ALH Block upgrade options ???

JetPo · Feb 1, 2016

Hi guys !

I need your advice for my ALH rebuild. My goal is at least 200hp and reliability since this is my daily driver engine. I know there are many options to upgrade the block but I wanted to know what is the most important to upgrade ?

Are the pistons or rods more prone to failure or are they both prone to failure at 30 psi ? I was thinking of keeping my ALH pistons since I dont want to reduce my compression (cold start ...) and I would not have to get my block machined and go with Rosten or IE rods to give me more strenght to support the higher boost.

Or would I be better to get BHW pistons (get my block machined)and BEW rods ?

Im looking for the cheapest way to get a reliable engine that is not overkill for the power it will be putting out.

Thanks for any info !

mk1-83 · Feb 2, 2016

pd 130-150 pistons, with H beam rods and sputter rod bearings afn.

and use 12.9 headbolts from arl and cut to length 120mm with washers.

Fix_Until_Broke · Feb 2, 2016

The block itself does not really need any "upgrades" and torque is what is hard on the engine, not so much power.

What turbo/tuning are you planning on running and how do you drive?

If you're going to run a VNT20 or something that does not make a lot of low RPM power, you could probably get by with a stock ALH bottom end (pistons/rods/etc) as your cylinder pressures won't be that high.

If you're going to run something a lot more responsive in the low RPM range (2500 RPM and below) and/or do a lot of low RPM power, towing, etc, then you'll usually take out head gaskets, and OEM rods first. If you do a lot of long term/high load driving, then you can crack pistons.

I went with ARL pistons in stock size so no block boring required, Rosten rods, ARP bolts in the heads and rods, 12.9's in the mains, etc.

If you keep the torque below 275-300 ft-lbf, you can usually keep the stock bottom end together for 100K miles with minimal issues if you're nice to it.

I ran 275 ft-lbf or so for a lot of miles, and ended up cracking a stock piston when pulling a 2500lb trailer for a few hundred miles with the EGT's never below 1400F, coolant temps at 225F, etc for hours at a time.

Pat Dolan · Feb 3, 2016

I have been away from being able to play for 7 years, but where we left off I was doing a 200HP build on one of the ALH cars, and will now come back to exactly that same place. My conclusion many years ago was Rosten rods, PD150 pistons, COATED crown (as it seems heat is the source of piston failure from prolonged high load - exactly why the engine in question blew up in the first place) and ARP studs. Seven years later, it seems to be the same case, just that 200 HP is now rather normal and we have the benefit of many people having experience at that power level.

TDIMeister · Feb 3, 2016

If the block is going into your Audi, I'd just find a complete BHW short block, convert to a geared BSM or delete it altogether and leave it otherwise stock. It has a much stronger bottom end than the ALH, has internal piston oil cooling channels and you have the bonus of the slight added displacement. It's more than sufficient to support 200 HP. More importantly, it will have the brackets and everything else to fit the longitudinal layout of your Audi without any parts bin diving or potential machining/fabrication/clearancing work needed. Weigh that against buying upgraded rods, pistons, etc. to adapt your ALH ...

JetPo · Feb 5, 2016

Fix_Until_Broke said:
The block itself does not really need any "upgrades" and torque is what is hard on the engine, not so much power.

What turbo/tuning are you planning on running and how do you drive?

If you're going to run a VNT20 or something that does not make a lot of low RPM power, you could probably get by with a stock ALH bottom end (pistons/rods/etc) as your cylinder pressures won't be that high.

If you're going to run something a lot more responsive in the low RPM range (2500 RPM and below) and/or do a lot of low RPM power, towing, etc, then you'll usually take out head gaskets, and OEM rods first. If you do a lot of long term/high load driving, then you can crack pistons.

I went with ARL pistons in stock size so no block boring required, Rosten rods, ARP bolts in the heads and rods, 12.9's in the mains, etc.

If you keep the torque below 275-300 ft-lbf, you can usually keep the stock bottom end together for 100K miles with minimal issues if you're nice to it.

I ran 275 ft-lbf or so for a lot of miles, and ended up cracking a stock piston when pulling a 2500lb trailer for a few hundred miles with the EGT's never below 1400F, coolant temps at 225F, etc for hours at a time.

The original plan was to run a GTB2056vl since it is water cooled and would help warm up the engine in winter. I was able to get a almost new holset He221w from work so I was thinking of trying that out for this year, so low RPM power is not going to be a problem lol

I was thinking of going with BEW rods, ARL pistons and ARP studs. I dont drive my car real hard, but since I have the motor in my hands I want to buy some peace of mind.

JetPo · Feb 5, 2016

TDIMeister said:
If the block is going into your Audi, I'd just find a complete BHW short block, convert to a geared BSM or delete it altogether and leave it otherwise stock. It has a much stronger bottom end than the ALH, has internal piston oil cooling channels and you have the bonus of the slight added displacement. It's more than sufficient to support 200 HP. More importantly, it will have the brackets and everything else to fit the longitudinal layout of your Audi without any parts bin diving or potential machining/fabrication/clearancing work needed. Weigh that against buying upgraded rods, pistons, etc. to adapt your ALH ...

I didnt know that a BHW block could fit on a ALH head without big work. Since I would use the ALH IP wouldnt I still need to modify the drive side engine mount bracket ?

I will look into the BSM delete and what it includes. Do you know where I could find a BHW block ? lol

Fix_Until_Broke · Feb 5, 2016

Please keep us posted on how the HE221W runs as a single.

JetPo · May 3, 2016

Ok so ive decided to go with a ASZ (PD130) block instead of upgrading my ALH block since the final price is about the same but alot less work.

I know I need to change the trigger wheel, lower timing belt sprocket and the main seal plate. Is there anything else I will need to change ?

I was also wondering what head gasket I will need ? Since the compression is lower, should I just go with the ''one hole'' gasket from an ALH ?

TDIMeister · May 3, 2016

ASZ doesn't exist in North America. Why not just go with the plentiful BHW? Moreover, you get a bit of extra displacement.

PM me please.

JetPo · May 3, 2016

TDIMeister said:
ASZ doesn't exist in North America. Why not just go with the plentiful BHW? Moreover, you get a bit of extra displacement.

PM me please.

I know ASZ engine were not sold in Amercia, I found an engine block that has been imported from Europe.

I tried finding a BHW block without any luck, it seems they are prety rare, and people that have one do not want to sell it.

ALH Block upgrade options ???

JetPo

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mk1-83

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Fix_Until_Broke

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Pat Dolan

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TDIMeister

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JetPo

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JetPo

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Fix_Until_Broke

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JetPo

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TDIMeister

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JetPo

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