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Author Topic: 1.7 KY / AHU Hybrid project  (Read 976 times)

November 11, 2016, 09:33:01 am

metalpecker

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1.7 KY / AHU Hybrid project
« on: November 11, 2016, 09:33:01 am »
Hello fellow dieselists! I have '88 VW Transporter with rare stock 1.7L NA diesel (KY model) rebuilt just 20000kms ago. This motor has the same stroke (86.4mm) as well-known 1.6D, but cylinder diameter is the same as 1.9D (79.5mm). I like its simplicity, but need more power (who don't?). My friend offers me good rebuildable AHU from Passat B5 with all necessary things, such as wiring, gauges etc. But I'd like to keep my engine as simple and reliable as possible (TDI is quite simple compared to Common Rail anyway, right?). To make long story short, I need an info if it's possible to put my pre-TDI 1.9D-esque head over AHU short block? I know that AHU is Direct Injection and I'll need to change at least pistons. Any input and suggestions will be hugely appreciated!

Thank you!

Andrey



Reply #1November 11, 2016, 11:42:55 pm

libbydiesel

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Re: 1.7 KY / AHU Hybrid project
« Reply #1 on: November 11, 2016, 11:42:55 pm »
Simplest would be to install the AHU and use a mechanical TDI injection pump. 

If you swapped your 1.7 head onto an AHU bottom end but swapped the pistons to AAZ pistons it would probably work but your compression ratio would be overly high due to the proportionately smaller pre-chambers in the 1.7L head.  If you really wanted to keep it an IDI, easier would be to source an AAZ.
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Reply #2May 05, 2017, 05:13:23 pm

fatmobile

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Re: 1.7 KY / AHU Hybrid project
« Reply #2 on: May 05, 2017, 05:13:23 pm »
I stuck those 1.7 pistons in my 1.6TD block.
 You need the head gasket from AAZ so it's wide enough for the pistons.
 It needs to be a hydrolic block because the pistons will hit the head gasket on a mechanical block.
Tornado red, '91 Golf 4 door,
with a re-ringed, '84 quantum, turbo diesel, MD block

Reply #3October 20, 2017, 10:13:15 pm

SR Heer

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Re: 1.7 KY / AHU Hybrid project
« Reply #3 on: October 20, 2017, 10:13:15 pm »
I stuck those 1.7 pistons in my 1.6TD block.
 You need the head gasket from AAZ so it's wide enough for the pistons.
 It needs to be a hydrolic block because the pistons will hit the head gasket on a mechanical block.

Where did you buy or where is a source for 1.7 pistons?

How did the 1.7 pistons affect the power band (more low - mid - or high range power)?- any difference in performance - and efficiency of 1.7TD motor?

Any tendency for motor to run hotter?

I guess one can put the 1.7=1.9 diameter pistons in a 1.6TD block? I didn't think the 1.6 block could safely be bored out to accommodate 1.7 pistons? But - is this what you did?

Is not the difference between the 1.7 and 1.9 pistons wrist pin diameter with the 1.9 being larger and 1.7 being same as 1.6?

« Last Edit: October 20, 2017, 10:33:24 pm by SR Heer »
97 Passat 1Z, 98 Jetta AHU, 91 Jetta AAZ TD, and 81 Rabbit Pickup

Reply #4November 30, 2017, 10:35:21 am

marcel.w

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Re: 1.7 KY / AHU Hybrid project
« Reply #4 on: November 30, 2017, 10:35:21 am »
if you just want some more power put a turbo from a 1.6TD on the 1.7D and put a intercooler on.
a friend of mine runs this setup on his 1.7KY and it works reel good.
Greetz marcel
VW bus mTDI roling work in progres

 

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