T]

Looks good I'll have to try this

I would be careful because there are too many unknowns. One question would be did I weaken the combustion chamber by removing material? Also it appears that detonation resistance is still ok or improved but have I now invited pre ignition?

 

[PSID6]

I did the chambers many years ago but I'm almost certain they ended up around 53cc or about 5cc over stock. The valves and a surface cut made up some of the ccs.

BTW thanks for my new alarm clock.......

Wow , I would have thought more than 53 cc's . Sorry about the clock lol, damn fat fingers didn't even realize

 

[PSID6]

have them put on a flow bench and see what you have there. I have stock head flow numbers at the shop for reference if you wanted them.

I have always wondered what the stock ports flow! Could you post them?

 

[TURBOELKY]

I have always wondered what the stock ports flow! Could you post them?

Yes. I have my flow sheet at the machine shop. Monday I'll be there and hopefully have my hands on a pair of champion irons. I've wondered this and looked so long, I will have a definitive answer soon.

 

[Jerryl]

Sticky in this section.

http://www.turbobuick.com/forums/threads/gn1-rs-ported-unported-stock-heads.216319/

 

[TURBOELKY]

Sticky in this section.

http://www.turbobuick.com/forums/threads/gn1-rs-ported-unported-stock-heads.216319/

That's a good sticky but pics are gone and not much actual flow numbers. Tons of what people have ran with different heads but way too many variables to compare. Only flow numbers I saw in all 5 pages were ported stock heads at 28" water

 

[Mike T]

Friend of mine did that on a set he ported. He said the guides were completely wiped out at just a couple thousand miles (though, knowing how he drives, they were hard miles). Doesn't champion put bronze guides in their iron heads?

I found this cutaway doing a google search. It was originally posted by Turbofabricator on the other board back in 07.

I added the lines to illustrate what the guide length may look like after typical modifications. The line below the curved section represents approximately where the guide would end when the upward radius of the exhaust port is considered.

I know Champion has been doing this for years but I'm not sure how much flow can be gained here? It's definitely a bottle neck when you look at the flow path.