how should a 4g63 ported head look exhaust side for a holset turbo?

[pj91gsx]

How should the exhaust side look for my 2003 automatic holset turbo look? Or how should my ported head look for a turbo car? I have access to a flow bench

 

[mach4g63t]

***Forewarning***

Stock 1g heads flow pretty well from the factory. You really don't need to do much porting to the intake side without a bit of 'experience' on your side. The exhaust side, however, can ALWAYS use a good polish.

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The way I like to do all and any porting I do is take your time, remove a nice layer with a fine grit. Especially be careful on something like a 4G63 head that is all aluminum. Even 160 grit sand bits will chew threw it like a kid with laffy taffy.

I wish I was in your shoes with the flow bench. But for any portion of exhaust, turbo or head, you want the ports to be as smooth, and mirror-like as possible. This helps prevent carbon build up and helps promote a sort of 'slick', frictionless surface for the hot exhaust gases to travel out on.

For the turbo, it's not too bad. If you really think it needs ported, take a little out at a time. Go for the smooth, flowing cuts rather than trying to gouge out material. You want it to be smoother than wet glass in the end.

ALWAYS make sure you're keeping the natural shape. If you work one area for too long and realize you've made a dent or dip in the material, you'll spend twice as long 'TRYING' to work the rest of the area back down to match in the original shape.

For the turbo, just keep moving, never focusing on one spot too long. The same should be said for the head, but with much more care. Overall, I recommend using high grit sanding bits/flapper wheels the whole time to ensure you're going nice and slow but making things smooth. If this is your first time, its the best option until you get a little more experience under your belt.

If you DO plan on porting the intake side, I recommend the same methods, however, do everything as equally as possible across all 4 intake runners and flow bench OFTEN since you have the ability.

I love DIY stuff like this. If you do attempt it, try to post some pictures and results of what you accomplished. I saw one guy on here who gained something close to 30 cfms of flow on all runners from his DIY porting.

Slow'n'stady is the key!

 

[pj91gsx]

***Forewarning***

Stock 1g heads flow pretty well from the factory. You really don't need to do much porting to the intake side without a bit of 'experience' on your side. The exhaust side, however, can ALWAYS use a good polish.

---

The way I like to do all and any porting I do is take your time, remove a nice layer with a fine grit. Especially be careful on something like a 4G63 head that is all aluminum. Even 160 grit sand bits will chew threw it like a kid with laffy taffy.

I wish I was in your shoes with the flow bench. But for any portion of exhaust, turbo or head, you want the ports to be as smooth, and mirror-like as possible. This helps prevent carbon build up and helps promote a sort of 'slick', frictionless surface for the hot exhaust gases to travel out on.

For the turbo, it's not too bad. If you really think it needs ported, take a little out at a time. Go for the smooth, flowing cuts rather than trying to gouge out material. You want it to be smoother than wet glass in the end.

ALWAYS make sure you're keeping the natural shape. If you work one area for too long and realize you've made a dent or dip in the material, you'll spend twice as long 'TRYING' to work the rest of the area back down to match in the original shape.

For the turbo, just keep moving, never focusing on one spot too long. The same should be said for the head, but with much more care. Overall, I recommend using high grit sanding bits/flapper wheels the whole time to ensure you're going nice and slow but making things smooth. If this is your first time, its the best option until you get a little more experience under your belt.

If you DO plan on porting the intake side, I recommend the same methods, however, do everything as equally as possible across all 4 intake runners and flow bench OFTEN since you have the ability.

I love DIY stuff like this. If you do attempt it, try to post some pictures and results of what you accomplished. I saw one guy on here who gained something close to 30 cfms of flow on all runners from his DIY porting.

Slow'n'stady is the key!

thanks, I am port matching both sides, I was thinking about taking out the humps after the valve guides, good or bad idea?

 

[mach4g63t]

It's a good idea. But like I said, be cautious not to remove too much material. Just try to blend the runner into a smooth transitioning passage.

Hopefully there will be before and after pictures? The best part of this site is you can start, get about half way done, test it, post your results, and get critiques from members who have more experience in porting or having seen ported heads and then continue from there. Remember, there is no need to rush!

 

[pj91gsx]

It's a good idea. But like I said, be cautious not to remove too much material. Just try to blend the runner into a smooth transitioning passage.

Hopefully there will be before and after pictures? The best part of this site is you can start, get about half way done, test it, post your results, and get critiques from members who have more experience in porting or having seen ported heads and then continue from there. Remember, there is no need to rush!

ok. I have a head that I did that kind of porting to, Ill post some pictures later on.

 

[mach4g63t]

Also, are you removing the valve train while you do this work?

 

[pj91gsx]

Also, are you removing the valve train while you do this work?

yes, the valves and guides are out. Ill post some pictures of what I have so far.

 

[asd_gst]

are you going to put bronze guides in it after you port it? and yes like mach4g64t said take your time, if you rush through it there wont be good resluts, im taking my time porting my 14b and 2g manifold at work. i work at a machine shop and i know the best way to port anything is get it as smooth as you can and try to keep everything all ported the same. how serious of porting are you doing?

 

[pj91gsx]

are you going to put bronze guides in it after you port it? and yes like mach4g64t said take your time, if you rush through it there wont be good resluts, im taking my time porting my 14b and 2g manifold at work. i work at a machine shop and i know the best way to port anything is get it as smooth as you can and try to keep everything all ported the same. how serious of porting are you doing?

I will get you guys some pictures, I have 4 heads, one ported and realized its too much, 2nd probably just right, 3rd port matched, 4th stock. Ill send pictures.

 

[pj91gsx]

The head with guides, i think its over ported for my setup. the head without guides, i think will be perfect once I sharpen the divider and my friend to flow bench it.

Just too add on the head with guides, I think it would work perfect for N/A. I started porting the bend on the bottom(opposite of the guides)

 

[mach4g63t]

What is that hole in the side of the port? The port looks good in the first picture, just take a really good fine grit bit and try to polish everything up as much as possible. You could try to blend the 'humps' around the valve guides a little more, but I don't know how much more material you would want to take away from them.

Looks good in terms of original port shape too. Polish those things up and it should be really nice. Also, just a FYI, from what I know about exhaust porting is that you generally want to try and raise the roof of the port rather than the bottom. I can't remember EXACTLY why, but I believe it deals with hot gas rising, thus increasing the roof gives it better flow.

 

[->PrOjEcTGS<-]

That's the passage for the EGR.

 

[mach4g63t]

That's the passage for the EGR.

That's what I ended up realizing. It's really early (5am).

 

[HIGHPSI4]

One of the best things I found to use when porting my head a few years ago was a worn out carbide rotary file. I ported a lot of steel housings and wore it down. When it came to alum. it cut clean and did not clog up. It did not chew up the material and excessive cuts yet worked much faster than sanding.

 

[->PrOjEcTGS<-]

That's what I ended up realizing. It's really early (5am).

Sorry, I work overnight Wednesday into Thursday. I have nothing better to do...

 

[havoc742]

Looks good in terms of original port shape too. Polish those things up and it should be really nice. Also, just a FYI, from what I know about exhaust porting is that you generally want to try and raise the roof of the port rather than the bottom. I can't remember EXACTLY why, but I believe it deals with hot gas rising, thus increasing the roof gives it better flow.

You want to raise the roof of the port to eliminate the void that naturally occurs at the top of the port. Reducing or eliminating the void increases flow.

 

[pj91gsx]

Thanks you guys, If thats all I need to know, then Ill just polish it up and get it flow benched and then finally get this thing together.

I wonder if I welded up that egr valve hole if it would give me quicker spool.

 

[livedsm4g63]

thanks, I am port matching both sides, I was thinking about taking out the humps after the valve guides, good or bad idea?

i thought that would create a low pressure area?

 

[pj91gsx]

i thought that would create a low pressure area?

I dont know thats why I asked. Maybe I should ask a vender.

 

[viprez586]

There is a theory on porting the intake side, the grit or imperfect surface gives an area for air to "stick" and form a surface for the rest of the air/fuel mixture to slipstream right on through.
The best way i can explain this is look at the dimples of a golf ball and how it travels through the air.

Props on the DIY though, I'm way to scared to port my head, I'll just leave it to the pros to get that amazing finish.

 

[pj91gsx]

There is a theory on porting the intake side, the grit or imperfect surface gives an area for air to "stick" and form a surface for the rest of the air/fuel mixture to slipstream right on through.
The best way i can explain this is look at the dimples of a golf ball and how it travels through the air.

Props on the DIY though, I'm way to scared to port my head, I'll just leave it to the pros to get that amazing finish.

well. I know how to do the intake that is done, the exhaust is where I was stuck, I dont want lag. right now I have 510 injectors and a holset from a 2003 auto dodge cummins. Its a little smaller than the manual, but its good for a 400 hp goal.

 

[dsm-onster]

thanks, I am port matching both sides, I was thinking about taking out the humps after the valve guides, good or bad idea?

Do you mean these humps? I'm porting my head and I'm not sure what to do with these. . .

 

[pj91gsx]

Do you mean these humps? I'm porting my head and I'm not sure what to do with these. . .

not those humps, I was referring to the humps that come after the valve guides. they are the most obvious ones and I took them out completely on these two heads. on two other heads they are still there. It would be nice if I vender would step in and help us out.

 

[Freerevving]

There is a theory on porting the intake side, the grit or imperfect surface gives an area for air to "stick" and form a surface for the rest of the air/fuel mixture to slipstream right on through.
The best way i can explain this is look at the dimples of a golf ball and how it travels through the air.

Props on the DIY though, I'm way to scared to port my head, I'll just leave it to the pros to get that amazing finish.

Good thing it's a theory.... useful for carbureted engines and not EFI. Dynos proved that an extremely rough surface actually increases Hp on carbureted engines. It's thought to increase fuel atomization. No dyno charts ever proved that a rough surface is beneficial with EFI, which already atomizes fuel 100-1000X over carbs.

The dimples in the golfball create resistance and turbulence, but due to the backspin it acts as an airfoil and also gives you hangtime.

The air/fuel mixture is the same air that will be "sticking" to the rough surface, which is nothing more than a thick (slow-moving) boundary layer on a rough surface, and a thin (fast-moving) layer on a mirror surface.

 

[Freerevving]

not those humps, I was referring to the humps that come after the valve guides. they are the most obvious ones and I took them out completely on these two heads. on two other heads they are still there. It would be nice if I vender would step in and help us out.

take the humps out, they're another example of overengineering