Jump to content
SAU Community

Vct Alternative For 25/30

CEF11E

By CEF11E,
in Engines & Forced Induction

 Share

Recommended Posts

CEF11E Veteran

CEF11E

Posted
Posted

When I built my 25/30 I came up with the idea of taking out the VCT solenoid and replacing the solenoid with a tapped fitting. then feeding that fitting oil from a t peice just before the pressure sender.

this will mean VCT is always on. but supply the needed oil to the front cam journal.

all the parts needed cost me under $100 including the braided stainless line.

I have now been using this setup for over 6 months and it works perfectly. you would only use this setup if you were not going to retain vct.

hope this helps someone

Link to comment
https://www.sau.com.au/forums/topic/212063-vct-alternative-for-2530/
Share on other sites
Al Grand Master

Al

Posted
Posted

Correct me if i'm wrong:

Wouldn't removing the VCT completely and fitting a non vct cam and cam gear achieve the same results? With the ability to "dial" the cam in with the adjustable cam gear.

Most people upgrade cams during this build, as most purchase bigger turbos, etc, and the cams produce great results for very reasonable costs. So if you didn't want VCT, you'll be better off removing it completely and using an adjustable cam gear, just like the GTR setup.

bluegts Collaborator

bluegts

Posted
Posted
i know of a few vl's running around with 25det heads without any VCT oil lines etc etc

How? I have an RB30 bottom and 25det head sitting in the garage... I want the cheapest and easiest way of 'joining' them. lol. I only want about 250kw, its the torque I'm after. I don't wanna do any drilling/tapping though.

Cheers, Jack

CEF11E Veteran

CEF11E

Posted
  • Author
Posted
sorry guys, this might be a nub question but cant you put a T piece between the VCT solenoid and the head so you can retain VCT by doing it your way Nic?

unfortunately not :D the solenoid sits deep in the head and has a seal. it acts like a gate between 2 galleries. to taking it out and replacing it with a feed line removes this gate.

if you want to retain VCT you would need to tap into the vct gallery on the front of the head. :(

CEF11E Veteran

CEF11E

Posted
  • Author
Posted
How? I have an RB30 bottom and 25det head sitting in the garage... I want the cheapest and easiest way of 'joining' them. lol. I only want about 250kw, its the torque I'm after. I don't wanna do any drilling/tapping though.

Cheers, Jack

it really only costs about $100 to do it my way. if you do not supply oil to the front cam journal you risk scoring the cam and even causing it to seize or produce resistance putting strain on your timing belt.

this could cause you to skip a tooth or even snap a belt or a cam, all of witch would kill your engine. it can be done but i would not do it :(

Cheers!

Craved Grand Master

Craved

Posted
Posted

his = using the hole for the VCT solenoid to feed the oil (no drilling of the head)

way he wont do = not feed any oil at all by skipping the drill and tap or not using his method

His method is great if you dont run std cams OR if you dont run cams that are designed for VCT motors (IE. poncams are designed to retain VCT)

  • 4 weeks later...
fletch rb30 Enthusiast

fletch rb30

Posted
Posted

You drill and tap the plug just under the inlet cam, and pull it out with a slide hammer. its about 40mm long, but will prob snap in half when you pull it out. you can re-drill the bit left in the head and pull that out too. i would suggest drilling right through with say a 2mm drill bit first off.

This plug blocks the lifter gallery from the front cam journal.

Then you get a bit of brass machined to the correct diameter so you can tap it in for a pretty tight fit. get a 1.5mm hole machined into the end of it about 30mm deep.

Tap this plug into the hole until its flush.

drill down from the cam journal oil hole into the brass until you hit the center of the plug.

using this method you can run the vvt without the external oil feed, or you can run a non vvt inlet cam. just leave the solenoid in place but unplugged.

you only need the 1.5mm restriction down the centre of the plug so there is not too much oil flow dumping through the vvt solenoid from the lifter gallery when the solenoid is not energised. This method means you also dont have to weld up the oil gallery at the front of the head near the water jacket as it will be blocked off

you should have all the lifters out when you do this and throughly clean the head before re-fitting it.

hope this helps.

bluegts Collaborator

bluegts

Posted
Posted
it really only costs about $100 to do it my way. if you do not supply oil to the front cam journal you risk scoring the cam and even causing it to seize or produce resistance putting strain on your timing belt.

this could cause you to skip a tooth or even snap a belt or a cam, all of witch would kill your engine. it can be done but i would not do it :bomb_ie:

Cheers!

The cam journal is fed from both sides by a small hole anyway. One hole from the oil gallery. It wouldn't really matter if you didn't feed the vct with oil at all.

Jack

The Ant Contributor

The Ant

Posted
Posted
unfortunately not ;) the solenoid sits deep in the head and has a seal. it acts like a gate between 2 galleries. to taking it out and replacing it with a feed line removes this gate.

if you want to retain VCT you would need to tap into the vct gallery on the front of the head. :P

Does this solenoid need oil Pressure?

If your trying to keep VCT and did this and the solenoid needs oil pressure to operate this gate, hence this is why its screwed into an oil gallery, isnt this solenoid at a dead end of the oil gallery so running another flowing oil passage off it as in tapping into it and running another oil line before the solenoid, this would relieve the oil pressure not making the solenoid work the VCT or is there enough constant pressure to operate the solenoid?

I have never worked on a RB25 motor...even though I own 2 RB25 engines

fletch rb30 Enthusiast

fletch rb30

Posted
Posted

on the vvt motors there is a constant oil feed at the front which feeds the vvt only. it has a 1.5mm restriction in it at the top of the block and it runs straight up into the front cam journal. the front cam journal has 2 holes, one is a return back into the top of the head by the valve springs and stuff. on the way, the return goes through the solenoid. the vvt is engaged by the solenoid energising and blocking the return. this creates pressure in the front cam journal. you can see on the cams they have a groove on them, this goes right to the pulley on the front and when it gets oil pressure it moves the vanes inside the pulley and the camshaft position relative to the pulley changes. when the solenoid opens, the pressure drops off and the pulley goes back to normal timing.

clear as mud?? i think it makes sense

At first i was just going to run a rb20 cam, cut the solenoid in half at the pulg end and weld it up so it was always sticking out and blocking the return, then i would have engine oil pressure at the front cam journal and it would be lubricated.

  • 6 months later...
psi Experienced

psi

Posted
Posted

Ok, I have my head in bits (needs help poor thing!),

so, while its all apart, I'm going to do this mod. Its exactly what i was already looking at doing. Great minds ehh?

I will track the oil feeds and stuff and activate the solinoid just to check all is well before its all put back together.

I will take photo's along the way.. The best part is, with out the external feed in sight, who would ever know what they are looking at? hehe

Thanks for the tips..

  • 2 weeks later...
psi Experienced

psi

Posted
Posted

doing this mod, the VCT will work as normal..

The oil gallery that feeds the cam buckets will now also supply oil to the VCT. This removes the need for an external oil feed, and also will reduce the amount of oil going to the top end! so I will not be replacing any of the oil restrictors.

by doing this, it appears that the the solinoid may actually work backwards due to the reverse flow of the oil through it, however this will be easy fixed the ecu switching when it gets tuned..

I will be taking my head to get the orginal oil feed port welded today, and a surface grind. Will post pics soon of the bits I have done and plan to change.

that help?

fletch rb30 Enthusiast

fletch rb30

Posted
Posted
doing this mod, the VCT will work as normal..

The oil gallery that feeds the cam buckets will now also supply oil to the VCT. This removes the need for an external oil feed, and also will reduce the amount of oil going to the top end! so I will not be replacing any of the oil restrictors.

Correct, remember to drill a 1.5mm hole in the new bung you put into the gallery, or you will lose a lot of oil through the vvt feed past the cam, past the solenoid and into the head.

by doing this, it appears that the the solinoid may actually work backwards due to the reverse flow of the oil through it, however this will be easy fixed the ecu switching when it gets tuned..

The oil will flow past the vvt solenoid the same way as factory. the solenoid works by blocking the return oil AFTER it has been to the front cam journal. When it is energized, it blocks the return, the front cam journal is pressurised and this activates the vvt.

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
      My BMW E39 528i touring

      By GTSBoy · Posted

      Well, that's kinda the point. The calipers might interfere with the inside of the barrels 16" rims are only about 14" inside the barrels, which is ~350mm, and 334mm rotors only leave about 8mm outboard for the caliper before you get to 350, And.... that;s not gunna be enough. If the rims have a larger ID than that, you might sneak it in. I'd be putting a measuring stick inside the wheel and eyeballing the extra required for the caliper outboard of the rotor before committing to bolting it all on.
    • Duncan
      Neil's R33 Gts-t Build

      By Duncan · Posted

      OK, so again it has been a bit of a break but it was around researching what had been done since I didn't have access to Neil's records and not everything is obvious without pulling stuff apart. Happily the guy who assembled the engine had kept reasonable records, so we now know the final spec is: Bottom end: Standard block and crank Ross 86.5mm forgies, 9:1 compression Spool forged rods Standard main bolts Oil pump Spool billet gears in standard housing Aeroflow extended and baffled sump Head Freshly rebuilt standard head with new 80lb valve springs Mild porting/port match Head oil feed restrictor VCT disabled Tighe 805C reground cams (255 duration, 8.93 lift)  Adjustable cam gears on inlet/exhaust Standard head bolts, gasket not confirmed but assumed MLS External 555cc Nismo injectors Z32 AFM Bosch 023 Intank fuel pump Garret 2871 (factory housings and manifold) Hypertune FFP plenum with standard throttle   Time to book in a trip to Unigroup
    • PranK
      My BMW E39 528i touring

      By PranK · Posted

      I forgot about my shiny new plates!
    • PranK
      My BMW E39 528i touring

      By PranK · Posted

      Well, apparently they do fit, however this wont be a problem if not because the car will be stationary while i do the suspension work. I was just going to use the 16's to roll the old girl around if I needed to. I just need to get the E90 back on the road first. Yes! I'm a believer! 🙌 So, I contacted them because the site kinda sucks and I was really confused about what I'd need. They put together a package for me and because I was spraying all the seat surfaces and not doing spot fixes I decided not to send them a headrest to colour match, I just used their colour on file (and it was spot on).  I got some heavy duty cleaner, 1L of colour, a small bottle of dye hardener and a small bottle of the dye top coat. I also got a spray gun as I needed a larger nozzle than the gun I had and it was only $40 extra. From memory the total was ~$450 ish. Its not cheap but the result is awesome. They did add repair bits and pieces to the quote originally and the cost came down significantly when I said I didn't need any repair products. I did it over a weekend. The only issues I had were my own; I forgot to mix the hardener into the dye two coats but I had enough dye for 2 more coats with the hardener. I also just used up all the dye because why not and i rushed the last coat which gave me some runs. Thankfully the runs are under the headrests. The gun pattern wasn't great, very round and would have been better if it was a line. It made it a little tricky to get consistent coverage and I think having done the extra coats probably helped conceal any coverage issues. I contacted them again a few months later so I could get our X5 done (who the f**k thought white leather was a good idea for a family car?!) and they said they had some training to do in Sydney and I could get a reduced rate on the leather fix in the X5 if I let them demo their product on our car. So I agreed. When I took Bec in the E39 to pick it up, I showed them the job I'd done in my car and they were all (students included) really impressed. Note that they said the runs I created could be fixed easily at the time with a brush or an air compressor gun. So, now with the two cars done I can absolutely recommend Colourlock.  I'll take pics of both interiors and create a new thread.
    • 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.
×
×
  • Create New...