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Limo engine update

PostPosted: Tue Aug 06, 2013 5:07 am
by vwlimoguy
So I thought something blew up in the Limo engine due to all the blue smoke pouring out of the crankcase, the high head and oil temps and the fact that I had advanced the timing too much. Seems logical. So, I proceeded to tear the engine down last Monday. I found this on the #3 and 4 side of the engine. The spark plugs were perfectly tan.
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Hmmm, nothing wrong there, must have been the other side. Too bad I forgot to photograph that side. But nothing catastrophic there either. The #2 cylinder had a tan spark plug and showed some light scoring on the piston skirt. #1 cylinder also had light scoring but the plug was black and half the piston was washed clean by the gas. Seems as though there was an ignition failure on the #1 cylinder. Combine that with the over heating/scoring and I was getting blow by on the #1 cylinder pretty bad. I went ahead and put new rings in while I had it apart.

Re: Limo engine update

PostPosted: Tue Aug 06, 2013 5:09 am
by vwlimoguy
So I am blaming all of the problems on this:
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This is what the inside of my heater box looks like after I shortened it from the stock type 4 to fit into a Beetle. I never had any issue with it before, but I've never driven it that hard either. The black lines show the flow path and the red lines show the huge reduction in pipe size over a short distance on the #1 exhaust. So I built new headers and gave up on heat from the exhaust system (I'll figure out heat at a later date).
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These should flow much nicer and reduce the backpressure on the #1 and #2 exhaust greatly. Went from about 7/8" ID to 1 3/8" ID.

Why I blame the heat exchanger is because it was causing too much heat build up on the right side of the engine due to the lack of flow. That caused several things to happen. The rings over heated losing some tension allowing blow by and scoring the pistons. More heat got into the crankcase increasing the oil heat issues. It also caused the resistor in the spark plug terminal to burn out, causing the ignition problem. I only had a head temp sensor on the other side of the engine and I don't think I really want to know what the temps were on the #1 side (scary hot 8O ).

Re: Limo engine update

PostPosted: Tue Aug 06, 2013 5:10 am
by vwlimoguy
So while it was all apart I also made some alterations to the fan shroud to help cooling. I removed the outlets for the heat and welded over them.
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I widened the doghouse to fit a type 4 oil cooler.
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And I built a new duct to exhaust the heat from the oil cooler.
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I was using this for the duct. Made sense at the time with the existing hole in the tin and materials available.
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Re: Limo engine update

PostPosted: Wed Aug 07, 2013 8:59 am
by vdubjim
Looks legit to me.
With the length of the t4 the same no matter what its in, stock boxes don't fit?

Oh and what piston cyl were they to start with? New used?

Re: Limo engine update

PostPosted: Wed Aug 07, 2013 3:45 pm
by vwlimoguy
Motor was pretty much new. Had 2500 miles on it. The stock heater boxes extended out to the fenders of the Beetle, leaving no room for the muffler. Remember the cooling fan on type 4 is on the back of the engine and the heater boxes are as long as the entire motor.

Re: Limo engine update

PostPosted: Wed Aug 07, 2013 5:36 pm
by vdubjim
Ok just curious, ive heard stories of re-ringed aircooled stuff smoking after while. Thought maybe same issue.

Ahh ya, Darn fan!

Re: Limo engine update

PostPosted: Mon Sep 02, 2013 9:32 pm
by vwlimoguy
Finally got this damn thing wedged in there. Maybe I'll get it hooked up and running by next summer.
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Re: Limo engine update

PostPosted: Tue Sep 03, 2013 6:26 pm
by gimpy60
Luke boy, I got a 2 litre for ugly betty, might need some insight when I go to rebuild it. We could discuss it over one (or some) of your homemade brews. ;) c ya JP

Re: Limo engine update

PostPosted: Tue Sep 03, 2013 10:19 pm
by vwlimoguy
Anytime Gimpy. Just sampled a cranberry lambic that I kegged last night. Pretty darn good.

Re: Limo engine update

PostPosted: Wed Sep 04, 2013 3:14 pm
by vdubjim
Fire it up for Oktoberfest.
Not sure what I'll have, I sold it all lol.

Re: Limo engine update

PostPosted: Sun Nov 03, 2013 11:21 pm
by vwlimoguy
I finally got the engine all tuned up and running nicely. The ignition module had also fried and that slowed things down for a bit. Just needs a good wash down and I'll be ready to Dub the Plaza.

Re: Limo engine update

PostPosted: Sun Nov 03, 2013 11:41 pm
by vdubjim
Awesome!

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