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-   -   What to make of this head? Detonation? (https://www.miataturbo.net/engine-performance-56/what-make-head-detonation-51500/)

falcon 09-10-2010 09:46 PM

What to make of this head? Detonation?
 
8 Attachment(s)
So I bought a head from a friend who had it built by a local head guru guy. It was run on a turbo 1.6L that was tuned by an absolute moron. The amount of detonation on all 4 pistons when I broke down the engine was unreal. The guy who tuned my current engine is the owner of the dyno that this other guy used to tune my friends car. He said he was sitting in his office and could hear the car detonating on the dyno and he ran out to see what kind of hackjob tuning this guy was doing. The timing map must have been extreme. It made 269whp on 16PSI with an FM2 kit (GT2560R). 460cc injectors, stock FPR, stock fuel rail (not even dual feed) and stock fuel pump. No wonder the engine lasted 1500kms. When I pulled it apart 3 spun bearings and 2 cracked ring lands (cyl 3 and 4).

So I didn't know any of this when I bough the head... which kinda pisses me off but whatever.

Anyways... on to the head. I don't know what to make of it. I cleaned it up a bit to get a better look. The combustion chambers don't look smooth at all. I don't know if this is just stock or if it WAS smoothed and now has had detonation. I also don't know what to make of the valves.

Basic head run down
PnP intake/ exhaust ports
3 angle valve job
OS 1mm valves
new springs, retainers and lifters

Cyl 1
Attachment 194432
Cyl 2
Attachment 194433
Cyl 3
Attachment 194434
Cyl 4
Attachment 194435

Some pics of the intake porting... (one has a bit of oil on it from cleaning... that's not scoring or anything)
Attachment 194436

Attachment 194437
Attachment 194438
Attachment 194439

jtothawhat 09-10-2010 10:12 PM

Looks like a lot of pitting from the detonation; this can be fixed though.

falcon 09-10-2010 10:25 PM

Figured that would be the case. Time to dis-assemble, shave, clean up and put back together.

FML... this sucks. I didn't plan on putting any money into this head since it was sold as a "working" head. That's what happens when you don't check things closely yourself.

falcon 09-10-2010 10:26 PM

How to the valve faces look? Re-useable?

I can't believe a head with 1500kms looks like this. Unpossible. This "tuner" is a pretty big shop locally. Can't belive people go to him.

JayL 09-10-2010 10:36 PM


Originally Posted by falcon (Post 628161)
This "tuner" is a pretty big shop locally. Can't belive people go to him.

You should post up who it is so others can avoid him.

falcon 09-10-2010 10:43 PM

http://www.fireandfuel.ca/

Not to be mistaken with the guy who built the head, which originally did an excellent job. Looking at other port work on these heads posted on here and m.net the work on mine looks superb. http://www.haywardperformance.com/


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