[mitch32]

Hello,

As title says, I ordered the intake and exhaust 270 Procams with 10.25mm lift. My machinist (doing a 3 angle valve job) said he's going to have to make shims because of the valve job, I'm guessing he can just make the shims bigger to account for the small base circle of the cams. Is this advisable?

Also would it just be more simple to just cancel the procams and order HKS step 2 10.20mm lift cams with hks step 2 springs. I'm on a budget so I want to do cams and springs (no retainers or buckets).

Thanks,
Mitch

 

[Chris Wilson]

If they are small base circle cams you need the extended tappet buckets. A (much) deeper than stock shim will be potentially unstable and may flick out. I can't remember above what lift the cam lobes foul the head casting at the sides of the buckets, and need maching, as I have about 4 different engines on the go at the moment. You may need to relieve at 10.25 mm, I know at 10.8 mm I definitely had to. There's no such thing as a tuned RB on a budget

 

[[email protected] M/S]

10.2mm lift TOMEI,s will run in a STD head due to the small base circle,s but you def need the thick buckets and the springs to go with these.


Mark

 

[mitch32]

Thanks for the info. I actually decided to go with the Poncams in the end and tomei springs. After speaking to my tuner he said I'll keep better midrange and response with the poncams and some porting. The porting will cost more then the lifter buckets but I'll have around the same power but with better response (vs the procams/buckets/springs with no porting).

Mines R34 is said to be extremely responsive and have 620bhp with HKS2530 turbos and they run 260 dur 9.5mm lift cams (which are similar to the poncams). So I figure this is probably a better choice in the end. I really wanted to get the Procams cause they make some amazing noise, and I'd have better dyno numbers but the poncams are probably the more logical choice. It also seems almost everyone running HKS2530 or GT2860-5 turbos, run tomei poncams (if not stock cams). Hopefully I made the right decision.

 

[JD74]

Mines R34 is said to be extremely responsive and have 620bhp with HKS2530 turbos and they run 260 dur 9.5mm lift cams (which are similar to the poncams).

The Mine's Stage 2 Engine is what you are thinking of...and it uses unmatched Int/Ex camshafts.

Check it out here (10.2/260 Int, 9.5/252 Ex.):
Mine's COMPLETE EINGINE / RB26DETT

I doubt for a second that the Mine's Time Attack R34 uses that setup. Ever see the Vids ? it idles ROUGH.

Mine's 'response' way of tuning has more to do with Big Lift/Short Duration/Small Turbine and is most likely using somthing like THIS on their Time attack R34 (or a variant of):
Mine's SUPER CAMSHAFT SHORE PRO II

.....but we will never know the exact details, atleast I think anyways.

 

[Marko R1]

If they are small base circle cams you need the extended tappet buckets. A (much) deeper than stock shim will be potentially unstable and may flick out. I can't remember above what lift the cam lobes foul the head casting at the sides of the buckets, and need maching, as I have about 4 different engines on the go at the moment. You may need to relieve at 10.25 mm, I know at 10.8 mm I definitely had to. There's no such thing as a tuned RB on a budget

my head required relieving for the increased lift - im running 10.5mm