ALH vs AHU

Is the ALH and AHU the same except for the turbo?

i.e. engine mounts, IP, pretty much identical?

I want my conversion to ultimately be an mechanical TDI 1.9 and am researching more about the options. I already found a little about the IP conversion to mechanical and want to know more about engine selection.

Thanks,

Mark
'78 VW Bus (eventual diesel conversion)

markd89 said:

Is the ALH and AHU the same except for the turbo?

i.e. engine mounts, IP, pretty much identical?

I want my conversion to ultimately be an mechanical TDI 1.9 and am researching more about the options. I already found a little about the IP conversion to mechanical and want to know more about engine selection.

Thanks,

Mark
'78 VW Bus (eventual diesel conversion)

Click to expand...

The ALH has an internal waterpump.
The AHU has an external Waterpump and is very similar in block design to all other external waterpump VW engines made from 1974-2002.

The heads are not interchangeable

IPs can be swapped but you knew that.

The ALh has the motor mount bosses that the AHU has.

The VNT turbo on the ALH sits lower then the turbo on the AHU and interfers with the motor mount bracket used on Mk2/mk3 VW golfs and Jettas.

The transmission bolt pattern is the same on the ALH and AHU as well as all other watercooled VW 4 cylinders used in Mk1/mk2/mk3/mk4/mk5/B1/b2/b3/b4/b5/b6

The oil filter flanges are very different between the two block designs.

The intake manifolds and exhaust manifolds have the same exact patterns.

There are a lot of similarites and a lot smaller changes.

There have been a number of swaps using old and new engines in these things. Do some more reading. The best deciding factor might be the availability of a donor. Thats what drove my decision to install an ALh in my first corrado swap. With a big enough hammer anything can get done.

Mark, I have an ALH in my Diesel Vanagon. I see you intend to do a conversion on your bus. You should not need to lay the engine over to 50 degrees as I did. That complicates the install of the ALH. There is a bellhousing available that will allow to mount bolt the ALH up standing up without an adapter plate. You will still need to make custom engine mounts, but can be done. The M-TDI will solve a lot of wiring headaches for your first conversion. I like the flybywire and the ODBII on my Vanagon. I use the heck out of the cruise control. That is a "free" option with the ECU type engine management. You will also need to consider cooling your bus. That may prove to be the biggest challenge. You will also need to decide on an intercooler, recommended.

G60ING, thanks very much for your detailed, helpful response. I also appreciate the comment about the hammer. I do have one ;-) I am going to do more reading, as you suggested. I want to avoid as many issues by being better informed and planning up-front.

rsxsr, thanks for your response too. I know about the Vanagon diesel bellhousing. Is that the one you mean?

I know that works for a Vanagon, ubt I'm told that the starter will not fit if I try to go that route in a bay window bus. The diesel vanagon bellhousing has the starter on top. In the Vanagon, there is clearance for this to fit, in the bay window, apparently there's not. I'd use the hammer, but I think I'd be hammering the trans mount area, which unfortunately wouldn't do ;-)

What seems to have worked for people with 1.6TDs is to mount the engine at 15 degrees using the stock bellhousing, adapter plate and a special starter. That's my current plan. That plan is subject to change. I want to get a good idea how it's going to work before I get started so there's less trial and error once I do. If there's simpler ways to do it, I want to know!

Thanks again for your thoughts. I'd welcome more ideas

Mark

Mark, I came across these bellhousings on the internet. I have no affiliation with this company, but I believe they are South African bellhousings. They allow the engine to stand up. http://www.eurospecsport.com/products/Vanagon/Vanagon%20Page.html This would be better suited to installing in a bus. While there are adapter plates, if a bellhousing is available that does not require an adapter, that would be a cleaner installation I would think. The above page might give you some ideas of how to adapt your bus engine support as well.

Very interesting. I've been in contact with these guys and it does look (preliminarily) like I an use their bellhousing, etc.

I'm waiting back on some other questions (like vertical clearance, etc.) and will post what I find out.

Thanks again,

Mark