Thread: 1959 389 Engine
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Old 01-23-2016, 11:16 PM
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b-man b-man is offline
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Default Compression testing

Today I wanted to try to get some compression numbers, just to get an idea on the general health of the engine before I tear it down any further.

I put the auto trans bell and flexplate back on it along with the starter motor so I could run the compression test.



I also installed a nice tight lightly used double-roller timing set. This way the valve action wouldn't be retarded because of a loose chain, perhaps giving me a better chance of getting some decent compression readings.



I pirated a couple of good used battery cables from my stash and hooked up the battery. I also put the 2-barrel carb back on and blocked the choke plate and throttle linkage wide-open, to better simulate a test you'd do on a complete engine.



Now I'm ready to do some testing.



Since the engine is obviously cold and the lifters aren't pumped up the readings won't tell the whole story, but here they are:

1 - 110
3 - 80
5 - 65
7 - 105

2 - 95
4 - 70
6 - 65
8 - 110

Tested again after adding a squirt of Marvel Mystery Oil to each cylinder:

1 - 120
3 - 100
5 - 100
7 - 115

2 - 80
4 - 80
6 - 70
8 - 130

So at this point I'll let it sit for a week to give the MMO a chance to soak into the rings a bit more to perhaps free them some and test again, then I'll pull the heads.

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1964 Tempest Coupe LS3/4L70E/3.42
1964 Le Mans Convertible 421 HO/TH350/3.08
2002 WS6 Convertible LS1/4L60E/3.23
1966 VW Type 2 Single Cab Pickup 140hp 2276
1956 VW Type 2 Panel Van 36hp 1200
1957 VW Type 1 Beetle 180hp 2276