Jump to content
SAU Community

Tomei poncan RB26 info

Amaru

By Amaru,
in Engines & Forced Induction

 Share

Recommended Posts

Amaru Veteran

Amaru

Posted
Posted

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
Mik Experienced

Mik

Posted
Posted
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.

cameron Mentor

cameron

Posted
Posted

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

The Alchemist Collaborator

The Alchemist

Posted
Posted

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

pnblight Mentor

pnblight

Posted
Posted

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

Amaru Veteran

Amaru

Posted
  • Author
Posted

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

rev210 Grand Master

rev210

Posted
Posted

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • RP1421
      S15 Spec R

      By RP1421 · Posted

      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. 
    • joshuaho96
      R32 GTS (RB20DE) Injectors Replacement

      By joshuaho96 · Posted

      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.
    • perry_r33
      R34 GTR Vspec Garage Sale - All must go!

      By perry_r33 · Posted

      Pm sent 
    • Robot
      Skyline v36 350GT sedan hunting on idle

      By Robot · Posted

      Hi,  Just joined the forum so I could share my "fix" of this problem. Might be of use to someone. Had the same hunting at idle issue on my V36 with VQ35HR engine after swapping the engine because the original one got overheated.  While changing the engine I made the mistake of cleaning the throttle bodies and tried all the tricks i could find to do a throttle relearn with no luck. Gave in and took it to a shop and they couldn't sort it. Then took it to my local Nissan dealership and they couldn't get it to idle properly. They said I'd need to replace the throttle bodies and the ecu probably costing more than the car is worth. So I had the idea of replacing the carbon I cleaned out with a thin layer of super glue and it's back to normal idle now. Bit rough but saved the car from the wreckers 🤣
    • GabsReDeal
      R32 GTS (RB20DE) Injectors Replacement

      By GabsReDeal · Posted

      After my last update, I went ahead with cleaning and restoring the entire fuel system. This included removing the tank and cleaning it with the Beyond Balistics solution, power washing it multiple times, drying it thoroughly, rinsing with IPA, drying again with heat gun and compressed air. Also, cleaning out the lines, fuel rail, and replacing the fuel pump with an OEM-style one. During the cleaning process, I replaced several hoses - including the breather hose on the fuel tank, which turned out to be the cause of the earlier fuel leak. This is what the old fuel filter looked like: Fuel tank before cleaning: Dirty Fuel Tank.mp4   Fuel tank after cleaning (some staining remains): Clean Fuel Tank.mp4 Both the OEM 270cc and new DeatschWerks 550cc injectors were cleaned professionally by a shop. Before reassembling everything, I tested the fuel flow by running the pump output into a container at the fuel filter location - flow looked good. I then fitted the new fuel filter and reassembled the rest of the system. Fuel Flow Test.mp4 Test 1 - 550cc injectors Ran the new fuel pump with its supplied diagonal strainer (different from OEM’s flat strainer) and my 550cc injectors using the same resized-injector map I had successfully used before. At first, it idled roughly and stalled when I applied throttle. Checked the spark plugs and found that they were fouled with carbon (likely from the earlier overly rich running when the injectors were clogged). After cleaning the plugs, the car started fine. However, it would only idle for 30–60 seconds before stalling, and while driving it would feel like a “fuel cut” after a few seconds - though it wouldn’t fully stall. Test 2 – Strainer swap Suspecting the diagonal strainer might not be reaching the tank bottom, I swapped it for the original flat strainer and filled the tank with ~45L of fuel. The issue persisted exactly the same. Test 3 – OEM injectors To eliminate tuning variables, I reinstalled the OEM 270cc injectors and reverted to the original map. Cleaned the spark plugs again just in-case. The stalling and “fuel cut” still remained.   At this stage, I suspect an intermittent power or connection fault at the fuel pump hanger, caused during the cleaning process. This has led me to look into getting Frenchy’s fuel hanger and replacing the unit entirely. TL;DR: Cleaned and restored the fuel system (tank, lines, rail, pump). Tested 550cc injectors with the same resized-injector map as before, but the car stalls at idle and experiences what feels like “fuel cut” after a few seconds of driving. Swapped back to OEM injectors with original map to rule out tuning, but the issue persists. Now suspecting an intermittent power or connection fault at the fuel pump hanger, possibly cause by the cleaning process.  
×
×
  • Create New...