Serpentine Engine?

[chr15w]

I was just looking at a TVR site and noticed referrence to a "Serpentine" engine. Is this good or bad or just a variation of the Rover V8?

[wilf]

It is about the arrangement of ancillary drive belts on the front of the engine.

Older Rover V8 engines used V belts and an oil pump at the side of the engine driven by a shaft running down from the distributor.

Newer engines used a flat drive belt, which is wound around the various pulleys in a "serpentine" fashion. These engines also have the oil pump in the front timing cover, driven directly off the crank.

Similar thing on yank V8s, although they keep the oil pump where it was. Water pump runs in the opposite direction with a serpentine V belt drive.

HTH

[craggle]

On the Rover it refers to the type of drive belt used on the front of the engine.

The earlier Range Rovers and SD1 engines used standard V belts. My 4.2 Range Rover had 4, Vee belts, One for the water pump, one for the power steering, one for the alternator and one for the air con pump.

The later engines used a single multi vee belt which is about an inch wide with 6 grooves running right around the inside of the belt. This single belt snakes it way around all the accessories and drives everything at the same time.

There was two stages of serpentine development. The late Range Rover classics with the 3.9 and 4.2 engines had the same timing cover with a distributor but used the multi Vee belt. The later P38 type 4.0 and 4.6 engines had a different timing cover with a crank driven oil pump and no distributor. The main engine on all these motors is basically the same but the timing cover, Crank pulley and water pumps change according to age.
Serpentine water pumps are also driven from the back of the multi Vee belt so they rotate in the opposite direction to the earlier V belt ones.

And Wilf types faster than me!

Craig.

[Sidecarbod]

You might have issues if you intend to fit a serp engine into a cob, I know on the sumo that there's very little clearance between the front pulley and the chassis even with a non-serp engine. It's pretty close to the steering rack to!

As far as I know (which ain't much) the blocks are the same, you can therefore convert a serp block into a normal engine but it won't be cheap to buy the front cover, pumps etc. The crank nose lengths are different but again it is still possible.

Pete

[lutman]

Originally Posted by chr15w

I was just looking at a TVR site and noticed referrence to a "Serpentine" engine. Is this good or bad or just a variation of the Rover V8?

As already mentioned by previous collegues - the ' serpentine' system is the name of the drive belt system - its more flexible and a flatter belt profile as opposed to the v shape most of us are used to. It was developed by NASCAR racers to be more reliable at higher revs and under higher loads. Downside is the expense - you cannot fit a serpentine belt on standard pulleys, but its a good opportunity to replace the existing pulleys with polished alloy units.

[lutman]

Originally Posted by Sidecarbod

You might have issues if you intend to fit a serp engine into a cob, I know on the sumo that there's very little clearance between the front pulley and the chassis even with a non-serp engine. It's pretty close to the steering rack to!

As far as I know (which ain't much) the blocks are the same, you can therefore convert a serp block into a normal engine but it won't be cheap to buy the front cover, pumps etc. The crank nose lengths are different but again it is still possible.

Pete

You are correct in that it aint cheap - but in most cases there is a direct replacement serpentine pulley and on my set up (non Sumo admittedly) the main crank drive is less than 5mm wider than the equivalent V drive pulley - if the pulley can be seperated from what its driving it can be serpentined. I have not measured it but the serpentine belt is around 15mm wide

[lutman]

Originally Posted by lutman

You are correct in that it aint cheap - but in most cases there is a direct replacement serpentine pulley and on my set up (non Sumo admittedly) the main crank drive is less than 5mm wider than the equivalent V drive pulley - if the pulley can be seperated from what its driving it can be serpentined. I have not measured it but the serpentine belt is around 15mm wide

What a numpty I am !! If you go to my gallery there are some pics of my engine with a serpentine system installed - one pic worth a thousand words

[craggle]

Hi Chris

On the Rover the pulleys are a bit different and can't be dismantled. I always thought the standard Range Rover serpentine system was actually shorter that the Vee belt setup of the SD1 but not looked too closely at it.

Can I ask what make you manifold and throttle bodies are?

Craig.

[chr15w]

Originally Posted by craggle

Hi Chris

On the Rover the pulleys are a bit different and can't be dismantled. I always thought the standard Range Rover serpentine system was actually shorter that the Vee belt setup of the SD1 but not looked too closely at it.

Can I ask what make you manifold and throttle bodies are?

Craig.

You tell me?
TVR GRIFFITH/CHIMAERA V8 5 LITRE ENGINE 15100MILES 1998 on eBay, also, TVR, Car Parts, Cars, Parts Vehicles (end time 06-Aug-08 21:37:08 BST)

[wilf]

If it has been totalled there could be damage to thrust bearings. Always worth knowing just how it got totalled - i.e. the direction of the sudden deceleration.