From: Noah
Sent: Wednesday, 10 March 2010 2:35 p.m.
To: camshaft@kelford.co.nz
Subject: Kelford 272 Camshaft Questions

Hello,

I purchased a set of Kelford 272 camshafts for my 4G63 Evo IX street car and wanted to know if I need to upgrade my valve train?
Is it overkill to have dual springs and retainers when running a stock framed turbo?
In your R&D did you find that there is power to be had at the high RPM band?
My car has a stock bottom end, so I don't know how well it can handle high RPMs.

Thank you in advance.


Noah

Noah,

The stock spring has very limited valve train control because the cam is aggressive and needs more open pressure to control lofting etc.
People tend to ‘get away with using it’ to a certain extent but with boost and rpm increase combined with the more aggressive cam flank, it is asking for trouble.

We only recommend our beehive spring. NOT a dual spring.


Regards,

Kevin Ban
Managing Director
Kelford Cams & Camshaft Shop
PO Box 7505, Sydenham, Christchurch, New Zealand 8240

100 Mowbray Street, Waltham, Christchurch, New Zealand 8023

P: + 64 3 366 4514 F: + 64 3 366 4515

From: Noah
Sent: Friday, March 12, 2010 6:18 PM
To: camshaft@kelford.co.nz
Subject: Kelford 272 Camshaft Questions

Kevin,

Thank you for the reply!

Why NOT a dual spring?


Noah

Noah,


The dual springs have a lower natural frequency, their own mass working against them.

The beehive chases terminal harmonics further away than a dual ever will.

The KVS63 spring has 73lb on the seat and 200lb at 11mm lift

In high boost applications we use a 2mm spring seat to lift these figures by 20lb


Regards,

Kevin Ban
Managing Director
Kelford Cams & Camshaft Shop
PO Box 7505, Sydenham, Christchurch, New Zealand 8240

100 Mowbray Street, Waltham, Christchurch, New Zealand 8023

P: + 64 3 366 4514 F: + 64 3 366 4515