gonna comp. test my engine tonight

[FD3SNuttah]

hi i bought a compression tester on the weekend. before anyone says i should have done it before i bought the thing then obviously i know that now, but it pulled like a good un so didnt bother.

wish me luck lads. I will post the results on here later.

Oh before i break something, i might as well just double check..

1. REmove EGI fuse
2. REmove the trailing sparkie
3. Plug the tester in
4. Get an assistant to floor the accelerator and crank the engine
5. look at gauge and press the valve in on the side so that it "bounces" read it three times.

-- anything above 6 bar will do nicely??

7. Do the other rotor..

[asp]

wen i did mine,like ur goin to do,the readins where alot lower than the readins i had from carl,i think ul find no2 is leadin plugs:D

[FD3SNuttah]

cheers mate! just to confirm the leading sparker is the lower one?

[bnaellis]

I think you\'ll find comp test will differ quite a bit form depending on where your car goes. Don\'t ask me why?

rgds

[FD3SNuttah]

Originally posted by rotaryimports.com
I think you\'ll find comp test will differ quite a bit form depending on where your car goes. Don\'t ask me why?

rgds

im not taking it to anyone, im going to do the test myself with a tester i bought off ebay for £12.50! God i hope i dont get a crap result otherwise that car is gonna hurt my feelings as well as my wallet!

[asp]

Originally posted by TURBOIINUTTAH
cheers mate! just to confirm the leading sparker is the lower one?

yes

[Grizzly]

Does it make any diffrence? Are you doing it hot or cold?

[Carl]

You must do the test in the top plug holes,the trailing ones.
The reason for a disrepancy in comp testing with a piston engine tester is that you are having to bleed some some compression by holding the release in to get seperate readings.
The test should allways if at all possible be done when hot.
Regards
Carl

[asp]

oh my god,4 some reson i though it was the leadin,
what a plonker,:eek:

goes off all:o

[FD3SNuttah]

ASP - lol i was pretty sure i was right the first time,

I didnt get to do it last night, got home from work and had my tea and then found that the battery was flat! hopefully it will have charged fully by the time i get home today. I will post up what i found out...

cheers for all the help lads!

[FD3SNuttah]

ok car isnt running right so had to do the test cold...  I think i need new plugs cos i inspected them and they are pretty much shocking! i have some on order and hopefully they will arrive tomorrow...

i will do the test again when its warm.

anyway here are the cold results

the needle was bounncing just over 6 bar on both rotors but didnt quite reach 7 bar, it was moving pretty fast so i let it cycle like four times (one cycle being all three faces) on each rotor.


ok some more questions..

am i right in assuming i will i get a lower result when im doing it warm cos of the expansion when the engine metal warms up?? if so whats the typical amount of drop?

also whats the minimum pressure you can have before it needs a rebuild? am i right in saying that "minimum" is when it stops workin lol?

thanks in advance guys..

[nikp]

am i right in assuming i will i get a lower result when im doing it warm cos of the expansion when the engine metal warms up?? if so whats the typical amount of drop?

No, I believe you should get a higher result when it\'s warm, as them oil flows better, therefore lubricates better, therefore allows the apex eals to move more easily, and therefore allows them to create a better compression better.

Right?

[FD3SNuttah]

No, I believe you should get a higher result when it\'s warm, as them oil flows better, therefore lubricates better, therefore allows the apex eals to move more easily, and therefore allows them to create a better compression better.

hmm, i thought i read it somewhere on here that it was the other way round,. ie you get less compression when its warm! not to worry there is only one way to find out!! unfortunatly that wont be until the weekend.

thanks again everyone.

[asp]

i got over 1bar when the engine was warm

[FD3SNuttah]

i got over 1bar when the engine was warm

nevermind! i had to edit what i wrote, cos then i realised what you meant,

i will do the test anyway but im satisfied i havent bought a lemon, now all i gotta do is fix the missing/lumpy idle issue!