RB25DET Neo head repair - Detonation damage - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Flatline1121 · 03-17-2014, 10:08 AM

So i got my hands on a Neo long block. Was told it wouldn't run after a headgasket replacement.

I got the block in 2 pieces. The head looks great in all ways except for damage to the combustion chamber on cylinder 3 and 4. 3 is the worst one.

I know the damage has to be repaired by welding the damaged areas and shaving the head straight. Ive never had this issue before so i have no clue how hard it is or how much a decent shop would charge for the repair. I dont even know if its so bad that a good machine shop couldn't repair it.

Im hoping after i finish another project, to actually build this for a reliable 4-500whp.

Anyone have any insight on this? Better to just get a bare neo head and start fresh?

TIA

G-E@Z31P · 03-18-2014, 10:02 PM

Might be cheaper to source a new neo head, call some importers see what they have?

Flatline1121 · 03-23-2014, 10:39 AM

Quote:

Originally Posted by G-E@Z31P

Might be cheaper to source a new neo head, call some importers see what they have?

If that was the case id probably just look into sourcing a whole swap and building the block. I messaged a machinist i know and asked him how bad he thought it was and he said it would be cake to fix.

He's also one of the best machinists/engine builders i know of in the south east, and that comes with a serious price tag. Ill have to bring it to him next time im that way and get a real idea of what it'll take $$$ wise.

supersayianjim · 03-23-2014, 10:58 AM

you need to look at my work log, the link in my sig. ive been there and done this, it should be the last few pages.

Flatline1121 · 03-23-2014, 11:22 AM

Quote:

Originally Posted by supersayianjim

you need to look at my work log, the link in my sig. ive been there and done this, it should be the last few pages.

Awesome, thank you. Ill dig into that soon.

Funny coincidence, im rocking my orange Goku shirt at work today lol.

codyace · 03-23-2014, 06:40 PM

While it's hard to give 100% perfect answer from a picture, I would say you would easily have that repaired by a good machine shop. They'll need to obviously resurface the sealing section, but the aluminum damage could easily be smoothed in/repaired. I've seen alot worse get fixed on cars that never had an issue again.

03-17-2014, 10:08 AM	#1
Flatline1121 Zilvia Member Join Date: Apr 2010 Location: West Palm Beach Age: 36 Posts: 166 Trader Rating: (1) Feedback Score: 1 reviews	RB25DET Neo head repair - Detonation damage So i got my hands on a Neo long block. Was told it wouldn't run after a headgasket replacement. I got the block in 2 pieces. The head looks great in all ways except for damage to the combustion chamber on cylinder 3 and 4. 3 is the worst one. I know the damage has to be repaired by welding the damaged areas and shaving the head straight. Ive never had this issue before so i have no clue how hard it is or how much a decent shop would charge for the repair. I dont even know if its so bad that a good machine shop couldn't repair it. Im hoping after i finish another project, to actually build this for a reliable 4-500whp. Anyone have any insight on this? Better to just get a bare neo head and start fresh? TIA

03-23-2014, 10:58 AM	#4
supersayianjim Nissanaholic! Join Date: Jan 2010 Location: location X Posts: 1,815 Trader Rating: (10) Feedback Score: 10 reviews	you need to look at my work log, the link in my sig. ive been there and done this, it should be the last few pages. __________________ http://www.240sxforums.com/forums/rb...ject-s-rb.html

03-23-2014, 06:40 PM	#6
codyace Post Whore! Join Date: Dec 2004 Location: Poconos, PA Age: 39 Posts: 8,030 Trader Rating: (58) Feedback Score: 58 reviews	While it's hard to give 100% perfect answer from a picture, I would say you would easily have that repaired by a good machine shop. They'll need to obviously resurface the sealing section, but the aluminum damage could easily be smoothed in/repaired. I've seen alot worse get fixed on cars that never had an issue again. __________________ *Want Air Conditioning in your SR20 Swapped car? Check out www.sr20acbrackets.com for more information! Quest Alternator Conversions for SR20!* Check my Group Buy! Tired of lousy internal gates? Go external wastegate with one of my manifolds, Check out my group buy

03-18-2014, 10:02 PM	#2
G-E@Z31P Leaky Injector Join Date: Sep 2012 Location: Toronto Posts: 126 Trader Rating: (0) Feedback Score: 0 reviews	Might be cheaper to source a new neo head, call some importers see what they have?