Lister ST2 Engine advice

[vindyboy]

Hi All,

 

Please can I get some information on Lister ST2 engine.

 

I have just had the inlet valve guide replaced,. It was done as a favour. When the head was returned it had a rubber o ring which he did know where it came from. Since found out it is the valve guide seal. Apparently it should be held in place a seal retaining plate. I have downloaded a manual but I cannot work out where it goes. Any advice will be much appreciated.

 

Thanks.

[Boater Sam]

Garbled post, can you re send then we may understand what you want?

[Stilllearning]

Do STs have valve stem oil seals? I can’t remember.

[Boater Sam]

He said valve guide seal. Its too confusing to be able to help.

[vindyboy]

2 hours ago, Boater Sam said:

Garbled post, can you re send then we may understand what you want?

Sorry, you did not understand.

 A new Inlet valve guide was fitted to the head because original guide was damaged. When I got the head back with the new guide fitted the person who fitted it gave me a small o ring. He said he did not know where it came from. To remove the guide he submerged the head in hot water and removed the old guide.

 

I downloaded the lister ST repair manual and looking at the picture in the manual it shows the o ring. According to the manual it says it is Valve  guide seal, which fits under  seal ring retaining plate.

My question is where does the seal ring and plate fit .

 

I have added scan of the manual page I am referring to. I cannot see where the seal fits, and there certainly was no retaining plate.

 

Hope this helps.

 

 

[bizzard]

The seal seals the outside of the valve guide and is held down by a plate which is in turn held down by the valve spring.

[vindyboy]

Magic, makes sense now. Problem is there was no retaining plate when the valve spring was removed. At a guess seal must must have been there and either came off when the head was put into the hot water and may have fell off or when the old insert was pressed out. Perhaps the engine had work before and the retaining plate not fitted because it was not there.

[bizzard]

3 minutes ago, vindyboy said:

Magic, makes sense now. Problem is there was no retaining plate when the valve spring was removed. At a guess seal must must have been there and either came off when the head was put into the hot water and may have fell off or when the old insert was pressed out. Perhaps the engine had work before and the retaining plate not fitted because it was not there.

Where did he find the sealing ring.  When I find my manual I'll stick a photo up of the arrangement. Watch this space.

[vindyboy]

Quote

 

Really not sure. He is away for a few weeks so I can't ask sorry/

[bizzard]

3 minutes ago, vindyboy said:

Really not sure. He is away for a few weeks so I can't ask sorry/

No 7 is the seal and No8 is the plate. I should I think be held down with a couple of screws. The plate straddles both valve guides.

[vindyboy]

Excellent, thank you very much. All clear now.

There was no retaining plate when valve spring was removed. I will have to source one.

Thanks ever so much again.

[TheBiscuits]

 

2 minutes ago, vindyboy said:

There was no retaining plate when valve spring was removed. I will have to source one.

Try these lot, they are more reliable than random forum members

http://www.mes-midlands.co.uk/

[vindyboy]

1 hour ago, TheBiscuits said:

Quote

 

Try these lot, they are more reliable than random forum members

http://www.mes-midlands.co.uk/

Okay, thank you. I will give them a try.

Thanks again

[RLWP]

3 hours ago, bizzard said:

The seal seals the outside of the valve guide and is held down by a plate which is in turn held down by the valve spring.

Is it? I think you'll find it is the O ring that goes between the top and bottom halves of the head

 

Richard

[vindyboy]

Please can you be a bit more specific. The head has not been separated. Only the inlet valve guide was replaced.

 

Thanks,

Jeff.

[bizzard]

59 minutes ago, vindyboy said:

Please can you be a bit more specific. The head has not been separated. Only the inlet valve guide was replaced.

 

Thanks,

Jeff.

Its some while since I had one of these to bits. I don't remember there being an O ring seal trapped between the heads two halfs, where RLWP suggests. The two halves of the head are held together by the valve guides. The seal around the guide under the plate as per my photo is under the inlet valve only.  If the chap actually separated the two halves he would almost certainly have noticed a recess for a trapped seal between them if there was one. 

[vindyboy]

I know he did not separate the head.

He told me he submerged the head in hot water and drifted out the old guide and inserted the new one.

He gave me the seal saying he did not know where it was from.

If it was from inside the head as you suggest I thought head would need to be separated for it to have come out.

As I said earlier when the spring and valve was removed there was no seal ring retaining plate fitted, I guess the seal could have been in place and might have come off when the old guide was pushed out.

I am going to get a replacement seal retaining plate.

 

 

[john.k]

The O ring fits in a recess at the top of the guide bore in the rocker compartment(  called "top part of the head  here) and stops oil running down the outside of the guide into the head proper and blocking the fins...........IMHO,far more important is the valve spring seat  (called retaining plate) as it stops the spring going out of square ,and maybe even interfering with the adjacent spring...............get a replacement,if you cant buy one,get one made on a lathe...I have a couple of these motors,but no spares....but you can still buy spares from Lister Petter.

[vindyboy]

Thank you for your opinion. Same as bizzard suggests.

 

I am going to get a replacement retaining plate.

I have emailed a couple of suppliers but not had a reply yet.

 

Thank you for your advice.