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View Full Version : Cylinder compresion test. Expert Help!!



locote
01-05-2006, 06:57 PM
i got 200psi at all 4 cylinders its a stock B18B.
Thats the norm for a 160 000 k motor????

LowEk
01-05-2006, 07:09 PM
as long as they are all round the same not much diffrence its all good.

newmski
01-05-2006, 07:15 PM
200psi is quite normal but as mentioned variation (5% or more) between cylinders is not good.

dsp26
02-05-2006, 09:31 AM
^^^as above

however, if you have a lower CR in 2 adjacent cylinders its most likely a a blown HG.

but it sounds like you got perfect 200 an all 4. thats awesome for a 160k motor. at least it shows you take care of your ride.

Slow96GSR
02-05-2006, 10:49 AM
200 all across is great. Up at this sea level we get 160-170's. As long as they are almost all the same then you are good. Now do a leak down test and see what you come up with there.

ECU-MAN
02-05-2006, 07:28 PM
yeah dude as above

for an engine that age, your doing really well.

SiR JDM
02-05-2006, 07:33 PM
Ive never had one of these done. How much roughly would it cost? How much extra is a leak down test?

locote
02-05-2006, 07:38 PM
I had a mate do it.
What is a leak down test???
ill be turboing the motor in a month thats why i tested it.

dsp26
02-05-2006, 07:42 PM
Ive never had one of these done. How much roughly would it cost?

goto supercheap and pay $20 for a cylinder compression tester. get one that has the extended hose with multi size screw end.

-disconnect lead that goes from dizzy to coil (either ground it or make sure its not near anything as it will spark)
-take plug out one at a time.
-screw tester in properly
-hold throttle at WOT and crank a few times
- take the reading down and repeat on the other cylinders


200 all across is great. Up at this sea level we get 160-170's
for the B18B stated above?? man i didn't realise altitude played THAt much of a diff???

yourfather
02-05-2006, 11:37 PM
well, I have between 170 and 180 psi and my motor has done 170k

So doing good dude!

CUL8R
03-05-2006, 12:02 AM
lol i wanted to get one of these done, but im super scared if something was wrong itll cost me a couple k for a rebuild lol! i think ill have this test done in about 2k time.

Slow96GSR
03-05-2006, 06:29 AM
... for the B18B stated above?? man i didn't realise altitude played THAt much of a diff???

At this alt we lose 30% of our power. That's why we do F.I. and very little N/A/ tuning. You can't get much on a N/A motor here. For every 100 feet you lose something like 1-2 hp and at 5000 feet, that's a butt load. I'll have to check. I don't really remember exact numbers, everyone here know so I don't have to explain it much!!

The less air you have due to pressure, a.k.a. thinner air, the lower the actual compression is. Also the thinner oxygen doesn't burn as much/hot/fully/whatever you want to say, and so we run F.I. to get it up. At this alt don't even have to lower the comp ratio of the pistons to run boost unless you want to go really high. I have to have many maps for my ecu, one at each alt. It's not that bad since it takes like 30 seconds to load a new one. It's what you have to do to run a car nationally. There are a few people here with n/a cars but they don't get too high until they spend a lot of money, 10k-15k+ USD, some times less but not to often!



On the main topic, a cylinder leak down test puts compressed air in to the cylinder at TDC and checks the valves, head gasket, and rings for leaks. It measures based on a percentage. You hook it up just like a compression tester but you add the air compressor line to it. Read this (http://www.geocities.com/dsmgrrrl/FAQs/leakdown.htm)! Should help you all!

dsp26
03-05-2006, 08:39 AM
^^^oh yeah forgot about air pressure. and yeah i just saw USA under your avatar and didn't notice Colorado till just now lol so yeah now i gets.

as for the leakdown/compression test. better to get it done sooner than later before it gets worse.. dont take it as bad news. for all you know a slightly lower compression in 1 cyl could just be a stuck valve it carbon buildup etc...

Slow96GSR
03-05-2006, 11:04 AM
Also if 1 (or 2, or 3, or if all 4 cylinders are gone you're not going anywhere.) cyl is dead, the others try to make up for it. Makes it ware harder on the motor too. Fix things before they break, if you can't, fix them as fast as you can. It will cost you more in the long run if you leave something damaged or broken for when you "have" the time and money. If you fix it later you may end up buying/paying more to fix the problem... brakes are that way 99% of the time when people don't fix them when that annoying squeal starts. Also that squeal make you look poor and like you have a P.O.S. car!!

czy_sol87
29-05-2006, 12:59 PM
i got a b16a2 with about 190k on the clock
and my compression test showed
155, 150, 160, 160
isnt vtec engines surpost to have high compression
can anyone help me out, would it be time for a rebuild or recondition?
and i wanna run boost later on so would it be worth saving up for a rebuild setup that can run boost safely, or would it be better to rebuild back to stock and then get a bolt on kit running low boost??
thanks for any help

dsp26
29-05-2006, 07:30 PM
i got a b16a2 with about 190k on the clock
and my compression test showed
155, 150, 160, 160
isnt vtec engines surpost to have high compression
can anyone help me out, would it be time for a rebuild or recondition?
and i wanna run boost later on so would it be worth saving up for a rebuild setup that can run boost safely, or would it be better to rebuild back to stock and then get a bolt on kit running low boost??
thanks for any help

whereabouts you located, if someone here with an FSM could check their B16 book for tolerances then you should be sweet... at this stage i'm not sure if those figures are OK....

These are tolerable figures at AMERICAN SEA LEVEL
Stock b16a with 93k miles:

cylinder 1: 181
cylinder 2: 185
cylinder 3: 195
cylinder 4: 195

Taken from:
http://www.hondacivicforum.com/m_91564/mpage_1/key_/tm.htm#91846

panda[cRx]
29-05-2006, 09:31 PM
These are tolerable figures at AMERICAN SEA LEVEL


lol isn't sea level the same everywhere?

it is the same world wide, it doesnt have height variances, it's not like thre are mountains of water :confused:

dsp26
29-05-2006, 10:07 PM
^^^bah thanks for the pickup... i meant altitude in general as discussed above by Slow96GSR and myself :p

czy_sol87
29-05-2006, 10:19 PM
im from melbourne, im not sure but does the altitude here have anything to do with it?

spanks
30-05-2006, 11:22 PM
The leak down test will give you a much more accurate view of engine condition..there are some variables in compression testing such as battery voltage that can affect readings..is good for preliminary testing but not the test to really establish engine condition

czy_sol87
30-05-2006, 11:24 PM
The leak down test will give you a much more accurate view of engine condition..there are some variables in compression testing such as battery voltage that can affect readings..is good for preliminary testing but not the test to really establish engine condition
thanks for that, i'll get the mechanic to do a leak-down test, when i get my major service done

dan_lee
03-06-2006, 06:22 PM
can any mechanic do a leak down tesT?