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Valve Seat Recession questions

Posted: Tue Apr 02, 2024 8:19 am
by Major_Tom
..my car is having trouble starting (again). It does not like turning over, as if the ignition timing is out and it's kicking back. The timing isn't out, the distributor weights aren't sticking. It is suffering from VSR a little though and needs regapping now (I am saving to get unleaded valve seats fitted but for now I'm making do).

My question is.. on a modestly high compression engine, would VSR on a couple of cylinders be enough of an extra factor for the starter motor to struggle to turn it over? Disconnect the ignition and it turns over freely all day long. Connect it and it struggles and kicks back. Not all the time, but bad enough that it kills starter motors.

Re: Valve Seat Recession questions

Posted: Tue Apr 02, 2024 8:22 am
by Paul G
I would say VSR would cause a loss in compression and if anything make the starter spin faster.

Re: Valve Seat Recession questions

Posted: Tue Apr 02, 2024 8:30 am
by Major_Tom
Thanks. Bloody hell maybe my wandering timing issue is back, I thought I'd sorted that :evil: :banghead: :deadhorse:

Re: Valve Seat Recession questions

Posted: Tue Apr 02, 2024 9:19 am
by pbar
Paul G wrote: Tue Apr 02, 2024 8:22 am I would say VSR would cause a loss in compression and if anything make the starter spin faster.
What a great point. I reckon thousands of people have benefitted from your advice and knowledge Paul.

Re: Valve Seat Recession questions

Posted: Tue Apr 02, 2024 9:22 am
by pbar
Major_Tom wrote: Tue Apr 02, 2024 8:19 am (I am saving to get unleaded valve seats fitted but for now I'm making do).
Out of interest Tom, what kind of price range is that?

Re: Valve Seat Recession questions

Posted: Tue Apr 02, 2024 9:50 am
by Major_Tom
pbar wrote: Tue Apr 02, 2024 9:22 am
Major_Tom wrote: Tue Apr 02, 2024 8:19 am (I am saving to get unleaded valve seats fitted but for now I'm making do).
Out of interest Tom, what kind of price range is that?
£40 for the seats themselves, £74 for the machining and about £50 for doing the guides if they need doing.. plus VAT. Cheaper than I thought it was going to be tbh!

Re: Valve Seat Recession questions

Posted: Tue Apr 02, 2024 10:38 am
by pbar
Goodness me that's cheap as chips! Didn't realise it was so inexpensive. Completely pointless using lead additives for years on end then surely.

Re: Valve Seat Recession questions

Posted: Tue Apr 02, 2024 10:40 am
by Major_Tom
Suspiciously cheap 🤔 I thought it was going to be at least twice that.

Unless I misunderstood something.

Re: Valve Seat Recession questions

Posted: Tue Apr 02, 2024 3:06 pm
by pbar
Do it, quick, in case they realise they've missed a zero or two off.

Wonder what the average cost of this typically is.

Re: Valve Seat Recession questions

Posted: Tue Apr 02, 2024 4:27 pm
by Major_Tom
:lol:

Re: Valve Seat Recession questions

Posted: Tue Apr 02, 2024 5:58 pm
by SCP440
That is very cheap, are you sure that is not per valve?
My local guy charges between £350 and £500 for a 4 cylinder head depending on how bad they are. I am sure he said the inserts alone are about £30 each.

Re: Valve Seat Recession questions

Posted: Wed Apr 03, 2024 6:00 pm
by D366Y
I got a quote recently of £240+VAT from a company in MK to supply and fit the valve seats (all 4) - not including new valves if needed etc

I was about to book it in but Phil at Capri Care has thrown me - he has said that he has never hardened any valve seats on any car he runs and never had an issue so doesn't think it is a necessary job to do and more often than not reckons that worn camshaft is more likely culprit for valves constantly needing adjusting

Now I have no idea what the best thing to do is - everywhere you go the information is different

Re: Valve Seat Recession questions

Posted: Wed Apr 03, 2024 6:09 pm
by pbar
D366Y wrote: Wed Apr 03, 2024 6:00 pm I was about to book it in but Phil at Capri Care has thrown me - he has said that he has never hardened any valve seats on any car he runs and never had an issue so doesn't think it is a necessary job to do and more often than not reckons that worn camshaft is more likely culprit for valves constantly needing adjusting
That's very interesting indeed. Certainly, I've known many who just run on unleaded with no additives, for years with no issues.

Are you going to turn your attention to the camshaft then?

Re: Valve Seat Recession questions

Posted: Wed Apr 03, 2024 6:28 pm
by D366Y
pbar wrote: Wed Apr 03, 2024 6:09 pm
D366Y wrote: Wed Apr 03, 2024 6:00 pm I was about to book it in but Phil at Capri Care has thrown me - he has said that he has never hardened any valve seats on any car he runs and never had an issue so doesn't think it is a necessary job to do and more often than not reckons that worn camshaft is more likely culprit for valves constantly needing adjusting
That's very interesting indeed. Certainly, I've known many who just run on unleaded with no additives, for years with no issues.

Are you going to turn your attention to the camshaft then?
For now I've decided to ignore it completely :lol:
Changed the points at the weekend and experimented with a new coil (didn't start the car though so think it is broken) to see if it runs any better, but I haven't adjusted the valves since about December I think and still running fine so am going to see how it goes for the next few months and assess it again...

Re: Valve Seat Recession questions

Posted: Wed Apr 03, 2024 6:45 pm
by pbar
D366Y wrote: Wed Apr 03, 2024 6:28 pm For now I've decided to ignore it completely :lol:
Fair enough, a technique I often use :xd:

Sounds like a plan, good luck with it Danny. Just one thing, if the coil happened to be an Intermotor one, then they are known to be problematic.

Re: Valve Seat Recession questions

Posted: Wed Apr 03, 2024 7:12 pm
by D366Y
pbar wrote: Wed Apr 03, 2024 6:45 pm
D366Y wrote: Wed Apr 03, 2024 6:28 pm For now I've decided to ignore it completely :lol:
Fair enough, a technique I often use :xd:

Sounds like a plan, good luck with it Danny. Just one thing, if the coil happened to be an Intermotor one, then they are known to be problematic.
It was!
Good to know Paul thanks - is there a decent one you'd recommend? I have a Lucas at the moment but the negative connection is rubbish for the condenser

Re: Valve Seat Recession questions

Posted: Wed Apr 03, 2024 7:30 pm
by pbar
D366Y wrote: Wed Apr 03, 2024 7:12 pm
pbar wrote: Wed Apr 03, 2024 6:45 pm
D366Y wrote: Wed Apr 03, 2024 6:28 pm For now I've decided to ignore it completely :lol:
Fair enough, a technique I often use :xd:

Sounds like a plan, good luck with it Danny. Just one thing, if the coil happened to be an Intermotor one, then they are known to be problematic.
It was!
Good to know Paul thanks - is there a decent one you'd recommend? I have a Lucas at the moment but the negative connection is rubbish for the condenser
I can't really recommend one, but I had loads of issues with a brand new Intermotor one, and as I researched it I discovered that others had issues with that make too. So I put the original Bosch one on and have had no issues since. So perhaps buy an original good one if you can.

Re: Valve Seat Recession questions

Posted: Wed Apr 03, 2024 8:24 pm
by SCP440
I have seen engines with the valves so far recessed into the cylinder head they had gone into the water jacket and wrecked the heads.
If it was a Camshaft wearing the valve gap would be getting bigger not smaller.
If you are doing a nominal mileage annually, check your valve gaps every 500 miles you will get away with it for a while.
If you are doing several thousand miles a year it makes sense to get it done.
These engines are a doddle to work on and probably the worse part apart from paying for it will be removing the exhaust manifolds.
If the head has not been removed for a long time the valve guide oil seals will probably be knackered anyway and I suspect the valve guides will be well past there best. If your engine is using oil it is more likely to be getting past the valve guides and seals that piston rings.
The additives do help but are not a permanent fix and add about £5 to each tank of fuel, the only proper way of doing this is to fit hardened seats into the exhaust ports, in a lot of cases you are likely to need some new valves and these do wear where they run through the guides.
You can often save some money getting a head converted to Unleaded by first of all cleaning it and I dont mean a quick wipe with a cloth and secondly striping it down. If you do this label all the parts from which port they were removed from.
I would avoid getting a cheap job on such an important part of the car, if a valve seat falls out or they dont fit new valves or guides if needed it will bite you.
The local engineer I use has done numerous heads for me and not one has had a problem in the last 25 years.

Re: Valve Seat Recession questions

Posted: Wed Apr 03, 2024 9:30 pm
by Major_Tom
D366Y wrote: Wed Apr 03, 2024 6:00 pm I got a quote recently of £240+VAT from a company in MK to supply and fit the valve seats (all 4) - not including new valves if needed etc

I was about to book it in but Phil at Capri Care has thrown me - he has said that he has never hardened any valve seats on any car he runs and never had an issue so doesn't think it is a necessary job to do and more often than not reckons that worn camshaft is more likely culprit for valves constantly needing adjusting

Now I have no idea what the best thing to do is - everywhere you go the information is different
I ran mine with no additive as an experiment to see what would happen precisely because of the conflicting information.

I have a Newman Cams cam in mine and one of my first questions to Peter Newman was, with the uprated valve springs I needed for it, would the lobes wear out quicker? He told me that a chilled iron camshaft will not wear out assuming the spray bar is changed etc. It is.

Mine didn't suffer from closing up valves for a good few years of thrashing. Then 3 started doing it. Then 4. 1 and 2 held out for a while longer, but seems to be closing up too now.

So unless my cam is wearing in a strange way, I'd say it's VSR.

I'd have thought after adjusting the valves a few times in the last few years, some ridge or wear would be detectable on the cam lobes, but I can't see or feel anything unusual.

Re: Valve Seat Recession questions

Posted: Wed Apr 03, 2024 9:33 pm
by Major_Tom
SCP440 wrote: Tue Apr 02, 2024 5:58 pm That is very cheap, are you sure that is not per valve?
My local guy charges between £350 and £500 for a 4 cylinder head depending on how bad they are. I am sure he said the inserts alone are about £30 each.
I'll double check when I call back, but I don't think it was per valve.. I was expecting it to be more though!