compression numbers, rebuild or not to rebuild??

Reading higher than factory compression numbers? Nice. Um, try flushing your engine and then run the test again.
 
Tonymac said:
Reading higher than factory compression numbers? Nice. Um, try flushing your engine and then run the test again.

I was hinting that the gauge was inaccurate. Carbon deposits on a good running engine might add 1psi to total compression when warm. Use a different gauge if you care for an accurate # opposed to a consistent number.

if the head has been resurfaced or block decked it will increase compression numbers as well.
 
i did the test twice and got the same numbers and i did the test on a hot engine i also have no idea besides that on the condition of the motor besides that other than that it runs good

but i am going to rebuild the motor mostly because i'm going to have to change a syncro in my transmission, get a better clutch, weld the oil return line in my oil pan, and i already changed the clutch one so i know how much of a pain in the ass it is. so i'm thinking pull the motor and tranny then do all the work i have to do outside the car then drop the rebuild turbo motor back in

i'm going to miss my 240 while the engine is out tho ..... lol
 
obby said:

1. You should be able to adjust your fuel and spark advance where needed, dont have crucial places where you are letting the management switch cells or interpolate and possibly knock.

2. Tune the engine well, preferably on the dyno with a water brake so you can tune individual VE\fuel\MS and ignition advance cells.

3. What makes power inside the combustion chamber, air and fuel. If you add water mist into the cylinder, you are taking up critical space where air could be in the combustion chamber. Thus loosing power. Why do rich air fuel ratios make less power (10.0:1 vs 12.0:1) in a piston engine running 93 octane? In the engine running the 10.0:1 ratio it has room for 10 parts of air for every part fuel, and 12:1 is 12 parts of air to fuel. The more air you can controllably burn in the combustion chamber the more power you will make. Now throw water in there some place? Yeah it dose not sound like it belongs there. Just something else to reduce the amount of air, reducing the amount of power that can be made.


The reason why you might be able to benefit from water injection on a factory turbo car is because you are limited on the amount of fuel being delivered; which will result in detonation from lean AFR's. On the other hand you will never run out of spark advance. SO you run the water\methanol injection to reduce knock from lean afr's, but you gain your power from more ignition advance. Which is a band-aid on a pre existing problem.
 
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