ALH ported head - "free hand"

ducatipaso

Airhead Butcher
Joined
Nov 17, 2001
Location
norcal
TDI
2002 Jetta TDI
What's the cam? The stage 4 colt I have in my 12 valve has zero overlap. It's actually -15.5* overlap. Ie, intake and exhaust are not open at the same time.
https://photos.app.goo.gl/ELqLmyNyX5JUc5mQ9
Screen shot after ran through a cam profile calculator.
techtonics 264/260s - they really lit my engine up in combination with a United Motorsport tune. Tim at TST says I'm probably at 240 crank HP with this setup. it really rips.
 

Franko6

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Jetta, 99, Silver`
I'll put my $0.02 in.

I don't know why you would leave the exhaust guides in. They are in the way, it make it harder to hand port and there is an obvious misunderstanding what's needed in the exhaust port. Intakes are a 'touchy-feely' thing I think hard to get just right.

I refer to the air dams as reversion stops. Since meeting someone who worked for Dart over 40 years, I learned their great purpose. It does a mysteriously great benefit, which I think is largely misunderstood.

Port, yes. Polish I don't think so. Another misunderstood value of a port is making vortices close to the walls as possible. Smooth, polished walls do not improve the small vortice concept and probably will lose high-end performance. When some of the other guys who have been porting head across the ditch came hijacking a thread of mine, that topic came up. There was another post that explained my purpose to make a port shine; so you could actually see the shape better. It got roughed up before that head went out.

In my investigation, the advantages of dimpling was for engines that the air speed of the port is approaching supersonic. As example, the Vtech Honda would acheive a negligible 5+ hp at speeds over 9500-10,500 rpm. You want to choose dimpling in a TDI? Choose racing stripes instead. They always work...

There is a lot of hyperbole, but not a lot of proof for who does what. There are tricks that I have been doing in my CNC porting and even if your staring at it, you might not understand or see some of it. And then, there is the heating issue, which makes any version of port roughness design so much talk. But when you reach the point that ceramic coating is required, forget what the surface prep needs to be. It will be smooth, flat, ceramic. But at that point, carrying the heat out of the head and into the turbo becomes the important issue.

I don't worry for competition. I have more than I can do. I don't try to 'get it all' from porting, which is better said,"All of WHAT?" Because no one port will do the greatest advantage in all situations.

I remember an Englishman who made a high rise piston with a cam intended for overlap in a 16V gasser converted to TDI engine. But that was a single instance and when I hear what it took to make it work, I lost interest and never heard any more about it. The speed of the intake ram effect would be all designed to make it run at low rpm, and that same length intake would not work for higher rpms.

So, to be blunt, there is no overlap in an interference engine. There is a reason they are called 'interference engines'. An example, the MeisterCam, MUST be closed when the piston comes up. There is very little, if any margin for error. I only recommend those for the most ourtrageous intents, and another rebuild will be required in that engine's future, soon. Same with mine. I design into the cam enough 'margin of error' that the novice can make a mistake and not destroy the engine.
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
I don't understand the hesitance to grinding on the valve guides
I always thinned out mine on every head I've ported since they do protrude into the port, get those things less blocky, more flowy

ETA: mostly on the exhaust side, the intakes are pretty shrouded
 

dieseldonato

Veteran Member
Joined
Mar 10, 2023
Location
Us
TDI
2001 jetta
techtonics 264/260s - they really lit my engine up in combination with a United Motorsport tune. Tim at TST says I'm probably at 240 crank HP with this setup. it really rips.
I'm assuming you're not talking about a cummins at this point, lol.
 

mrchill

TDIClub Enthusiast, Super Secret Diesel Ninja Vend
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this is my 3rd head i've ported - it's going to go into @braddies alh mk4 when we do an in-car rebuild (hone, maxpeeding rods, new rings).....

gasket matched.
left the swirl in the intake ports, just enlarged a little bit towards the bowl, shaved out a bit all-round.
exhaust ports opened up quite a bit, but kept the shape expanding in volume outward.

comments welcome. it's hard to get good pics of this stuff, did my best with my phone :)

it could use a bit better polishing, but i think is good enough. this one i was able to get done in <8hrs.

next head, i'm going to try and find some better bits and techniques for getting the final round a little more even and polished

tools used were mostly my 3000rpm drill + carbide burrs, but i did use makita 1/4 die grinder with a rough cut carbide bit to more quickly get the exhaust ports opened up. also a little bit of dremel for polishing, but it's really too weak, so i mostly used the drill + die grinder













you can always copy a well ported head like everyone else has.
 

jmodge

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TDI
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Franko6

Vendor , w/Business number
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May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
486, That is part of my porting program. What you say about the intake is my arguement against larger intake valves.
 

Franko6

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Location
Sw Missouri
TDI
Jetta, 99, Silver`
I keep hearing how the MS rods are 4340, CrNiMo. Then why when you put a drop of water on any surface, they rust? Because they are high carbon steel. Cheaper is not better. And even if they are titanium coated, where the last finishing is done, on the big end bearing surface, it is not coated, because that is the last step to finish the rod.

But then, they are also called forged, which is simply not true and "Titanium Coated", which is such a useless thing to do, UNLESS you are trying to hide that the rod is high carbon steel. High carbon steel will NOT rust if you ever so lightly plate the rod with titanium. That is trickery, but shouldn't we all be used to that with the Country or origin?

The advantages 4340 steel has high strength, ductility, toughness, creep resistance, and fatigue resistance relative to most other steels. If your goal is medium range of power, maybe those MS rods will work. But then, so would some PD rods.

But it's not just the steel that is wrong, it is often that the sizing is not done well. The tolerances I use for the big end is measured to .0002"+,-.0000". But from what I regularly measure with my bore gauge, the rods I work with are on the black line under the Zero as measured from my platen on the wall. I do like accuracy. Although the rods I use are given an allowance of .0002", I know Tom Molnar must be using the standard machinist tehcnique..."To accurately measure to Ten Thousandths of an inch.(.0001"), you need to be able to measure to the 10th power, or One hundred thousandths of an inch (.00001"). Why so much accuracy? Because it matters.
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
for a while they were japanese made, chinese resold
dunno nowadays, mine have held up well enough to drain the gears outta the drain plug of an 0a6, so what more can you want than that

yeah nitriding doesn't have much purpose on a connecting rod, but whatever, if it helps sell a product... (and those ones don't look like the nitrided ones)
 

GlowBugTDI

Veteran Member
Joined
Jul 20, 2018
Location
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2001 Beetle GLS TDI (BIODSL). 01 original Glow Bug TDI (sold)
I keep hearing how the MS rods are 4340, CrNiMo. Then why when you put a drop of water on any surface, they rust? Because they are high carbon steel. Cheaper is not better. And even if they are titanium coated, where the last finishing is done, on the big end bearing surface, it is not coated, because that is the last step to finish the rod.

But then, they are also called forged, which is simply not true and "Titanium Coated", which is such a useless thing to do, UNLESS you are trying to hide that the rod is high carbon steel. High carbon steel will NOT rust if you ever so lightly plate the rod with titanium. That is trickery, but shouldn't we all be used to that with the Country or origin?

The advantages 4340 steel has high strength, ductility, toughness, creep resistance, and fatigue resistance relative to most other steels. If your goal is medium range of power, maybe those MS rods will work. But then, so would some PD rods.

But it's not just the steel that is wrong, it is often that the sizing is not done well. The tolerances I use for the big end is measured to .0002"+,-.0000". But from what I regularly measure with my bore gauge, the rods I work with are on the black line under the Zero as measured from my platen on the wall. I do like accuracy. Although the rods I use are given an allowance of .0002", I know Tom Molnar must be using the standard machinist tehcnique..."To accurately measure to Ten Thousandths of an inch.(.0001"), you need to be able to measure to the 10th power, or One hundred thousandths of an inch (.00001"). Why so much accuracy? Because it matters.
What rods do you recommend for high hp ALH builds then?
Seems lots of people in MN use maxspeed.
 

jmodge

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Joined
Jun 18, 2015
Location
Greenville, MI
TDI
2001 alh Jetta, RC2 w/.205's 5speed daily summer commuter and 2000 alh Jetta 5spd swap, 2" lift, hitch, stage 3 TDtuning w/.216's winter cruiser, 1996 Tacoma ALh

jmodge

Top Post Dawg
Joined
Jun 18, 2015
Location
Greenville, MI
TDI
2001 alh Jetta, RC2 w/.205's 5speed daily summer commuter and 2000 alh Jetta 5spd swap, 2" lift, hitch, stage 3 TDtuning w/.216's winter cruiser, 1996 Tacoma ALh
What rods do you recommend for high hp ALH builds then?
Seems lots of people in MN use maxspeed.
Tom Molinar was on top of the Oliver rod and main cap project for NASCAR in the 1980’s
 

scrambld

Veteran Member
Joined
Jun 26, 2004
Location
Belchertown, MA
TDI
'06 Jetta...TDI/5spd :) >>>now a '15 Passat TDI/DSG
Makes me wonder where the blanks are sourced from though, and with that said, one might question quality. I'd imagine Molinar is on top of QC.
"All Molinar VW conrods are finished in the United States at the Molinar Technologies shop in Michigan."....and the website does state, " All Molinar pistons rods are finished...."
 
Last edited:

J_dude

Veteran Member
Joined
Jan 9, 2020
Location
SK Canada
TDI
2003 1.9l “Jedi”
I keep hearing how the MS rods are 4340, CrNiMo. Then why when you put a drop of water on any surface, they rust? Because they are high carbon steel. Cheaper is not better. And even if they are titanium coated, where the last finishing is done, on the big end bearing surface, it is not coated, because that is the last step to finish the rod.

But then, they are also called forged, which is simply not true and "Titanium Coated", which is such a useless thing to do, UNLESS you are trying to hide that the rod is high carbon steel. High carbon steel will NOT rust if you ever so lightly plate the rod with titanium. That is trickery, but shouldn't we all be used to that with the Country or origin?

The advantages 4340 steel has high strength, ductility, toughness, creep resistance, and fatigue resistance relative to most other steels. If your goal is medium range of power, maybe those MS rods will work. But then, so would some PD rods.

But it's not just the steel that is wrong, it is often that the sizing is not done well. The tolerances I use for the big end is measured to .0002"+,-.0000". But from what I regularly measure with my bore gauge, the rods I work with are on the black line under the Zero as measured from my platen on the wall. I do like accuracy. Although the rods I use are given an allowance of .0002", I know Tom Molnar must be using the standard machinist tehcnique..."To accurately measure to Ten Thousandths of an inch.(.0001"), you need to be able to measure to the 10th power, or One hundred thousandths of an inch (.00001"). Why so much accuracy? Because it matters.
@CanadianALH
 

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
It's not nitrided. It's Titanium coated. NItriding would be even less purposeful. Don't get me wrong, I know MaxSpeeding sells a lot of their junk. I get the same comment every time I send a set back. "We never see this problem with them." Only if someone knows what they are doing and talking about...

Seriously, do you honestly think the Chinese are going to buy Japanese engine parts to relabel them? NO! The might buy ONE part, then copy it and sell the stuff themselves without a middlman. Another thing the Chinese never do. Throw away a part. They get a part back as unacceptable and try to sell it to the next sucker. I think a Norweigan guy that might know something about that... Sold me that CRAP.

As for using PD rods, I just got done bending some, in a build I made only in January. I was going for the gusto. .260 nozzles, BRM .5OS pistons,the PD rods from a BRM, a 1856 turbo. Stage 4 RC tune. A really great 10mm pump (I don't think 11mm is all that necessary...) Missed 2-3 shift. Thought I was going to trash the 02J 5-speed. 95mph through the trap in my totally stock chassis. Did not get the ET. Broke the #1 top ring, galled 3 pistons, all the rod bearings, bent #3 rod. I think my current rebuild with my Molnars are going to hold up.

I'll tell you this: I don't have a failure rate with Molnar rods except for those overzealous guys who go way big on injectors, split the piston in two and flame cut the top of rod above the wrist pin. They were still perfectly straight, but that is compromised. I replaced them, but not as a warranty.
 

CanadianALH

Veteran Member
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Canada
TDI
2002 Jetta 5spd 2006 Jetta DSG (wifes)
there's your problem
stop moving air where you can't use it
This is interesting. I have been asking the question about 1752 or 1856 for a bit now. If you don’t mind could you share your thoughts and opinions?
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
This is interesting. I have been asking the question about 1752 or 1856 for a bit now. If you don’t mind could you share your thoughts and opinions?
They're far too small, when they're most efficiently moving air you should be limiting torque on the fuel side, and up in the revs you're running out of air when you don't need the torque limiters. When you have the air and try to use it you'll kill your engine, when you can use the air you're killing your engine trying to force exhaust through the tiny little turbine side as if it is an air compressor rather than an engine.

go with something with at the very least a 50mm inducer, for a general 'size range' and avoid all the aftermarket hybrid trash that's been assembled out of whatever parts happen to drop together, get a used running takeout
 

GlowBugTDI

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2001 Beetle GLS TDI (BIODSL). 01 original Glow Bug TDI (sold)
They're far too small, when they're most efficiently moving air you should be limiting torque on the fuel side, and up in the revs you're running out of air when you don't need the torque limiters. When you have the air and try to use it you'll kill your engine, when you can use the air you're killing your engine trying to force exhaust through the tiny little turbine side as if it is an air compressor rather than an engine.

go with something with at the very least a 50mm inducer, for a general 'size range' and avoid all the aftermarket hybrid trash that's been assembled out of whatever parts happen to drop together, get a used running takeout
Ok, so something along the lines of a 2056 or a 2256 ect. Can a stock ALH head flow anything much larger than that without porting? At least making it worth an even larger turbo and cost?
 

burpod

teh stallionz!!1
Joined
Nov 27, 2004
Location
cape cod, ma
TDI
82 rabbit vnt ahu, 98 jetta vnt ahu, 05 parts car, 88 scirocco.. :/
They're far too small, when they're most efficiently moving air you should be limiting torque on the fuel side, and up in the revs you're running out of air when you don't need the torque limiters. When you have the air and try to use it you'll kill your engine, when you can use the air you're killing your engine trying to force exhaust through the tiny little turbine side as if it is an air compressor rather than an engine.

go with something with at the very least a 50mm inducer, for a general 'size range' and avoid all the aftermarket hybrid trash that's been assembled out of whatever parts happen to drop together, get a used running takeout
not really sure how i feel about that. i haven't bent any stock rods or blown my stock bolted head gasket with my gt1856 and tunes. power from 2500 up to 5500 was pretty outrageous. 2000+ rpm power more than enough for my desires. EGTs under control, boost control pretty decent.

and due to vanes sticking and then internal bolts breaking while trying to disassemble, i had to put in a gt1752. same tune, just some n75 adjustments + limiting max fuel a bit... definitely lost something. other than being not as good as a newer gen gtd/etc, i don't really see the gt1752/1856 as being as bad as many think they are. id say the fault of that might be more in tuning, JMO. or at least trying to do too much at too low rpm
 

mrchill

TDIClub Enthusiast, Super Secret Diesel Ninja Vend
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not really sure how i feel about that. i haven't bent any stock rods or blown my stock bolted head gasket with my gt1856 and tunes. power from 2500 up to 5500 was pretty outrageous. 2000+ rpm power more than enough for my desires. EGTs under control, boost control pretty decent.

and due to vanes sticking and then internal bolts breaking while trying to disassemble, i had to put in a gt1752. same tune, just some n75 adjustments + limiting max fuel a bit... definitely lost something. other than being not as good as a newer gen gtd/etc, i don't really see the gt1752/1856 as being as bad as many think they are. id say the fault of that might be more in tuning, JMO. or at least trying to do too much at too low rpm
Have any dynos to support that? Preferably with different hardware profiles? Also, the old school 1752 and 1856 arent even cheaper than the newer stuff in most cases. It isnt near as good...and you arewnt usually saving money either. Serious disadvanteges. Tuning is important sure...but starting with good hardware is key to making good reliable power.
 

burpod

teh stallionz!!1
Joined
Nov 27, 2004
Location
cape cod, ma
TDI
82 rabbit vnt ahu, 98 jetta vnt ahu, 05 parts car, 88 scirocco.. :/
Have any dynos to support that? Preferably with different hardware profiles? Also, the old school 1752 and 1856 arent even cheaper than the newer stuff in most cases. It isnt near as good...and you arewnt usually saving money either. Serious disadvanteges. Tuning is important sure...but starting with good hardware is key to making good reliable power.
i havent' 'had the chance/time to do any dynos. and yes, i know the GTD turbos can be had for no more $$ than an older GT-based turbo and i always suggest a GTD over a GT. but a lot of people draw the line at redoing their downpipe. for anyone who can weld i always say a GTD would be a no-brainer. or, if you're redoing the exhaust for whatever reason/build, then it's also a no-brainer. but if someone isn't looking for the ultimate and money/time is a constraint, and if all they're looking for is the power level of a 1752/1856, it's a perfectly acceptable turbo for most, in that situation.
 

CanadianALH

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Canada
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2002 Jetta 5spd 2006 Jetta DSG (wifes)
When I do a turbo I am going to go to the dyno with burpods tune. I want to before as well but it’s not really in the budget unfortunately.
 

Franko6

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Location
Sw Missouri
TDI
Jetta, 99, Silver`
I am open to suggestion. The 1856 was on the shelf and I had the manifold to go with it. This was just another experiment. I don’t think I was overfueled or there was too much air. The nozzles were set at very high pressures IMO, to 240/340 (Burpod’s request for customer) and fully ported head, I do not think it was ‘too much air’. The boost was checked prior to speed run. Only 3bar MAP. I sure didn’t run out of fuel.

The fact I was only 6500 miles on the engine rebuild, I ran close tolerances and I should maybe open up clearances. It was nowhere near completely broken in. I don’t think the PD rods helped any more than stock ALH rods. Oil pressure was good throughout. No girdle.

The 1856 is not ‘crazy air’. The only thing I did not do prior to the speed run is check the IQ level and optimize. If anything, it was running slightly rich.

I did a non-conservative test. None of my run under powers was below 2,000rpm, none over 4,500rpm. Except an unloaded missed shift, it was not over-run or do I expect damaged like that, although 3 shifts were abrupt power. That is probably where the damage occurred.

Turbos are as many as the opinions for them. In the final analysis, I tend to let the customer decide how far to go with the turbo. In general application, if you run out of fuel, you need bigger nozzles. A bit too much air is better than too much fuel, based on the melted pistons I’ve seen.

So, 486, I don't know what exactly what you mean, but when you run out of fuel, the additional air may be useless, but it's not damaging. There is just no more additional power is made.
 

burpod

teh stallionz!!1
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Location
cape cod, ma
TDI
82 rabbit vnt ahu, 98 jetta vnt ahu, 05 parts car, 88 scirocco.. :/
Probably just too much advance for that fueling
 
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