What Exactly is the FFF Cylinder Head and Why is it so Good,

[SHARKBITEATTACK]

So I always hear people talking about the FFF1 and FFF2 heads for the speedsix. I've established that it means finger follower free and that it uses buckets instead. Why is this good though? I was under the impression that finger rollers were the best compromise for low inertia and reduced wear allowing high ramp cams and high rpm? For example the BMW S54 used finger followers where as the other inline sides of that era used the conventional buckets...

Was this cylinder head initially something developed by TVR or was it always an aftermarket item?

Any other things that make this cylinder head superior? Flow rates, valve size, heat dissapation, VVT, chamber design, weight etc.?

[nawarne]

You've probably answered your own Q - in broad terms!

Agreed, most current DOHC engines have direct acting cams. However in the (very successful) F1 Renault turbo engine of the 90's (?) they chose to use finger followers to actuate the valves.... As I understand it, the 'fingers' are merely a lever giving increased valve opening for the same lobe profile.

I guess doing away with the followers, you are reducing moving parts and complexity.

The FFF head was entirely developed by Racing Green with the help of a well respected race engine engineer. Several folk on here have got this head on their Speed 6's.

IMHO.
Nick

Edited by nawarne on Tuesday 14th November 09:43

[monty quick]

From what I have read the designers (AJP - engine guru Al Melling along with John Ravenscroft and the then boss of TVR Peter Wheeler) felt that finger followers would offer the highest performance and the lowest height although Al Melling has since agreed that this was probably 'overkill'.
The only problem with the roller finger follower design is that it creates inherent wear on the surface of the finger and the cam and therefore material finishes have to be the very best to provide longevity.
Why the early SP6 engines had problems is still open to debate but later engines were definitely better and I believe the Powers engines (with incredible warranty cover) still use the finger follower design.
The Racing Green FFF design is more like the tried and tested direct acting mechanical bucket systems which arguably introduces the risk of 'flex' in the actuation but avoids the concern of wear.
I have only heard good things about the Racing Green heads.

[Sagi Badger]

The FFF heads have equal combustion chambers, the cast head TVR used cooled asymmetrically and bowed slightly as a result so when machined on the mating face it reduced the capacity of 1 and 6. If you want to raise the compression ratio or reduce pre ignition risk as you advance the ignition timing you need to match the chambers as 6 will be the first to suffer if you don't, it runs hot and will already have a higher compression ratio, slightly, than 3 or 4. If it is a road car don't bother, get the upgraded MBE ECU with knock, not the single lambda offering by someone else, I use a pair of wideband sensors and it shows an imbalance in O2 caused by the throttle bodies when they are half a point out on air volume so don't skimp and run on one!

Inertia is probably less with a standard head as the finger follower only rotates around a point but the whole mass of the bucket of the FFF stops and reverses each time, waiting for someone to do the maths on this but consider that the 4.0RS Porsche has finger followers before you jump to conclusions.

The exhaust manifold is a restriction and really breathing externally, in and out, are the best value mods but these are quick enough cars already and now originality seems to be important in resale so mod with care.

Personally I wont be bothering, I am building another engine over the winter months and will pop a few pics up in good time.

If you want the safe bet for peace of mind and use-ability, go to see Dom at Powers

J

[Clockwork Cupcake]

The FFF2 also has extra oil and coolant pathways, as I understand it. And, yes, it addresses the weakness of #6 cylinder, which is what failed on my first engine and caused me to investigate alternatives and go for the FFF2.

One thing to look out for is premature wear on the buckets, though. Other than that it has been very reliable.

(Apologies for the thread resurrection)

[s6boy]

It's great that these threads get updated for those of us who may need to make the desicion for a rebuild. Currently on 75k and no problems other than what sounds like a sticky valve when cold.

I went along to Racing Green for a demo when they first developed this head. Apart from how much quieter the engine was I was told there was, by design, less wear and therefore cooler running and longer life. Interesting then after a relatively short time your head is showing signs of wear which surely was the selling point in the first place. How are RG addressing this?


ETA: I should have added my head was replaced because of valve wear due to detonation about seven years ago.

Edited by s6boy on Friday 27th July 08:44

[Clockwork Cupcake]

s6boy said:

How are RG addressing this?

Apparently it was a 'bad batch'

They did not address it as it was out of warranty.

[Stunned Monkey]

I posted a little comparison video here which I took during my engine build

https://www.youtube.com/watch?v=SeRezlwQ4Ok

One factoid to note is that unless you also buy RG/TPL's simplex chain upgrade, you can't adjust the tappets without removing the timing cover. And because you can't remove the timing cover without pulling the "harmonic damper" off (it's just another flywheel guys), it's basically an engine-out job.

My blog: fb.com/mys6cerbera

[Clockwork Cupcake]

Stunned Monkey said:

One factoid to note is that unless you also buy RG/TPL's simplex chain upgrade, you can't adjust the tappets without removing the timing cover. And because you can't remove the timing cover without pulling the "harmonic damper" off (it's just another flywheel guys), it's basically an engine-out job.

Are you absolutely sure about that? Because both Lee and I had our timing adjusted on SRR by Woody of TVR101, and for both of us he removed the timing cover in situ in order to adjust the timing on the fly between rolling road sessions.

We both have the FFF2 head, btw. And we both have the Simplex Timing Chain conversion too.

Edit: Oh sorry, I just re-read what you said. You said *unless* you buy the Simplex Timing Chain conversion. Sorry, as you were.

Edited by Clockwork Cupcake on Thursday 16th August 12:24