Jump to content
SAU Community

Couple Of Questions Regarding The Rb25det Head On Th Rb30

tai_180sx

By tai_180sx,
in Engines & Forced Induction

 Share

Recommended Posts

tai_180sx Enthusiast

tai_180sx

Posted
Posted

I have an RB25det head that i am in the process of putting on the RB30. now the head that i bought didn't come with cam gears so i am purchasing aftermarket adjustable cam gears for both the inlet and exahust. From my understanding this will get rid of the VVL on the inlet cam, right? well if this is true then there would be no point in me drilling and tapping a new oil line into the head to run the VVL???

now the second question is, with welding up the oil hole in the RB25det head.... is it really necessary to actually weld up the hole and destroy the head? can you just pick up some thin copper shim and place in over the hole and bolt the head down over it? Now before you say too much, i know this sounds dodgy... very dodgy, but i am using a multi layer metal head gasket that i can easily slide the shim inside it and secondly where the oil hole is (right at the front of the motor, and right next to a head bolt) i'm sure that it will sit down fine and not create any problems for the rest of the motor.. can anyone confirm if they have done this before, is it even possible? honest opinions would be appreciated.

now my last question is in regards to the timing belt. I have bought a Gates performance timing belt for the RB30det conversion and after sitting the head/cam gears/balancer/belt and tensioner on, it all seems to fit really well with the tension in the standard position... Is there a specific reason why all the articles say that you have to move the tensioner and put in an extra idler pulley? i don't plan on running the covers over the cam gears either..

TiTAN Grand Master

TiTAN

Posted
Posted

With the oil feed for the VCT, it also supplies oil to the front cam journal. See the following thread.

http://www.skylinesaustralia.com/forums/Vc...30-t212063.html

As far as blocking the feed into the head you can drill it out, tap it and fit a grub screw if you do not want to weld the head.

Is that a gates racing belt specifically for the RB30 twin cam conversion? they make one that uses the stock tensioner locations, but the teeth on the belt sit a little close together for comfort for some people.

tai_180sx Enthusiast

tai_180sx

Posted
  • Author
Posted (edited)

yes it was the gates belt designed for the RB30det conversion.

i didn't think about tapping a thread in the oil hole, thats a good option.

with the cam journal oil feed... this is from the post you just mentioned..

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.

going by this, i would say that really i don't need to feed oil to the VVL... but thats only if by putting on the aftermarket cam gears i will lose the VVL anyway..

Edited by tai_180sx

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
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      Yeah, that's fine**. But the numbers you came up with are just wrong. Try it for yourself. Put in any voltage from the possible range and see what result you get. You get nonsense. ** When I say "fine", I mean, it's still shit. The very simple linear formula (slope & intercept) is shit for a sensor with a non-linear response. This is the curve, from your data above. Look at the CURVE! It's only really linear between about 30 and 90 °C. And if you used only that range to define a curve, it would be great. But you would go more and more wrong as you went to higher temps. And that is why the slope & intercept found when you use 50 and 150 as the end points is so bad halfway between those points. The real curve is a long way below the linear curve which just zips straight between the end points, like this one. You could probably use the same slope and a lower intercept, to move that straight line down, and spread the error out. But you would 5-10°C off in a lot of places. You'd need to say what temperature range you really wanted to be most right - say, 100 to 130, and plop the line closest to teh real curve in that region, which would make it quite wrong down at the lower temperatures. Let me just say that HPTuners are not being realistic in only allowing for a simple linear curve. 
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      I feel I should re-iterate. The above picture is the only option available in the software and the blurb from HP Tuners I quoted earlier is the only way to add data to it and that's the description they offer as to how to figure it out. The only fields available is the blank box after (Input/ ) and the box right before = Output. Those are the only numbers that can be entered.
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      No, your formula is arse backwards. Mine is totally different to yours, and is the one I said was bang on at 50 and 150. I'll put your data into Excel (actually it already is, chart it and fit a linear fit to it, aiming to make it evenly wrong across the whole span. But not now. Other things to do first.
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      God damnit. The only option I actually have in the software is the one that is screenshotted. I am glad that I at least got it right... for those two points. Would it actually change anything if I chose/used 80C and 120C as the two points instead? My brain wants to imagine the formula put into HPtuners would be the same equation, otherwise none of this makes sense to me, unless: 1) The formula you put into VCM Scanner/HPTuners is always linear 2) The two points/input pairs are only arbitrary to choose (as the documentation implies) IF the actual scaling of the sensor is linear. then 3) If the scaling is not linear, the two points you choose matter a great deal, because the formula will draw a line between those two points only.
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      Nah, that is hella wrong. If I do a simple linear between 150°C (0.407v) and 50°C (2.98v) I get the formula Temperature = -38.8651*voltage + 165.8181 It is perfectly correct at 50 and 150, but it is as much as 20° out in the region of 110°C, because the actual data is significantly non-linear there. It is no more than 4° out down at the lowest temperatures, but is is seriously shit almost everywhere. I cannot believe that the instruction is to do a 2 point linear fit. I would say the method I used previously would have to be better.
×
×
  • Create New...