Engine compression

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normality78

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Guy's,

Other than reffered to manufacture spec list, is there any other way we can tell the actual compression ratio of our engine?
 

gavan

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talking bout compression, is it possible for us to skim the lower part of the engine head or the upper part of the engine block to increase the compression? would it have any side effects? what i meant by skimming here is to shave off just a lil bit of the top and bottom of the block and head respectively to get a clean new flat surface and also to maybe increase a lil of the compression. is it possible to do so?

this is for NA cars btw =)
 

boyzone

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Need to watch out on engine internal parts balancing... and cooling system.
 

vantageX

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gavan said:
talking bout compression, is it possible for us to skim the lower part of the engine head or the upper part of the engine block to increase the compression? would it have any side effects? what i meant by skimming here is to shave off just a lil bit of the top and bottom of the block and head respectively to get a clean new flat surface and also to maybe increase a lil of the compression. is it possible to do so?

this is for NA cars btw =)

Sure its possible. But why would you wanna do this? If its to gain a few BHP then I don't think its worth it in the long run. A lot of things would have to be taken into consideration, like how much of an increase are you gonna get. Even a bit off the top will be a significant difference and if you do so will a standard gasket be able to handle it?

Will your valves have enough clearance and not collide with the pistons. This especially comes into effect if you have an aftermarket camshaft.

As for measuring compression, you can use a compression gauge to check the health of your engine but to get a car's actual compression ratio then a lot of things will have to be measured. All depends on what your final goal is.
 

Doink

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u can skim the head...but there is a limit to how much u can skim...if u skim too much the valve will knock onto the piston...
or u can use a thinner gasket to increase compression..

i did my old car with high compression...by skimming the head...
the benefit of higher compression is improved torque...even at quite low RPM(my old car is 1.5 and can climb steep hill at barely 2k rpm...
 

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