Jump to content
SAU Community

Crank Collar Clearance Issue

urtwhistle

By urtwhistle,
in Engines & Forced Induction

 Share

Recommended Posts

urtwhistle Proficient

urtwhistle

Posted
Posted

Hey guys,

I have done a bit of a search and can't find any thing that helps.

I have just had my rb30 crank machined and a crank collar put on. I just test fitted the oil pump gear on the collar and noticed there seems to be a lot more clearance than what I would have expected. I measured a total of 12 thou, Ie 6 though on each flat face. Firstly is that normal? that amount of slop I would have expected to negate the whole purpose of the collar.

Do people shim up there gears? I'm think about getting 2 small peices 4 thou shim and loctite 406'ing it to the crank collar just to tighten it up a little. I noticed tonight that the glue added about 1 thou. so In theory it would bring it down to about 2 thou.

What does every 1 else do?

Lastly when using a standard rb25 pump on a built rb30, do people put say a 2mm washer in the oil relief valve?

regards

Chris

Link to comment
https://www.sau.com.au/forums/topic/368570-crank-collar-clearance-issue/
Share on other sites
bubba Grand Master

bubba

Posted
Posted

Chris, that is why I'm a fan of welding the snout up and machining to suit the particular gears you are using. For me, 12thou is way too much slop!

As for the oil pump relief, I'm running a stock RB30E pump on my next engine and I shimmed the relief spring with an approx. 2mm washer.

urtwhistle Proficient

urtwhistle

Posted
  • Author
Posted

Hey Mr Bubs, In hind sight I think your onto something and I probably should have gone the welded route.

12 thou makes the oil pump gear rock back and forth like its on a rocking chair. I don't understand why there isn't alot more post's relating to this subject I mean its so damn obvious to me lol

r33_racer Grand Master

r33_racer

Posted
Posted

Yeh that point is a good one. However, What does the clearance become when the engine is running and everything has heated up and expanded?

Also another point is the crank doesnt run perfectly centred at xxxx rpm, there is always a certain amount of runout. Too tight on that clearance and it will be just as bad as not having a collar at all. How much runout there is i dont know, But there is no way the snout is always perfectly centred when your at 7000rpm bouncing off the limiter.

But 0.012" is alot, and no doubt it can probably be run abit tighter. But there is no way of knowing until someone who has run tighter can say its been fine and tells you what clearance they actually did run. Or you try it yourself and see what happens.

But I dont think 0.002" is enough. Hopefully someone else with more exp can shed some light here.

If I was going to machine a collar Id probably aim for about 0.006" overall, 0.003" per side. But thats just my own guess. Without knowing expansion and run out its hard to say.

MrStabby Grand Master

MrStabby

Posted
Posted

Yeh that point is a good one. However, What does the clearance become when the engine is running and everything has heated up and expanded?

If both pieces are made from the same metal (or if they have the same coefficient of thermal expansion), the clearance will not change if they stay at the same temperature.

t_revz Grand Master

t_revz

Posted
Posted

Chris, that is why I'm a fan of welding the snout up and machining to suit the particular gears you are using. For me, 12thou is way too much slop!

how hard did this hit the back pocket? significantly more than collar?

urtwhistle Proficient

urtwhistle

Posted
  • Author
Posted

Doesnt the aftermarket crank collars and a std r33/r34 crank measure up the same OD?

I think you might be right but I no longer have the neo Rb25 block to mic it up. I went with the 4thou shim and its still possible a bit tight. I'll have more of a look tonight now that the glue has dried and I can take the sharp edges off the shim.

bubba Grand Master

bubba

Posted
Posted

how hard did this hit the back pocket? significantly more than collar?

Not sure on cost as I haven't done mine yet as my forged build is on hold for a while, chuckie should know soon. We had it done to my mates 30 in his GTS4 and that thing cops an absolute beating, 8500rpm limiter launches and burnouts, still going strong.

Realistically, it should add much onto the cost of machining at all. Wouldn't take more than an hour to weld the snout up and if just fitting a collar the snout needs to be machined right down anyway.

On the topic of crank runout.... why would a splined setup ala JZ, not completely destroy itself?

sky30 Mentor

sky30

Posted
Posted

Not sure on cost as I haven't done mine yet as my forged build is on hold for a while, chuckie should know soon. We had it done to my mates 30 in his GTS4 and that thing cops an absolute beating, 8500rpm limiter launches and burnouts, still going strong.

Realistically, it should add much onto the cost of machining at all. Wouldn't take more than an hour to weld the snout up and if just fitting a collar the snout needs to be machined right down anyway.

On the topic of crank runout.... why would a splined setup ala JZ, not completely destroy itself?

is you mates motor rb26 or rb30?

r33_racer Grand Master

r33_racer

Posted
Posted

Not sure on cost as I haven't done mine yet as my forged build is on hold for a while, chuckie should know soon. We had it done to my mates 30 in his GTS4 and that thing cops an absolute beating, 8500rpm limiter launches and burnouts, still going strong.

Realistically, it should add much onto the cost of machining at all. Wouldn't take more than an hour to weld the snout up and if just fitting a collar the snout needs to be machined right down anyway.

On the topic of crank runout.... why would a splined setup ala JZ, not completely destroy itself?

Whats the 2J setup look like exactly? How many splines and do you know what sort of clearance it runs? No doubt its better then our nissan design. Seems toyota also improves on everything nissan didnt :( Splined from the get go sounds alot better.

Im guessing it probably has ample clearance as well, or maybe their cranks are made of better material and dont flex/runout as much?

bubba Grand Master

bubba

Posted
Posted

is you mates motor rb26 or rb30?

25t/30

We had it done to my mates 30

:thumbsup:

Whats the 2J setup look like exactly? How many splines and do you know what sort of clearance it runs? No doubt its better then our nissan design. Seems toyota also improves on everything nissan didnt :( Splined from the get go sounds alot better.

Im guessing it probably has ample clearance as well, or maybe their cranks are made of better material and dont flex/runout as much?

It looks pretty much like an axle end where it goes into the diff.. as for clearance, I have no idea. Shanef was working on a splined setup for RB's but got ripped off by his machinist or something :/

2JZ-GE oil pump..

oilpump.jpg

urtwhistle Proficient

urtwhistle

Posted
  • Author
Posted

Hey so it turns out that 4tho shim is still too tight and I can't get the oil pump gear on. which is a pain when I know that if the gear is in position I can push 2x 6 tho feeler gauges under it.

Also Loctite 406 is not a valid option as it is extremely hard to get it to key on and stop the shim from peeling off. Thats If you are quick enough to actualy get the glue on without gluing the shim to your hand first.

My boss suggested using Loctite 680 high strength retaining compound. So I'll let you know I go with that experiment.

At the rate I'm going this motor is going to take about 2 years to get running. Almost give you a run for your money ay Bubba????

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...