Let's talk about my compression numbers.. (D1)

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Harv
Knight of the Green Oval
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Joined: Sun Oct 16, 2011 9:38 pm

Let's talk about my compression numbers.. (D1)

Post by Harv » Thu Jul 24, 2014 3:10 pm

Finally had time to run a compression test on my D1. Just rolled 175,000 miles.

It does overheat going up steep hills after it's been running for awhile. I can pull the temp gauge back down if I throw the heat on full blast. Doesn't overheat at all during the cold months. Leaks a little coolant somewhere under the motor. Have no idea if it's random hoses, rear valley pan, or the gasket between the heater plate. Yes, I have a new OEM radiator and new fan clutch.

Motor was warm enough to not burn myself on the manifolds when I ran the test.

I was actually surprised at how well it came out. I think 170ish is a good number for a newer motor, but at 175k I can't really complain for 140 numbers.

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'95 D1
'97 D1

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jagspeed
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Re: Let's talk about my compression numbers.. (D1)

Post by jagspeed » Fri Jul 25, 2014 11:35 am

170 is really a big wish unless you're running high-compression pistons. 150 is more normal...

140 is good for a high-mile engine. I often see 125 in engines with 6-figure mileage.
More important than the actual number is the difference between the highest and lowest values. A deviation of 10% or more is cause for concern.

With a median value of 142 and a max deviation of just 3%, you should be happy.
Sir Harold, Lord Jagspeed

I know how to operate a vehicle

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