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Discussion Starter #1
Hi everyone,

I just made a compression test on my engine (opel ascona b - cih 1.6 N (suspected head gasket failure between cylinders)) and I would like to know what are the normal values of pressure for this engine.

If someone can tell those particular values I would greatly appreciate it.

Thank you all :)
 

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THere is no said and fast rule..

170-170-165-155 would be good numbers but so would 120-115-120-110

Anything north of 120 and up to about 180 is normal.. average I see is 145-150 on new rebuilt motors that are pretty stock.

These numbers are PSI ( 150 PSI = about 10.3 bar & 100 PSI 6.8)

No matter the numbers uses as long as the lowest number and the highest number are within 10% your fine.
 
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Hi everyone,

I just made a compression test on my engine (opel ascona b - cih 1.6 N (suspected head gasket failure between cylinders)) and I would like to know what are the normal values of pressure for this engine.

If someone can tell those particular values I would greatly appreciate it.

Thank you all :)
The 1.6 N in the Ascona B is a low compression engine with only 8.0 :1 and 60 hp!
So I think a rate from 9 to 11 bar would be okay!

Norbert
 

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Discussion Starter #5
wow, i'm honestly amazed with this community. you guys are helpfull.

Thank you for all your inputs.

The initial readings in psi goes as follows:

Opel ascona B 1.6N (I think its a N)
Cylinder 1: 140 psi / 140 psi
2: 129 psi /121 psi
3: 119 *at this point, the battery began to fade*
4:108 psi / 98 psi

Those values were probably compromised by the fading battery which died at the end.

I will recharge the battery and try again.

Thanks again.
 

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Opel Tinkerer and Rescuer
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wow, i'm honestly amazed with this community. you guys are helpfull.

Thank you for all your inputs.

The initial readings in psi goes as follows:

Opel ascona B 1.6N (I think its a N)
Cylinder 1: 140 psi / 140 psi
2: 129 psi /121 psi
3: 119 *at this point, the battery began to fade*
4:108 psi / 98 psi

Those values were probably compromised by the fading battery which died at the end.

I will recharge the battery and try again.

Thanks again.
Yes the fading battery can do it..

Overall I hope so as the #4 nyumber is off a lot..

Now sometimes you can have one get really high.. so if they are all averaging 120, but one is 140.. then thats not a real big problem. Just maybe harder to tune.

But if you have a 140, 120, 119 and that last number prove to be accurate then you have issues.

After you get the dry numbers squirt oil into each cylinder and do it again.

IF numbers go up its worn piston rings, the the numbers stay stable.. bad head.

Be sure all 4 plugs are out when testing.
 

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Discussion Starter #7
Great tip GoinManta! Thanks, I will get that battery charged and I will tell you what the numbers were while "wet".

I suspect it is a bad head gasket since the car lost all power somehow and i can fell it working on what I believe are 3 cylinders. A very irregular rumble with an almost impossible to hold idle.
Also there is a brownish bubbly paste in my coolant, so it might have coolant to oil ruptures in the gasket as well.

Another thing I noticed pulling the plugs is that the car ran way too rich.. and to add to the problem, the radiator is "aftermarket" (previous owner) and it's enormous which causes the car to work cold. Since the time I had it, it never even got to the working temp (middle of temp gauge).. :no:

I will soon create a thread so that anyone can follow the repair job. (I am no mechanic, college kid trying to learn something)

:)

EDIT:
I will leave this link as I found some useful info regarding the CIH tunning (compression test values included)
http://www.opelclub.com/TuneUpPart1aJune2006.pdf
 

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Opel Tinkerer and Rescuer
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Great tip GoinManta! Thanks, I will get that battery charged and I will tell you what the numbers were while "wet".

I suspect it is a bad head gasket since the car lost all power somehow and i can fell it working on what I believe are 3 cylinders. A very irregular rumble with an almost impossible to hold idle.
Also there is a brownish bubbly paste in my coolant, so it might have coolant to oil ruptures in the gasket as well.

Another thing I noticed pulling the plugs is that the car ran way too rich.. and to add to the problem, the radiator is "aftermarket" (previous owner) and it's enormous which causes the car to work cold. Since the time I had it, it never even got to the working temp (middle of temp gauge).. :no:

I will soon create a thread so that anyone can follow the repair job. (I am no mechanic, college kid trying to learn something)

:)

EDIT:
I will leave this link as I found some useful info regarding the CIH tunning (compression test values included)
http://www.opelclub.com/TuneUpPart1aJune2006.pdf

Hate to tell you.. may not be the head gasket, maybe the head itself..

Also if you have a charger.. hook up the charger while doing the test. It will help the test be more consistant. Especailly with a weak battery.
 

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Really? Why would you say so?
Because head gasket failures often happen between two cylinders so you should have two cylinders with a *lot* less compression than the other two. Even your weakest cylinder, the only one significantly below the rest and probably influenced by a weak battery, is above what you'd normally see with a blown head gasket.
 

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Can be as simple as a worn lobe on the intake or a bad adjust on the valve(s)
 

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Can be as simple as a worn lobe on the intake or a bad adjust on the valve(s)
True but thats FAR less common on a Opel CIH than a cracked head or bad rings.
 

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True but thats FAR less common on a Opel CIH than a cracked head or bad rings.
I'm not going to argue but adding in that the 1.6 head should be beefier than the 71+ 1.9 heads, I'd not assume a cracked head off the bat.

I've rounded enough lobes and had enough rocker nuts back off to know that there's a good chance that the culprit might not be a cracked head.

Also, for diagnostic purposes, usually the engine won't hold water if the head is cracked. A simple way to fine what's the deal is to run the cylinder to TDC on the compression stroke and add some compressed air into the cylinder. It will tell if it's a valve open, or closed, cracked head, head gasket, rings, or whatever. All you have to do is listen for where the air is going (or not going).
 

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I'm not going to argue but adding in that the 1.6 head should be beefier than the 71+ 1.9 heads,
Actually, the 1.6 heads came out in 1970, so they're really the same as the 1.9 castings. The exception being the spark plug side of the chamber being much thicker. But that's not where they crack anyway....
 
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Because head gasket failures often happen between two cylinders so you should have two cylinders with a *lot* less compression than the other two....
:yup:

For example blown H/G between #2&#3 might look something like this...

#One 150
#Two 50
#Three 50
#Four 160
 

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Discussion Starter #16 (Edited)
Hey guys, I know it's a bit off topic and I've seen a couple of topics on this so and not to create another thread I'll just ask away here.

How do I know if my lifters/tappets are solid or hydraulic? The engine is one of a ascona B CIH 1.6 N and i'm preparing to adjust/check the valve lash, in order to see if that solves the problem previously explained.

Thanks for your knowledge everyone :D

EDIT: From what I've understood from the haynes manual for the B series they are hydraulic and showld be set to 0.30 mm.
 

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Discussion Starter #18


Solid on the left..hydro on the right.
From what I've understand solid are...well, solid, and hydro are 2 piece. But the thing is the engine is assembled and i'm not sure i'll be able to check when they are on.

I thought there were a way of knowing for sure without disassembling the parts.
 

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It's very simple to tell.

 

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