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

    • MBS206
      Recommendation for engine oil funnel spill free

      By MBS206 · Posted

      I thought I'd come back and add something I JUST learned. A Toyota LandCruiser with a 1HZ, mates perfectly with a bottle of Nulon brake fluid. As in, it perfectly screws in. Great make shift funnel when you cut the bottom of it off. This may work for your Corolla.   Unfortunately, tipping a 10L drum is much harder than a 4 to 6L bottle, and they no longer include the easy pour tap which was just perfection to use previously.  
    • EndZee
      Fuel Pump Control Module & Dropping Resistor

      By EndZee · Posted

      Guys since i bought r33 gts25t coupe 1994 automatic a/t(manual swap 350z gearbox)  all i got is problems, always problems. Lets start with that when i turn key into ignition(ON) fuel pump doesnt always works. Sometimes i have to turn key twice Off/on/off/on until it primes. Its new, dw300 - 340lph. My gearbox broke so i did gearbox swap, install different intake manifold, injectors and i take pipes. Car was sitting in garage for more than half a year. I did assembly all not that long ago and when i turn ignition cant hear prime. All of sudden it stopped working. Theres many videos on YouTube how to make relay mod on r33 straight from battery so i did and it doesnt work! 😰 30 - battery positive  87 - positive from fuel pump to relay 85, 86 - one of two wires from original fuel pump wires(light blue, grey) and it didn’t work. so I check on ignition and took original BLUE relays wires from trunk, next to fuses. (I believe it’s IGN+ and ECU pin 18. it didn’t work…  tried connecting (IGN+ from og relay) and (ECU 104 from 1of4 FPCM wires) to my new relay 85/86 and it didn’t work.  I unplug FPCM. Didn’t work. im thinking what’s wrong   fuel pump is working, if I leave IGN+ on 85 and 86 straight to ground it works but it’s just nonstop. Since it getting constant 12v after key in ON. light blue wire gives me 6-8v.  so how this should be connected? What causing ECU not giving — on pin? Or I did sth wrong and that’s why it doesn’t work? I need negative signal on ECU that control fuel pump. What this should be?
    • Duncan
      M35 Brake caliper replacement

      By Duncan · Posted

      You can use your VIN to look up the factory part number somewhere like amayama, and then look to order new if necessary. https://www.amayama.com/en/genuine-catalogs/nissan Depending on price you might want to rebuild instead. @GTSBoy I had an interesting insight into US market parts when the Titan rear calipers were sticking. New calipers were dirt cheap, about 20% more than a rebuild kit....they are just considered throw away maintenance items
    • Duncan
      Most women will agree that parking is the most taxing part of driving

      By Duncan · Posted

      Funny, but really not funny. Thank god (most) f the world has moved on since then
    • Duncan
      Jacks that fit under GTR lips that can reach the subframe?

      By Duncan · Posted

      Lots of votes for driving onto a plank first; that is the quickest way I've found, 25mm is enough for my case but that will vary by car It also depends where you are going for. On the 32 I can get to the rear diff with my floor jack if I do that end first, and get it up on stands. Then I lift the front from either front tow hook as high as needed, also onto stands. Sometimes I need a small lift on the other tow hook to get it level enough If I do the front first I can't get to the rear diff because of the angle of the car Other options are getting to the front mount of the rear subframe from in front of the wheel (if only lifting one side, or just do both which is a bit of a pain compared to one lift from the diff), or also the gearbox cross member mount on the driver's side if you are  just trying to lift the driver's side. I This is the jack I use; it says 75mm clearance but of course that is only on the lower section so if you have to reach too far in like the diff you still get stuck. https://www.snapon-bluepoint.com.sg/category/Floor-Jacks/product/Floor-Jack,-2-Ton-Low-Profile
×
×
  • Create New...