Valve clearance with Kent FT10

Road-race engines and ancillaries - general discussion
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HFStuart
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Valve clearance with Kent FT10

Post by HFStuart » Fri Mar 22, 2013 1:16 pm

I've bought a pair of Kent FT10 Cams (blanks not regrinds) for use in my Lancia Beta Spider 1995cc. They are used but after cleaning they look unmarked.

I have the timing details for them and a pair of adjustable pulleys so that should be OK but the Kent website says to use clearance of 0.008" / 0.2mm both inlet and exhaust. This is obviously tighter than the standard 0.42mm & 0.48mm used by Fiat / Lancia.

What should I set the clearances to ?

Many thanks,

Stuart

(Edit due to typo)
GC 158

Guy Croft
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Re: Valve clearance with Kent FT10

Post by Guy Croft » Fri Mar 22, 2013 1:30 pm

The setting of 8thou cld is correct, yes!

I know it seems weird but running clearances do vary according to the design of the cam!

G
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Guy Croft
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Re: Valve clearance with Kent FT10

Post by Guy Croft » Fri Mar 22, 2013 1:32 pm

The setting of 8thou cld is correct, yes!

I know it seems weird but running clearances do vary according to the design of the cam!

G
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HFStuart
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Re: Valve clearance with Kent FT10

Post by HFStuart » Fri Mar 22, 2013 2:26 pm

Thanks as ever Guy.

I thought that might be the case but best to ask...
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Graham Stewart
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Re: Valve clearance with Kent FT10

Post by Graham Stewart » Sun Mar 24, 2013 1:12 pm

Rather than start a new thread I thought I'd continue with this one, as it does have to do with Kent FT10 cams. They seem to be a bit like busses; you wait ages for one, then two come along together...

Basically I've been offered a set of nearly new Kent FT10 cams, and was wondering how much improvement they would make to a fast road engine. I'm gradually buying parts ready to take the plunge in the near future and this is the tentative spec of the engine (Beta Spider 2 litre):

Raised compression Vick Auto pistons (new, cast) - approx 10.2:1 CR
Ex-Eric Weston EVO Engineering head (Pinto springs) and Vernier cam wheels
GC Cunningham race rods
2 x DCOE 45 Webers with 36mm choke
GC offset Beta manifold
MSD 6AL ignition

I'm intending to get the crank and bottom-end prepped by Guy and don't intend to scrimp on important work, but the top-end spec will be as above.

This engine is purely for road use; I doubt it will ever even see a track day. I'm far more interested in drivability and torque than outright HP. On that basis, would the addition of set of Kent FT10 cams to this mix make a good recipe, or will the standard Beta cams be more than sufficient for my needs? From Kent's own publicity, they say the cams are optimised for power between 2k and 6k rpm, which sounds exactly where I would want the power to reside.

All opinions (especially Guy's!) gratefully received.

Guy Croft
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Re: Valve clearance with Kent FT10

Post by Guy Croft » Sun Mar 24, 2013 2:26 pm

You'd best junk the Pinto springs and get some GC ones...

G
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Graham Stewart
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Re: Valve clearance with Kent FT10

Post by Graham Stewart » Sun Mar 24, 2013 4:00 pm

Guy Croft wrote:You'd best junk the Pinto springs and get some GC ones...

G
OK - I'll do that. Will be in touch shortly to arrange. Are they a straight swap or will I need any other parts? And any view on the Kent FT10 cams?

Guy Croft
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Re: Valve clearance with Kent FT10

Post by Guy Croft » Sun Mar 24, 2013 5:32 pm

The FT10 should be OK, never used it but it's not particularly radical and has the kind of duration and lift you'd want.

I've never used them as I've had my own profiles for years, but I never known Kent (or Piper for that matter) to produce a blank or billet profile that did not work!

GC springs will go straight in, yes.


G
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Graham Stewart
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Re: Valve clearance with Kent FT10

Post by Graham Stewart » Sun Mar 24, 2013 6:13 pm

Thanks Guy. Will call tomorrow re: springs.

FiatRally
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Re: Valve clearance with Kent FT10

Post by FiatRally » Wed Mar 12, 2014 7:51 pm

If I may resurrect this thread?

What is the tightest clearances one can run with standard Fiat/Lancia cams and the Abarth 068 cams?

I have seen people play around with clearances on various engines and all I can understand is expansion of material under operating temperature?

Does the materials used to manufacture the valve train and cams make the deciding factor or the ramp design of the cam?

I have an Alfa 2000 GTV that has a competition engine running very high compression and very nice cams in it. The original manufacturer of the cam is missing in action and no specs on clearances available!

At this stage I am running standard Alfa spec clearances, my gut feeling is to decrease these clearances and reset the cams.

What is the risks and what should I be looking out for?

Any advice would extend my knowledge.

Ernst
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Guy Croft
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Re: Valve clearance with Kent FT10

Post by Guy Croft » Sat Mar 15, 2014 2:55 pm

If in doubt - tight is better than loose.

Loose - the follower will not follow the profile of the opening and closing ramps properly, usually leading to valve float on lift & bounce on closure. Never mind the noise & clatter generated...

Ramps are there to lead the follower progressively into the main lift phase. I have marked the opening ramp on the attached picture.

Of course ramps are designed for particular clearances with engine fully up to temperature. Always better to follow the designer's recommendations if you can get them..

In this case I would say 16 thou" inlet and 18 thou ex with tolerance +/- 2 thou should be ok....

G
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FiatRally
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Re: Valve clearance with Kent FT10

Post by FiatRally » Tue Mar 18, 2014 7:09 am

Thanking you so much!

I will get things moving along now and see what the Dyno reports back after build is complete.

This will be done next week Thursday or Friday.

If my understanding is correct: The sharper the ramp area plot is the more careful one should be with clearance on valve train.

I hope I get time to plot out the cam profile that we have been using on the Alfa engine.

All the best!
GC_75

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