Do I Need To Do Any Headwork I I Want These Cams?

[TP_]

Hello!

Yesterday my Tomei inlet poncam broke during installation, it seems that it already had some cracks before it chopped off totally.

I´m in discussion with some sellers, and it seems that the Poncams can´t be bought separately (1 cam), so i have thoughts of buying the HKS 272dur 10.2lift step 2 cams to my engine. But ive read that there has to be som headwork done, i thought that it would be fine if i change the valvesprings to HKS ones for max. 10.2mm lifting. Is there anything more that has to be done?

I´m looking for much high end power, and here´s my engine spec. Going for bigger injectors and turbo next winter when i have finished the "break in" period for my new engine. Nearly everything is new, expext for the poncams, wich of there now more is only 1.

Head&exhaust:

Tomei Poncams 260/9.15

Tomei cam pulleys

Nismo timing belt

Greddy exhaust

Custom downpipe/midpipe stainless

Custom manifold (hks copy)

ARP bolted head

Tomei 1.5mm mls headgasket

Garrett GT35R (GT3582R) with .64a/r exhaust housing

Pipercross breeather filter

Apexi 4row intercooler

Tial wastegate 44mm

Tial bow 50mm

Fuel&Ignition:

Nismo 600cc injectors

Nismo fuelpump

Autronic SM2 with cdi iginition

Bottom&cooling:

R34 GT-R -02 engine block -87mm newly drilled and horned

CP pistons weight adjusted and balanced

Verdi rods weight adjusted and balanced

Hardened crank, balanced

Tomei oilpump &restrictors in head

Tomei Buffelplates

ACL Calico coated main&rod bearings

The oil pan is extended with 1.9 liters

N1 waterpump

HKS oil radiator

HKS oil relocation kit

Greddy oilcatchtank

Exedy 2 disc clutch

//Tompa from Sweden

Edited July 16, 2008 by TP_

[TP_]

No one?

[R31Nismoid]

With a .64 housing, big cams are a waste.

The housing will restrict power, not the cams/head

[dano4127]

With a .64 housing, big cams are a waste.

The housing will restrict power, not the cams/head

Yeah but he said he is going bigger later on, you wouldnt buy cams to suit a turbo your changing soon anyway...

[rb26s13]

you can actually buy a single pon cam you dont have to buy a pair. email dan at erd [email protected]

[TP_]

I have decided to go for poncams again, but i´ll buy both inlet and exhaust new. This time with the 260 degree exhaust cam, instead of the 252 which i have now to have some more high end power.

Thanks for the answers!

[Adriano]

I would also get a cam stud kit, to prevent the new cams snapping due to incorrect installation technique.

[saliya]

I´m in discussion with some sellers, and it seems that the Poncams can´t be bought separately (1 cam), so i have thoughts of buying the HKS 272dur 10.2lift step 2 cams to my engine. But ive read that there has to be som headwork done, i thought that it would be fine if i change the valvesprings to HKS ones for max. 10.2mm lifting. Is there anything more that has to be done?

I have these same cams; yes, head clearances for the cam lobes needed to be adjusted (I use the HKS springs too).

Apparently there's not room for the cam to rotate without clearancing.

There are other cams with a smaller base circle but similar lift that do not need clearancing (the lobe's final rotating radius is smaller).

You probably want uprated springs with any lift over 10mm but I'm sure there are people running higher-lift cams without them.

Regards,

Saliya