Jump to content
SAU Community

Recommended Posts

Yet another question,

Tomei 260 in/ex 9.15mm lift camshafts for RB26 should be a direct bolt in and then you just adjust the clearances? There shouldnt be any machining work required? (keeping in mind the head has already been machined to take large lift camshafts).

Thanks :P

Link to comment
https://www.sau.com.au/forums/topic/53584-tomei-poncan-rb26-info/
Share on other sites

Yet another question,

Tomei 260 in/ex 9.15mm lift camshafts for RB26 should be a direct bolt in and then you just adjust the clearances? There shouldnt be any machining work required? (keeping in mind the head has already been machined to take large lift camshafts).

Thanks :P

I'm pretty sure they are designed to drop straight in. The head doesn't even need to be machined. Technically, if valve clearences were right before changing the cams, they should be right after you drop in the new cams too.

Valve Guide clearance:

The vale should be approx 15mm from valve guide hole into combustion chamber you can measure it by using a dial guage. - If thats what your were talking about ?

You'll proberly need to adjust the timing on a cam gear for the cams to work properly. The RB25 ones bolt up and are perfect with out adjusting but the RB26 do need adjusting with cam gear.

Dont forget the seals for the camshafts.

If you are installing the valves your self were safety glasses and gloves because the exhaust valves a filled with metal lic sodium and if exposed to eyes you can have eye dammage.

:P

Jun

you will almost certainly need to re-shim them depending on the age of the car and the wear on the original cam shafts. because there will be wear, you can't simply measure the clearences of the original cams then make the assumptions that when you fit the new ones that they will be the same. They almost certainly will not be.

You have to do a dummy fit with the new cams then check all clearences, calculate any shim adjustments you may need to make> get any new shims you may need as a result of your dummy run, dismantle dummy run and fit new shims then recheck. This is a very time consuming process that took me and a fully trained nissan A grade mechanic 2 weekends to complete. I needed 11 new shims and had them made in a machine shop and heat treated to 50 rockwell hardness. Was well worth the result though with the engine now running very smooth with no valve noise as start up like I used to get cos clearences are all perfect. Boost ramps up by 3500rpm now and pulls hard to 5000rpm were I am now having boost creep problems due to excessive back pressure from the now restrictive turbine. It can't handle the air flow the engines putting through now so I am going to remove the turboes and machines out the little GTR wastegate holes into big holes to help the exhaust escape and minimise backpressure.

So you see, cams are great but can cause other problems down the road. It seems the GTR was built to a certain spec and has limitations once you start pushing things along a bit ..

Mike

poncam means bolt in in japanese and i fitting these cams in a matter of a few hours check all my clearances f.....g spot on the japans know how to make good gear ,the car ran 500 plus at the wheels and has run happierly ever sence, Amaru dont let these guys scare you it not like performing brain surgery and hope you enjoy the new cams god knows me rev210 are :D

pnblight thanks for that, they were put in and found out the clearances were all wrong for the camshaft, im putting that down to general wear and tear on the engine.

The Alchemist, thanks for the info, exactly what I was after

:D

I put my cams in last night without a shim, checked clearences (spot on). My engine has more than 230,000kms as well (engine well serviced). Go Tomei poncams!!!

Base circle diameter is the same on both the factory cam and the tomei replacement this is the ONLY factor. If you need shims for the tomei you would have/should have needed them for the factory cams.

The 260deg 9.15mm lift units are mint ! :D

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Even more fun, leave all the ADAS stuff plugged in, but in different locations, hopefully avoid any codes!   And honestly, all these new cars with their weird electronics. Pull all the electronics out Duncan, and just shove an aftermarket ECU and if needed a trans controller in, along with a PDM. Make it run basic but race car styled!
    • To follow up a question from earlier too since I had the front bar off again (fking!) This is what is between the bumper and the drivers side wheel And this is the navigator side, only one thing but its a biggy! So basically....no putting coolers in the wheel arches without a lot of moving other stuff. Assuming I move to properly race prepping this car I'll take that job on and see how the computers respond to removing a whole bunch of ADAS modules
    • So I prepped the car for another track day on Wednesday (will be interesting to see coolant temps post flushing out and the larger reservoir, with a forecast of 3-14 being 20o cooler than last time I took it out). Couple of things to mention; since I am just driving the car and not taking a support vehicle, I took the rear seats out and just loaded the back up Team Trackday style. Look at all that space! To cover off removing the rear seat....it is weird (note the hybrid is probably different because it wouldn't have folding rear seats) Basically, you remove the lower seat base, very similar to a r series but it is a clip that pulls forward to release the base rather than it being bolted down. Easy Then, you need to remove the side section of the rear seat on each side. There is a 14mm head nut at the bottom of the side piece, the it slides upwards off a hook at the top to release; you also need to unhook the seatbelt from the loop at the top. Then the centre piece is weird. You need to release/fold the seats forward with the tab in the boot on each side From there, there are 2,x12mm headed bolts holding the rear of each seat to the folding bracket, under the trim between the rear seat and the boot (4x christmas tree clips there, they suck). The seat is out but you can see where the bolts attach to the bracket
    • As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
    • I would put a fuel pressure gauge between the filter and the fuel rail, see if it's maintaining good fuel pressure at idle going up to the point when it stalls. Do you see any strange behavior in commanded fuel leading up to the point when it stalls? You might have to start going through the service manual and doing a long list of sensor tests if it's not the fuel system for whatever reason.
×
×
  • Create New...