96mm kit for stock 1.7 D-jet, dos and dont's?

[Lars S]

I have an new AA 96mm piston/cylinder kit that will convert my 1.7 to 1911cc, the heads have been opened up to 105mm, no other change.

I will be running without a head gasket so compression ratio will be (from measuring deck height and combustion chamer cc) about 8.2:1 (which is almost the same as standard 1.7 D-jet). I will continue running stock cam, stock D-jet and likely I will have to adjust fuel pressure, MPS etc for the extra cylinder volume.

Im not looking for a race engine just a rebuild which hopefully will bring a few extra hp and add some torq.

Are there any dos and dont's you would share with me before I put it together? (I have heard of risk of running hot, bad gas milage etc)

/Lars S
_________________
Porsche 914 -72, Bahia Red daily driver
VW411 2-d -70, White, sold
VW412 4-d, -73, Gold Metallic, daily driver
Suzuki T500, -69, Candy Gold, sold
Suzuki K50, -77, Black, daily driver
BMW R69S -69, White, sold
Husqvarna 118cc, -47, Black, Sold

[APPLEGREENVW]

[Lars S]

It worked out wery well!
Still running that engine and as i supposed there may not be so much more top end power but it pulls wery strong from the bottom.
I have added 914 2.0 injectors and manifold and also a wbx plenum trying to bring some more air in...not sure how much it gives...

Lars S
_________________
Porsche 914 -72, Bahia Red daily driver
VW411 2-d -70, White, sold
VW412 4-d, -73, Gold Metallic, daily driver
Suzuki T500, -69, Candy Gold, sold
Suzuki K50, -77, Black, daily driver
BMW R69S -69, White, sold
Husqvarna 118cc, -47, Black, Sold

[APPLEGREENVW]

Do you think the 96mm kit, with 1.7 stock heads with a Web 73 camshaft and dual 40mm IDF carbs on work well together? Will the 8.2:1 CR ratio be good enough for the cam to work right?
I don't have all the parts listed above available yet.
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Parts for sale https://www.thesamba.com/vw/classifieds/search.php?username=APPLEGREENVW

02/76 Beetle sedan

[Lars S]

Sorry I have no experience with carbs on these engines...maybe someone else will chime in...?


Lars S
_________________
Porsche 914 -72, Bahia Red daily driver
VW411 2-d -70, White, sold
VW412 4-d, -73, Gold Metallic, daily driver
Suzuki T500, -69, Candy Gold, sold
Suzuki K50, -77, Black, daily driver
BMW R69S -69, White, sold
Husqvarna 118cc, -47, Black, Sold

[KTPhil]

Do you plan to adjust he MPS after all these changes?

[Lars S]

[Pepperbilly]

[Lars S]

[Pepperbilly]

Ah ha! Did not realize your first post was from 10 years ago. I need to read the fine print

Well, I am not an expert engine builder but I have always understood type 4 engines (especially fuel injected) were set up on the lean side. Of course that means hotter running. Are you sure you’re not running too lean? Also, is all your engine tin installed. Is your engine compartment foam seal all there and the fan bellows not collapsed or leaking. You know how it is… all these things need to be in place and working. Do you have a properly functioning thermostat and flaps? Your oil temps sound pretty high considering you live in Sweden.

Bill

[Lars S]

Yes I have all flaps and tin etc in order, adjusted AFR by wideband lambda however sensor placement is a dilemma. I also expect more cc would add more temp and as I say my experience is that already stock 1,7 likes to run a bit hot at 77F/25C outdoors.


Lars S
_________________
Porsche 914 -72, Bahia Red daily driver
VW411 2-d -70, White, sold
VW412 4-d, -73, Gold Metallic, daily driver
Suzuki T500, -69, Candy Gold, sold
Suzuki K50, -77, Black, daily driver
BMW R69S -69, White, sold
Husqvarna 118cc, -47, Black, Sold

[Pepperbilly]

When sniffing your AFR, do you have the type of tester that uses a probe into the exhaust pipe? Has your tester been calibrated properly? Leaks in the exhaust system anywhere will give false readings. Another question, you say you have a potentiometer on the cylinder head temp sensor. Are you then adjusting it manually? I know Ray was once considering a manually adjusted setup, but I have never actually seen this.

My stock 1700 is running on the rich side of things, how rich thru out the range I donot know. I need to get a good sniffer. When I rebuilt my MPS with a new diaphram, I set it up as closely as possible to what the stock position was. I just simply took the diaphram measurements and ran with that. So far the engine runs so strong and so smooth I don’t want to mess with it. Richer better than leaner I say.

Bill

[Lars S]

I ran an in muffler Bosch lamda with a cockpit meter when I checked the AFR.
The potentiometer is now by the engine but during the tests above I had it in the cockpit, adjusted it during running and learned a bit how much influence it has on the AFR.

At the hottest days I use to turn the pot up a bit to make a richer mixture and at the yearly smog inspection it for sure sits on zero Ohms!

Lars S
_________________
Porsche 914 -72, Bahia Red daily driver
VW411 2-d -70, White, sold
VW412 4-d, -73, Gold Metallic, daily driver
Suzuki T500, -69, Candy Gold, sold
Suzuki K50, -77, Black, daily driver
BMW R69S -69, White, sold
Husqvarna 118cc, -47, Black, Sold

[Pepperbilly]

It would be interesting to see some photos of your testing setups. Are you able to drive the car with the probe in the tailpipe? In the State of Washington here, we don’t have to go through these emissions checks if the car is 25 years or older. We can even use old license plates as long as they are period correct for the year of the car. One time fee only and then you are good to go forever! This is what I have done.

The other big factor with tuning is the condition of your MPS. I had to rebuild mine. Tangerine Racing has new diaphrams and tool adjustment kits.

Bill

[Lars S]

Sorry Bill, my bad explanation.
With "in muffler Bosch lamda" I mean a welded stud in the muffler body with the sensor in it, so it is fixed in the muffler, not at the tailpipe.
Besides the AFR gauge I have a vacuumeter in cockpit so I can see at what vaccum I should adjust the MPS. Adjusting the MPS is done in the bench with a vaccum pump an a inductance meter - not while driving!

Yes also here in Sweden old cars dont have to do the yearly inspection but not before 50 years old and the last inspection will happen to my 412 this spring - time to celebrate!


Lars S
_________________
Porsche 914 -72, Bahia Red daily driver
VW411 2-d -70, White, sold
VW412 4-d, -73, Gold Metallic, daily driver
Suzuki T500, -69, Candy Gold, sold
Suzuki K50, -77, Black, daily driver
BMW R69S -69, White, sold
Husqvarna 118cc, -47, Black, Sold

[Pepperbilly]

So are you guys in Sweden subject to very complete annual inspections, say like TUV in Germany? I actually wish that here in the states we would have stricter car inspections, especially safety related things. I am often appalled by dangerous cars that are allowed to drive on our streets.

Bill