Installing camshafts

[Alecci]

Hi mates,

I'll be installing my new camshafts shortly. I'll be running the following items:

TOMEI ProCam 260° Lift 10.25mm Intake Camshaft
TOMEI ProCam 252° Lift 9.15mm Exhaust Camshaft

Is there any work that needs to be done when installing them, or any extra parts that I must (not should) include?

Since I'm putting about £8,500-£9,000 into the car for this season, funds are a little low and amount of time available is even lower. Therefore I intend to upgrade valve springs, lifters, etc only after this year's season is over.

According to my interpretation reading on various sites on the Internet, uprated valve springs and/or lifters are only necessary when going higher than 10.25mm lift.

This can be read about the TOMEI Valve Lifters:

Originally Posted by TOMEI

RB26DETT Valve Lifter
- Height of the base: 1mm
- Small base circle diam: 30
- Corresponding to the TOMEI camshaft of more than 10.25mm lift
- High strength by cold forging lightweight model approximately 32g***65288;STD 33g)

Italic and bold format applied by me.

There are also only valve springs for 10.85mm and 11.50mm lifts available, thus suggesting that uprated valve springs are not necessary to run the 10.25mm lift camshafts. Comment?

Cheers!

/ Alex

[pupsi]

I'me installing Tomei 280 duration 10.8 lift, was advised by almost everyone to change springs and install solid lifters, recommended with these cams. Hope this has helped.

[Mark@Abbey M/S]

All RB26DETT have solid lifters.

If you run anything over the 9.15mm in the TOMEI cam range, lift you need to fit the Tomei Valve springs and the thicker lifter (buckets) as the 10.25mm lift cams have smaller base circles , this is how they get the extra lift.

[Alecci]

Now I'm a little bit confused, maybe it's my crappy language skills... How come I need springs and lifters when there's no springs available for that lift and it's clearly stated that the lifters are for lifts higher than 10.25mm?

I don't mean to be a bitch about it, since I'm in need of help and when such is given I'm very grateful for it. But why these contradictions?

Also, is there any work needed to be done prior to the installation? Someone suggested the camshafts needs shimming (if that's the proper term for it in English)?

[shanef]

What was your reasoning behind chosing a smaller cam for the exhaust side? Really you should be running the smaller cam on the intake.

If your running the 10.25mm lift cam/s, you should (not have to) install the Stage 1 valve springs from Tomei. It's just a bit of premediated servicing, and i dont think youd like it if you developed valve bounce after you installed ur nice new cams

[Alecci]

Originally Posted by tyndago

...

Stock cams have more duration and lift on the intake side than exhaust side.

Stock intake valves are bigger than the exhaust valves.

...

Its harder to get the air in, than it is to get it out.

Mine's run the same config on their car (they have Mine's camshafts though and lifts are a little different).

Originally Posted by Mine's

MINE'S Shore 260° Lift 10.2mm Intake Camshaft
MINE'S Shore 252° Lift 9.5mm Exhaust Camshaft

[akasakaR33]

Just an FYI - the Tomei website (in Japanese) explains the 260/252 set up (their "Type A" cams) thusly: "By setting the exhaust side angle lower, we are able to obtain stable idling and improve response at low/mid speeds. Ideal for those with normal or N1-class turbines."

In contrast, their Type B cams - 260/260 - they claim "by increasing the exhaust cam angle compared to Type A, can have both improved response, and improved peak engine power, even if using mid-size/large-size turbines."

Hope this helps.

[GarethK]

Originally Posted by shanef

What was your reasoning behind chosing a smaller cam for the exhaust side? Really you should be running the smaller cam on the intake.

Most non-jap aftermarket cam setups are longer inlet than exhaust. The standard cam setup is also longer inlet, and higher lift on the inlet than the exhaust. The longer exhaust is a Jap thing I wouldn't be so sure to jump in and follow.

[Alecci]

Instead of creating a new thread I thought I'd just revive this one. I bought the following parts (that applies to the head):

TOMEI Intake Camshaft Pulley
TOMEI Exhaust Camshaft Pulley
TOMEI ProCam 260° Lift 10.25mm Intake Camshaft
TOMEI ProCam 252° Lift 9.15mm Exhaust Camshaft
TOMEI Valve Lifters
TOMEI Valve Springs Lift 10.85mm

Any suggestions to what maximum safe RPM would be?

[nismo1118]

Well what crank and crank pulley will you be running?

[Alecci]

Crank and crank pulley will be standard.

I've been looking for a good alternative for a new lightweight crank pulley, but I've not been able to find one suiting to this season's budget. If you have any suggestions, I'm all ears.

Crank will be balanced, etc after this year's season, and then I'll also install new pistons, conrods, bearings and bolts.

[shanef]

Ross Tuffbound do an aftermarket harmonic balancer, its a bit under half the price of an ATI one too

[tyndago]

When you rev them high , the crank dampeners come apart. We tossed a couple on the GT42R - 2.8 car.

I like the ATI dampener , and SFI approved for racing in the US , the Ross , we could not use in an event.