Jump to content
HybridZ

Japanese N/A L6 400hp, how they do it, pictures I've found, etc. Not 56k safe


josh817

Recommended Posts

I like this topic a lot! :) tons of info to learn (and understand...)

 

Regarding the tau layer, I believe some can also used this technique to vaporize the fuel mix. With our "out-dated" fuel injection system (as opposed to new direct injection systems), to have fuel mix going against hot valve & runners can also help. They take some energy out of the mechanical parts, temperature of the mix goes up, liquid mix becomes gases so mixture would be much easier to burn afterwards...

Condensation on hot runners is lowered compared to cold one.

 

This is one of the reason why engine when cold needs more gas than when hot.

 

Flow discussions on the side, what would be the effect of a polished runner on tau layer? Can we consider the less, the better?

I believe we wan the least possible close to the throttle and some at the back of the valves.

 

Regarding flow, can the valve seat be also design to create some "shape" in the flow such as a swirl.

Same remark for valve back face, we could have also grinded them in order to create some kind of swirl. Since it is not done, I guess there's a reason: is Flow > Swirl for max power?

Link to comment
Share on other sites

In that Jim Cowart video he talks about fuel puddling, the example he uses shows a horizontal port which would be applicable to a L6 in configuration. But what about most V engines which have downward sloping inlet ports? From what he said fuel would still be deposited on the inlet port walls so the effect he talks about would still exist to some degree but obviously fuel would tend to run down into the cylinders and not puddle as such. The timing of that process would of course be relevant, particularly if the fuel did not run down quickly enough to sufficiently negate the effect he talks about. Which I guess is what happens.

Link to comment
Share on other sites

  • 7 months later...
  • 3 weeks later...

I'd hate to bump but one thing to note in case none of you have noticed on any other motors you may be working on... But the ring on the back of the crank to center the flywheel can also be found in BMW 2002's with their M10 motor. For what it's worth, one version or another of the M10 motor was used as for an F1 car in the 80's...

 

Disregard the knife edged part, that's not stock.

20pd15v.jpg

Link to comment
Share on other sites

  • 1 year later...
  • 6 months later...
  • 1 year later...

I know im bumping an old thread for no real reason lol :P..... except the fact that the very first page ...first post.....second video of the blue Z on the drag strip.....

That should be a damn sticky lol

 

I want that exact same motor....that exact same sound!!! That dude just standing there kills me lol ...i would probably do the same thing!

 

What ever the parts are I want it !........

 

I would love to know the true facts on that car....is it all Kameari .......or did as-watanabe have something to do with this .....hmmmmm

Edited by theatriks
Link to comment
Share on other sites

A similar engine build was used on my 1970 hakosuka - although this specific one is not rated for 400hp

Seat of the pants would guesstimate mid 200s. Anyways, I thought I'd throw up a couple detailed pics to add to this thread

The build was done by RHFactory in Nagoya - they were pretty well known for L6 builds but the financial meltdown of 2008 did them in - they are now out of business

The PO of the car had all this done - I'm the first US owner of the car & have had it 3 years now. Very quickly early on I had to tear it down and refresh it with new rings / bearings - it's been faultless since.

 

3096cc

N42 head & block

89mm bore

1.2mm thick headgasket with a 90.5mm bore

V07 diesel crank

L24 lightened rods

Flat top cast pistons 2.7cc valve relief and 33.5mm pin height

N42 cyl head heavily re-worked to 37cc with giant 42mm IN ports & match ported to intake manifold

I had Rebello flow test it and he confirmed that in his opinion it was garbage until you got to really high revs - then it sang

I never got a full print out / report from him

 

Aftermarket cam

I had the cam measured by Isky - I'll have to get you those specs at a later date as I don't remember them by heart.

Power comes on after 4k rpm and runs strong up to 7500 - 7750rpm

 

Mikuni 44PHH S5 triple carbs with unknown jet bodies, and 230 main air / 210 main jet / 62.5 pilots / and some hand ported venturis that were 34mm when new

(Excessive, right? lol...)

 

Ignition is an MSD7AL2 with an 8500rpm rev cut pill

(Funny how the Japanese want US parts, and the rest of the world wants Japanese parts ... )

 

12:1 CR by my math

 

KGC10_132.jpg

Mystery jet bodies

 

KGC10_097.jpg

42mm IN ports

 

KGC10_099.jpg

 

KGC10_096.jpg

OS Giken TS2- twin plate clutch

 

KGC10_102.jpg

Unknown mfg 6-2 stainless. The OD of each pipe at the bottom flange is 50mm.

Exhaust is twin 50mm pipes running all the way back

I removed PO header wrap and had it JetHot coated instead

 

KGC10_130.jpg

Kameari makes big port (41mm) IN/EX gaskets for this application

 

KGC10_0136.jpg

The lightened L24 rods

 

KGC10_0139.jpg

Work of art!

 

KGC10_0141.jpg

Cast (Nissan bowtie) piston - looks A LOT like the Kameari street unit ... not sure if it is or not

 

KGC10_0142.jpg

 

KGC10_0145.jpg

Everything balanced

 

 

Anyways, hope that helps anyone looking to duplicate something similar ...

 

It makes all the right noises - you can hear it sing here:

https://www.youtube.com/watch?v=3LWWS4SsgaE

https://vimeo.com/41685762

Edited by ericbauer
Link to comment
Share on other sites

Somehow I don't think those are the specs theatriks is looking for. Nice build though! I like the Nissan pistons cast with reliefs. Hang onto those!

As for the blue car... ironically, the green one edges it out in the race. Happens right before the guy walks in front of the camera.

High-end NA L6s have radically different sounds from the ones I've heard, to include both in this video. The green sounds like a much higher pitch, really gargly. Sounds like it's more highly tuned up to the top of the RPM band, and the blue one sounds like it's the muscle car and has the grunt. But that's my ear.

Is that why you like the blue one?

Link to comment
Share on other sites

I get embarrassed every time this thread pops up. The main contribution is seeing all the internal pictures but that first page on exhaust stuff, when I look at it now, I laugh...

 

For more reading on scavenging and intake runner lengths I would read my more educated thread where I utilized a shock tube lab at our university to relate to pipe pressure impulses:

http://forums.hybridz.org/topic/117954-a-better-explaination-to-exhaust-scavenging/

 

As a quick summary... Had a disk that ruptured at a certain pressure. The pressure traveled down a length of pipe that was open at the end. This was the pressure data from a sensor just after the disk. Imagine the rupturing disk as an exhaust valve opening. There is a region behind it where the pressure is lower than ambient. Time it correctly by varying your primary length and/or diameter.

cRXuAWG.jpg

 

Also don't use tinypic to host images because I just saw one of my posts was some half nekkid cartoon chick that didn't seem to fit in anywhere in my discussion........... I'm still very confused.

 

 

Another note, your 41mm diameter manifold gasket that fits your ports. I measured the ports on my mystery head at 39mm and I have another picture of someone porting a head with a guide valve labeled "40.5". When my father use to port heads he would use a set of guide valves like these. Valves cut to a certain size so you can ensure a relatively circular port as well as taper the port how you want to.

 

Honestly don't know who the source is anymore.

MqPJGDo.jpg

 

 

 

Here is another one of the green car. The sound is nice but honestly irrelevant...

 

Edited by josh817
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...