High RPM From an F4R Engine.

[Michael Woodford MST]

Does anyone know how high you can rev an F4R before the oil pump and crank fail?

Cheers

 

[drhowser]

I'm not sure about the oil pump and crank, but I think you start to see valve float above about 8k.

 

[Jonny1*2]

Solid lifters would prevent that though ^^.

 

[Tony Hunter]

Why rev it that high?

 

[Michael Woodford MST]

Because I'm doing a hi comp build with forged rods and pistons and what to know how safe other parts are at hi revs.

 

[chrispy.clio]

As long as you fit the ARP bolts then you'll be fine reving the b*llocks off it.

 

[Silent_Scone]

Speak to Matt Faulks at TDF. 8k is indeed the limit before float though, oil pumps good for a fair bit more

 

[drhowser]

Solid lifters would prevent that though ^^.

They do, but £££!!

 

[john lloyd]

didnt ktec test a head years and years ago at high rpm for periods circa 8400rpm and the rockers began to break up?

but as above speak to matt at tdf

 

[Jonny1*2]

They do, but £££!!

Isn't everything on a clio

 

[Michael Woodford MST]

I'm looking at revving mine to 8200.

I'm already on the case of having some solid lifters manufactured.

 

[Icarus]

You don't need solid lifters for 8200RPM but what you do need is sensible life on the roller rockers. They don't last long above 8000RPM and 8500RPM is the absolute limit for them. We have uprated ones with a DLC coating that last longer but still only rated for 1000KMs of race use in the S2000 engines.

7800RPM can be done on stock stuff, 8250RPM requires stiffer valve springs and good quality new lifters. Be aware that by increasing the valve spring stiffness you are also increasing the load on the cam drive and as such should investigate if the clamping load on the cam and crank pulleys to ensure they are sufficent to retain positive location as well as what second and fourth order vibrations are present. You will want to keyway both the crank and cam pulleys for sustained used above 8000RPM.

The entire bottom end rotating assembly needs to be balanced to a sensible tolerance (note not crazy money heavy metal weighting type stuff just sensible), the stock crank is fine to 8500RPM but we do a steel one should you feel the need to be £2200 poorer. We also do an uprated steel rotor for the stock oil pump assembly which is safe to S2000 rev limits but you're probably fine on an OEM spec pump to a transient 8200RPM.

 

[Michael Woodford MST]

Thanks mate, that's some really good information. Thank you for taking the time to post

How much are the rockers and oil pump internals? Id rather the oil pump is over spec'd for the application rather than on the limits.

The R.A. Is being balaced at the moment.

Cheers Mike

 

[Icarus]

PM me for prices but not cheap. IIRC the rockers come in at over a grand, DLC coating alone is £350 as essentially they're 32 bits not 16 as the roller and arm require seperate coating operations. Do you really need another 200RPM that much?

 

[Michael Woodford MST]

TBH no. the extra 200rpm isnt be all and end all. But if you could p.m. me the price of the pump internals that would be great!

 

[Fred@BTM]

sub 8000rpm = 240bhp no bother, you don't need anymore than that