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Post by dluber on Dec 31, 2017 15:23:37 GMT -5
Bruce,
I performed the compression test as described but the OTC tool instructions - got the engine to operating temp, removed spark plugs, unhooked coil, hooked up the hose and gauge, cranked engine 5 rotations.
I checked each cylinder and I got 1 - 90, 2 - 90, 3 - 91, 4 - 90. This is a chain driven L134.
The only think I know about this engine from the previous owner is that he had his shop put new gaskets in probably around 2012. The engine was never started by the shop because they did not finish the build.
I spent about 2 hours this morning trying to get a single, decent 4008 distributor setup. I still need to pickup some parts to complete one of the distributors. Do you know the significance of the small metal clip at the end of the distributor - where the tip fits into the oil pump?
Thanks, Dave
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Post by Scoutpilot on Dec 31, 2017 15:28:32 GMT -5
Ninety on a dry test is not good. Do a wet test (a teaspoon of oil in each cylinder). The clip is an Anti-rattle clip. Don’t lose it. Nearly irreplaceable.
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Post by dluber on Dec 31, 2017 16:03:22 GMT -5
Here is the results for the wet test. 1 - 100, 2 - 90, 3 - 95, 4 - 91 (only 1 and 3 had slight improvement)
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Post by dluber on Dec 31, 2017 16:06:00 GMT -5
I also found this on the web - not sure how this factors in based on my local altitude of 5500 ft..
I found this table to adjust for altitude when performing compression tests:
Altitude Factor 1000 .9711 2000 .9428 3000 .9151 4000 .8881 5000 .8617 6000 .8359 7000 .8106 8000 .7860
It looks like a logarithmic curve starting at roughly 3% loss in pressure every 1000'. So at my elevation (5500'), I'd be looking at about a 15% loss. That explains why my as-new 361 only reads 148 psi. It's actually 170.
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Post by dluber on Dec 31, 2017 16:15:43 GMT -5
Here is another reference: in my case, if we were looking for 110lbs and I'm at 5500 ft = 110 * .853 = 93.83 lbs
Altitude Correction Factor Table for Compression Testing
Expected compression tests are specified at sea level. Altitude has an effect on readings obtained and a correction factor must be applied to expected readings taken at other than sea level.
For example: Specified compression = 150psi, Altitude = 2000ft, (150 x .943 = 141.5psi expected@2000ft)
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Post by Scoutpilot on Dec 31, 2017 19:40:19 GMT -5
Even with the correction, I’d say you may be looking at worn rings.
And where did you find this table? Can you send a link? I definitely need to include a formalized version here.
Great job dluber!
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Deleted
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Post by Deleted on Dec 31, 2017 19:54:23 GMT -5
What's the history on the engine, a rebuilt, low mile older rebuilt, old runner, old tired runner, ?
Lee
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Deleted
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Post by Deleted on Dec 31, 2017 20:00:32 GMT -5
just wondering!
Lee
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Post by dluber on Dec 31, 2017 20:22:58 GMT -5
The link for the altitude compression adjustment is: kawtriple.com/mraxl/tips/compression_test.htmI really don't know the history of the engine. The previous owner had it at a shop in Arizona for about 5 years. The project was abandoned in 2012 and I purchased the jeep in parts in early 2017. The PO said it was his grandfathers for about 50+ years. Used mostly as a hunting vehicle.
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Post by dluber on Dec 31, 2017 20:34:39 GMT -5
Break Break... Okay so remember when I said I was a novice... I pulled out my electronic distributor and put in my version of a rebuilt 4018. I put new points (they are adjusted), a new condenser, rotor and cap. The 4018 went in fine, but I know I'm off on my wiring as I'm only getting an occasional backfire. Any suggestions on how to get this working so I get the distributor at a starting point that I can set the timing?
I should have mentioned that I got all my parts from NAPA - same part numbers as on the NAPA parts list on this site.
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Deleted
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Post by Deleted on Dec 31, 2017 22:30:04 GMT -5
Pretty sure your NAPA parts are not the issue!, by the sounds of it your most likely 180 deg. Off on the plug wires!. #1 should be at the 4 o'clock position, going counter clockwise from there 3-4-2. If that's where your at, then perhaps the oil pump was clocked 180 deg off, or the advance assembly in the distributor head was assembled 180 deg off. In either case, try moving the #1 wire to the 10 o'clock position, and CC from there 3-4-2. It will not hurt anything to try!.
As far as compression goes, it should run fine at 90 psi across the 4, below 80 things go sour!, I'd run it as is and see what happens after some excercise.
Lee
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Post by Scoutpilot on Jan 1, 2018 6:54:17 GMT -5
Is the exhaust smoky?
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Post by dluber on Jan 1, 2018 7:40:53 GMT -5
I would say the exhaust was a bit smokey.
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Post by Scoutpilot on Jan 1, 2018 8:19:37 GMT -5
Blue/Grey = oil, worn rings.
white = coolant, head gasket or crack in the water jacket.
black = fuel, mixture too rich.
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gmcjr
KJRT
Posts: 897
First Name: Gary
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Post by gmcjr on Jan 1, 2018 8:48:36 GMT -5
Pretty sure your NAPA parts are not the issue!, by the sounds of it your most likely 180 deg. Off on the plug wires!. #1 should be at the 4 o'clock position, going counter clockwise from there 3-4-2. If that's where your at, then perhaps the oil pump was clocked 180 deg off, or the advance assembly in the distributor head was assembled 180 deg off. In either case, try moving the #1 wire to the 10 o'clock position, and CC from there 3-4-2. It will not hurt anything to try!. As far as compression goes, it should run fine at 90 psi across the 4, below 80 things go sour!, I'd run it as is and see what happens after some excercise. Lee I agree 100% with Lee. As to compression, anything above 80 or 90 psi should start and run. Hell, I've seen 60 psi start. IMHO, I dont get to hung up on the actual number, there are why too many variables. Who says my compression gauge is accurate? Then cranking speed, throttle position, engine temp all have an effect on the compression gauge reading. I pay more attention on the difference between cylinders. That way you have a constant and variables to go by. To really get a feel for cylinder condition, a leak down test is the way to go. In your case, I'd run 'er, you might be surprised!
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