Ask a Shiter

[Asimo]

It's the UV from sunshine that yellows plastic headlights - on the outside where you can polish it off.

[Lacquer Peel]

Can you buy thermostat o rings on their own? It's a bit skin flint I know but the OE thermostat works fine and is probably much better than some shite hawk pattern part.

[Richard]

I've a feeling Lidl were selling selection packs of O rings this week.

[egg]

It's the UV from sunshine that yellows plastic headlights - on the outside where you can polish it off.

 

I think this on both sides of the reflector.

[Richard]

I know that yellowing lenses on Mk1 Mondeos were blamed on the wrong kind of bulb. I'd be more inclined to blame it on the wrong kind of lens material.

[skattrd]

Can you buy thermostat o rings on their own? It's a bit skin flint I know but the OE thermostat works fine and is probably much better than some shite hawk pattern part.

 

No idea, but what about a bead of silicon type instant gasket around the old one?

Oh, and I agree new thermostats are generally shit. I've had 2 fail in less than a year and think the one I put in the aerodeck in July has died as well.

[Lacquer Peel]

No idea, but what about a bead of silicon type instant gasket around the old one?

Oh, and I agree new thermostats are generally shit. I've had 2 fail in less than a year and think the one I put in the aerodeck in July has died as well.

I'm not sure it'd work unless you get it bang on.

 

Euro Car Parts do the gasket but there are none in stock locally and they charge a fuckton to deliver here.

[rantingYoof]

With cambelt intervals, is the mileage a more important factor than the number of years that have passed?

 

Possible stupid question, as the car has been used less. But for all I know parts can wear out just by being old.

[Pillock]

Both. It can have done zero miles and still be cracked and stiff if it's been sat for years - it's just rubber after all, and you wouldn't go bombing down the motorway on old, cracked tyres.

 

Probably depends slightly on whether it's an interference engine or not though, whether you feel it's worth the risk - one way you've got the inconvenience of getting recovered home, the other way you've got the inconvenience of fishing valve heads from the bottom of the crank case via the big hole in the piston. Ask me how I know.

[rantingYoof]

Yeah, complete inactivity is obviously a bad thing, I was more thinking of a situation where the time interval was about up but the mileage interval was around halfway through.

 

A couple of my cars were well overdue a change in terms of time, but fine for mileage. The Lexus had no history at all, apart from a change 15 years/80,000 miles previous.

 

Why aren't non-interference engines the norm? I'm supposing that they are more expensive to engineer.

[Pillock]

I'd say you're still into dodgy ground, the duration is there for a reason and I wouldn't feel too comfortable going much past it - but then it likely takes into account high stress use such as constant engine off / restarting like in a delivery van or whatever, or being used in the arctic circle or summat - so if it spends every day doing 1600rpm on the motorway, who knows how much longer it will last.

[rantingYoof]

It's one of those things where all debate is instantly rendered meaningless by someone saying "the cambelt lasts as long as the engine does" and you realise that if in doubt, it's worth doing.

[HH-R]

I'm a complete cambelt gambler and have never lost yet, but of course it's a lottery.

 

The car I have now is overdue by 4 years and spends its life doing shitty start stop driving, and judging by the previous owner's mileage it has been for a long time. Maybe being started 8-10 times a day sometimes so I am thinking of getting it done. Sometime. Eventually.

 

I think non interference engines pretty much died out with 16 valves though there are a few exceptions to the rule - less space in ever more packed engine bays?

[Bfg]

Exhaust Wrap - Pros.

 

Last year I had an S-type Jaguar 3.8 ltr (1966) I called 'Flirt '.  Despite bullshit, sorry bar stool, advice - engine cooling is fine on these Jags as long as the cooling system is thoroughly cleaned out and then 50/50 glycol antifreeze is used.  But  that six cylinder engine does heat up the rather tiny engine-bay somewhat.  So..,

 

1. Wrapping the exhaust manifolds keeps the heat within the exhaust system until its out of the engine bay (into the under car air-stream).  Less heat in the engine bay = less heat permeating through the bulkhead and gearbox tunnel into the car's interior.  Heat is of course nice in the winter months.., but those old Jags    tend to be flippin hot in the summer time. 

 

Not much aside from the engine like that much heat, certainly not the battery nor electrics, nor even the fluids, nor any of the rubber & plastic parts :

 

2. six downpipes (or cast iron manifold branches into two downpipes) at 850 degrees radiate a flippin' lot of heat.  6" away from these is the black-painted cast-iron engine block ...perfect for absorbing that radiated heat back into the water jacket.    And just 2" away from the rearmost manifold is the passenger foot-well's bulkhead.. toasty toes.  Then.., 6" -12" away on the inner wheel arch is the PAS reservoir,  wiring & fuse box, etc..  Above the exhaust manifolds is (or rather was on my car) the air filter intake !  Again, just forward of the manifold was its dynamo with the PAS pump mounted onto it ..likewise not liking such excessive heat.

 

3. those that know better than I say that higher exhaust down-pipe temperatures are better for performance / engine efficiency.  So the performance chaps like to keep the heat in the pipes.

 

4. the exhaust's twin downpipes run immediately (3") below the passenger foot well. These also radiate their heat directly through the floor.  Again toasty even in summer time, especially when sitting in traffic.

 

5. noise through exhaust bindings tend to be less intrusive, especially wrapped around SS exhausts which often sound rather tinny.  IMO exhaust note from the tail-pipe is one thing (not least because it's behind me), but I do like a quiet engine bay.  

 

6. I also happen to like the look of the wrapping, when neatly done.  Certainly its much nicer than rusting ones (see below).

 

7. It is very inexpensive, as well as convenient to buy and fit yourself  (no send of exhausts away to be coated).  Anyone wish to share with us how much ceramic coating a pair of Jag XK manifolds + downpipes cost !? 

 

8. I'm sure there are others good reasons..

 

You can decide if any of these might be worthwhile benefits on your particular motor..  

 

Personally speaking.. I'll definitely be doing so on my newly acquired car (a 1974 Shitroen) as I recommission her.

 

Re. holding moisture. Your new exhaust should be protected from rust, if not then they can be coated with an extreme temperature paint before you wrap.  Even if damp - they dry very quickly !!

 

 

'Flirt ' .. my old Jag's 3.8 litre 'slightly revised' engine bay (before lagging) :

[skattrd]

Exhaust Wrap - Pros.

 

1. Wrapping the exhaust manifolds ...

 

Yes, the manifolds, but the rest of the system? and is it worthwhile on a normal car/diesel ZX?

[Bfg]

"Yes, the manifolds, but the rest of the system?  imo., No to the rest of the system, as the benefits of lagging (on a non race engine) are primarily to minimise the damaging or uncomfortable radiant heat from the exhaust to ancillary components in very close proximity, or the interior. Those components of course being in the engine bay.  On the Jag - it's useful to take the lagging back to the first silencer box. Thereafter it's too bloody awkward to efficiently wrap, the exhaust system is in the air stream under the car, and because even the advantages of high temperature gasses being less viscous to push out of the exhaust are nil and void when a silencer box is placed mid-line ..which involves the gases expansion & diffusion within..

 

and is it worthwhile on a normal car/diesel ZX? " When the jag was built - it too was a normal car.!    but..

Catalytic converters are very inefficient until up to their designed operating temperatures, and I understand they don't like cold engine emissions clogging them up, so yes, if the exhaust downpipes are lagged then the system should work more efficiently and cleaner.  On your car's engine / exhaust layout ; I speculate that there's not much in the way of ancillaries to damage in direct radiant eye-line.., aside from the engine block / cooling jacket.  So, if the engine's water temp has a tendency to overheat, then yes.

 

Otherwise, when sitting in traffic on a hot day - Can you feel the heat coming through the bulkhead of your car ?  If so, then again yes.  Conversely, you might easily fit a shield between the exhaust and the bulkhead. This can be done with a metal plate (like the E-Type Jaguar had) or with thermo-lagging sheet material. 

 

At one time I clipped a welder's asbestos (or similar) pad (12" sq x 1/4" thick) onto my passenger footwell's bulkhead, adjacent to the exhaust manifold.  Before fitting I couldn't rest my hand on that part of the bulkhead - even inside the car. Thereafter it was surprisingly cool.  Confirming radiant heat to be the problem and not conduction (engine bay air temperatures) nor convection.

 

Finally, the Jag's oil dip-stick was also close under the rearmost manifold. Bastard place to put it if there ever was one.! Lagging that manifold stopped further burns. If your car has anything similarly dumb design layout - then again why not ?

[Lacquer Peel]

I'm a complete cambelt gambler and have never lost yet, but of course it's a lottery.

 

The car I have now is overdue by 4 years and spends its life doing shitty start stop driving, and judging by the previous owner's mileage it has been for a long time. Maybe being started 8-10 times a day sometimes so I am thinking of getting it done. Sometime. Eventually.

 

I think non interference engines pretty much died out with 16 valves though there are a few exceptions to the rule - less space in ever more packed engine bays?

 

I think that's right, and all diesels are interference engines due to the compressions involved.

 

What car are you playing the cambelt roulette with? My van has a receipt for the cambelt, etc. but not the fitting, I don't know if it was ever fitted, about 60k ago...

[Bfg]

Done quite a bit of research on cam belts last week for my recently acquired old an flimsy-bodied shitroen...

 

Seems that most timing belt manufacturers have a shelf life of 5 years and actually only guarantee their belts for one year once fitted.  However 'Gates' have a shelf life of 7 years and a fitted life of 2 years for their belts..  Naturally when the belt is unopened / untouched in its original packaging - it's not exposed the extreme changes in engine heat nor contamination from oil, dirt, etc.  

 

'Continental' still do belts for my car (a high revving 4-cyl boxer engined OHC) and those I've just bought have a 2019 shelf expiry date on the base of the packaging. 

 

However, because I think they are probably better, and I spotted them at a good price from the same supplier..,  I also bought a set of Gates timing belts (even though they've now discontinued making belts for my car). 

 

A call through to Gary in their technical dept in Dumfries ..and I learn that their belts are date coded on a ten year cycle. And the manufacturing date of my newly bought / now discontinued belt set was either March 2005 or 2015.  As the packaging of my belts is crisp & fresh, and the parts came from a company that trades across Europe, and the rubber feels even more supple than the Continental belts.. then I think it fair to assume the Gates belts I bought were made last year.

 

...Brilliant that means they'll still good (if stored in a cool dark place that's protected from mice) until March 2022.  Though I'll fit the Continentals now  (together with SKF tensioner bearings) and replace those belts in 2 - 3 years with the Gates. The workshop manual says <20,000 miles. 

 

NB. The Gates belts cost £19, so I can't be arsed to even think about risking the engine and all the hassles that would give me.

 

When asked ; Gary (the Tech guy) chuckled at car makers giving really extended change mileages.. simply suggesting I try getting a new engine out of them if or when the belt breaks.

 

On one of these posts, someone suggested that my car's motor was non-interference.  I asked for them to confirm this, as from the workshop manuals I gathered otherwise.., but I've had no reply.  However... whether valves hit each other or the piston or not - I'd still need to be bloody careful because the oil pump is driven off the LHS cam-belt.! 

[D Spares & Tyres]

I think that's right, and all diesels are interference engines due to the compressions involved.

 

 

A 1996 Astra diesel I had was a non interference engine. It was the Vauxhall engined one not Isuzu

[Lacquer Peel]

Maybe non interference by chance, but not by design.

[Asimo]

Looking at this cross section drawing of the Citroen flat-four engine you will see minimal space between the Closed valves and the piston crown; this is typical of "hemispherical" type combustion chambers.

 

Bad things will happen if the cams get out of phase with the crankshaft.

 

[Bfg]

That too was my observation..    Interferance is possibly necessary (?) to achieve an efficient combustion chamber shape with good compression, using this type of valve..

 

Otherwise it's a nice, tidy and efficient engine design..  shame about the plumbing.! Though twin carbs or fuel injection has been shown to loose most of those pipes.   Sometime I'll have a nosey to see how Honda dealt with their Goldwing (similar ?) engine's plumbing. 

 

These engine obviously have a very low c of g., and boxer engines are also compact lengthwise.  This one, being air cooled / no radiator, allows for a very low bonnet line / frontal area. The crankcases and cyl. heads are alloy, the finned barrels are iron. The front panels of the car are removable and so two people can manually lift the engine with gearbox & anxilleries out of the car.

 

Mine is the 1015cc motor (61 bhp SAE @ 6,750 rpm / 53.5 bhp DIN @ 6,500 rpm) with 74mm bore x 59mm stroke. That pretty short stroke / high revving for a 1970's saloon car !  Max torque @ 3,500 rpm. 

 

A bugbear of ownership is that the distributor is mounted directly onto the back end of the LH camshaft - which, with the engine set low down between wheelarches, isn't easy to see into or adjust accurately. So, you take the dissy off and set the points on the bench. There are optical electronic ignition kits now available, but these are expensive. (£240+ for my car). Instead I've bought a Bransden-Boyer ignition unit (under £40 inc. p&p.) which reduces the electrical current through the contacts to mAmps.  As the contacts don't burn away or become pitted - they remain accurately set for years.

 

Oil leaks from the oil return tubes is common on this age (42 years) of car, as the o-rings were rubber. Replacing these for Viton pretty much sorts that out, but to do that - the heads have to come off.  So then it comes down to cam-belts ; every 24k miles (40k km).

 

The famed areodynamically efficient Citroen GS has hydraulic suspenion ..which seems to scare the b'jeepers out of anyone who's not familiar with the set up.  Mine (an Ami-Super) has the beefed up / stiffer version of the 2cv / Dyane / Ami-8 setup, with seperate chassis.  Its front brakes are the same as the 1220cc GS model, and the rear brakes are common to the A-series vans. 

 

oops sorry..,    I'm rambling on here..  Shut up Pete ...go do some work 

 

 

updated 1st March :  I've started a new thread re. my Shitroen

< http://autoshite.com/topic/23665-yugoslavian-ami-continuing-on-from-now-autoshites-flimsy-bodied-shitroen/ >

[bub2006]

Quick question regarding Volvo auto box. The two autos I've had previously were relatively modern ecu controlled boxes on the Vectra and focus. The older auto I gad was the metro and cant remember much of that but the question is the Volvo as very smith changes. Seems to go up gears around 2.5k and unlike moderns it wont go into top fannying about town so it doesn't hunt either. The thing I've noticed is when slowing down you can feel it changing down the box. I think this is normal but hope someone can just clarify!

[Timewaster]

My 2 penorth...

 

Cam belts do not break in service.

 

Water pumps, pulleys, tensioner and idlers seize or snap out go loose or whatever but the fault is never the cam belt.

 

This above came from a gates sales manager and I have no reason to disbelieve him.

[Richard]

I seem to be seeing an awful lot of cars in ditches this winter. Has something changed that makes cars/drivers more averse to staying on the road?

[Lacquer Peel]

Quick question regarding Volvo auto box. The two autos I've had previously were relatively modern ecu controlled boxes on the Vectra and focus. The older auto I gad was the metro and cant remember much of that but the question is the Volvo as very smith changes. Seems to go up gears around 2.5k and unlike moderns it wont go into top fannying about town so it doesn't hunt either. The thing I've noticed is when slowing down you can feel it changing down the box. I think this is normal but hope someone can just clarify!

 

Sounds like an auto box that works properly.

 

I seem to be seeing an awful lot of cars in ditches this winter. Has something changed that makes cars/drivers more averse to staying on the road?

 

Is it the prevalence of modern cars with oversized wheels? If it costs £150 for a tyre from a decent brand you're probably going to go for the £60 "Roadway".

[spike60]

I seem to be seeing an awful lot of cars in ditches this winter. Has something changed that makes cars/drivers more averse to staying on the road?

Folk seem to forget how slippery frozen water is when they haven't driven or walked on it for a while. They'll get the hang of it. Then forget again when it disappears!

[Richard]

I'm sure it's happening more this year than previous years.

 

The budget tyre theory does sound plausible.

[Bfg]

"Cam belts do not break in service.

Water pumps, pulleys, tensioner and idlers seize or snap out go loose or whatever but the fault is never the cam belt.

This above came from a gates sales manager and I have no reason to disbelieve him."

 

With such confidence, why then not put a 5 or 10-year guarantee (after fitting) instead of two ? 

 

I have replaced timing belts in the past because the rubber had cracked, polished and otherwise showing signs of wear and perish.  

 

Must admit my Chrysler Voyager shred the teeth off it's ancillaries belt, but that was due to the A/C pump suddenly seizing, I'm told because I never used it.!?  Bugger was that the alternator is driven by the same belt and so it all came to a standstill in the middle of Norfolk, in the middle of the night.

[scaryoldcortina]

I've never seen a cambelt fail in service either. I've seen plenty of shed or snapped ones, and ones that ripped out at the crank pulley but the root cause is always something else, never the belt.

 

I have seen an engine that stood for many years break a belt while cranking, but it was a pinto so it survived.