Head porting pictures

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
We do our share of porting.

The profile pics that fettig and FUB show are similar to what we make. We do not go as radically close to the water jacket at FUB's picture shows. But as those pictures indicate, you can't see most of the critical modifications unless you cut the thing apart.

Every time we have shown porting pics, someone always comes out and says how we did it wrong... but here is what we do, based on our goals.

There is a problem with the intake port, as we do not agree with the right angle at the apex of the swirl chamber going into the bowl under the valve. If the head is going to crack, and a hard-driven engine is more prone, it will crack into the water jacket at the intake port beginning at that right angle. We round out that corner... carefully. We make about a 3/8" radius.

We remove material at the inside radius of the exhaust. Some who do porting feel that the exhaust gases aren't affected by that corner. We disagree. That is exactly where the bottle neck is. You have to be careful removing too much metal around the valve guide on the exterior radius of the exhaust port, or you will have a very poorly supported valve guide with a greatly reduced heat transfer area. Exposing more of the exhaust guide also creates a heat absorption in the guide, which is a negative effect. So, removing metal from the opposite side of the bottleneck is a good idea. Also, if you make comparisons to the later exhaust ports, say in the BRM and CBEA, VW has taken steps to smooth and open up that inside corner. So, what we have been doing on the inside radius is vindicated.

Between the ALH and the AHU, there is a major difference in location of a water jacket. We found out early when practicing on AHU cylinder heads. If you match the port to the exhaust manifold and go straight back on the head gasket side, you will break into the water jacket. Basically, we match the port opening to the exhaust manifold, then angle up and over the water jacket. We remove only a little material over the water jacket at that point.

Also for both ALH and AHU, you have to watch out for the head bolt holes in the exhaust. If you were to grind straight back from a line that matched the exhaust manifold, you will break into the head bolt holes. We believe it is good practice to match the port opening size, but not very good when you break into a head bolt hole...angle your cut around the bolt hole.

On the intake, we open up the bowl and smooth the angles going back from the swirl chamber. If you think there is much room in the intake runner to remove metal, just feel the web between the two center intake ports. It's very thin.

For about 3 inches, the intake only gets smoothed up with very little material removed. We do not build a full race head, so we do not remove the swirl chamber. A swirl chamber cannot work unless there is turbulence, so some expectation of flow loss is mandatory, with the payoff that you are going to make a cylinder head that will work efficiently when cruising. That is our opinion.
 
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JFettig

Vendor
Joined
Aug 18, 2010
Location
Blaine, MN
TDI
B5 Passat, 2010 Jetta
Thanks for the post Frank, can you outline where the waterjacket is on an AHU head with a pic maybe? I feel like I went a little large based on what you say about the AHU.
If I had to guess, I'm guessing you are outlining the top side of the port in this pic where it is outlined in red? http://i121.photobucket.com/albums/o229/shortysclimbin/for sale/head4mod.jpg
Also, where do you put that 3/8" radius? If its where I'm thinking, it would hurt flow, but I'll let you show us where it is. It isn't right in the center where this pic is focused is it?
http://pics.tdiclub.com/data/500/Jetta_Head_Intake_Port_4_Cylinder_Sdie_-_Unported_-_r.JPG
The external corner or internal corner?
 

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
Sorry the picture didn't come out very good...

We use a 3/8" sanding drum on a die grinder. Work the right angle until it's smooth.
 

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
2footbraker,

Yeah, you know what I mean... The older heads are a bit rougher on the castings and more variance. The good thing is that you can probe those water jackets to see how far you want to go.

If I find $1200 burning a hole in my pocket, there is an ultrasonic depth gauge that you can accurately determine wall thickness. So far, the money is still in my pocket.
 

JFettig

Vendor
Joined
Aug 18, 2010
Location
Blaine, MN
TDI
B5 Passat, 2010 Jetta
Does anyone have any volumetric efficiency figures for these heads or at least some direction in figuring it out?

I'm looking for volumetric efficiency over the rpm range.
 

JFettig

Vendor
Joined
Aug 18, 2010
Location
Blaine, MN
TDI
B5 Passat, 2010 Jetta
How? I'm not sure, I sure would be interested in learning.

What I'd use it for is calculating flow on compressor maps for sizing turbos.
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
Well, lets see...

1) You could evaluate the VE of an engine, then port the head and re-evaluate the VE. You'd have to insure that cam timing was identical before/after though.

2) You could have a valve that seats on a tube the same diameter as the valve seat that is 20+ diameters long (for established flow). Evaluate the pressure drop vs flow at the same length as the runner in the actual head. The thought being that this would be the ideal port - no bends, no swirl, constant area, etc. This gets a bit messy though because you want swirl and the ports are not constant area and the flow is not steady state.

3) The typical that I've seen is a comparison to a stock head on a flow bench - % increase/decrease in flow/swirl/tumble over stock.

These are just a couple ideas off the top of my head...For it to be an efficiency, you need something to compare it to - what is 100%? Also, putting the RPM component in adds another few dimensions of complexity.
 

sam2007

Veteran Member
Joined
Aug 15, 2012
Location
california socal
TDI
beetle TDI 2000
I see people here keep asking about hogging out ports go check out motoman.com good information there, last time i checked the the 1.9 tdi's etc. are small bore 4 cylinder motors large ports are for large motors and top end HP. if you make these ports much larger you can loose power everywhere else

here is some information for porting the 1.9 alh > EXHAUST PORT as viewed mounted on the motor > the top only of the exit area of the exhaust port runner where it meets the manifold to about one inch in only remove about one mm or so there. 2 smooth the ridge in the bowl clean up under the seat where the bowl hog from the factory ended maintain a circle in the bowl go for the consistent radius 3 short side very slight rounding of the sharp edge.

intake port its a large runner and port don't enlarge it anywhere 1 clean up just under seat where the bowl hog from the factory ended> maintain a circle in the bowl go for the consistent radius. 2 short side very slight rounding of the sharp edge.
make that the end all of the porting its only a 4 cylinder > if you only care about hp. and top end only power open the exhaust port like above but more. i would avoid at all cost excessive rounding of the short side areas.all.
 
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MarkoP

Veteran Member
Joined
Mar 5, 2005
Location
Finland
TDI
2.0 BKD 140hp
5-years old pictures, but still valid =)
Not actually molds of ported heads, but good view about what we are talking here about:







 

JFettig

Vendor
Joined
Aug 18, 2010
Location
Blaine, MN
TDI
B5 Passat, 2010 Jetta
Marco, your contributions are much appreciated!

I'm assuming in your last pic that most of the bump in the swirl port on a PD must be left alone?
 

MarkoP

Veteran Member
Joined
Mar 5, 2005
Location
Finland
TDI
2.0 BKD 140hp
I'm assuming in your last pic that most of the bump in the swirl port on a PD must be left alone?
It depends what are the goals, but I have ad more luck with swirl than no swirl.
7-years ago I ported one with swirl removed and it made extremely smoky 295hp.. of course injectors and turbos are improved, but now days I can make same or more flow and more power without smoke and that's enough for most.

PD and VE intake ports are the same and they also flow the same.
 

JFettig

Vendor
Joined
Aug 18, 2010
Location
Blaine, MN
TDI
B5 Passat, 2010 Jetta
Marko - The bump I'm speaking of is the extra material in the PD bowl that allows clearance for the injector, its 5 oclock to the valve guide.

So you have removed swirl all together in a port? Thats interesting and good to know someone has done it :)
 

MarkoP

Veteran Member
Joined
Mar 5, 2005
Location
Finland
TDI
2.0 BKD 140hp
If you remove injector hump completely, you might end to injector hole, or at least really close.

We made some trials without swirl, but I made another head later for that engine with swirl.
 

chapelhill

Veteran Member
Joined
Aug 19, 2005
Location
Scotland
TDI
03 Ibiza pd13- 2260vk Turbo etc.., Merc E280cdi
Injector bump on pd. I rounded port to follow the natural curve as if the bump had never been there and then ground away at the point to see how much material was left. Unless you are going to go to bigger valves I don't think there was much risk of breaking through. I am sure I saw some pictures of a ported head somewhere where it looked like it had broken through. I think the cylinder is sealed by the copper washer and the fuel channels by the seals on the injector, so in theory it might no be an issue, but I don't know if there are other considerations.
[url=http://pics.tdiclub.com/showphoto.php?photo=83491&title=experiment-with-pd-inlet-port&cat=5440][/URL]

I have some moulds of pre and post porting for my cylinder head but not much time, but since I am a DIY porter I have no idea if they are any good. I also have a mould of the area between inlet manifold and inlet port for about an inch each way. I will try to get it done in the next week or so.
 

GOFAST

Well-known member
Joined
Oct 1, 2014
Location
nederland
TDI
vento afn
wow that looks really nice.
wish mine was like that.
how many hours of work did you spend on it ?
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
wow that looks really nice.
wish mine was like that.
how many hours of work did you spend on it ?
it goes reasonably quick, long as you've got a coarse tooth die grinder burr that's made for aluminum
ETA: and enough air compressor to run it for a while, hah
 

vwUMO

TDIClub Enthusiast
Joined
Aug 5, 2003
Location
Maine
TDI
2003 JSW TDI 5MT ,2012 Jetta TDI 6MT, 2013 jetta TDI 6MT
I just finished on my CJAA head and there doesn't appear to be many places to improve on stock other than casting/machine marks and polishing. I removed so little material, I thought I was on season 1 of Gold Rush :). The effort feels like a waste of time but now I know what things look like in there. Time to get it buttoned back up and get this part of the project reassembled. This mod. Brought to you by red bull. :)
 

Sebster

Member
Joined
Sep 22, 2015
Location
UK
TDI
Passat b5.5
Just wondering why people touching inlets and changin geometry of them???
That not good idea, there is just nothing to do with inlets. They can be just smoothed what not changing any thing.
You can do exhaust for mearly 10mm bigger and deeper and thats all.
+ ofcourse polish it up.

Il upload picture if some one tell me how :(
 
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