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Discussion Starter #21
Hi Everyone, replace 2 valves , same issue, knocking head cylinder. Remouve again head cylinder 2 valves still stay out . I need To rebuild entire cylinder or replace by à new one if I can find. Still work To do. N
 

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Are the valves bent or is the problem something else?

You should always tear down & inspect a cylinder head before reinstalling - have a good machine shop check valves, guides, surface, etc.
 

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Discussion Starter #23
Are the valves bent or is the problem something else?

You should always tear down & inspect a cylinder head before reinstalling - have a good machine shop check valves, guides, surface, etc.
Hi,

New valve, when you make a cycle by turning with a key the camshaft the exaust valve stays out and dont return totaly back in the guide. I can replace valve lifter or guide but that s going to cost a lot of money if I replace all set. Thanks . N
 

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Greg

I'm not sure from your description but I think you have some stuck hydraulic tappets (the valve lifters that sit on the cam) and these may be what are keeping the valves from closing.

If you look at the whole cam-lifter-valve interaction, the only things that can keep a valve open when the timing gear rotates are:

1. A stuck cam (broken cam shaft or the drive sprocket is loose) the valve is kept open by the cam lobe
2. A seized cam follower/hydraulic tappet. This is either stuck in the bore it sits in, or it is fully expanded and cannot let out enough oil to allow the valve to return.
3. A seized or obstructed valve. This can be a bad valve guide, bent valve stem or a physical obstruction in the valve seat (I have seen small nuts dropped into the inlet that stuck in the inlet seat!).

You can see if the cam is broken by rotating the sprocket and checking all lobes along the whole shaft are moving.

Pulling out the cam followers will allow you to check them either being stuck in their bores or failing to contract.

Obstructed or bent valves can be checked with the cam removed and simply compressing the valve spring to see the full range of valve movement.

My guess is the followers!

Let me know if you need anything (I have a couple of used complete B205 cylinder heads I have spare) and would be happy to supply what you need at a very sensible cost.
 

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Discussion Starter #25
Greg

I'm not sure from your description but I think you have some stuck hydraulic tappets (the valve lifters that sit on the cam) and these may be what are keeping the valves from closing.

If you look at the whole cam-lifter-valve interaction, the only things that can keep a valve open when the timing gear rotates are:

1. A stuck cam (broken cam shaft or the drive sprocket is loose) the valve is kept open by the cam lobe
2. A seized cam follower/hydraulic tappet. This is either stuck in the bore it sits in, or it is fully expanded and cannot let out enough oil to allow the valve to return.
3. A seized or obstructed valve. This can be a bad valve guide, bent valve stem or a physical obstruction in the valve seat (I have seen small nuts dropped into the inlet that stuck in the inlet seat!).

You can see if the cam is broken by rotating the sprocket and checking all lobes along the whole shaft are moving.

Pulling out the cam followers will allow you to check them either being stuck in their bores or failing to contract.

Obstructed or bent valves can be checked with the cam removed and simply compressing the valve spring to see the full range of valve movement.

My guess is the followers!

Let me know if you need anything (I have a couple of used complete B205 cylinder heads I have spare) and would be happy to supply what you need at a very sensible cost.
Hi, thanks for this expertise and knowledge. I go step by step from your advise to qualify. Thanks . Are you base in thé US. N
 

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Discussion Starter #29
Hi, no I don't have all that. With the situation I m enable to do work shop for investigation , I 'm block at home. Thanks . N
 

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  1. Hi, do you have a picture of the headcylinder, mileage. N
    I can probably get you pictures over the weekend. Mileage may seem quite high (but not for a Saab) at 123,000 (that is miles not Km) but it was on a good engine that ran well, just the turbo was smoking.

    In the meantime, BobSaabit has shared the ESSENTIAL links for the WIS and EPC. If you are isolated at home it is great time to download them and to explore two fantastic resources.
 

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Discussion Starter #33
Greg

I'm not sure from your description but I think you have some stuck hydraulic tappets (the valve lifters that sit on the cam) and these may be what are keeping the valves from closing.

If you look at the whole cam-lifter-valve interaction, the only things that can keep a valve open when the timing gear rotates are:

1. A stuck cam (broken cam shaft or the drive sprocket is loose) the valve is kept open by the cam lobe
2. A seized cam follower/hydraulic tappet. This is either stuck in the bore it sits in, or it is fully expanded and cannot let out enough oil to allow the valve to return.
3. A seized or obstructed valve. This can be a bad valve guide, bent valve stem or a physical obstruction in the valve seat (I have seen small nuts dropped into the inlet that stuck in the inlet seat!).

You can see if the cam is broken by rotating the sprocket and checking all lobes along the whole shaft are moving.

Pulling out the cam followers will allow you to check them either being stuck in their bores or failing to contract.

Obstructed or bent valves can be checked with the cam removed and simply compressing the valve spring to see the full range of valve movement.

My guess is the followers!

Let me know if you need anything (I have a couple of used complete B205 cylinder heads I have spare) and would be happy to supply what you need at a very sensible cost.
Hi , I'm blocked at home for a long time with no access to my Saab. Can you send me pictures of the headcylinder and possible price. I got one at Ferrari garage near Paris , but I have to 3 hours work to take it out and I m not sure if in good conditions. Thank. N

  1. I can probably get you pictures over the weekend. Mileage may seem quite high (but not for a Saab) at 123,000 (that is miles not Km) but it was on a good engine that ran well, just the turbo was smoking.

    In the meantime, BobSaabit has shared the ESSENTIAL links for the WIS and EPC. If you are isolated at home it is great time to download them and to explore two fantastic resources.
Hi, yes I will do , I have no chance the Saab in not near , if not I will plenty of time to rebuild the engine and the Saab. N
 
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