Summer engine into 68 Westy - questions

[SGKent]

Double check it but here is what Old Volks says. You may be running way too much advance. If so, bad things will happen.

Old Volks = Timing Set At:: 0deg TDC Static or @800-950rpm w/strobe w/vacuum hose disconnected and plugged
Advance/Retard Range: Vacuum (Advance Only): 17-19deg @ 1.3 In. Hg, 32-35deg @ 3.2 In. Hg
https://oldvolkshome.wetwesties.org/ignition.htm#B1968

One cannot run that kind of advance except under light load 7.5 + 33+/- = 40 degrees at 3.2 In Hg. Hg. 3.2 In. Hg is nothing as to vacuum signal.
_________________
Canned Water - the new California approved parts cleaner (except in a drought in which case rub it with sand).

George Carlin:
"Most people don't know what they're doing, and a lot of them are really good at it."

Skills@EuroCarsPlus:
"never time to do it right but always time to do it twice"

[soissisc]

They are Bosch 7902 WR8AC I got from Autohaus AZ.

Does that tell you enough to help?
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[soissisc]

SGKent I have a 30pict1 carb paired with a 205K distributor, all from a 67 beetle. I had the carb restored and also the distributor by the guys on the samba here (their names escape me now). So the 205K I believe has the vacuum curve that you set it at 7.5° BTDC etc etc. I think the 205M and 205T have a different advance curve so you are correct but that is not what I am running. Anyway, I followed this from old volks (I used strobe not static):

Beetle 1966-1967 * 1300/1500
Distributor: VW 113-905-205K/L, Bosch 0231 137 009/010
Spark Plug: W8AC
Timing Set At:: 7.5deg BTDC Static or @ 800-950rpm w/strobe w/vacuum hose disconnected and plugged
Advance/Retard Range: Vacuum (Advance Only): 17-19deg @ 1.3 In. Hg, 24-28deg @ 3.2 In. Hg

Let me know what you think. Can I do a full advance at 3500 rpm or whatever, just to see where the advance ends? I didn't know if that was accurate with vacuum only advance?
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[SGKent]

The consequences of too much heat. Bays are much more prone to it. Running Beetle timing in my 1971 back in the mid 1970's killed it the same as in the photo below.

from the gallery, there are many more like this
_________________
Canned Water - the new California approved parts cleaner (except in a drought in which case rub it with sand).

George Carlin:
"Most people don't know what they're doing, and a lot of them are really good at it."

Skills@EuroCarsPlus:
"never time to do it right but always time to do it twice"

[airschooled]

Wow yeah, you could melt a piston if something goes wrong, or maybe everything goes right and you have a great road trip.

First up is a fuel pressure check. Watch it at idle and with a little rev.

Your timing is perfect.

I’m on a 3,000 mile road trip right now, and the last week had really hard hot starts just like yours. Floor the accelerator to get it going or crank almost indefinitely… When I got back to California the problem went away. I think fuel mixture plays a part of this as well. Things change even seasonally at the same pump. Have you tried running several tanks of specific fuels through it? Ethanol-free, local premium, and local cheap gas will all have different additives. A flooded engine needs a healthy spark too; battery voltage drop combined with a weak coil or condenser won’t help.

I have my personal car tuned all kinds of crazy for extreme fuel economy on California summer gas, so I can’t recommend my jetting, but I would absolutely start with the Without Guesswork options for your carburetor. Are you familiar with those books? And did you know VW needle valves came in different flow sizes? No manufacturer makes them, only NOS on Samba/ebay for now.

https://www.thesamba.com/vw/archives/manuals/withoutguesswork.php

Fuel pressure test first
Robbie
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[soissisc]

Robbie, I am going to get on that fuel pressure check this week. I will post back with the results. I will also check out that book you are talking about, and no I was not aware of it. Thank you for the info.

SGKent - I believe that my dist (205K) only has 24°-28° total advance, which with the initial 7.5° BTDC timing setting, that puts the total advance in the same ballpark as the 205M and 205T distributors that you are talking about - 32°-35° total advance. I for sure, could be wrong, but can I test that by watching the advance as I take it up to max advance? That would be me just running the rpm up at the engine back there with the timing gun, so "no load", but would that be accurate to check max advance?

rustavenger - I think that I was running hot for a bit with that 120 main jet. Would that skew what you are seeing now on those plugs? Like I said, this plug that I show is a Bosch 7902 WR8AC I got from Autohaus AZ. I do have a new set of Bosch WR8AC plugs I could install as a clean slate to take readings from. What do you think?

Thanks for the input guys.
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[SGKent]

you can use a hand vacuum pump on the can to pull max vacuum and see where it stops.
_________________
Canned Water - the new California approved parts cleaner (except in a drought in which case rub it with sand).

George Carlin:
"Most people don't know what they're doing, and a lot of them are really good at it."

Skills@EuroCarsPlus:
"never time to do it right but always time to do it twice"

[soissisc]

I did a timing sanity check.

With no vacuum to the canister at idle it is dead on 7.5° TDC. When I max out the advance with vacuum to the canister it ends up 32° - 33°. I think that is correct for the 205K distributor.

The TDC mark on my pulley I made when I was putting the engine together, so I am pretty confident that I am measuring correctly.

Dwell is right at 48°

I am going to get a fuel pressure check next.

I wonder if that lean 120 main jet is what caused the plugs to look so hot? Should I pull max advance back down to 30°?

Thanks for your insight.

Mark
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[SGKent]

I'd bring the total advance back to 28 - 30 degrees. It may not affect how well it runs but it will help prevent piston and head overheating. Buses just generate so much heat. Below 28 - 29 degrees you'll feel power fall off but between 29 and 32 the only side effect seems to be less heat going into the heads and piston crowns. You'll find that recommendation over and over in the forum. Years ago I melted a piston crown in my 1971 1600 dual port at 34 degrees BTDC.
_________________
Canned Water - the new California approved parts cleaner (except in a drought in which case rub it with sand).

George Carlin:
"Most people don't know what they're doing, and a lot of them are really good at it."

Skills@EuroCarsPlus:
"never time to do it right but always time to do it twice"

[soissisc]

I will do that. Thank you. EDIT - it is done. Max 29°-30°.
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[Abscate]

[soissisc]

I decided to change out the plugs, to start from a clean slate. They are the same p/n Bosch plugs gapped at .024".

Here are the 4 plugs I removed. This was before timing change to bring it down to 29° - 30° max ever (at idle vac line off and plugged it is around 4°-5° BTDC instead of the 7.5° BTDC that the book says to do). This is a few hundred miles with 127.5 Main jet with 30pict1 carb and 205K dist.

I also did a fuel pressure check at idle and above idle. I used 2 different gauges that I have here, one said a tick above 4psi at idle and slightly more above idle, and the other gauge said slightly under 4 psi at idle and right around 4 psi above idle.

That seems slightly high either way?

Thanks.
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[SGKent]

try to get the fuel pressure down a little if you can. $4 looks a bit rich but not bad. How does it feel?
_________________
Canned Water - the new California approved parts cleaner (except in a drought in which case rub it with sand).

George Carlin:
"Most people don't know what they're doing, and a lot of them are really good at it."

Skills@EuroCarsPlus:
"never time to do it right but always time to do it twice"

[soissisc]

It runs pretty good, feels pretty good. I have not gotten out on the hills too much to see if I notice the timing change.

I checked the fuel pressure gauge about an hour after running the engine and it was at 0 psi. I would have thought it would maintain the pressure.

Thanks.
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[soissisc]

I am going to have to order some gaskets for the fuel pump side and the engine side of the spacer. I am all out of stock in my drawer of stuff.

I do not recall measuring the rod height but I am going to take a look at that. It seems like the spacer heights can vary and I do not have written down where I was when I put this together.

Maybe the slightly higher pressure can overwhelm the float / needle valve after shut down on the smaller round float of the 30pict1 carb?

Thanks.
_________________
Mark

68 Westy
92 Jetta (oh it is retired)
99 Eurovan
05 NBC
06 Audi A3
72 Westy (I am going to fix it up)

[SGKent]

since it is running well now, are we chasing a boil over problem when it restarts? What is going on? On a stock type pump, lowering the rod height as described in Bentley will lower pressure.
_________________
Canned Water - the new California approved parts cleaner (except in a drought in which case rub it with sand).

George Carlin:
"Most people don't know what they're doing, and a lot of them are really good at it."

Skills@EuroCarsPlus:
"never time to do it right but always time to do it twice"

[soissisc]

[SGKent]

make sure the choke is all the way open when the engine is hot. Also if it is really a hot day, hold the pedal all the way to the floor and do not lift your foot at all until it starts. Every time you push the pedal it adds fuel and if you are already a bit flooded, it just floods it more. This is what happens to some people.

Incorrect way to start flooded engine
Flooded engine a bit from boil over or whatever
Press pedal to the floor and crank it (adds more fuel)
stop to give starter a break, lifts foot. (Closes butterfly so traps excess fuel)
Presses pedal part way to floor and cranks (adds more fuel to already flooded engine)
Hits pedal one more time to see if that helps (adds more fuel to already flooded engine)
Lifts foot and stops cranking. Thinks about it. (butterfly closed so excess vapor trapped)
Presses pedal to floor and tries again (adds more fuel to already flooded engine.)
Problem continues

Proper way
Has a history of flooding in the conditions.
Press pedal to floor and crank the engine, never lifting foot (pushes some excess fuel out)
Does NOT lift foot (no additional fuel added. Vapor can escape)
Waits a minute still holding pedal down (more vapor escapes)
Cranks again and engine sputters, does NOT lift foot. Waits 10 -15 seconds and tries again without lifting foot. (Excess fuel pushed out no additional added)
Cranks and engine starts, as soon as rpm comes up a little, lets it idle for a few seconds and drives off.
_________________
Canned Water - the new California approved parts cleaner (except in a drought in which case rub it with sand).

George Carlin:
"Most people don't know what they're doing, and a lot of them are really good at it."

Skills@EuroCarsPlus:
"never time to do it right but always time to do it twice"

[soissisc]

I believe that I have the choke set up well for this summer weather. I will double check that though. Thanks.

As far as my starting routine - when it is cold, I blip the pedal, to release the choke, hit the key and it fires up instantly.

When hot, I slowly depress the pedal while cranking and usually by halfway down (depressed pedal) it fires up. Sometimes I make it to the floor before it fires. (I read to depress the pedal slowly to limit the effect of the accelerator pump) It has always started when hot, just sometimes more begrudgingly than others, but honestly I think that I was running hot (lean) with that 120 main jet, which may have made matters worse for sure.

Well except for that one time recently it did really seem flooded when I parked on that exaggerated slant, it was difficult to start.

In the future I plan to employ this is excellent advice:

[SGKent]