n42/n47 na build

[madkaw]

Just remember that the power is in the head and tune on this motors. Any serious monies should be on the head ( cam, valve job, ) and induction system. Of course if want a decent bump in power you want to significantly change the cam specs. But then that leads into the relationship of CR and cam. These motors like cams and can be very street friendly and still make power to 7k. Most go with flat tops for bump in CR , but as mentioned you would have basically a ZX motor . The 79 head would have to be shaved to bump compression , but that’s not too $$. 

Don’t forget about gearing . Proper gearing with differential and trans can make for a fun , quick car with less power.

[Rij Martin]

After some more research I think I have a more clear idea on what I would like to do. ITMs (flat tops of course) with a 2mm head gasket and a 280ish cam. (Post #6 from http://forums.hybridz.org/topic/43671-n47-head-l28/) The thicker head gasket should keep the compression lower and hopefully keep the engine away from pinging. Thoughts on this build?

Here are the threads I pulled info from

http://forums.hybridz.org/topic/70335-n47-head-on-a-flat-top-l28/

http://forums.hybridz.org/topic/43671-n47-head-l28/

http://forums.hybridz.org/topic/85907-attn-flat-top-28-with-e31n42-head-guys/

http://forums.hybridz.org/topic/11398-raising-cr-on-l28-worth-the-effort/

Also I have read that when putting a new cam in you have to replace the rocker arms or else you'll annihilate your new investment. Is that true?

I would also like to mention that I have been toying with the idea of leaving the motor, for the most part, stock. Just lighten the flywheel a little bit, and, as Steve mentioned above, play with the gearing. This way I would have a little bit more money to put into suspension work where the z is really supposed to shine.

Edited April 30, 2018 by Rij Martin

[rdefabri]

On ‎4‎/‎13‎/‎2018 at 5:41 PM, Diseazd said:

I like the torquey 3.1 liter, 7500 rpm screamer that goes “rumpety-rump!”   

 

Me too!!

[rdefabri]

On ‎4‎/‎13‎/‎2018 at 8:53 AM, siteunseen said:

Good stuff here if you haven't already read it. 

datsunzgarage.com, http://datsunzgarage.com/engine/

P79 head, http://datsunzgarage.com/p79/

Cylinder heads in general, http://datsunzgarage.com/heads/

Engine calculator, http://atlanticz.ca/zclub/techtips/calcs/engine builder/index.html

What happened to Bryan Little's site / Datsun Z Garage?  Can't access it any longer   Good thing I printed all the pages, have it somewhere in my mounds of junk.

Been a while since I've been here, but every so often, I get the bug.  I'd love a car that looks like Diseazd's (really all of his and father's - great 510 and some killer Z cars), but being on a budget a 3.1 stroker isn't in the cards.  Playing around with Z cars my entire driving age life (with some gaps in between, but always reading) tells me there's a lot to get from the mix / match route a la Bryan Little.

Digging deeper, I think a budget builder looking for a N/A L28 build could probably get away with leaving the lower parts / block alone.  So with the right carburetion and exhaust, I would think head work is where the focus should be (IIRC, the Honsowetz book spends a good amount of time on the head).

Sunbelt came and went - does anyone build a nice street performance head that is optimized for a stock lower end?

Edited May 17, 2018 by rdefabri

[siteunseen]

http://www.rebelloracing.com/nissan1.htm

You'll need to call them to get a ballpark price.

After reading on here for quite a few years about frustrated buyers of heads off e-bay from California Datsun I would steer clear of him.  Al Allen is his name I think?

Somebody could have a good one on here.  @madkaw had one not too long ago.  maybe start a new thread, "looking for a complete cylinder head" or something similar.

Good luck.  Cliff

[Kurbycar32]

My Rebello motor is an N42/N42 combo at roughly 3 liters.   Even 3 years ago neither Rebello or I were able to find a serviceable N42 head.  We sourced 5-6 of them but most were degraded past what could be used.  Luckily my car already had an N42/N42 setup so instead of swapping motors with a replacement he rebuilt what I had.

[siteunseen]

11 minutes ago, Kurbycar32 said:

My Rebello motor is an N42/N42 combo at roughly 3 liters.   Even 3 years ago neither Rebello or I were able to find a serviceable N42 head.  We sourced 5-6 of them but most were degraded past what could be used.  Luckily my car already had an N42/N42 setup so instead of swapping motors with a replacement he rebuilt what I had.

Did you leave the dished pistons or go with flat tops?  I'm curious as to whether I can swap out my dished with some flats from a ZX motor and top it with an N42 head I am currently running without any problems from too much compression on pump gas.

Thanks for a reply.

[Kurbycar32]

4 minutes ago, siteunseen said:

Did you leave the dished pistons or go with flat tops?  I'm curious as to whether I can swap out my dished with some flats from a ZX motor and top it with an N42 head I am currently running without any problems from too much compression on pump gas.

Thanks for a reply.

Is got 89mm Nissan KA24E pistons in it.  They appear to be "reversed dome" style dished pistons.  Also remember that here in California the highest octane fuel available is 91, and its got ethanol in it.  While I only use the best (garbage) gas available it runs fine in day to day usage.  I also told Dave that I prioritize daily driving over power so he may have chosen dished pistons to match that request.  This thing makes plenty of power without flat tops so I have no regrets.

[SoCalJim]

On 4/29/2018 at 11:20 PM, Rij Martin said:

I would also like to mention that I have been toying with the idea of leaving the motor, for the most part, stock. Just lighten the flywheel a little bit, and, as Steve mentioned above, play with the gearing. This way I would have a little bit more money to put into suspension work where the z is really supposed to shine.

I really like this idea as a Stage 1 kind of effort.  It might be satisfying enough, or it might be a gateway to pursue engine mods without wasting anything done in Stage 1.

[siteunseen]

+1 for a lighter flywheel.  I have an aluminium one that is a lot of fun to drive.  Takes a minute to get used to it but that's it, then "vrooooooom, vrooooooooom!" like a street bike.

[Kurbycar32]

45 minutes ago, siteunseen said:

+1 for a lighter flywheel.  I have an aluminium one that is a lot of fun to drive.  Takes a minute to get used to it but that's it, then "vrooooooom, vrooooooooom!" like a street bike.

+2 I also have one, a Fidanza mated to a centerforce.  I love it

[Rij Martin]

I guess this means the search for flywheels is on! Should I lighten my stock one or should I just go ahead and buy an aluminum one?