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  #16  
Old September 4th, 2017, 09:07
@dam @dam is offline
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Re: Looks like my engine is toast. Opinions on these compression #'s?

I read that if wet compression was higher than dry compression by over 10%, your rings are considered bad
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  #17  
Old September 4th, 2017, 09:45
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Re: Looks like my engine is toast. Opinions on these compression #'s?

Quote:
Originally Posted by @dam View Post

Regarding mpg, it is a 5 speed and the high altitude helps (less drag), but I did spend a good portion of both those tanks going 75 with the AC on.
That makes sense, also thinner air means less fuel for the proper ratio. Forgot about your altitude.
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  #18  
Old September 5th, 2017, 21:27
Afireinside Afireinside is offline
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Re: Looks like my engine is toast. Opinions on these compression #'s?

That actually looks pretty good!
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  #19  
Old September 6th, 2017, 21:17
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Re: Looks like my engine is toast. Opinions on these compression #'s?

Nothing wrong with those numbers at all. Drive it.
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  #20  
Old September 7th, 2017, 09:41
denverd1 denverd1 is offline
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Re: Looks like my engine is toast. Opinions on these compression #'s?

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Originally Posted by @dam View Post
I read that if wet compression was higher than dry compression by over 10%, your rings are considered bad
what I was thinking since wet #s were quite a bit higher. I wouldn't say bad, just got a few miles on them. get a lot of blow by?

still wouldn't be afraid to drive it like I stole it
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  #21  
Old September 10th, 2017, 18:58
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Re: Looks like my engine is toast. Opinions on these compression #'s?

Double check your distributor indexing. It can be off in the direction that causes problems at real low rpms as well as off in a direction that causes problems at higher rpms.
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  #22  
Old September 12th, 2017, 18:28
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Re: Looks like my engine is toast. Opinions on these compression #'s?

Where can I get the 4 hole injectors for a 97, 4.0?
Thanks,



Quote:
Originally Posted by @dam View Post
I just got back from a 2 tank road trip...rural highways in New Mexico. I got 23.2 and 25 mpg- my best ever. I don't get why my mpg is so good if my wet vs dry compression numbers are so different.

I'd love to drive the wheels off it, but if I can't get it by emissions without a rebuild, I might buy something more comfortable and with modern safety features like ABS. A stroker with a higher compression ratio to make up for the altitude would be fun though.

Oh yeah- the following are brand new
4-hole injectors
Cap, rotor, wires, plugs
The actual complete distributor. Old one had a little play in it so I thought it might be the cause of my miss, but it didn't make a difference

It has quicker starts and better throttle response now (and apparently REALLY good mpg), but I took it to an emissions bay and there was no improvement in the emissions at idle- like 500 ppm at idle and 180 is the limit (which I squeaked pass by revving it way up to heat up the cat just before the test)

IAC motor is a year old. Old one was fine. I also ran a can of mopar combustion chamber cleaner through before I did the emissions test and compression test.

Got about 100k on the cat, but I doubt the cat is causing the miss

Oh yeah- fuel pressure is 33 psi and oil pressure is about 45
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