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Tue Jul 17, 2012 5:40 pm

I've been trying since yesterday to set my points at 50* and its just not working! I finally managed to get it at 50* and then realized (when I disconnected the lines) that the analyzer wasn't quite zeroed, and in fact was about 3 mm from the bottom.

So tried again and again, and when I finally get it...the gap is only about .008!!

I tried a new set of points, same deal. Took out the entire distributor, to MAKE SURE that I set it at .016 on the bench vise, and damn if the angle was closer to 40*.

I'm at a loss. Ideas anyone?

Tue Jul 17, 2012 6:13 pm

Use a dwell meter to set the points. The gap will be approximately .016, but use the dwell meter to set it correctly. Dwell will affect timing, but timing does not affect dwell. After the dwell is set correctly then set the timing.

Aloha
tp

Tue Jul 17, 2012 6:14 pm

If your dwell meter works go by it's reading. I have never had to go less than .014 to get that 44-50 dwell reading. I suspect your meter is set for 8 cylinders.

Tue Jul 17, 2012 6:17 pm

bsairhead wrote: I suspect your meter is set for 8 cylinders.
Winner, winner, chicken dinner.

Tue Jul 17, 2012 6:21 pm

Nope. Its not set to 8. I checked. :D

And I have another dwell meter that a friend just gave me. I checked with that one and the readings concur.

I just thought that there could be some hidden meaning behind the closeness of the gap required to get 50*. Like maybe my condenser was going, or something?

--
Edit: I just ran downstairs into the garage to check again. Confirmed...set at 4 cyl. And the other dwell meter, well, it has no settings, its all in the dial reading itself.

Tue Jul 17, 2012 6:37 pm

On a Type 1 engine - I hand rotate the crank until I'm at top dead center for #1. Then I remove the 13mm nut that holds the distributor clamp to the case - which allows me to not disturb the clamp position on the distributor.

The clamp and distributor will now come out of the case as a single unit.

Set the points - while sitting at a table, working good light.

Reinstall the distrbutor and clamp to the case.

Last - but not least - I'd rather see a dwell of 46 or 47 degrees than 50 degrees. 46 degrees is a tad wider than a .016" gap. 47 degrees is spot-on.

- Andrew in Austin, TX -

Tue Jul 17, 2012 6:44 pm

Rubber Duck wrote:
I tried a new set of points, same deal. Took out the entire distributor, to MAKE SURE that I set it at .016 on the bench vise, and damn if the angle was closer to 40*.

I'm at a loss. Ideas anyone?

Which side of 40 degrees? 42 degrees is a bit wide. A dwell reading of 45 degrees would be better.

It could be your technique, use a .015" gauge with a slight drag.

- Andrew in Austin, TX -

Tue Jul 17, 2012 7:12 pm

The higher the dwell the smaller the gap. The lower the dwell the larger the gap.

If your points are not new they probably have a pit on one side and a high spot on the other which makes adjusting them with a feeler gauge imposible.

Ignore the gap and go with what the dwell meter(s) says.

If you're bored try this method...

Tue Jul 17, 2012 7:30 pm

aryue wrote: Rubber Duck wrote:
I tried a new set of points, same deal. Took out the entire distributor, to MAKE SURE that I set it at .016 on the bench vise, and damn if the angle was closer to 40*.

I'm at a loss. Ideas anyone?

Which side of 40 degrees? 42 degrees is a bit wide. A dwell reading of 45 degrees would be better.

It could be your technique, use a .015" gauge with a slight drag.

- Andrew in Austin, TX -

Could be. I'm at the parts store now. Just bought new points/condenser/rotor and cap. Who knew that Lordco had Bosch stuff!! Might as well change these out as I've been meaning to anyways. Only the condenser and points are beck something.

I will do it again on the bench probably tomorrow.

Tue Jul 17, 2012 10:17 pm

The specified point gap is .016 - .020". I set new points to the wide side of the spec. Be sure to use the appropriate lube on the cam and wear block, and lube all the other suggested locations with motor oil, wiping off the excess.

Tue Jul 17, 2012 11:53 pm

I don't run points but if I did I'd set them at .018" mid spec and then go drive it and enjoy it.
A few months ago when I was temporarily running points for about a week I set them mid spec and it ran great.

Wed Jul 18, 2012 9:57 am

The condenser won't affect the dwell - only the points gap will.

Dwell effectively measures the ratio of the amount of time the points are closed to the total points cycle time. Since the points open and close four times per distributor rotation on a VW, that makes the total points cycle angle 90 degrees. if the dwell is, say, 45 degrees, this means that the points are closed 50% of the time. Higher dwell numbers = longer points closed time.

Wed Jul 18, 2012 8:21 pm

aryue wrote: Rubber Duck wrote:
I tried a new set of points, same deal. Took out the entire distributor, to MAKE SURE that I set it at .016 on the bench vise, and damn if the angle was closer to 40*.

I'm at a loss. Ideas anyone?

Which side of 40 degrees? 42 degrees is a bit wide. A dwell reading of 45 degrees would be better.

It could be your technique, use a .015" gauge with a slight drag.

- Andrew in Austin, TX -

This is what worked eventually! I took it out and set it at .015 with a slight drag. This meant that .016 would fit well...in fact, it probably is .016 now.

I also changed out the rotor as well as the cap for new ones. Timed the engine to 28* at max revs of about 3,500 and left it at that. At idle its just 4* BTDC now.

I feel the idle is a little low, and the bus seems harder to start now...starts in about 6 to 8 seconds vs 2 cranks before. I wonder if this is a good thing.

Anyway, too tired now, but will look at it again tomorrow. :?

Wed Jul 18, 2012 10:15 pm

Rubber Duck wrote: I feel the idle is a little low, and the bus seems harder to start now...starts in about 6 to 8 seconds vs 2 cranks before. I wonder if this is a good thing.

Yup, that's what an idle of 4* BTDC did for me too. You can open up the idle air to work out the low idle, but the starting issues will probably remain. I'd nudge it up to 6* BTDC and see how it feels. You may have to give and take on either end.

Thu Jul 19, 2012 5:41 am

I see no need to bump the timing just because the engine settles to 4* BTDC @ idle speed - if this is a SVDA distributor.

4*degrees BTDC @ idle is what my aftermarket 034 Bosch SVDA timing settles down to - when the engine is timed so that the 3500 rpm mechanical max advance is set to 28* BTDC.

The aftermarket Bosch SVDA 034 in is made in Mexico. I mention it because this could be one variable for each Bus, as is my engine combo below.

I'm still using the stock Solex 34 PICT 3 to break-in my 1776cc - which has a more aggressive camshaft than stock. With a 60 idle jet @ 500 ft above sea level, I do have to back out the large by-pass screw past the stock settings to maintain a 900 rpm idle.

I'm happy with with the set up for now. The engine idles smooth and doesn't wander. It may take me about 4 to 6 seconds to crank before it starts - on a 75 degree morning. The choke is set up for a 60 degree morning.

Again, I see no need to bump the timing past where it is now. The main thing is to set the timing so that it is 28* BTDC when the mechanical advance is maxed out @ 3500 rpm.

- Andrew in Austin, TX -

Thu Jul 19, 2012 6:16 am

I say set the dwell and don't worry about the gap - don't even check it. When I put in new points I put them in and gap them by eye. I start the engine and then check and adjust the dwell... no feeler gauges are involved in the process. I recheck and adjust after a 100 miles or so.

Thu Jul 19, 2012 9:00 am

The stock specs for most distributors works out to 28-32° at full mechanical advance. It probably will not hurt you much to bump it up to 30 or even 32° if that improves low speed running. Another alternative is to bend the taps that limit the travel of the weights so they can't move out as much.

Thu Jul 19, 2012 10:08 am

Thanks for all the input guys. I actually initially did have upper limits of 32*, but thought that was too high, and backed it down to 28*. When it was 32*, the idle was nice at about 950 or so, with the timing at about 8*BTDC. I actually felt that the bus ran smoother and nicer. I scaled it down to 28* and 4* cos I thought it might be too hot.

When I get home today, I'll break out the timing light again and set it at 32*/8* and take it for a spin to see how it goes.

I hear you-all on the "set the dwell not gap" crowd and see what you mean. I could very well have been messing with something that I should've left well enough alone.

Andrew, mine is a DVDA, the correct dizzy for my 74 bus. However, I am using only the Advance port, with the Retard port not hooked up to anything. The Advance port is hooked up to my twin weber 34 ICTs and both carbs are balance-ported.

I should add that the reason I did this whole exercise was a result of a stranger coming up to me and telling me I should adjust my valves. I stopped and listened to my running bus and thought that maybe he was right...cos it did sound kinda quiet.

However, on adjusting them all, I found only slight tightness on the #3 Exhaust valve...I thin it was .005, marginal tightness. I still adjusted it to .006 buttoned up the valve covers. I then thought...hmmm, maybe it was too advanced. And one thing led to another....

I really should leave well enough alone. Yet, this weekend, I am going to drop my engine, and FINALLY remove the helicoil on Cylinder #3 and put a timesert in there. I only remembered it cos on searching for info on timing and stuff, I came across one of my old posts where I discovered the helicoil just before a trip! Heck that was in 2009 and here I am still haven't changed it out yet!!

Well, better late than never I guess . :oops:

Thu Jul 19, 2012 10:24 am

Would seem to me that some shop with a distributor machine could advertise on The Samba and do a reasonable business optimizing the advance curves on distributors, such that one could both idle properly and not over-advance at speed....

Thu Jul 19, 2012 11:22 am

A lot of variables - I tune my 1776cc Type 1 - with a stock Solex - to the 28* BTDC spec' to idle well at 900 RPM for my elevation - which is 500 feet above seal level.

That gives me some wiggle room to set the total mechanical advantage to 31* or 32* when I'm in New Mexico or Colorado.

You've have a dual ICT set up - :D

Your ICT set up should do fine with 30* BTDC @ 3500 rpm - since, you're not driving in the Texas summer heat and finessing the Solex 34 PICT 3 idle circuit, so it works without any hiccups on a 1776cc with a non-stock camshaft.

- Andrew in Austin, TX

I had a stranger come up and tell me that my rear tire needed air. It had 38 PSI in it when I checked the next day. :roll: