Have you checked your compression?
12-28-07, 01:46 AM
#1
Compression King
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Have you checked your compression?
I am just wondering what others are getting for numbers on their engines.
PSI on front and rear rotors, or whatever the numbers mean on the mazda compression tester.
Read my sig for mine.
I was told it was the highest seen on the mazda tester at the Ottawa meet this summer.
PSI on front and rear rotors, or whatever the numbers mean on the mazda compression tester.
Read my sig for mine.
I was told it was the highest seen on the mazda tester at the Ottawa meet this summer.
12-28-07, 09:01 AM
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Had somebody do a piston engine checker on it, and got 60-70 on both faces. Somethings wrong, I'd think, because that was almost a year ago. I figured my car would have blown up by now :P
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12-28-07, 09:09 AM
#8
I am just wondering what others are getting for numbers on their engines.
PSI on front and rear rotors, or whatever the numbers mean on the mazda compression tester.
Read my sig for mine.
I was told it was the highest seen on the mazda tester at the Ottawa meet this summer.
PSI on front and rear rotors, or whatever the numbers mean on the mazda compression tester.
Read my sig for mine.
I was told it was the highest seen on the mazda tester at the Ottawa meet this summer.
12-28-07, 09:28 AM
#9
12-28-07, 10:04 AM
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Compression King
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It's a rotary specific tester that displays readings for each rotor face.
Looks like this:
I don't remember what the measurement units were.... I think it might have been in kg/cm2 or something like it.
Last edited by ViperBart; 12-28-07 at 10:21 AM.
12-28-07, 08:59 PM
#17
All testers read differently--so you've got to keep that in mind. I've been using my current "piston" tester with the check-valve removed for about three years now. I hope for numbers of 100PSI or more. 
The highest PSI I've seen yet has been a Series 5 13BT with 120k miles on it. On my tester it was seeing 115PSI front and rear (cold). It was beautiful watching that needle bounce. 
Most of my FC's have had engine's with numbers hovering between 95-105PSI--although some have ran and drove excellent with numbers closer to 90-95PSI.
The highest PSI I've seen yet has been a Series 5 13BT with 120k miles on it. On my tester it was seeing 115PSI front and rear (cold). It was beautiful watching that needle bounce. Most of my FC's have had engine's with numbers hovering between 95-105PSI--although some have ran and drove excellent with numbers closer to 90-95PSI.
12-28-07, 09:42 PM
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Not an expert on the subject, but wouldn’t you expect the best compression on high mile engines (at least ones that have been rebuilt). I have herd racers like to use well warn parts to build their engines
12-28-07, 10:34 PM
#22
My engine- with 176k showing- reads 80-85psi front and back with healthy bounces.
Starts fine, no smoking or unusual oil consumption (although oil pressure reads kinda low) and gets decent mileage (16 city/25 highway).
Decided not to worry about it till something actually went wrong.
Starts fine, no smoking or unusual oil consumption (although oil pressure reads kinda low) and gets decent mileage (16 city/25 highway).
Decided not to worry about it till something actually went wrong.
12-28-07, 10:34 PM
#23
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I think the "worn" part has to do with the break in period, for example if you use new apex seals with older housings the compression won't be as good(in the beginning) because the seals haven't worn down enough to make the best seal if that makes any sense...someone jump in if this info is a bit off. The real difference I would say is racers like engines that have been properly broken in rather than well worn.
12-28-07, 11:13 PM
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I think the "worn" part has to do with the break in period, for example if you use new apex seals with older housings the compression won't be as good(in the beginning) because the seals haven't worn down enough to make the best seal if that makes any sense...someone jump in if this info is a bit off. The real difference I would say is racers like engines that have been properly broken in rather than well worn.
