valve stem seals

[sixtwoeight]

44 minutes ago, Bigj66 said:

Can you get composite gaskets for the 4 pots as you can for the V8? Might be slightly more forgiving of slight surface variations once you’ve given the block a clean although I’ve seen worse than what’s in your photos before. These old engines are quite resilient.

Thanks, good to hear, I may have a chance then.

8 minutes ago, Bowie69 said:

As its an iron head and block, hit it with a wire brush in a drill (or grinder if careful), that will remove most skunge very quickly.

Rust is 50 times greater in volume than the iron that forms it, so I reckon you have a good chance of seeing that good enough to work again.

A head skim it not pricey BTW, 30-40 quid would do it.

Excellent, seems the consensus is going the same way.  So we all know how il be spending tomorrow.
£40 for a head skim is fine, but then id have to do the block as well really which I really don't want to be removing and stripping that as I know it will throw up more issues and then probably rebuilding at more expense.

Thanks to all replies, much appreciated.

[lo-fi]

Just one last thing. A cheapo way back of checking the block for cracks is seat it upside down and level, fill the combustion chambers with petrol. If it leaks out, you've got a problem. It'll either run through a crack or through a badly sealing valve. Can also be done right way up and poured into the rocker space. 

Keep us posted, looking forward to seeing how you get on, and the beasty running. Good luck, and may your elbows never run out of grease 

[Peaklander]

Just to make you smile whilst you’re doing it, many years ago I had to clean up an Ali head from my car once when I was working on a site in contractor day is cabins. Encouraged by the older guys I took the glass out of our cabin window and used it as the flat together with grinding paste. It worked and the head was refitted and the glass  put back in the window frame too.

A few days later the boss came to visit and was courious about the window with opaque swirls. I daren’t say anything but the others said it had been done for privacy. 😀

[sixtwoeight]

2 hours ago, lo-fi said:

Just one last thing. A cheapo way back of checking the block for cracks is seat it upside down and level, fill the combustion chambers with petrol. If it leaks out, you've got a problem. It'll either run through a crack or through a badly sealing valve. Can also be done right way up and poured into the rocker space. 

Keep us posted, looking forward to seeing how you get on, and the beasty running. Good luck, and may your elbows never run out of grease 

Thanks, that's a good tip for the head and I will definitely do it.  Elbows still have some grease left at the moment, if I can still type by the end of the weekend il report back.

2 hours ago, Peaklander said:

Just to make you smile whilst you’re doing it, many years ago I had to clean up an Ali head from my car once when I was working on a site in contractor day is cabins. Encouraged by the older guys I took the glass out of our cabin window and used it as the flat together with grinding paste. It worked and the head was refitted and the glass  put back in the window frame too.

A few days later the boss came to visit and was courious about the window with opaque swirls. I daren’t say anything but the others said it had been done for privacy. 😀

Good story, thanks for that.  Made me smile!

[Gazzar]

We've all done it the wrong way, out of necessity or ignorance. 

 

We forget when it works but remember the disasters, and so when we see someone going down the same route we offer our experiences.

Try it, if you get away with it, great!, nothing ventured and all that.

And, those old cast iron engines are robust, a good gasket can solve a lot of problems.

 

Have fun. And well done for bringing another one back from the grave.

[lo-fi]

I've also successfully filled divets in gasket surfaces with chemical metal epoxy type stuff before 

You have to make sure everything is scrupulously clean, and opened up to get enough epoxy in to be able to bind, but it can work well. I can't vouch for absolute longevity, and the same applies as above, but it saved me £2000 worth of new rotor housings on my RX7. Ali corrosion had taken chunks out of the coolant seal faces, which you can't TIG as there's a steel liner pressed in right next to it. You can't even have them skimmed or they end up too narrow and there's no side clearance for the rotors, so you're well and truly snookered. I cleaned out the mess with a die grinder, applied the high tech goop and flattened using the glass method above. It worked a charm for the five years I had the car after that. 

Also chuckling at Peaklanders story above. Brilliant!

[AV8R]

7 hours ago, lo-fi said:

I've also successfully filled divets in gasket surfaces with chemical metal epoxy type stuff before 

I regularly use Devcon F for repairs upto 120 ºC or Devcon Ti for upto 170ºC. Normally not on engine repairs but I did a repair on a RRC oil pressure sender mounting once. The original threads in the front casing were cracked and a replacement piece was bonded on with the engine in situ. The secret is like Lo-fi mentioned: clean, clean and clean again.

[sixtwoeight]

Took the valves out the head and the seals were very hard and brittle and crumbled, also some were missing the little spring that goes around the top of the seal??

Mine also has double valve springs, which I always thought was a performance thing but did some searches and found the following statement...

"This is one of the reasons why I realised the head had been fitted with the wrong valve stem seals - the inner spring rips the new style valve seals to pieces. The correct seals for Ciggys engine should have been O rings down the stem tube. My old Series 3 2.25d was a later engine with single springs and the later stem cap seals. I assume this is normal".

So if that is correct does that mean the wrong seals were fitted to mine and in which case the seals I have bought are wrong?  Or is that possibly just a diesel thing??

There is a little bit of play in the valve guides but I don't know how much is too much.  Has anyone replaced their guides - I looked on Turners website and it says they need reaming to size after fitting but have also found threads were a bloke in his shed (like me) has fitted new guides and not mentioned having to ream to size..

Any ideas?

[sixtwoeight]

Looking at the valve springs and the seal I can't really see that there will be a problem with compatability between the 2 but definitely interested to know either way.

[sixtwoeight]

Pictures of the seals.

Missing springs in seals

Used a piece of glass with wet and dry taped on the rubbed away...

So a before and after

As far as  I can tell with a piece of glass and my feeler gauges the head is within 0.1mm ( 4thou I think)  - is that acceptable??

The block also got the same treatment and is within the same tolerance.  Were they ever perfect when new??

 

Edited May 12, 2018 by sixtwoeight

[AV8R]

I would be happy if everything was within 0,1 mm. If torqued up gently the cast iron head is quite able to form itself to the block.

[Bigj66]

I very much doubt the original factory tolerance was anywhere near 0.1mm 😐

You’ve done a good job there and should have confidence that with a decent gasket the engine will run fine. Good luck with the rest of the rebuild.

[lo-fi]

Double valve springs were common on older engines of all types, often to overcome resonance issues. Modern winding and material tech have largely removed the need, though you're right that double springs are now used in performance apps. 

If you can feel significant play with a bit of oil on the stem, it's probably out of spec. I've seen people fit new guides with nothing more than an oven and some freezer spray, but also a lot of failures too. They should be reamed to finished size after pressing in as they'll get compressed by the interference fit. Reaming also assures a round hole. You've then also got to look at the valve seating too as it's not guaranteed the old seat grind will be concentric with the new guide. A modern technique I've seen used at a rebuild shop is to accurately through drill the guide and fit a sleeve, which is cheap and easy. If someone has a scrap head you can have, have a go at pulling a guide and see if it's something you want to tackle, maybe? 

A look in a parts book might verify you've got the correct seals for that type of spring. They've certainly seen better days, haven't they! 

Great work on the gasket surfaces! I'm sure there's a spec in the BGB - I'll check for you tomorrow. 

[sixtwoeight]

Thanks for the help and encouragement, couldn't be doing this without your input.

So the valve stem seals...

Looked on a parts catalogue online and it seems to show a different seal - more like an O ring with the double valve springs.  I typed the part numbers of the O rings into google and one came up as superceded (ETC4709 originally, superceded ERR1510). The other one didn't say superceded but pictures of the later type of seal popped up - from this I'm thinking I can use the later type.  If you think I'm wrong please shout.

I also checked the valve stems in the guides after I wiped them dry, so maybe if I oiled them they might feel a bit tighter.

[lo-fi]

Sharing knowledge; that's what we're all here for It's turned into a really interesting thread! 

Oil will just take the rock out of a couple of thou. Exhaust valves usually have a little more clearance. 

I can't see any problem with the later type of seal. 

By the way, oven cleaner will do a smashing job of cleaning the gunge off the valves.

 

[sixtwoeight]

Im glad its interesting and hopefully it will help others in the future.

 

Had another good look over the head and noticed a depression in one the core plugs (I think that what they are?), so had a poke and opened up a hole in 2 of them.

Are these just pressed in?

Edited May 13, 2018 by sixtwoeight

[lo-fi]

Yeah, pressed in with a bit of sealant. A good find, that would painful after putting it back together. They're an interference fit, but I don't know the specs I'm afraid. Have a good look at the ones in the block too. I remember someone in here that did core plugs himself... Maybe Western? They're not expensive to get done at a machine shop, though. You've saved a ton of money on other jobs! 

The BGB isn't terribly helpful and doesn't list a spec I could find for head or block flatness. If you can get it down to 2 thou without a huge amount of work, go for it, but I'm sure that'll be fine. 

[Gazzar]

Core plugs tap in with a socket, and a smear of sealant. Satisfying job. 

[rtbarton]

I had a leaky core plug of the kind shown above and fixed it by fitting another core plug inside it.  IIRC the 2nd one was one of the slightly dished types which spring flat when you hit them with a hammer & drift.

[sixtwoeight]

Thanks lo-fi, Gazzar and rtbarton.  I'm glad I found that, it would have been painful indeed!

I have a gasket set with a copper head gasket in, but will order a composite one, taking the advice from this thread that the composite ones maybe a bit more forgiving.

With a thin film of oil on the valve stems the valves felt much better with virtually no detectable sideways slop - so they will stay for now.  The valve seats are not the best to be honest, I gave them a light grind, which will have to do for now.  If the work ive done only lasts for a few thousand miles il be happy, if and when that time comes hopefully I will have forgotten about my feelings I have at the moment and be in a position to spend a bit more money on it again.  I know its a false economy but needs must.

Good idea with the core plugs with fitting one inside the other, il have a measure tomorrow and see what I can find as looking at the usual suppliers and the parts book on line I cant find what I need for some reason.

[AV8R]

44 minutes ago, sixtwoeight said:

Good idea with the core plugs with fitting one inside the other, il have a measure tomorrow and see what I can find as looking at the usual suppliers and the parts book on line I cant find what I need for some reason.

You will be the first to know if the old plug will stay put when you hammer in the new one inside it . . . . . . . . . .

I would not take a chance on it and work the old one out. It's not much work to do it proper now and fit the size that belongs there, that will most likely be easier to get.

As Lo-fi said, check the ones in the block too. They are probably the same vintage.

[Gazzar]

It is an easy job. Screw in a self taper, use a claw hammer to pull out the core. 

Drift in the new one with a socket to fit in the recess.

When I did my TDI I found a 6 inch long slug of silicone in the gallery, so do take the time to have a poke around for odd stuff. 

G.

[rtbarton]

OK if there's enough meat for a self-tapper to grip.

Another one I removed I made a tool similar to this:

Drill a hole in plug, slide the slot into the hole and pivot on the heel.

[Gazzar]

Perfect. Many ways to skin a cat .

Chisel at one side so it pivots, vise grips to remove, etc, etc.

[sixtwoeight]

Gutted 

Finally had time to put this back together and its no better.  I honestly thought it was going to be ok, I was happy with how I did things ( yes I know it was the wrong way) and was meticulous in re assembly and keeping it all clean.

Problem is I know the block and head aren't perfectly flat, so no point in just doing the valve guides, but then it could be rings?(compression test seemed ok - only did it cold), so need to get this done once and for all but without ending up doing a full engine rebuild.

So if anyone has a reasonably good engine that doesn't smoke that they'd sell me please shout, 2.25 petrol or even a 2.5 as I believe its a straight swap?

A very disappointing day all in all.