Differences between 3.6 and 4.0?

[ukkid35]

What are the most important differences between the two engines as standard from the factory, and the differences assuming one rebuild to resolve valve train issues?

[Sagi Badger]

Crank, rods, pistons are the mechanical differences

[spitfire4v8]

There are several permutations of rods and pistons but essentially it's extra capacity from a longer stroke. Red rose and S models got bigger (cerbera 4.5) injectors. 4 litre S and red rose cam timing different to std 4litre.

If you were a bit closer you could have come up, I have both a 3.6 and a 4litre in build at the moment so you could come and have a look.

Edited by spitfire4v8 on Thursday 1st October 08:16

[glow worm]

From a drivers perspective and I'm no expert but I was under the impression a 3.6 needs to rev higher to achieve the same BHP because of the shorter stroke, also the torque will be less at low revs and fall off quicker at higher revs. Some expert will come along and correct me if I'm wrong.

[ukkid35]

spitfire4v8 said:

If you were a bit closer you could have come up, I have both a 3.6 and a 4litre in build at the moment so you could come and have a look.

Thanks, much appreciated

The friend of mine who introduced me to Cerbs has just bought a 3.6 Tamora

I don't understand the strategy behind the 3.6, since as far as I can tell it was introduced after the 4.0

So additional production costs incurred to create a 'detuned' 4.0, how does that work?

[monty quick]

If you are planning a rebuild I am sure the best advice is to talk to Dom - I haven't heard a bad word and he can talk you through 'standard' 3.6 and 4.0 plus his own 4.2 & 4.5 options.

I think the 3.6 design was for a very 'free revving' engine and 'ample' power.
'Stroked' engines will always give a different (better??) torque curve but will be less happy to rev.

I have a standard 3.6 and have driven a red rose 4.0 and (on the road) really couldn't tell any difference. I am assured Dom's 4.5 changes the character of the car a lot and provides a noticeable power gain.

[900T-R]

The 3.6 has a different crankshaft, but the same con rods - in a typical move to reduced parts cost they used one con rod with an elongated casting where the small end goes so they could drill the hole for the small end in two different places!

This also means the balance of the rod is upended as the small end is heavier than the big end...

[ollyh1988]

I had a 4.0 first and now the 3.6. As a previous post said, the 4.0 felt like it had slightly more torque low down, but the 3.6 makes up for this by being much more eager to rev. It felt a bit ‘sportier’ to me but it is a minimal difference.