How bent is the bent one and how straight is the straight one?  Just curious.  I have an N42 head with a.007" upward bow in the middle.  It actually worked fine on the engine, but leaked coolant from the rear passenger corner.

 

The Modify book describes how to bend a bent head back to straight.  Also says that up to .015" bend can just be milled, both sides, without straightening.

Zed,

the bent one is high in the middle. I really do plan on trying to straighten it out a bit first before thinking about milling. When you are starting with such a small chamber you are limited with the shave fix. I'm looking at 11 to 1 now without shaving. There is too many variables that I need to research first before I know what exactly what route I am going yet. Waiting on a CC kit to see how much I can gain in chamber volume with some unshrouding. 

Maxima chamber volume is large!

 

Maxima N47 is 38.5cc

 

My Nissan N47 on Blue is 32.0cc 

Maxima chamber volume is large!

 

Maxima N47 is 38.5cc

 

My Nissan N47 on Blue is 32.0cc 

 

It's all relative I guess. Your running 32cc's on flat tops?

Ozdat says the N47 chamber is 44.6 cc.  Is the Blue N47 head milled?

Yup 2mm shave of N47 gave 32cc & CR 10.2

 

 

 

And I thought only P79 and p90 got that close of a shave!

Okay- took cam and towers off the warped head and popped them on the rusty head for a fast dirty test and the cam spun fine. So took everything back off the head and sent it to the machine shop for a pressure test.

If that passes then it's time to play valve swap.

I took everything off the warped head because it all looked clean and hopefully serviceable. So the only parts that will be used off of the rusty head is the core itself and the Rocker base nuts. I think they will be fine with a little cleaning. Got a new valve spring compressor and it works pretty dam well. Had the valves out in just a few minutes.

Hopefully it tests out good...

fantastic news - looking forward to the results.

 

i'm impressed with the tight tolerances and level of consistency with which these engines were made. i was gonna toss my old warped 150K mile head and literally just held onto it because i was too lazy to put it out on the curb and i'm glad i still have it, as it's a parts goldmine. i was able to swap out an entire cam, rocker & lash setup between motors with perfect fit. also was able to replace a bent valve on a new head with one from the old one and it seals perfectly and lash/wipe is spot on. 

 

somebody knew what they were doing with these things on the assembly line.

I keep everything! It just needs to be cleaned usually.

Need more storage space though, it's getting hard to find stuff. Maybe more brain storage would be better?

site, every time I see your avatar I want a hamburger! Where were you when you snapped that pic?

 

I envy you guys that get to do all these engine mods! I can't do S@*t when it comes to mods for my 77 280 because of CA. I should buy me a 240. I need something to tinker on.