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Here we go again...

This is about flat spot.

I had a 1972 AB 1300DB engine with a 31 Pict 3 carb with flat spot.

I rebuild it with new 1600 pistons and cylinders. The Heads were open to 1600.

Everything is sock inside the case.

I have the same distributor 113-905-205AL. This distributor was also used on US on a 1600DP engine with manual transmission as mine. It is a SVDA.

I changed the manifold and the carb to a 34 Pict-3 (I don?t know the size of the jets)

Do I have an AD engine? I don?t know want type of engine I now have and I would like to have our opinion on this to set the timing.

I asked the opinion to a mechanic that worked on the VW dealer here where I live for 30 years and worked on my car for more than 15 years and he knows it very well and he told me that I should set the V notch mark on the case split to avoid a hole on a piston, because I still have a flat spot from the idle. This should be a static set-up. When I told him that I changed the pistons and the carb we told me that now I have to mess with the jets to end with the flat spot.

If it is an AD with SVDA the V notch should be set 7º BTDC at 800-900 rmp with stroboscope and then I have to mess with the jets until I end with the flat spot. Is this correct?

Any suggestion on the jets sizes?

Joao

72 Super 1302
Reply to
Joao Eliseu
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I have to find the problem...

If I have a flat spot with a SVDA it must be because the vacuum can is not working properly. I do believe it is not the original so I order a new one from Bosch. When sucking the ar from it I can feel that the membrane isn?t stressed, because I can hear it, so the vacuum advance will always response with a delay causing the flat spot. Do you think that this make any sense?

I can't find the correct Bosch part number of the vacuum can for my distributor in the internet.

113-905-205AL VW 0231-146-101 BOSCH

Joao

72 Super 1302
Reply to
Joao Eliseu

Joao,

Try sucking on the vacuum line with the distibutor top off - you should be able to see the points plate moving with the suction - if it doesn't (or it moves but then drifts back when you cover the vac line with your tongue) then the canister diaphragm is leaking.

You should be able to get vacuum canister and/or componenets from

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- email John on snipped-for-privacy@aircooled.net if you can't find what you want on his site.

For a 1600 with 31PICT/3 (or the modern reaplcement carb for it - the H30/31), try using a 55 idle jet (right side of the carb - closest brass jet to the float bowl) 125 (or just possibly a 127.5) main jet (bottom of the float bowl) and a 125 or 130 air correction jet (take the top off the carby to find it - a vertcial brass screw head between the float bowl and the main throat - careful as it's about an inch long - has the emulsion tube attched underneath). The other jet in the right side (angled) is the power jet - should be a 65. This one only works at high power high rpm.

The correct timing for your combo of 1600 and single vacuum distrtibutor is 7.5BTDC. Make sure you KNOW what that timing notch on the pulley is. If there is only one notch and no dimple on the other rim just to the left of the notch then it's a 5ATDC notch with is used with the double vacuum distiburos to set 5ATDC at idle. Using this with a single vac distributor would result in 12.5 degrees of underadvance - the car will lack power, overheat and have the stumbles.

How do you check the notch? Put a pencil or straw down No1 (right front) plug hole and feel for the piston top - get the piston as high as it will go and then look at the timing mark near the top of the pulley. If it's to the left of the crankcase split - it is indeed a

5ATDC notch and you need to make a new mark 11mm to the right for TDC and 18mm to the right of that original notch for 7.5BTDC.

If you have a pulley with one notch and a dimple on the other rim (to the left of the notch), the dimple is TDC and the one notch is

7.5BTDC.

Timing can be set static, or at idle with a timing light and the vac line removed from the carby and plugged, so there's no chance of the carby vacuum spoiling the setting. Don't forget to reinstall the vac line after the adjustment.

Regards Rob Rob and Dave's aircooled VW pages Repairs and maintenance for the home mechanic htpp://

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Reply to
Rob

This is what I have...and that is why the mechanic I spoke with told me that? He knew that I have that dimple (TDC) on the rim and he smiling when he told me that.

I have read you web page a lot of times and I never saw anything relayed with this dimple on the rim. I will check it right now.

Thanks very much

Joao

72 Super 1302
Reply to
Joao Eliseu

I?m so hungry with myself. I can?t understand how I could I miss that. After read your post I open the Haynes on page 72 and here it is:"see also that the V notch in the crankshaft puller wheel is clean and visible (...).The notch should line up with the crankcase joint." I do believe that many engines are working at 15º BTDC instead 7.5º BTDC, because many people think that the V notch indicates the TDC. Since Ingles is not my first languish I can easily miss something and this was one of that situations. This was unbelievable...

Joao

72 Super 1302
Reply to
Joao Eliseu

*holds up index finger with puzzled/questioning look on face*

Usted habla ingles mas bueno que yo habla espanol. :-)

Reply to
Shag

You where not the only one darling...

J. :O]

Reply to
P.J. Berg

Hola Shag,

Mira, también entiendo un poquito de Español e Portugues.

Saludo Joao

Joao

72 Super 1302
Reply to
Joao Eliseu

Ay Carambola :)

I used to date a girl named Mira once. hehe.

Jan

Reply to
Jan Andersson

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