Jump to content
SAU Community

Recommended Posts

I was at a local workshop,and noticed a bare RB26DETT head. The exhaust ports each had a "bulge" that seemed to be factory cast( I haven't seen many heads actually bare and off an engine to notice this cating thing...). The extend a reasonable way back into the head,and I'd offer an opinion that they'd take up a reasonable bit of real estate in the port,flow wise. The front three cylinders' bulge was facing,I think, rear + lower in the port,with the rear three cylinders facing forward + lower. I've heard a theory that they protect a waterjacket,but I've also heard that workshops grind them down to improve exhaust gas flow...so,no waterjacket. Are they fine on a standard engine,but removed on bigger power-up jobs? Nissan wouldn't have put these bulges there because they were bored. So;what gives?

Link to comment
https://www.sau.com.au/forums/topic/79215-rb26dett-exhaust-port-bulge/
Share on other sites

Its to help direct the flow in the stock manifold. :D

Remove it if you are planning on using a nice tubular manifold.

In reality there is bugger all in it.

Thanks,Cubes! I hoped that was the idea. I have a really nice set of HKS extractors(the ones whose model escapes me-they have the "balancer" tubes between the front and rear three cylinders)that will most likely benefit from said removal ,and subsequent matching,when my head work gets done. If I was leaving the engine as standard,I wouldn't have touched these bulge things,but with what I have planned...well,it looks like they'll probably have to go! Thanks too for the more learned of my fellow SAU'ers that've kept an eye on my inexperience via this thread and helped accordingly! Cheers guys! Jayce.

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

    • ok so if i wanted to go 18's i would go for 8's  in front 30+ or 32+ off set at front and the back 9 would be ok? what offset should i aim for.. then can i do some  hunting for wheel rim choices..   
    • Absolute f*cking nightmare. I had to take breaks constantly, and I was always pissed off when I got home. The line split in Italy on day 2 (we drove from the Netherlands), lol. Driving any narrow European town was... well, sh*t.   Appreciate it man. Here, I'll just drop a favourite from the load I took on Saturday.   I'll update here when things happen with the car, the thing is, with stock power and almost everything chassis-wise taken care of, there really are no problems. 268,000kms now and counting.  
    • Ah! I actually managed to snag a lightly used set.... that aren't so suitable for me right now. They don't work on a GTT without some cutting or creative heat moulding. I thought about reselling them myself cause I didn't want to murder them, but it looks like I'm probably going to attempt to murder them/melt them because I may as well. @GTSBoy @PranK can somebody close this thread?
    • Hey mate,  I have a set, one is slightly damaged but wont be noticable once installed.  Shoot me a message if your still after them 
    • I couldn't wait But, the black constant tension hose clamps were too thick and there wasn't enough clearance at the T/B and I couldn't get it to seat properly, so I had use a silver one there I also added some 3" silicone over the alloy bit that goes through to hole on the radiator support as it looked like it was sitting on the edge of the hole in the radiator support, I never noticed a rattle or anything, but there was a witness mark It is basicly done, and I can live with the silver hose clamp at the T/B, I will get a black clamp for the head vent though where it is attached to the bulkhead fitting  It never stops...LOL, only issue now with the shock tower brace is it slightly touches the under bonnet liner now, if I leave it it will either wear some paint off the brace where it touches, or damage the liner, so I removed the liner to see what I have to work with, with the liner removed I have about 20mm of clearance, but sadly the middle part of the underside of the bonnet is only dusted with paint and looks crap, so I cannot have that, but.... as I have a roll of Carbuilders premium under bonnet insulation in the garage laying around that is only 5.5mm thick (we were going to use it on the boys Patrol, but he crashed the front of it a few months and it was written off, hence why he now drives my old Honda Accord Euro), I'll use the OEM liner as a template and get the Carbuilders stuff fitted up to cover that dusted paint up
×
×
  • Create New...