Jump to content
SAU Community

Dialling in cams

MonstaS4

By MonstaS4,
in Engines & Forced Induction

 Share

Recommended Posts

MonstaS4 Collaborator

MonstaS4

Posted
Posted

I'm after some advice on dialling in cams on an RB30DET. Due to the positioning of the belt tensioners, the cams do not line up with the marks on the back plate when at TDC. My guess is they are 5 or so degrees out. It's an R33 head so the VCT gear is adjustable from behind, and i have an adjustable exh. gear.

I've made up a degree wheel which is bolted on the crank, but there dosn't seem to be alot of room on the lifter to place the dial guage on. Is there a trick to this? There's no way a dial guage can sit perpendicular to the lifter as the cam gets in the way. Help!

Link to comment
https://www.sau.com.au/forums/topic/73332-dialling-in-cams/
Share on other sites
Warpspeed Experienced

Warpspeed

Posted
Posted

I have been all through this myself. You need to take a bit of time and do it properly, otherwise it's a complete waste of time.

The first thing you need is a decent dial indicator with the little screw in ball in the end, and it must also have enough travel to work over the full valve lift (obviously).

Next get a small flat metal strip, and drill a suitable hole in one end and fit it under the screw in ball on the end of the dial indicator. It should stick out a right-angles, like a foot sticks out from a leg. That way, the projecting metal "foot" can sit on the very edge of the cam follower without the lobe hitting the stem of the dial indicator as it rotates past. Until you have tried this, you will not realise how little room there is.

The last, and most important thing is to make up a very solid mount for the dial indicator. It absolutely MUST be mounted parallel with the axis of the valve stem, otherwise the metal "foot" will slide around on the follower and the readings will be all over the place. I made up a special fixture that bolts on top of the camshaft bearing saddles. It requires a couple of longer bolts, but it is extremely rigid, and mounts the dial gauge exactly true. If you are clever, it can be turned around and used on both inlet cam and exhaust cam.

Another handy little gadget I fabricated from an old spark plug body, is a fixture for very accurately finding TDC. It has a long threaded bolt that hangs down inside the combustion chamber, and it stops the piston coming up at exactly 90 BTDC.

With the degree wheel fitted, the engine can be turned both ways to hit the stop, and it should show exactly 90 BTDC one way, and 90 ATDC the other. If the bolt length is not exact. both readings should still be identical. When they are, remove the spark plug fixture and TDC should be exact on the degree wheel.

If you take the time to set it all up and make some special tools, cams can be dialed in very quickly and accurately. This might be important if you are trying a few different cams and have adjustable pulleys.

A really convenient way to turn the engine over is to place the car in fifth gear and just roll it backwards and forwards. It is the easiest way.

Link to comment
https://www.sau.com.au/forums/topic/73332-dialling-in-cams/#findComment-1349771
Share on other sites

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

    • GTSBoy
      R33 Fuel Pump & Brakes after alarm swap

      By GTSBoy · Posted

      Power is fed to the ECU when the ignition switch is switched to IGN, at terminal 58. That same wire also connects to the ECCS relay to provide both the coil power and the contact side. When the ECU sees power at 58 it switches 16 to earth, which pulls the ECCS relay on, which feeds main power into the ECU and also to a bunch of other things. None of this is directly involved in the fuel pump - it just has to happen first. The ECU will pull terminal 18 to earth when it wants the fuel pump to run. This allows the fuel pump relay to pull in, which switches power on into the rest of the fuel pump control equipment. The fuel pump control regulator is controlled from terminal 104 on the ECU and is switched high or low depending on whether the ECU thinks the pump needs to run high or low. (I don't know which way around that is, and it really doesn't matter right now). The fuel pump control reg is really just a resistor that controls how the power through the pump goes to earth. Either straight to earth, or via the resistor. This part doesn't matter much to us today. The power to the fuel pump relay comes from one of the switched wires from the IGN switch and fusebox that is not shown off to the left of this page. That power runs the fuel pump relay coil and a number of other engine peripherals. Those peripherals don't really matter. All that matters is that there should be power available at the relay when the key is in the right position. At least - I think it's switched. If it's not switched, then power will be there all the time. Either way, if you don't have power there when you need it (ie, key on) then it won't work. The input-output switching side of the relay gains its power from a line similar (but not the same as) the one that feeds the ECU. SO I presume that is switched. Again, if there is not power there when you need it, then you have to look upstream. And... the upshot of all that? There is no "ground" at the fuel pump relay. Where you say: and say that pin 1 Black/Pink is ground, that is not true. The ECU trigger is AF73, is black/pink, and is the "ground". When the ECU says it is. The Blue/White wire is the "constant" 12V to power the relay's coil. And when I say "constant", I mean it may well only be on when the key is on. As I said above. So, when the ECU says not to be running the pump (which is any time after about 3s of switching on, with no crank signal or engine speed yet), then you should see 12V at both 1 and 2. Because the 12V will be all the way up to the ECU terminal 18, waiting to be switched to ground. When the ECU switches the fuel pump on, then AF73 should go to ~0V, having been switched to ground and the voltage drop now occurring over the relay coil. 3 & 5 are easy. 5 is the other "constant" 12V, that may or may not be constant but will very much want to be there when the key is on. Same as above. 3 goes to the pump. There should never be 12V visible at 3 unless the relay is pulled in. As to where the immobiliser might have been spliced into all this.... It will either have to be on wire AF70 or AF71, whichever is most accessible near the alarm. Given that all those wires run from the engine bay fusebox or the ECU, via the driver's area to the rear of the car, it could really be either. AF70 will be the same colour from the appropriate fuse all the way to the pump. If it has been cut and is dangling, you should be able to see that  in that area somewhere. Same with AF71.   You really should be able to force the pump to run. Just jump 12V onto AF72 and it should go. That will prove that the pump itself is willing to go along with you when you sort out the upstream. You really should be able to force the fuel pump relay on. Just short AF73 to earth when the key is on. If the pump runs, then the relay is fine, and all the power up to both inputs on the relay is fine. If it doesn't run (and given that you checked the relay itself actually works) then one or both of AF70 and AF71 are not bringing power to the game.
    • Kinkstaah
      My BMW E39 528i touring

      By Kinkstaah · Posted

      @PranK can you elaborate further on the Colorlock Dye? The website has a lot of options. I'm sure you've done all the research. I have old genuine leather seats that I have bought various refurbing creams and such, but never a dye. Any info on how long it lasts? Does it wash out? Is it a hassle? What product do I actually need? Am I just buying this kit and following the steps the page advises or something else? https://www.colourlockaustralia.com.au/colourlock-leather-repair-kit-dye.html
    • GTSBoy
      My BMW E39 528i touring

      By GTSBoy · Posted

      These going to fit over the big brakes? I'd be reeeeeeeeaaaall hesitant to believe so.
    • PranK
      My BMW E39 528i touring

      By PranK · Posted

      The leather work properly stunned me. Again, I am thankful that the leather was in such good condition. I'm not sure what the indent is at the top of the passenger seat. Like somebody was sitting in it with a golf ball between their shoulders. The wheels are more grey than silver now and missing a lot of gloss.  Here's one with nice silver wheels.
    • soviet_merlin
      My BMW E39 528i touring

      By soviet_merlin · Posted

      It's amazing how well the works on the leather seats. Looks mint. Looking forward to see how you go with the wheels. They do suit the car! Gutter rash is easy to fix, but I'm curious about getting the colour done.
×
×
  • Create New...