Rover V8 camshaft

[richb]

rev-erend said:

I've always wondered the question - what makes an engine really rev high..

I understood that the hydraulic cam followers were a limitation which is why a common mod is to swap to solids. ? Rich...

[RichardD]

rev-erend said:

...I've always wondered the question - what makes an engine really rev high....

Have always thought this a bore/stroke thing, ie less stroke and more bore, also suiting lighter vehicles that benefit from more revs and less torque (e.g. motorbikes).

There is a LOT more to it than just this though (if I knew what it was I'd say!).

Doesn't Rob have a race RV8 that will out rev a SP6 ?

[rev-erend]

richb said:

rev-erend said:

I've always wondered the question - what makes an engine really rev high..

I understood that the hydraulic cam followers were a limitation which is why a common mod is to swap to solids. ? Rich...

I have solid lifters..

Should have also added that sufficinent airflow (butterfly) needs also to be large enough..

As for an RV8 out reving an S6 - don't think so..

But I know an RV8 could go to 8K with the right internals and Rob says his 5.5 does rev to 8K..

I could easily see the S6 reving to 9K with the right internals .. easy.

[RichardD]

rev-erend said:

...As for an RV8 out reving an S6 - don't think so..

But I know an RV8 could go to 8K with the right internals and Rob says his 5.5 does rev to 8K..

I could easily see the S6 reving to 9K with the right internals .. easy.

Good point, given the ability to upgrade necessary components, a longer stroke engine is always going to be at a disadvantage.

[v8 racing]

richb said:

rev-erend said:

I've always wondered the question - what makes an engine really rev high..

I understood that the hydraulic cam followers were a limitation which is why a common mod is to swap to solids. ? Rich...

A hydraulic lifter is not really a limiting factor providing you use the correct lifters, a decent set of anti pump lifters will rev to around 8000 rpm, the main difference between solid and hydraulics is on a solid lifter cam you can open the valves much faster, if you try and open the valves too quick on a set of hydraulics the followers would just collapse, so you can still run a long duration and get the revs on a hyd.. cam but you wont get the imediate lift you want like you can with a solid cam

[v8 racing]

rev-erend said:

richb said:

rev-erend said:

I've always wondered the question - what makes an engine really rev high..

I understood that the hydraulic cam followers were a limitation which is why a common mod is to swap to solids. ? Rich...

I have solid lifters..

Should have also added that sufficinent airflow (butterfly) needs also to be large enough..

As for an RV8 out reving an S6 - don't think so..

But I know an RV8 could go to 8K with the right internals and Rob says his 5.5 does rev to 8K..

I could easily see the S6 reving to 9K with the right internals .. easy.

Basically it boils down to having light interals, a good flowing cylinder head, and a small combustion area, and low piston speed ie short stroke cranks, the cam itself helps where peak bhp can be acheived but it is certainly well down the ladder as far as making an engine rev! for instance a rover v8 with a cam of 285 deg will peak around 5500 rpm a suzuki gsxr 1000 with a 285 deg cam will peak at around 12000 rpm!