Oh the fun of timing and carbs

kerian159 · Last edited by kerian159 on Sat May 30, 2009 9:33 am; edited 1 time in total

If you hear your engine pinging from pre-detonation listen to it, this might happen to you

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Nice ain't they Crying or Very sad

my theory is I had a leak at the head causing the hole in the piston on #4 and providing too much air for the air/fuel mixture which caused the rest of the problems with the pistons. When the hold formed in the piston that caused loss of oil which could have ruined the rings? I'm going to have to replace all four of the pistons but as I do i'm trying to figure out what exactly went wrong so I will not repeat my mistakes. Any information is much appreciated! Oh btw this engine ran fine all the way from p'cola, FL to chattanooga, tn for bug-a-pulluza after we got back it started having problems which of course led to this. Thanks again for the help!
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1976 Type II Westy P22

"Growing older, but not up!"

Bleyseng · Posted: Sat May 30, 2009 9:30 am Post subject:

and running freakin lean!! Too hot and pinging mean death!!! Shocked

time for some AA p&c's and new Jake heads.

What carb/s are you running? Stock? rebuild em.
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70 Ghia Black convert-9/69 build date-stock w/133k 1600 SP-barn find now with a rebuilt tranny and engine
77 Westy 2.0L w/Ljet, Camper Special engine-95hp and with LSD!(sold)
76 Porsche 914 2.1L L20c, 120hp Djet (sold)
87 Syncro Westy Titan Red 2.1L 2 knob 100k miles

kerian159 · Posted: Sat May 30, 2009 9:35 am Post subject:

the carb i'm running is for now a weber progressive (bad words i know) but it's all i've got at the moment and when it ran it ran real well getting 20mpg on the trip to TN. I've got the rebuild kit for it and i'm going to rebuild it before putting it back together. The reason I think I was leaking at the head is that I tried to adjust the carb but all adjustments were not changing the engine at all.
_________________
1976 Type II Westy P22

"Growing older, but not up!"

Randy in Maine · Posted: Sat May 30, 2009 10:31 am Post subject:

kerian159 · Posted: Sat May 30, 2009 10:42 am Post subject:

I would like to have dual carbs on it but due to lack of $ i'm kinda stuck with what i've got at the moment.
_________________
1976 Type II Westy P22

"Growing older, but not up!"

Bleyseng · Posted: Sat May 30, 2009 11:07 am Post subject:

Then atleast setup the jetting right! too lean!

Heck there was a 914 guy who did what you did twice!! only took 3 laps on a track to do it too...sold everything. Now if only he got the AFR down before driving it around like you should too.
_________________
70 Ghia Black convert-9/69 build date-stock w/133k 1600 SP-barn find now with a rebuilt tranny and engine
77 Westy 2.0L w/Ljet, Camper Special engine-95hp and with LSD!(sold)
76 Porsche 914 2.1L L20c, 120hp Djet (sold)
87 Syncro Westy Titan Red 2.1L 2 knob 100k miles

kerian159 · Posted: Sat May 30, 2009 11:39 am Post subject:

I will be looking very closely at the AFR after I put the engine back together! Before when the engine was still running I set the timing at 30 degrees and was messing with the carb to try and get it to stop pinging but nothing I did on the carb would effect the engine. So i'm trying to figure out if the head leak would actually cause that much of a differance on the AFR.
_________________
1976 Type II Westy P22

"Growing older, but not up!"

busdaddy · Posted: Sat May 30, 2009 11:52 am Post subject:

But what did you actually do to the carb? No screw on the outside is going to fix an issue like that, you have to dismantle it and change the jets. How were the rubber boots on the intake runners? I think the head leak was a result of the lean condition, not the cause.
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kerian159 · Posted: Sat May 30, 2009 12:01 pm Post subject:

the boots on the intake runners are new. and the engine was running great then all of a sudden it started to ping.
_________________
1976 Type II Westy P22

"Growing older, but not up!"

SGKent · Posted: Sat May 30, 2009 12:14 pm Post subject:

How many times have I written here to stop playing with the timing as this will result? 30 to 32 degrees max advance or this will happen.

Classic detonation damage on a VW bus. It is literally like 1000 little hammers pounding on the top of the piston.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

kerian159 · Posted: Sat May 30, 2009 12:40 pm Post subject:

it was set to 30 degrees. set with a timing light at 2000 rpm
_________________
1976 Type II Westy P22

"Growing older, but not up!"

Randy in Maine · Posted: Sat May 30, 2009 1:34 pm Post subject:

I don't know what distributor you have in there, but the centrifical advance should all be in by about 3500-3800 RPMs. Vacuum hose(s) off.

When it is all in, it just will not advance anymore no matter how high the engine revs up.

SGKent · Posted: Sat May 30, 2009 4:09 pm Post subject:

kerian159 · Posted: Sat May 30, 2009 4:23 pm Post subject:

ahh thanks. would there be any other damage inside the case due to pre-detonation that I should look for?
_________________
1976 Type II Westy P22

"Growing older, but not up!"

Wildthings · Samba Member Joined: March 13, 2005 Posts: 50348


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