ALH piston, rod & ring Upgrade?

turbovan+tdi

Top Post Dawg
Joined
Mar 23, 2014
Location
Abbotsford, BC.
TDI
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
Thanks, it was hard to find any write ups or picture to compare the pins.
If I have a standard ALH piston, is there any pros or cons on going with Tapered small end rods vs non-tapered?
When you say Tapered pins you mean the rod end?
Not really, the ALH piston is already lighter so no point unless you already had some, these aren't rpm crazy engines. If the budget allows then sure, it won't hurt.

Tapered at the piston clip end, they are thick in the middle and taper out towards the piston clip.

Piston wrist pins. Tapered is lighter. Would you notice a difference in an engine build? Doubt it.

Tapered rods not necessary with ASV pistons. You could use tapered rods, but again I wouldn't expect any gain.

On rod ends. Kerma has tapered version of IE tuscan I-beam and claim to be the only ones. For some reason they mistakenly refer to them as H-beam, however I-beams are pictured.. I'm sure a machine shop could put a taper on non-tapered rods if you really wanted though.

http://www.kermatdi.com/integrated-engineering-connecting-rods-pd150-tuscan/
Not sure if I'd modify a set unless that was the only option to run PD pistons.
 

Digital Corpus

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Joined
Mar 14, 2008
Location
Ontario, California
TDI
'97 B4 w/ 236K mi body, 46K mi soul
Balanced rods after manually tapering them:
http://forums.tdiclub.com/showpost.php?p=4380321&postcount=160

Glamor shot of final rods, pistons, tapered wrist pins all together waiting to go in their homes, along with final balanced weights on all:
http://forums.tdiclub.com/showpost.php?p=4391194&postcount=162

Despite my own anal retentiveness, I opted to not balance the small and big ends separately. You need incredible precision in order to pull that off appropriately. In my mind, "appropriately" means 0.1 gram precision. Please keep in mind that my scales were calibrated with M2 class weights which are +/- 0.3 gram accurate.
 

john.jackson9213

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Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
Ya I wouldn't put the ebay rods in my car, I just took the picture from there just to show what a Tapered small end rod looks like.

From my understanding Roston either went cheaper (Chinese) or stopped making rods for the ALH. That's why I am looking into getting the IE Tuscan rods or the rod Frank sells.
Roston used to use a supplier in Japan to have his designed rods made for him. The supplier started using Roston's design and selling those rods in large quanties to other vendors who sold them on Ebay at prices below Roston's cost because they were buying large quantities. At that point Roston changed his supplier to Pauter Machine here in San Diego.

You may recall my earlier post telling you that Pauter Machine will make any kind of con rod you want to pay for(post #15). Pauter has a very long and very good reputation for custom rods.

I "think" VW also makes/uses stronger rods in their European high horsepower TDI engines. I would have to research if these fit the ALH engine with ASV pistons. For my own engine I will likely go with the IE or Frank06 supplied rods. Simply because they are easy to source upgrades, but I would/will also check with Dark Side in the UK or Dutch Auto Parts.
 
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turbovan+tdi

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Joined
Mar 23, 2014
Location
Abbotsford, BC.
TDI
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
I "think" VW also makes/uses stronger rods in their European high horsepower TDI engines. I would have to research if these fit the ALH engine with ASV pistons. For my own engine I will likely go with the IE or Frank06 supplied rods. Simply because they are easy to source upgrades, but I would/will also check with Dark Side in the UK or Dutch Auto Parts.
Correct, BEW and PD engines use a stronger rod, that will take more abuse. Can't remember reading what HP level they are good for.
 

turbovan+tdi

Top Post Dawg
Joined
Mar 23, 2014
Location
Abbotsford, BC.
TDI
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
Balanced rods after manually tapering them:
http://forums.tdiclub.com/showpost.php?p=4380321&postcount=160

Glamor shot of final rods, pistons, tapered wrist pins all together waiting to go in their homes, along with final balanced weights on all:
http://forums.tdiclub.com/showpost.php?p=4391194&postcount=162

Despite my own anal retentiveness, I opted to not balance the small and big ends separately. You need incredible precision in order to pull that off appropriately. In my mind, "appropriately" means 0.1 gram precision. Please keep in mind that my scales were calibrated with M2 class weights which are +/- 0.3 gram accurate.
What rods did you use? Can't remember, :(
 

Digital Corpus

Top Post Dawg
Joined
Mar 14, 2008
Location
Ontario, California
TDI
'97 B4 w/ 236K mi body, 46K mi soul
What rods did you use? Can't remember, :(
First post of my thread
...
Thanksgiving, 2013:
In order to drive the car without having to worry about exploding engine bits, a number of support mods were done in conjunction with the engine rebuild:
...
 

GOFAST

Well-known member
Joined
Oct 1, 2014
Location
nederland
TDI
vento afn
I had ASV pistons / lowerd compression.
230hp and a peace broke off between 1st and 2 piston ring.

Nou i use PD AXR piston and rods.
They have the tappert small end two.
I would recomend them
 

D-cappz

Veteran Member
Joined
Jul 10, 2013
Location
Victoria
TDI
2003 Jetta ALH, 6 speed, 4motion, fully loaded, leather heated interior, sunroof, steering wheel controls. Over 420,000km
Piston wrist pins. Tapered is lighter. Would you notice a difference in an engine build? Doubt it.

Tapered rods not necessary with ASV pistons. You could use tapered rods, but again I wouldn't expect any gain.

On rod ends. Kerma has tapered version of IE tuscan I-beam and claim to be the only ones. For some reason they mistakenly refer to them as H-beam, however I-beams are pictured.. I'm sure a machine shop could put a taper on non-tapered rods if you really wanted though.

http://www.kermatdi.com/integrated-engineering-connecting-rods-pd150-tuscan/
Thanks, I am still unsure what pistons I will be running with as GOFAST mentioned that he broke a ASV piston.

Not really, the ALH piston is already lighter so no point unless you already had some, these aren't rpm crazy engines. If the budget allows then sure, it won't hurt.
Tapered at the piston clip end, they are thick in the middle and taper out towards the piston clip.
Not sure if I'd modify a set unless that was the only option to run PD pistons.
Thanks for the info.

Balanced rods after manually tapering them:
http://forums.tdiclub.com/showpost.php?p=4380321&postcount=160

Glamor shot of final rods, pistons, tapered wrist pins all together waiting to go in their homes, along with final balanced weights on all:
http://forums.tdiclub.com/showpost.php?p=4391194&postcount=162

Despite my own anal retentiveness, I opted to not balance the small and big ends separately. You need incredible precision in order to pull that off appropriately. In my mind, "appropriately" means 0.1 gram precision. Please keep in mind that my scales were calibrated with M2 class weights which are +/- 0.3 gram accurate.
Thanks for the read.

Roston used to use a supplier in Japan to have his designed rods made for him. The supplier started using Roston's design and selling those rods in large quanties to other vendors who sold them on Ebay at prices below Roston's cost because they were buying large quantities. At that point Roston changed his supplier to Pauter Machine here in San Diego.

You may recall my earlier post telling you that Pauter Machine will make any kind of con rod you want to pay for(post #15). Pauter has a very long and very good reputation for custom rods.

I "think" VW also makes/uses stronger rods in their European high horsepower TDI engines. I would have to research if these fit the ALH engine with ASV pistons. For my own engine I will likely go with the IE or Frank06 supplied rods. Simply because they are easy to source upgrades, but I would/will also check with Dark Side in the UK or Dutch Auto Parts.
The Crank end is larger on the European TDI rods, so they cannot be used unless you changed to a BEW crank I think it is.
Darkside doesn't have any rods for the ALH. If it comes down to it, ill have to contact pauter to see what the cost is to make some rods for me. thanks.

I had ASV pistons / lowerd compression.
230hp and a peace broke off between 1st and 2 piston ring.

Nou i use PD AXR piston and rods.
They have the tappert small end two.
I would recomend them
Thanks, i will take this into consideration when purchasing the pistons.
 
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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 79.50mm +0.5

I picked up a set of 0.5mm over ARL pistons


ARL Right & ALH Stock Left



Here are the measurements for the ARL 79.96mm
Weight


Bowl water test. The bowl holds 22g of water.


Pin weightwas 203g, it was 4g lighter than the ALH and ASV pins, 207g

Skirt


Crown


Crown Thickness


Bowl thickness


Bowl Depth
 
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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 0.5mm over on left, ALH Stock piston on right


The ARL 0.5 over measures the same from the pin to the crown as the stock ALH piston


ARL Oil Gallery
 
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smelly621

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Nov 13, 2008
Location
Sonoma County, CA
TDI
2001 Golf, 2003 Tacoma
D-Cappz - Thanks for all the great pictures and measurements of different piston options.

Just wanted to correct one point for future readers - there are several euro, and even US PD rod options which will fit the smaller diameter ALH crank. I am running BRM rods in my ALH block, but BEW would also fit. I can't remember what the engine codes are for the euro options, I want to say the crank journal size increase started with the PD130 power levels.
 

D-cappz

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D-Cappz - Thanks for all the great pictures and measurements of different piston options.
Just wanted to correct one point for future readers - there are several euro, and even US PD rod options which will fit the smaller diameter ALH crank. I am running BRM rods in my ALH block, but BEW would also fit. I can't remember what the engine codes are for the euro options, I want to say the crank journal size increase started with the PD130 power levels.
Hi Smelly621, I don't remember saying that there wasn't options for the connecting rods. But yes I do know there are many options for connecting rods. I can only confirm information on parts I have got in hand.

Thanks for mentioning this though.

Frank06s Molnar H-Beam rods, Only tapered available (from what I was told)

Integrated engineering rods, I-Beam or H-beam with tapered or non tapered small end options

Rosten rods, with tapered or non tapered small end options

BEW rods
BRM rods, like you use
and these have tapered small ends if im not mistaken
I also believe the PD100, PD110, PD115 Rods will work.

But I am specifically looking for H-Beam connecting rods to handle the high rated low end torque.

yes the PD130/PD150 have a Larger crank journals

I will be posting the rods I get once I receive them. =D
 

D-cappz

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Jul 10, 2013
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2003 Jetta ALH, 6 speed, 4motion, fully loaded, leather heated interior, sunroof, steering wheel controls. Over 420,000km
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
 

D-cappz

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2003 Jetta ALH, 6 speed, 4motion, fully loaded, leather heated interior, sunroof, steering wheel controls. Over 420,000km
Oil Gallery

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 or catch oil better.

The ARL pistons have 2 holes, and the hole that would receive the oil from the oil jet/squinter 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.

ASV Piston oil galleries


ARL Piston oil galleries
 
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D-cappz

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Victoria
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2003 Jetta ALH, 6 speed, 4motion, fully loaded, leather heated interior, sunroof, steering wheel controls. Over 420,000km
Wrist Pins

Beveled wrist pin from ARL pistons on the Left 203g
Square/non beveled wrist pin from the ALH pistons on the Right 207g


ARL beveled wrist pin


ALH square wrist pin
 
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InfoSec

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Jul 4, 2000
Location
Brighton, MI
FWIW: I went with stock internals on my ALH, GTB1756VK, Race520's, upgraded intercooler and piping all the way around, and with the Malone State 5 custom tune, I swear, it's all in the tune. I'm pushing 28psi and have 20K on my build. No issues. I do plan on upgrading to a ported head, hotter cam, (all head parts are stock, except for the ARP head studs), and turning up the turbo AFTER I get better rods. Pistons should still be ok as long as I'm just ripping through the gears from time to time... I know the tune works very well with the 1756 and I would recommend that turbo and tune set-up to anybody. Starts very well in the cold, no smoke until I get on it but the things runs awesome. (Thanks, Matt W.)
 

red16vdub

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(617) City of CHAMPIONS
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03 JSW 5spd
FWIW: I went with stock internals on my ALH, GTB1756VK, Race520's, upgraded intercooler and piping all the way around, and with the Malone State 5 custom tune, I swear, it's all in the tune. I'm pushing 28psi and have 20K on my build. No issues. I do plan on upgrading to a ported head, hotter cam, (all head parts are stock, except for the ARP head studs), and turning up the turbo AFTER I get better rods. Pistons should still be ok as long as I'm just ripping through the gears from time to time... I know the tune works very well with the 1756 and I would recommend that turbo and tune set-up to anybody. Starts very well in the cold, no smoke until I get on it but the things runs awesome. (Thanks, Matt W.)
Sounds like our setup is similar, I do believe it's all in the tuning.
 

D-cappz

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2003 Jetta ALH, 6 speed, 4motion, fully loaded, leather heated interior, sunroof, steering wheel controls. Over 420,000km
FWIW: I went with stock internals on my ALH, GTB1756VK, Race520's, upgraded intercooler and piping all the way around, and with the Malone State 5 custom tune, I swear, it's all in the tune. I'm pushing 28psi and have 20K on my build. No issues. I do plan on upgrading to a ported head, hotter cam, (all head parts are stock, except for the ARP head studs), and turning up the turbo AFTER I get better rods. Pistons should still be ok as long as I'm just ripping through the gears from time to time... I know the tune works very well with the 1756 and I would recommend that turbo and tune set-up to anybody. Starts very well in the cold, no smoke until I get on it but the things runs awesome. (Thanks, Matt W.)

Do you know what Ur putting down at the wheels??
 

D-cappz

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2003 Jetta ALH, 6 speed, 4motion, fully loaded, leather heated interior, sunroof, steering wheel controls. Over 420,000km
Rod length

Does anyone wonder why every single VW engine from 2004 to current have beveled wrist pins? On all these engines have between 100-170hp. And yes, they are I-beams. I-beams are cheaper to make and price drives that market.
I could not agree more that stock rods propensity to bend make me leave the I-beams behind, stock or anything else... and work with H-beams.
This is not just my thinking, but from a rod designer with nearly 50 years experience, two companies he has built, now on his third, and he is a consultant in the rod manufacturing industry for a lot of the big-name companies people talk about.
I'm not going to get into CR too much, but lowering CR is a friendly thing to do with a big build. .5 is not much. Mid range, we like the BHW 81mm pistons with 18.25 CR. BRM style pistons 79.5mm pistons are 19.0 CR. Crafters are 16.8 for monster builds. So don't think .5 loss is a big deal. I'd go bigger.
Last thing. Weight. Our H-beams are almost 100 grams lighter than our competitor's I-beam. Pistons with an oil galley are lighter. All pistons with beveled wrist pin bushings and rods also have lightened wrist pins, which weight about 60 grams less.
Yeah, I like the beveled wrist pinned pistons for a lot of reasons.
Hey Frank, Iv had ppl asking me if the Molnar rods are shorter than stock rods on the ALH and if they need to deck the block? Unfortunately I lost my images and measurements of my Molnar rods so I cannot confirm. But I know I did not need to deck my block. Please confirm this for me. Thanks.
 

Franko6

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May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
Damien,

The length of the connecting rods becomes a question of piston projection (protrusion).

The Molnar rods are intentionally about .004" shorter than the most common length VW connecting rod. There are a few rod lengths that are shorter, but not many. Those OEM blocks built with 'short' rods would require decking in order to get proper protrusion of the piston. Usually, when we figure piston projection with the Molnar rods, we most often use a 1-hole head gasket. The length of the OEM connecting rod can vary .040" when .004" makes a difference. We are not going to make a variety of different length Molnar rods. So, with our Molnar rods, there are cases that the block will require decking.

Lengths of OEM rods for the older AHU and ALH engines do vary to adjust for crank to block height, and the engines can vary a lot. The misconception is that a rod marked '65', which is very common; that all of the same numbered rods are the same weight and length. This is not true. One time, just to prove the point, we matched rods marked '54', '57', 63' and '65' in a set, both for weight and length. We have an engine running with that 'matched set'. the only way to know is measure each VW rod by length and weight. So, in our opinion, the only way to know is to weigh and measure each component. In spite of claims, we have taken apart virgin engines with the average imbalance between reciprocating sets at 8 grams and between reciprocatings sets, 6 grams. The Molnar connecting rods have a variation of not more than 1gr +/-. It definitely makes a difference to balance the rods and pistons, and get projection accurate as the engine will run noticeably smoother. From the AHU to the ALH, some factory improvement in weight and length occurred. The PD motors are much more accurate, one to another. We don't have enough information to determine how the Common Rail engines run, but I think VW continued an upward trend.

All that said, as a rule we find that the block needs decked simply to remove the 'valley' down the middle of the block. At each of the webs between the cylinders, there is a propensity for the sides of the block to become higher than the line down the center of the block. In other words, the bolts 'pull' the head up on the sides. When heated, the cylinder head tends to warp lengthwise, high in the middle; the block tends to valley the opposite direction; low in the middle, for the length of the block.

When measuring the block projection correctly down the centerline of the block, the fact the block at the bolt holes is high compared to the centerline cylinder webs will not be seen. What is worse, it is difficult to measure. The only thing we can offer 1) Strike the top of the block with a fine, single cut bastard file, or better, 2) lay a machinists block side-to-side on the head bolt holes in line with the cylinder webs between 1-2, 2-3, and 3-4, then shine a bright light from behind the machinist's block. Either method, you can witness the gap. Although you can pinch a .001" feeler gauge in the gap under a straight edge, on average, we remove .002"-.005" to cleanly flatten the block corner to corner, while just touching the center webs.

The thought is if you are going to make the cylinder head flat, so also should you make the block flat for the best mating surface. In this manner, there is very often, NO CHANGE in piston to deck height (protrusion) and the same head gasket is used as before machining the block's deck.

The only other point is that the bottom of the block and the head gasket surface are not on the same plane. The block is decked at the factory using the main journals. In order to match their results, the block should be milled from the main journals. Instead of building that jig, our method is to either shim from the block's base so each corner of the block touches the cutter. Otherwise, flip the block upside down and deck the bottom first, so both top and base are on the same plane. Yes, I know... it's a PITA. But if you don't correctly deck the block, the result is usually the #1 piston will protrude .004" more than the #4 piston. .004" additional protrusion = one size difference in head gasket thicknesses and a .5 compression ratio difference. Decking the block properly adds time and trouble to the build, but removes an avoidable weakness between the head and block along with a compression error consequence.

I hope that clears things up...
 
Last edited:

Chuck78

Member
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Feb 24, 2019
Location
Columbus, Ohio USA
TDI
Suzuki Samurai LWB / 1.9mTDI project, '02 1.9TDI Jetta Wagon Stage 1 tuned, '82 Rabbit Pickup 1.6TD
Damien,

The length of the connecting rods becomes a question of piston projection (protrusion).

The Molnar rods are intentionally about .004" shorter than the most common length VW connecting rod. There are a few rod lengths that are shorter, but not many. Those OEM blocks built with 'short' rods would require decking in order to get proper protrusion of the piston. Usually, when we figure piston projection with the Molnar rods, we most often use a 1-hole head gasket. The length of the OEM connecting rod can vary .040" when .004" makes a difference. We are not going to make a variety of different length Molnar rods. So, with our Molnar rods, there are cases that the block will require decking.

Lengths of OEM rods for the older AHU and ALH engines do vary to adjust for crank to block height, and the engines can vary a lot. The misconception is that a rod marked '65', which is very common; that all of the same numbered rods are the same weight and length. This is not true. One time, just to prove the point, we matched rods marked '54', '57', 63' and '65' in a set, both for weight and length. We have an engine running with that 'matched set'. the only way to know is measure each VW rod by length and weight. So, in our opinion, the only way to know is to weigh and measure each component. In spite of claims, we have taken apart virgin engines with the average imbalance between reciprocating sets at 8 grams and between reciprocatings sets, 6 grams. The Molnar connecting rods have a variation of not more than 1gr +/-. It definitely makes a difference to balance the rods and pistons, and get projection accurate as the engine will run noticeably smoother. From the AHU to the ALH, some factory improvement in weight and length occurred. The PD motors are much more accurate, one to another. We don't have enough information to determine how the Common Rail engines run, but I think VW continued an upward trend.

All that said, as a rule we find that the block needs decked simply to remove the 'valley' down the middle of the block. At each of the webs between the cylinders, there is a propensity for the sides of the block to become higher than the line down the center of the block. In other words, the bolts 'pull' the head up on the sides. When heated, the cylinder head tends to warp lengthwise, high in the middle; the block tends to valley the opposite direction; low in the middle, for the length of the block.

When measuring the block projection correctly down the centerline of the block, the fact the block at the bolt holes is high compared to the centerline cylinder webs will not be seen. What is worse, it is difficult to measure. The only thing we can offer 1) Strike the top of the block with a fine, single cut bastard file, or better, 2) lay a machinists block side-to-side on the head bolt holes in line with the cylinder webs between 1-2, 2-3, and 3-4, then shine a bright light from behind the machinist's block. Either method, you can witness the gap. Although you can pinch a .001" feeler gauge in the gap under a straight edge, on average, we remove .002"-.005" to cleanly flatten the block corner to corner, while just touching the center webs.

The thought is if you are going to make the cylinder head flat, so also should you make the block flat for the best mating surface. In this manner, there is very often, NO CHANGE in piston to deck height (protrusion) and the same head gasket is used as before machining the block's deck.

The only other point is that the bottom of the block and the head gasket surface are not on the same plane. The block is decked at the factory using the main journals. In order to match their results, the block should be milled from the main journals. Instead of building that jig, our method is to either shim from the block's base so each corner of the block touches the cutter. Otherwise, flip the block upside down and deck the bottom first, so both top and base are on the same plane. Yes, I know... it's a PITA. But if you don't correctly deck the block, the result is usually the #1 piston will protrude .004" more than the #4 piston. .004" additional protrusion = one size difference in head gasket thicknesses and a .5 compression ratio difference. Decking the block properly adds time and trouble to the build, but removes an avoidable weakness between the head and block along with a compression error consequence.

I hope that clears things up...

I'm sold...
I might even make a very long drive to drop off my block and heads to you once I figure out if I'll be using a BHW block or ALH block... ALH crank vs BHW crank...
I think with my low end torque goals for my TDI 4x4 Suzuki Samurai LWB swap, H-beam Molnar rods and upgraded pistons are the way to go for me even with lower peak power goals. I'm thinking the ALH crank + upgraded rods/pistons will do, but the extra 0.1L will also help with torque, using the BHW block (& bigger crank as a bonus).

Thanks for being such a great resource of information and the highest level of quality & precision in TDI engine machine work, Frank!
 
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Franko6

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

Thank you for the compliments, but don't lay it on too thick. I can still do bonehead things. But I have gotten better over the years.

The one thing I can tell you for sure about a Samurai, There isn't much weight, so the HP to weight aspect is a bit stunning. I am thinking the stock Jetta is around 3,200 lbs, compared to the Samurai which is around 2,000 lbs... The results are obvious.

The block for the BHW and the ALH are functionally different in ways that are insignificant. There holes you might want to drill to modify the BHW to work with ALH parts. For example one of the rollers (maybe two..) have to be drilled, as the BHW does not use them. Also, the larger and more expensive front crank seal flange can be replaced with the more prevalent ALH cover by drilling new front flange screw holes. Seriously, I don't see a really good reason to go to the BHW engine. Even though there is the crank, which has a larger 53.7mm connecting rod journal, a 200 hp engine is going run like 250 in that little punk Samurai.

Plus, if you want anything 'better', steal the crank out of the BHW and install in the ALH. The one problem with that is the flywheel side of the crank on every BHW I've seen is for a driveplate/ torque converter setup. Either the centering 'nose' of the BHW crank has to be converted with an adapter, or you get the flywheel version that is intended to install a clutch from our European salvage experts. The BHW has a larger 53.7mm connecting rod bearing and the oil cooler is about twice the size.

The BHW block and the later ALH block (post 2002) have the greater rigidity with the larger ear for the top rear engine mount bolt. The center boss in the block's manifold center head bolt is a larger casting. The difference can be easily measured by looking at the manifold side of the block, timing belt side. There is an ear with a 10mm bolt hole intended for a motor mount. The older ALH have a 1/2" thick ear. The later 2002-03 ALH and the BHW have a 5/8" ear.

There is one more reason to stick with the ALH block. Full rebuild of the BHW usually means bore out and 81.5mm pistons. Every time you get larger and larger cylinder bore, the more the cylinder bore warps out of shape from head bolt pressure. The blocks absolutely must be torque-plated. That is exacerbated by the use of the ARP studs, which you probably will need and we do supply. So, there are some issues 'going big.'


Upshot, in the Suzuki, I would suggest using the later model block from an ALH. If you really want, we do have an ALH block already punched out the BHW pistons, and we can put the block together with the larger crank or just use the standard crank.
 

Chuck78

Member
Joined
Feb 24, 2019
Location
Columbus, Ohio USA
TDI
Suzuki Samurai LWB / 1.9mTDI project, '02 1.9TDI Jetta Wagon Stage 1 tuned, '82 Rabbit Pickup 1.6TD
Frank, thank you so much for the detailed reply... I was not aware of the difference in the cranks.
This would not be an issue when using a TDConversions.com/NorthWest FabWorks adapter, as they are 2pc & 2" thick & utilize a crank flange adapter anyways... However the Doomsday Diesel adapter & ACME adapters will have very shallow pilot bearing engagement with the BHW crank... A custom lathe turned oilite bronze pilot bushing and good copper grease etc would be critical there.

BHW:



Info from another thread:
Use the crankshaft from an ARL (038105021K), also from a manual AVF or AWX car in europe, it has the proper protrusion for manual trans flywheel/pilot, and all other dimensions are same as BHW
 
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Chuck78

Member
Joined
Feb 24, 2019
Location
Columbus, Ohio USA
TDI
Suzuki Samurai LWB / 1.9mTDI project, '02 1.9TDI Jetta Wagon Stage 1 tuned, '82 Rabbit Pickup 1.6TD
ARL (and every other manual transmission VW crankshaft flange):

 

Chuck78

Member
Joined
Feb 24, 2019
Location
Columbus, Ohio USA
TDI
Suzuki Samurai LWB / 1.9mTDI project, '02 1.9TDI Jetta Wagon Stage 1 tuned, '82 Rabbit Pickup 1.6TD
Another question or two for you Frank. Do you ever see ALH crank failures in high power builds? Or big end rod problems or premature big end bearing wear on the ALH in high performance builds?

I already have a BHW bottom and most parts to make an ALH/BHW hybrid aside from a good head, which is what I inquired with you about welding repairs on cam journals or cracks between the intake valve and injector hole. The BHW bottom end has about 300,000mi on it, but upon visual inspection, the bores looked pretty good. do you find that most BHW blocks need bored out at that point? It already has the balance shaft delete also.
I also have a complete 03 ALH on the stand right now out of a runner, 197,000 mi., And was planning on using this as-is while I build a more stout engine. I also wanted to have at least one good spare for down the road somewhere when these engines are harder to come by.


If I use the crank flange adapter type VW to Toyota bellhousing setup, the BHW crank would be a non-issue. I would consider using the bhw crank and rods as long as I was keeping the build fairly mild, but I am going mechanical TDI and shooting for low-end torque. Not really needing to make more than 140 or 180 horsepower off of 20 or 27psi boost & a Giles Gallie or Andrew Libby pump, but trying to build lots of low end torque with moderately early boost and fueling. The BHW rods are significantly thicker than the ALH, and the factory put them behind a lot more power, so I think they should be fine for my goals???????

If using the ALH crank, I most definitely would want to look into your Molnar forged rods if I already have it apart.

Thanks for the tips on the late '02-'03 ALH blocks being an improved revision as well. Although I think I'd be fine on an AHU block even (with forged rods), that's good to know for ultimate reliability.
 
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Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
Actually, if I give complete answers to your 'two questions', I'd be here still writing tomorrow, so I won't. We have seen failures of many sizes and descriptions. Anything can happen, and it usually does. The harder you push the bigger the disaster. There is always the next 'weak link' for the next item that will fail.

I'm not sure why you'd want to go back to the AHU block. It's not like they made a weaker block just in the years '98-2000. You just don't have the same mounting points for the engine mount. The other weakness in that block is the smaller manifold-side center head bolt boss. Some overtighten the ARP head bolts and that will ruin the early ALH and the AHU's.

At 140, you don't need much.. At 180, you are modifying the engine in many ways. 2x horsepower will do that.

As for rods, I have a penchant for making a product as good as I can. We recently found a somewhat startling discovery. It cam from me 'assuming'.

One of the H-beam rods that we had foisted on us was actually one of the MaxSpeeding rods, you can get quite cheaply. After I dissed those rods, another builder of Cuban ancestry (I am guessing), who was strong and long to defend those CRAP rods. I unintentionally bought MaxSpeeding clones (I find that very funny, as they weren't even REAL MaxSpeeding Rods..) from an underhanded Foreign shore vendor. We kept some of those rods for 'show and tell' after a disastrous failure.

We included those rods in our 'Trophy parts' board. One of the rods got wet. It bled orange rust like cheap barn siding. Now, nobody ever TOLD me those were 4340 Chrome/ Nickel/ Moly rods... But in a side-by-side comparison, the VW cast steel rods and two of the competitors we have used before we have found are not 4340 steel, but much more likely high carbon steel, and they rust as you would expect. My Molnar rods went in the same test. No rust. The 4340 steel is appropriate for it's strength, toughness and has just enough spring. They are not prone to cracking and are structurally stable when heated.

After being screwed by a clone MaxSpeeding rod, my decision was to 'go it alone'. I had Molnar built a conventionally constructed H-beam rod from 4340 steel and 3/8" ARP 2000 rod bolts with asymmetrical threads. I explain my rods like this: 'Built for a Battleship; Installed in a dinghy'.

I have had two failures with those rods. Both were damaged when the pistons split and the top of the rod was flame-cut from over-fueling injectors. I did not set either set of injectors for these failures. Although the rod was still serviceable, we changed them out as a precautionary measure.

I don't know what the limits for a BHW 53.7mm or the BRM/ BEW 50.6mm rods torque limit is. I'm not really interested to find out. But I do know this much. Although the PD connecting rods are heavier, I can't really claim 'better'. The one thing about the PD connecting rods is that they are designed to break, as they are built in one piece, then broken by striking a weakened area, to split the cam cap from the body of the rod. I don't think you could do that with a 4340 rod... Therefore, it is my contention that in order for the company to create a cheaper to build rod, they have to sacrifice the quality of the material so it will break as and where they want it to. I'm wondering how many times the rod broke in the wrong place, especially after the assembly of the motor.
 

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
Oh, the nose of the crank when building a auto crank to convert.... the bearing we prefer is the OEM needle bearing. However, we do not think the bearing should protrude from its' housing. The ARL crank or a properly modified crank nose are the way to go.
 
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