Classic cars forum & vehicle restoration.

[Miken]

Some may not know this.
Adjusting valve clearances can be a bit fiddly depending on the engine.
You might have to wield 2 or 3 spanners plus a feeler gauge all at the same time with awkward access.
However, If the valve adjusters on your old car or motor bike happen to be threaded with a 26 tpi thread then it can become a lot simpler.
One revolution is ( very nearly) 0.040" .
So if you want, say, 0.010" ( typical exhaust clearance on a Triumph motorcycle) you just turn the adjuster to zero clearance and then back off 1/4 turn. Simple. No feeler gauge required.
This is of course exactly how a micrometer measures.
If you want 8 thou, then it's 1/4 turn minus a little bit.

[Penman]

Adjusting valve clearances can be a bit fiddly depending on the engine.
You might have to wield 2 or 3 spanners plus a feeler gauge all at the same time with awkward access.

And if it is pre-war OHV Vauxhall you will have to contend with the fact that the books tell you to do it with the engine running.
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Bristols should always come in pairs.

Any 2 from:-
Straight 6
V8 V10

[Ray White]

Possibly Ford side valve engines were the worst design where you had to grind the valve stems.
OMG.

[badhuis]

I have to adjust the valve clearances on my Lotus engine. I will take it easy and take the time it needs, and write down every measurement. 4 cylinder engine, 16 valves, two overhead camshafts need to be removed. The valves use shims to get the correct clearance.

Years ago I drove my Triumph 2000 big distances every day. I had converted it to LPG and as a result the tappets needed adjustment every week! Very easy to do though, just a big screwdriver, a ring spanner and feeler gauges. After a couple of weeks I had to remove the cylinder head because no adjustment was possible anymore. I had hardened valve seats inserted which solved the need
for weekly adjustments.



Note that the exhaust valves stick out much further compared to the inlet valves (they should stick out the same length). The exhaust valves hammered themselves into the head.
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a car stops being fun when it becomes an investment

[Miken]

[alastairq]

[Ray White]

Hi Alastair. I didn't say it was a difficult job to do, just that in my opinion it was a poor design; not least because the alternative is to grind the valves in further and further so they become pocketed - much like the effect of unleaded petrol on the Triumph engine (above).

Perhaps I have got it wrong. It's been many years since I touched a side valve Ford engine.

[Penman]

[Ray White]

[alastairq]

Simca [and Talbot?] engines of the 70's were fairly tappety engines in my view [Horizon, etc]...

I often wondered whether they had slack tappets , or valve clearances..or whether there was another reason for having such tappety engines?

RAy...I wasn't implying Ford [8 & 10HP engines] were easy to sort.....
After all, Ford spares were cheap enough in their day, and valves would be exchanged out once they got to a certain 'length??

The real difficulties arise when trying to maintain those same Ford engines in this day & age?
When spares prices are not only costly, but with a rarity value as well?

I had real shocks in the learning curve region when discovered there were one or two different valve lengths as well.

Those Ford sidevalves were cheap to make, no doubt. Plus, they were ''naturally'' limited in breathing[as stock] so didn't rev very happily in normal circumstances.
Only today do we come across the difficulties of valve seat recession.

I have a set of aftermarket adjustable cam followers for my Ford sidevalver....
To be honest, they are a pain to adjust, requiring modified spanners, etc. The engine block isn't 'designed' for easy access!!

I am seriously considering reverting back to the original Ford set-up. Having an adjustable follower seems to me to be introducing a potential weak spot in the valve train?
Ford 100E tappets are easier to adjust, being adjustable.
The only issue being getting one's hands down the side of the engine?
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Dellow Mk2, 1951 built, reg 1952.
Fiat 126 BIS
Cannon special [1996 registered. Built in 1950's]
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Ford Pop chassis, Ashley 1172 bodyshell, in pieces.

[bjacko]

Back in the 1960's I took my car in to a garage as the cylinder head gasket had blown. When I went to pick it up on my way home from work I was horrified to see the proprietor and his father adjusting the tappets with the engine running. It had hydraulic tappets which do not need adjustment and for a minute they did not believe me until they realised they were getting nowhere with their adjustments!.
Some time later I had to remove the rocker cover due to an oil leak and was shocked to see bits of metal. What had happened was that during their "adjustments" they had chipped all the push rod cups. It ran perfectly well and I did not do anything about it.
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1938 Morris 8 Ser II Coupe Utility (Pickup)
1985 Rover SD1 VDP

[MikeEdwards]

The slant-four Vauxhall engine is easy enough to do - the cam follower buckets have a cotter-pin and a flexible allen key is used to turn the cotter. Each turn changes the gap by, I think, 0.003".

The biggest problem is the nightmare that is sealing the cam cover gasket onto the cam carrier, leaks around that invariably result in oil dropping onto the exhaust manifold.
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1976 Vauxhall HP Firenza, 1976 Vauxhall Sportshatch (x2), 1986 Audi coupe quattro, 2000 Audi TT

[Ray White]

[MikeEdwards]

I have bought some, but not tried it yet. Not really willing to disturb it at the moment as it's reasonably dry, but I have it in store for next time.
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1976 Vauxhall HP Firenza, 1976 Vauxhall Sportshatch (x2), 1986 Audi coupe quattro, 2000 Audi TT