85 Compression Test Results
04-17-2010, 02:08 PM
#1
Rennlist Member
Thread Starter
85 Compression Test Results
Asking for input, ie, normalcy.
This is for the 85 Van Winkler car that slept for 10 years. Its running a tad on the warm side compared to my 86, much more gauge variation, so , like Fraggle a while back, I'm starting to diagnose.
Engine was started and run for about 2 minutes this morning, so it didn't even warm up. It was tested about 2 hours later, essentially cold. Ambient is about 75F.
Passenger Bank
1 175 170 (by radiator)
2 180 185
3 165 165
4 165 165
Drivers Bank
5 165 170 (by radiator)
6 175 175
7 165 165
8 170 165
This is for the 85 Van Winkler car that slept for 10 years. Its running a tad on the warm side compared to my 86, much more gauge variation, so , like Fraggle a while back, I'm starting to diagnose.
Engine was started and run for about 2 minutes this morning, so it didn't even warm up. It was tested about 2 hours later, essentially cold. Ambient is about 75F.
Passenger Bank
1 175 170 (by radiator)
2 180 185
3 165 165
4 165 165
Drivers Bank
5 165 170 (by radiator)
6 175 175
7 165 165
8 170 165
04-17-2010, 02:23 PM
#3
Rennlist Member
Those compression numbers look just fine. Especially for cold and dry. They're well within the 15% variation I've always been told.
I doubt the plugs have enough time from the short run to have
developed the color enough for a good read, and the exposure values seem to vary, but they appear fine.
I doubt the plugs have enough time from the short run to have
developed the color enough for a good read, and the exposure values seem to vary, but they appear fine.
04-17-2010, 11:21 PM
#7
Rennlist Member
Thread Starter
They're back.
Plugs must have been changed before it was put to sleep.
The temperature gauge acts like its a half order of magnitude more sensitive than the other cars. Last night, 15 miles to the store at about 85F ambient, gauge was at upper white line and electric fan was running. It runs just short of half gauge, not quite horizontal, but when it gets over 80 outside and especially if I push it a little bit, I'm close to the top white mark. Fans engage at the top mark. Viscous drive fan works fine. Maybe I have a radiator working at less than optimum.
86, same conditions, would be a bit over the first running mark, less than half-gauge in other words, with no aux fan operation. Same with the two sixteen valve cars.
The #8 wasn't wet or really much different than the others, and same compression, so I'm not thinking its an issue. I've had lots that were oily or carboned and this doesn't seem near that condition.
Plugs must have been changed before it was put to sleep.
The temperature gauge acts like its a half order of magnitude more sensitive than the other cars. Last night, 15 miles to the store at about 85F ambient, gauge was at upper white line and electric fan was running. It runs just short of half gauge, not quite horizontal, but when it gets over 80 outside and especially if I push it a little bit, I'm close to the top white mark. Fans engage at the top mark. Viscous drive fan works fine. Maybe I have a radiator working at less than optimum.
86, same conditions, would be a bit over the first running mark, less than half-gauge in other words, with no aux fan operation. Same with the two sixteen valve cars.
The #8 wasn't wet or really much different than the others, and same compression, so I'm not thinking its an issue. I've had lots that were oily or carboned and this doesn't seem near that condition.
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04-17-2010, 11:52 PM
#11
Rennlist Member
Thread Starter
All been done. Then completely disassembled, checked and reassembled. Including the new waterpump and timing belt.
The only thing I didn't do was pack clay in between block and pump to check clearance.
The only thing I didn't do was pack clay in between block and pump to check clearance.
04-17-2010, 11:56 PM
#12
Inventor
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Rennlist Member
Is the MAF original? Lean running may increase coolant temps.
04-17-2010, 11:59 PM
#14
Three Wheelin'
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So one car runs hotter than the other, and you want to know why?
Hell, maybe it really is just a radiator difference.
Does one have a heater core variance allowing hot water in when it shouldn't?
Hell, maybe it really is just a radiator difference.
Does one have a heater core variance allowing hot water in when it shouldn't?
04-18-2010, 03:02 PM
#15
Race Director
Drive on!!!!!!!!!!!!! CR is fine & the plugs also look fine......sure #8 is darker but it could just be the flash on the camera too......
One thing I REALLY like to track the "health" of my engine is Oil Analysis.....I use Blackstone labs & it is VERY informative to the internal condition of the engine...sure looking at the drain magnet helps & cutting open the oil filter helps too......but Blackstone is the final word & when used over time shows a pattern of wear-condition that can help you decide when its time to rod bearings-etc
One thing I REALLY like to track the "health" of my engine is Oil Analysis.....I use Blackstone labs & it is VERY informative to the internal condition of the engine...sure looking at the drain magnet helps & cutting open the oil filter helps too......but Blackstone is the final word & when used over time shows a pattern of wear-condition that can help you decide when its time to rod bearings-etc