VR Timing Chains Replace at mileage or on condition? Discuss

[coullstar 0]

Was a little paranoid about going to look at a high mielage VR this week but its had the chains etc done 3k miles ago, Im happy now.

[mariojoshi 1]

An interesting read....

 

Mine makes a bit of noise when you first start her up, but I'm not sure why exactly. It dies down pretty quickly though?!

 

My VR is on 96k and I've been thinking the clutch might be on the way out for a while, so obviously it makes sense to do the chains that the same time.

However, since I'm going forced induction and I don't want to be bolting on 90bhp to a standard old engine, I'm having the big three done at stealth before the vortech even looks at the engine bay.

 

If you're going FI without doing a rebuild.. you're asking for trouble IMHO!

[dinkus 10]

Just for reference my chains were on 157000 miles,

Quiet as you like but the top pad was f**ked, through the polymer and both top rivets were long gone.

Only way is visual inspection.

 

Ouch :(

 

An interesting read....

 

Mine makes a bit of noise when you first start her up, but I'm not sure why exactly. It dies down pretty quickly though?!

 

My VR is on 96k and I've been thinking the clutch might be on the way out for a while, so obviously it makes sense to do the chains that the same time.

However, since I'm going forced induction and I don't want to be bolting on 90bhp to a standard old engine, I'm having the big three done at stealth before the vortech even looks at the engine bay.

 

If you're going FI without doing a rebuild.. you're asking for trouble IMHO!

 

The older VRs tend to make a clattery piston-slap type noise when starting from cold (sounds bit like a diesel engine) - there's nothing you can really do about it, but it will go away when the engine's warmed up.

 

The tappets are also hydraulic (i.e. filled with oil), so old ones can take a while to properly fill up and thus rattle, or they could also not be filling quickly due to old oil and/or oil pump... :lol:

 

Paranoid much yet? :D

[was8v 0]

My take on it is the tensioners go through 3 phases:

 

1) The tensioners are quiet when new in normal operation (to 80k+ miles)

2) Then the tensioner pads wear away and you get the distinctive rattle of the rivets contacting the chains.

3) Once the rivets are gone the noise goes and the car sounds normal.

 

Once you just get into phase 2) (pref before) you need to replace just the tensioners as they could break up.

If you are in phase 3) replace chains as well as the rivets may have worn the chain / deposited bits of metal in the chain.

 

Obviously when you buy a used VR without history of tensioner replacement it might be quiet and you don't know if its in phase 1) or phase 3) so it wise to pull the covers off and inspect.

 

 

 

 

As an aside:

 

Deraileur geared push bike chains are VERY different to the chains on your engine - they are designed to flex horizontally to allow you to change gear - its a VERY crudeley engineered solution and consumes chains in use. As the chain has to flex in so many directions they are relatively weak and they stretch over time, which in turn wears the cogs into a sharper profile. By the time you notice the stretch in the chain it will have worn the cogs a little, hence why its best to replace the cogs too. Most amateur road racers I know use a new chain every competition.

 

Chains on motorbikes and push bikes without deraileur gears like BMXs (or hub geared bikes like Rohloff etc) do not have to flex in the horizontal plane and don't get dragged accross cogs so can be made much stronger so do not suffer from stretch so much. The main cause of wear IIRC in a motorcycle chain is from particles getting between the plates and pins of the chain and causing wear. This is because the chain is exposed to the elements. Hence why motorcyclists can get away with just changing the chain and cleaning the cogs regularly. Chains on motorcycles will stretch due to the relatively large load of driving the vehicle, but over a much longer period of time than geared bike chains.

 

The load of driving the cams in an engine is not so large so cam chains do not tend to stretch due to load. Also the cam chain is in a controlled environment so particles can't get between the plates and pins of the chain wearing it (as on motorcycle chains). This is why manufacturers say the chain doesn't need changing - its rather over engineered for purpose. Just look at the picture of a chain posted above and compare to the average cambelt doing the same job on other V6 engines!

 

Change the tensioners in time and as long as no foreign bodies conflict with the chain it will last a lifetime.

 

 

(obviously this post comes with no guarantees its just my opinion so don't blame me if your chain freakishly snaps for no reason :nuts:)