Loose Timing Chain

westOz74P6B

westOz74P6B

Member
Having just overhauled the fuel pump, I noticed through the front cover that my timing chain was quite loose with not a lot of tension in it. i am thinking this need looking at pretty soon as (not having a workshop manuel yet) I don't think there are any tensioners on this chain? so this would probably be my noise I am hearing the chain maybe hitting against the front cover? Also would I be right in thinking I can get to it after removing the front aluminium cover while leaving the engine in place (but removing the radiator for easier access?)

Regards,
 
There isn't a tensioner, and as you say the chains can wear and get slack, leading to the chance of the chain jumping, which will bend some of the valves. Best to replace the chain and gears sooner rather than later.
You will need to remove the front timing cover, and removing the rad makes this easier. Ideally you should remove the sump as you will break the gasket, but if it's an auto that means removing the downpipes and probably snapping the studs, so you can just fit the front portion of the gasket. Manual cars the sump comes off without touching the exhaust so it's worth doing the whole job properly.
 
thanks harveyp6, looks like this job is now top of the list, as you say I'll drop the exhaust (new one recently fitted, so studs/nuts should be ok) so as to fit a new sump gasket as this is weeping at the back and fit new chain and whatever else needs replacing (seals, etc) while I'm there. also the power steering pump is weeping and as that has to come out of the way I'll attend to that as well (and new belt for p/s pump while the chance is there as it looks awkward to replace otherwise).

Regards,
 
If you're in a position to be able to get at the chain, (in other words the timing cover is off) I can't see the point in not replacing it, along with at least the cam gear, unless it has been recently replaced in the past. They do wear and jump, particularly as the cam gear is only plastic. Steel ones are available and are a good upgrade.
Once the chains do get slack you can often see the ignition timing floating about when you set it with a strobe.
 
The standard Morse type timing set fitted to the V8 really only has a useful life of around 30,000 miles (50,000km). After that the amount of slack in the chain starts to effect camshaft timing...retarding it, which edirectly effects engine power and fuel economy. I really only became fully aware of this last year, when I had some major work done on my P6B, the engine being removed and dismantled. THe nylon toothed timing wheel only had one :shock: yes one :shock: tooth left. All the others had broken off, only jaggered stumps remaining. If the chain had slipped, then a valve and piston would have attempted to occupy the same space simultaneously :shock: . Not a pretty picture.

Full steel sets in various forms are available, and are vastly superior to the original.

Ron.
 
Here are some photos of the nylon toothed timing wheel and Morse chain set that were removed from my 3.5 litre engine. My Rover is a 1974 model, and at the time of removal the engine had covered just over 203,000 miles (327,000km). Engine oil was always changed every 2000 to 2500 miles.

As it was, the engine was still quiet and beautifully smooth, just really down on power.

Ron.

F1000008.jpg


F1000011.jpg
 
Good Grief! I ain't going anywhere in mine, only into the garage to fit a new steel gear and chain set, now that I have one, from; www.triumphroverspares.com.au (or, info@triumphroverspares.com.au) $130.00 delivered (the website indicated they were on special) from South Australia (to WA) a RollerMaster steel (CNC machined) gear wheel set and true roller type chain. Now that I've just finished in the garage working on my Mitsubishi Starwagon it's, out with the new and in with the old.

Regards,
 
didn't know cam gear was plastic! good grief. have 1974 35o auto and its showing under 38K which is assumed a true mileage as it coincides with old MOTs and 13 year lay up.
my car suffers low power and poor idling with cutting out at lights or when pulling away. Despite changing plugs , dizzy cap.rotor arm and upgrading to electronic ignition. fuel pump upgraded with electric facet pump. new filters and tank checked .cleaned etc coil connections tight. no visible shorts or chaffing on wiring.
looking thread here about cam gear , I am wondering if my car has a slack chain too? maybe even dodgy teeth?
as only way to check this is with a strip down, will have to wait until spring a moving home soon and won't have time to work on car for months. did compression test and though not terrific are all thing 10% values of high to low .so assuming clyinders and valves are good.
:shock:
i see we can buy new cam /chain sets so that isn't a problem. I cant see why a chain tensioner has not been devised and fitted ? surely this ought assist greatly? have the engines been re engineered for this ? if so there must be amid for older V8 units. ( hopefully) :eek:
 
classicalgreen wrote,...
have 1974 35o auto and its showing under 38K which is assumed a true mileage as it coincides with old MOTs and 13 year lay up.
my car suffers low power and poor idling with cutting out at lights or when pulling away. Despite changing plugs , dizzy cap.rotor arm and upgrading to electronic ignition. fuel pump upgraded with electric facet pump. new filters and tank checked .cleaned etc coil connections tight. no visible shorts or chaffing on wiring.
Click to expand...

My Rover's original timing set in the photo above had 203,000 Miles on it, and yet my engine behaved nothing like yours. No cutting out or rough idling, so I would suggest that the problem that plagues your engine is elsewhere.

The Rover V8 engine was never modified to accept a chain tensioner.

Ron.
 
I reckon the chain's too short to need a tensioner.

this is mine (a video) before I replaced it with a Croyes one from Real Steel

MOV_0525[1] by 1275midget, on Flickr

As harvey said, I borked my sump gasket and now it leaks :(
 
Cutting out at the lights sounds like it might be fueling related to me. I would recommend looking for vacuum leaks and a check of float levels and carb balance before panicking about the timing. Especially with the low mileage, I can`t imagine the chain would be too bad.

classicalgreen said:
didn't know cam gear was plastic! good grief. have 1974 35o auto and its showing under 38K which is assumed a true mileage as it coincides with old MOTs and 13 year lay up.
my car suffers low power and poor idling with cutting out at lights or when pulling away. Despite changing plugs , dizzy cap.rotor arm and upgrading to electronic ignition. fuel pump upgraded with electric facet pump. new filters and tank checked .cleaned etc coil connections tight. no visible shorts or chaffing on wiring.
looking thread here about cam gear , I am wondering if my car has a slack chain too? maybe even dodgy teeth?
as only way to check this is with a strip down, will have to wait until spring a moving home soon and won't have time to work on car for months. did compression test and though not terrific are all thing 10% values of high to low .so assuming clyinders and valves are good.
:shock:
i see we can buy new cam /chain sets so that isn't a problem. I cant see why a chain tensioner has not been devised and fitted ? surely this ought assist greatly? have the engines been re engineered for this ? if so there must be amid for older V8 units. ( hopefully) :eek:
Click to expand...
 
You must log in or register to reply here.
Back
Top