Jump to content
SAU Community

Recommended Posts

Hello I have started my rebuild of my rb25 it has been hone and bored to 87mm cp piston and manley rods.  I gapped all the rings and installed the pistons I made sure to deburr all the rings too.  I rotated the assembly and looked fine and then today I was putting on the oil pump and noticed that there is some light scratches on the cylinder walls.  I can't feel then at all I'm not sure if there wasn't enough oil in the bores or if I rotated the assembly too much but tomorrow I'm going to remove all the pistons and make sure the rings are all deburred please lmk what you guys think anything helps.

Doesn't sound like good news, if you can feel it with a finger nail it almost certainly needs a hone and possibly even a bore out.

Sucks, but not worth having an issue. I once had to get a block re-bored when I caught a ring installing it and scratched the bore. Might also be your ring end gaps were too tight

6 hours ago, Duncan said:

Doesn't sound like good news, if you can feel it with a finger nail it almost certainly needs a hone and possibly even a bore out.

Sucks, but not worth having an issue. I once had to get a block re-bored when I caught a ring installing it and scratched the bore. Might also be your ring end gaps were too tight

I took out the pistons today and found that all of them have some type of vertical scratch on the skirts I'm going to talk to my machinist today and see what there is to do.  Hoping for the best this is my first rebuild.

  • Like 1
10 hours ago, Murray_Calavera said:

If your concerned, why not take the block back to the machinist that originally did the bore/hone? They would be able to advise if the hone needs to be redone.  

I talked to my machinist he said to take a emery cloth and wipe out the scratches and it should be fine he said since the scratches don't catch my nail its fine

3 hours ago, Duncan said:

Good to hear. Did they have a theory why the scratches occurred? Are you certain the ring gaps are OK (check them before reinstalling pistons!)

I wiped the scratches and they went away it was only about 1-3 wipes from very fine emery cloth he said it could have been from not enough oil in the bores or too much rotating of the assembly also he said that the type of ring compressor I'm using can make the rings catch a bit.  Before I put the pistons back together I will check the gaps and double check the rings for deburring.

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


  • Similar Content

  • Latest Posts

    • I would just put EBC back on the "I would not use their stuff" pile and move on.
    • Can I suggest you try EBC directly again and link them to as many competitor catalogues as you can to show their listing is incorrect, eg https://dba.com.au/product/front-4000-series-hd-brake-rotor-dba42304/ If you have access to an R33 GTST VIN and your VIN, you could also use a Nissan Parts lookup like Amayama to show them the part number is different between 33 GTST and 34 GTT which may get their attention
    • So i got reply from EBC and they just this site where you can clearly see those 296mm fronts on R34 GTT. I send them photos and "quotes" that 296mm are not for 34 GTT and they are too small. But it will be very hard to return them cuz nobody here knows 100% and they just copy those EBC catalogue :-D https://ebcbrakesdirect.com/automotive/nissan/skyline-r34
    • Hi, is the HKS  Tower Bar still available ? negotiable ? 🤔
    • From there, it is really just test and assemble. Plug the adapter cables from the unit into the back of the screen, then the other side to the car harness. Don't forget all the other plugs too! Run the cables behind the unit and screw it back into place (4 screws) and you should now have 3 cables to run from the top screen to the android unit. I ran them along the DS of the other AV units in the gap between their backets and the console, and used some corrugated tubing on the sharp edges of the bracket so the wires were safe. Plug the centre console and lower screen in temporarily and turn the car to ACC, the AV should fire up as normal. Hold the back button for 3 sec and Android should appear on the top screen. You need to set the input to Aux for audio (more on that later). I put the unit under the AC duct in the centre console, with the wifi antenna on top of the AC duct near the shifter, the bluetooth antenna on the AC duct under the centre console The GPS unit on top of the DS to AC duct; they all seem to work OK there are are out of the way. Neat cable routing is a pain. For the drive recorder I mounted it near the rear view mirror and run the cable in the headlining, across the a pillar and then down the inside of the a pillar seal to the DS lower dash. From there it goes across and to one USB input for the unit. The second USB input is attached to the ECUtec OBD dongle and the 3rd goes to the USB bulkhead connected I added in the centre console. This is how the centre console looks "tidied" up Note I didn't install the provided speaker, didn't use the 2.5mm IPod in line or the piggyback loom for the Ipod or change any DIP switches; they seem to only be required if you need to use the Ipod input rather than the AUX input. That's it, install done, I'll follow up with a separate post on how the unit works, but in summary it retains all factory functions and inputs (so I still use my phone to the car for calls), reverse still works like factory etc.
×
×
  • Create New...