ALH piston, rod & ring Upgrade?

D-cappz

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2003 Jetta ALH, 6 speed, 4motion, fully loaded, leather heated interior, sunroof, steering wheel controls. Over 420,000km
Hello tdi Club, Iv been trying to research this for a few days now. I can't find a perfect/reliable answer, and most of the threads are quite old.

I have done some engine mods to my car. The last Dyno I was pushing 181hp & 325 ft lbs.
I have got a head made with larger valves, Ported, dual valve springs, stage 2 colt cam, new lifters and some ARP headstuds that I am going to be installing really soon. But while I have the engine open I was thinking I should put new pistons, rods and rings in being that I want to push over 200+hp.

Here is my questions:

What pistons would work best for the ALH that are
A. Standard ALH size (I don't want to bore the block)
B. Same hight so I don't have to shave the block
C. Can handle the power I want to push
D. Let's just say a drop in piston.
E. OR stick with stock ALH pistons.

Should I make the piston valve reliefs larger?
My intake valves are 36.9mm I believe, and my exhaust valves are 33.5mm
I have a stock core piston someone gave to me, and it seems that the intake relief grooves are 38.2mm and the exhaust reliefs are around 33.88mm

What rods would be best for the ALH that
A. Can connect to the ALH crank
B. Can handle the power
C. Can handle any upgrade I throw at them in the future.
D. Will work with the piston upgrade

What kind of power are the stock pistons & rods good for?

Should I upgrade to a set of gapless rings or standard?
Example of gapless is something like total deal or sealed power oil control.

If you have a List of parts I should get while doing this job, that would be great.

I came accross alot of Ppl suggesting to put ASV pistons in, and that they work. But I came accross this forum:
http://forums.tdiclub.com/showthread.php?t=443136&highlight=Alh+piston+upgrade

Let's stay on topic as alot of these forums I read seem to get lost.
Please keep in mind, this is my first TDI build, and first time I am opening up the engine.
Thanks =D

Piston UPDATE:

So here is the update on the Pistons
ALH, ASV & ARL +0.5 Pistons

ALH 79.44mm Stock Piston

Weight w/ Pin w/o Rings = 759g
Pin weight = 207g

Skirt = 79.40mm (used piston)
Crown = 78.87mm
Crown thickness = 6.06mm
Valve relief depth 1.03mm

Piston height (bottom of skirt to top of crown) = 71.83mm
Pin hole to crown = 32.9mm

Bowl depth = 16.6mm
Bowl width = 38.16mm
Weight with Bowl full of water = 780g
The bowl holds 21g of water.

ASV Standard 79.5mm (79.46mm) Piston

Weight w/ Pin w/ Rings = 771g
Pin weight = 207g

Skirt = 79.46mm
Crown = 78.99mm
Crown thickness = 8.91mm
Valve relief depth 1.03mm

Piston height (bottom of skirt to top of crown) = 68.69mm
Pin hole to crown = 32.9mm
ASV 0.5mm over may be shorter from Pin to Crown.

Bowl depth = 17.39mm
Bowl width = was not measured sorry.
Weight with Bowl full of water = 795g
The bowl holds 24g of water.

ARL 79.5mm +0.5 (79.96mm) Pistons

Weight w/ Pin w/ Rings = 797g
Pin weight = 203g

Skirt = 80.00mm
Crown = 79.33mm
Crown thickness = 11.65mm
Valve relief depth 1.10mm

Piston height (bottom of skirt to top of crown) = 68.50mm
Pin hole to crown = 31.46mm
BUT the valve relief does not have an edge so add 1.10mm = 32.56mm

Bowl depth = 17.64mm
Bowl width = 38.01mm
Weight with Bowl full of water = 819g
The bowl holds 22g of water.

This is as accurate as I could get with my Digital Caliper

Oil Gallery Update: FIND IMAGES ON PG.5 post #75 http://forums.tdiclub.com/showpost.php?p=5230411&postcount=75

The ASV & ARL oil gallery seem to be positioned a little differently.

The ASV pistons have 3 holes all together, I would think this would allow it to cool better and catch oil better.

The ARL pistons have 2 holes, and the hole that would receive the oil from the oil jet/squirter is closer to the pin and wall of the piston. I will be customizing this on the ARL pistons by funneling the gallery hole to help catch the oil better.
 
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mk1-83

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LUPO 1.9 tdi 300+ hp
Stock engine can handle a lot 230 chp only need upgrade headbolts 12.9 to hold the gasket on place
 

D-cappz

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2003 Jetta ALH, 6 speed, 4motion, fully loaded, leather heated interior, sunroof, steering wheel controls. Over 420,000km
Stock engine can handle a lot 230 chp only need upgrade headbolts 12.9 to hold the gasket on place
Really, the stock internals are good for around 230hp? . Good to know.
Ya iv got some ARP headstuds.

But in the case I want to push it over 230hp, what are some piston/rod combinations I should get??
 
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purediesel

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I hope you realize he said crank horsepower, not wheel horsepower. It sounds like you dyno'd your car and got 180hp which is right close to the 230hp mark at the crank. Just wanted to shred light on that subject. Anyways, sounds like you'll need rods and then just go with bhw pistons and be done with it. Anything less is a waste on my eyes. I'd also go with Rosten rods of it was my build.
 

FRtdilover

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europe
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2001 4motion ARL 150
Really, the stock internals are good for around 230hp? . Good to know.
Ya iv got some ARP headstuds.

But in the case I want to push it over 230hp, what are some piston/rod combinations I should get??
AFAIK, asz/arl pistons with good rods (that will make transition between alh crank and trapezoidal asz/arl pistons) should be ok
 

D-cappz

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2003 Jetta ALH, 6 speed, 4motion, fully loaded, leather heated interior, sunroof, steering wheel controls. Over 420,000km
AFAIK, asz/arl pistons with good rods (that will make transition between alh crank and trapezoidal asz/arl pistons) should be ok

Can the ASZ or ARL pistons be installed without modifying the block?
 

FRtdilover

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2001 4motion ARL 150
Same bore yes, the only thing is just that ARL and ASZ piston are trapezoidal small end, not VE's one. And asz/arl crankshaft has bigger rod/crank big end journal than other's one like VE. That's why some people has created H-beam rods that will fit VE engines like yours, in combinaison with ARL/ASZ pistons.. as rosten rods, IE or others
 

D-cappz

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2003 Jetta ALH, 6 speed, 4motion, fully loaded, leather heated interior, sunroof, steering wheel controls. Over 420,000km
Same bore yes, the only thing is just that ARL and ASZ piston are trapezoidal small end, not VE's one. And asz/arl crankshaft has bigger rod/crank big end journal than other's one like VE. That's why some people has created H-beam rods that will fit VE engines like yours, in combinaison with ARL/ASZ pistons.. as rosten rods, IE or others
I see that roston rods may not be available any longer for the ALH.

where could I buy a set of these pistons and a set of good rods that will work with the crank and piston connection?



I hope you realize he said crank horsepower, not wheel horsepower. It sounds like you dyno'd your car and got 180hp which is right close to the 230hp mark at the crank. Just wanted to shred light on that subject. Anyways, sounds like you'll need rods and then just go with bhw pistons and be done with it. Anything less is a waste on my eyes. I'd also go with Rosten rods of it was my build.

I would have to re bore to get the BHW piston in, They are a 2.0L. I want to stay away from boring the engine right now.
I think rosten stopped making rods for this application.
 
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turbovan+tdi

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2003 TDI 2.0L ALH, auto, silver wagon, lowered, Colt stage 2 cam, ported head,205 injectors, 1756 turbo, Malone 2.0, 3" exhaust, 18" BBS RC GLI rims. 2004 blue GSW TDI, 5 speed, lowered, GLI BBS wheels painted black, Malone stage 2, Aerotur
Check the vendors, IE Franko6, I believe he has mentioned stocking rods, if not, check out the vendor section. Some have used Ebay rods with relative success after having them checked out.
 

D-cappz

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2003 Jetta ALH, 6 speed, 4motion, fully loaded, leather heated interior, sunroof, steering wheel controls. Over 420,000km
Check the vendors, IE Franko6, I believe he has mentioned stocking rods, if not, check out the vendor section. Some have used Ebay rods with relative success after having them checked out.
I don't know how I feel about ebay rods, even if they are claimed to have been checked. =s
I'll have a look on the vendors page and see what there is. Thanks.
 

FRtdilover

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2001 4motion ARL 150
That's right, some guys are running ebay rod (maxspeedingrod if I remember well) without any issue, but I can't tell you the quality
 

D-cappz

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2003 Jetta ALH, 6 speed, 4motion, fully loaded, leather heated interior, sunroof, steering wheel controls. Over 420,000km
Now to the question of:
Between ASZ and ARL, which pistons are the better option.

Iv read on some forums and write ups that the ARL pistons have a larger bowl lowering the CR. Can someone confirm this?

Would lowering the CR be a good thing, or bad thing?

Thanks.
 

jptbay

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D-cappz

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2003 Jetta ALH, 6 speed, 4motion, fully loaded, leather heated interior, sunroof, steering wheel controls. Over 420,000km
Stock bore ASV pistons are same deck height as ALH, no decking required. Ended up with same height 2-hole gasket as before rebuild.

ARL's have lower compression.

Rebuilt my ALH this summer with IE Tuscan rods and ASV pistons with oil cooling galleys from ID parts.

http://www.idparts.com/piston-set-nural-alh-stock-bore-p-1487.html

http://www.idparts.com/integrated-engineering-tuscan-connecting-rod-set-a4-alh-p-3024.html

Thank you so much.

But why do I keep finding info about the ASV pistons having a shorterd hight??

What are the pros and cons to lowering the compression??
 

red16vdub

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Stock bore ASV pistons are same deck height as ALH, no decking required. Ended up with same height 2-hole gasket as before rebuild.

ARL's have lower compression.

Rebuilt my ALH this summer with IE Tuscan rods and ASV pistons with oil cooling galleys from ID parts.

http://www.idparts.com/piston-set-nural-alh-stock-bore-p-1487.html

http://www.idparts.com/integrated-engineering-tuscan-connecting-rod-set-a4-alh-p-3024.html
Great info, this is what I was inquiring about myself. I'm going this route.
 

jptbay

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But why do I keep finding info about the ASV pistons having a shorterd hight?
Near as I can tell, oversized ASV pistons are shorter because it is assumed that you will deck the block when having the cylinders bored oversized at the machine shop.

I too read every post I could find before rebuilding my engine. I had bent rods, but wanted to refresh the engine still in the car - so I wanted to avoid having to deck the block.

I even ordered a one hole BEW head gasket in anticipation of lower piston protrusion, (thinnest one you can get) and was surprised when I measured protrusion upon assembly.
 

D-cappz

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Thank you for that information on the ASV pistons jptbay.

Here is some information I gathered from some of the guys at Darkside and KermaTDI

Darkside: ARL are the better ones to use, most aftermarket use ARL in the ASZ's. The compression is 0.5 down on ARL pistons. The ARL pistons will need small journal tapered end rods.

KermaTDI: The standard size ASV engine piston, which is essentially an ALH piston with an oil cooling duct below the combustion chamber, will fit to the stock ALH connecting rods.

The ARL (PD150) piston uses 18.5:1 compression ratio vs the stock 19.5:1 CR; as well as oil cooling. In order to use these in an ALH, you'll need a set of compatible connecting rods and a set of compatible BHW oil cooling jets.

Lower compression ratio will put less stress on the rods and head gasket all other factors being equal.

The biggest draw back on the ALH is that you'll have some increased smoke at idle when the engine is cold. This is primary only a concern at high altitudes. Not really noticeable at sea level. this is due to less heat generated by compression

Other Forums:
The ARL rings are approx 4mm lower.

79.5mm ARL with wrist pin = 789g.

I think the lower rings on the ARL give less blow.

The rings are lower on the ARLs to help protect them from higher temps that come with higher spec HP.

PD100 pistons have the small journal (ALH Crank) and tapered ends (ALR/ASV pistons).

Cut a ARL piston and measured the thickness between the bowel and oil gallery (4.5mm - 4.8mm iicr). This was a lot more than the ASZ pistons.

Lowering the cr is to keep peak cylinder pressure under 200bar where the pistons is disgin for,
High pcp stress the piston and make it cracks and high pcp lift you're head and leak head gasket

Conclusion:
It seems to me that the best piston to go with for stock bore would be the PD150 (ARL) pistons.

Question still not answered:
would it be better to go with some gapless piston rings?
 
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D-cappz

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2003 Jetta ALH, 6 speed, 4motion, fully loaded, leather heated interior, sunroof, steering wheel controls. Over 420,000km
ARL Piston picture by Bobby Singh



BHW Piston Left, ARL Piston Right picture by CharlieT



BRM Piston Left, ALH Piston Right picture by Turbocharged798


BHW Left, .5mm over ASV right picture by brnsgrbr





ALH Piston picture by D-cappz

 
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D-cappz

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2003 Jetta ALH, 6 speed, 4motion, fully loaded, leather heated interior, sunroof, steering wheel controls. Over 420,000km
Here is where I am at.

The ARL pistons:
Standard will fit ALH
lower the CR (which can be a good thing)
From what I know they have lower piston rings (another good thing for heat)
BUT I have to change the oil jets, and that means I would have to remove the crank. pretty big job.
I have to upgrade the rods to a tapered small eye connecting rod.

The ASV Pistons:
Should be the exact same size if they are standard pistons
Should keep the same CR as stock
I don't have to change the jets.
I could keep stock connecting rods or upgrade to a set of Rosten rods or Integrated Engineering Tuscan Connecting Rods which would work with ALH pistons and crank


I did read that I could use the tapered small eye rods with either of the pistons (ALH, ASV, ARL, ASZ)
can someone confirm this?

Does anyone have any pictures of the ASV and ARL pistons with possible measurements. I am looking for the measurement of the crown thickness (top piston ring to top of piston crown)?
 
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jptbay

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Rings are lower on ASV piston as well.

You can use tapered small end rods on ALH/ASV style piston.

No need to change piston oil squirters. Stock ones can be easily realigned (bent).
 

D-cappz

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Rings are lower on ASV piston as well.

You can use tapered small end rods on ALH/ASV style piston.

No need to change piston oil squirters. Stock ones can be easily realigned (bent).
Do you happen to know how much lower the ASV rings are vs ALH?
Are the ASV pistons good for 220whp?

Thank you for the quick reply.
 

D-cappz

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ALH Right, ASV Left picture by Jonamond

 

jptbay

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Just watch out. It has been reported that some of the ASV pistons come without oil cooling galleys.

The ones from IDParts definitely have them. Think metalman parts has or had ones without.
 

D-cappz

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Lower CR or not to?

Should I lower the CR by one point?

Would that one point really make a difference?

My boost is set to 27 peak and 25 steady.
Will I have problems in the future if I don't lower the compression? Such as head gaskets blowing. I am doing alot of this work after I blew the head gasket.
 

jptbay

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I wouldn't bother lowering the comp. I run similar boost.

I would recommend ARP head studs if you don't already have, and be meticulous when cleaning the deck and head surfaces upon reassembly. Took me way longer to get things cleaned up to a point I was happy, than I expected. Took a lot of elbow grease.
 

D-cappz

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Can you tell me what engine balancing, and blueprint in the engine is?
Thoughts on coated pistons?
 
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vtpsd

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My personal opinion is that you do not need to build the bottom end at those levels. I tend to look to the crazy Finns and see what they are doing and think that we are fine with a good tune and levels around 250hp.

I need to dyno my car so I have something to back up my BSing, however my audi is heavy, awd, and hauls butt. The motor is stock with a ported head, stage 3 cam and ARP headbolts. To me it feels like its pushing 250hp crank, but I have not dyno'd it.
I have 10,000 miles on my car and run it pretty damn hard. Had the head off recently to port it, and the piston protrusion is perfect still. Compression still perfect.

Not telling you what to do, just adding another data point.
 

D-cappz

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My personal opinion is that you do not need to build the bottom end at those levels. I tend to look to the crazy Finns and see what they are doing and think that we are fine with a good tune and levels around 250hp.

I need to dyno my car so I have something to back up my BSing, however my audi is heavy, awd, and hauls butt. The motor is stock with a ported head, stage 3 cam and ARP headbolts. To me it feels like its pushing 250hp crank, but I have not dyno'd it.
I have 10,000 miles on my car and run it pretty damn hard. Had the head off recently to port it, and the piston protrusion is perfect still. Compression still perfect.

Not telling you what to do, just adding another data point.

I am currently at 181whp and 325 lbs, from what I was told, that is around 230chp.
Now that I am adding more to the car, I am possibly going to see over 200+whp.
 
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