Datsun Roadster Forum-311s.org

He’s made a few different designs. This one is for my LHD car. Is there a difference in where the steering shaft goes if you have recirculating ball or worm gear?

tangoterje wrote: Sun Jan 05, 2025 3:02 am He’s made a few different designs. This one is for my LHD car. Is there a difference in where the steering shaft goes if you have recirculating ball or worm gear?

Nope! Well, maybe he decided to address the issue! I'm excited for you, it's a beautiful header. Be sure to post some installed pics so we can see how it lays out. I hope you'll consider running the car on the dyno when she's all together... good tuning opportunity that could find a few more ponies and helps provide more objective info. Thanks for posting!

Well, this isn’t his BIG header, but I think it should be more than enough for my (hopefully HOT) street car.

I’ll see if I dare to post dyno numbers when time comes. But I’m pretty sure I’ll be happy in any case. When I
bought this car, I got 108(!) hp at the crank, and that was with a newly rebuilt solex setup and a 123 distributor, haha. Still, it felt ca twice as alive and fun than my Z. Actually, it was that moment I drove this low compression, wizards sleeve piston ring, worm down rocker arm, no lift camshaft, broken head bolt ROCKET that I realized what my Z was missing: ignition advance! Spent more than a year redoing my Z engine, trying to achieve that same feeling. Weird, eh?

Epilogue: Yes.

Gotta love ya man! Yep, ignition timing is critical! Doesn't matter how much air/fuel it can suck in, if it's not fired at the right time it doesn't like it! I'm curious about the 123 dizzy. It didn't exist when my fellow poster Daryl told me about Megajolt (crank-fired via a 36 tooth wheel) and got me started down this long journey that has ultimately led me to EFI and Microsquirt. It's been (still is) fun! And in process. Since you have the ability with the 123 to program your own timing map at any rpm/load, time on the dyno really becomes that much more helpful, especially when building an engine that's different from stock. You can program what YOUR engine wants, and you'll know for sure because the dyno tells you at every rpm you decide to test. I'm looking forward to my turn. It may be fine, it may be off... who knows. It has my best guess right now, and that's primarily based on not hearing knock and a "typical" curve. Trouble is, after playing drums for 45 years I have documented high frequency hearing loss so.....

I highly recommend this gizmo:

https://tunertools.com/products/link-g4 ... 9021594688

I too thought I could hear knocking, but decided to try this one out. I was shocked of how much unaudible knock there was! My dyno guy also has his own dual in-ear knock sensors, and both setups showed knocking at the same time, so I think it shows pretty true readings.

I scratched my head long and hard over the L engine knock. Max ignition is of course preferrable, or up until your «max brake torque», but if knocking occurs, power will be down (plus damage). On my last engine iteration where I had ca 12.5:1 static comp on a crap E88 head (the one with the lousy chambers), my ignition curve was ca 25 degrees max, it was ridiculous! Even if the dyno graph showed it was a «powerful engine» above 4000rpm, my foot certainly didn’t feel it. I tried various things to add a couple of points here and there on the ignition curve (cam timing, gasket thickness). Pedal immediately felt more responsive, but if I floored it, it knocked. My dyno guy was shaking his head. For every point he took OFF, the power increased again. But still, it wasn’t the engine I wanted. Installed a new head, but paying a lot more attention to chamber design and squish/quench, cam duration and cam timing. Going down to 10.5:1 actually gave me 10hp and 15Nm more. Doesn’t sound drastical, but what happened BELOW 4000rpm is the important part: throttle response increased, absolutely NO knockng under ANY circumstances. Max ignition 35 degrees at 3000rpm. A bit like roadster U20 curves

tangoterje wrote: Mon Jan 06, 2025 3:31 am I scratched my head long and hard over the L engine knock.

We're getting way off topic here so I'll write to you directly on Messenger

but had same basic issues on my Z made more power at 28 total timing , figured it out and fixed it running 35now (and much more on cruise)

@Darryl
To get us back on topic how about some 4-1 U20 and 6-1 Lseries exhaust music this why I like this configuration by the way the sound of it

Roadster https://i.imgur.com/rpMOGno.mp4


Z. https://i.imgur.com/LTkQSQ0.mp4

Tangoterje you obviously aren't new to this... thanks for sharing your experiences! One never knows what roads others have traveled, so my goal is to share whatever I've "learned" (good or bad!). Too bad you live so far away!

Pjackb, the z sounds awesome but unfortunately the Roadster one didn't pull up.

Gregs672000 wrote: Mon Jan 06, 2025 1:22 pm Pjackb, the z sounds awesome but unfortunately the Roadster one didn't pull up.

Fixed the link and for good measure here another one with an SR20 and what is best described as a 4-2.1 manifold
this is the experience I want also with my 2.2 U20 in terms of revs etc
https://i.imgur.com/xzdHpVd.mp4

Ya, they all sound great but it's hard to beat the smoothness of the inline 6.

Pjackb,
Both cars sound great.....but...I didn't hear a good, properly sized, 4-2-1 or 6-2-1 in there for a comparison.....

At a parts store today I happened across the exhaust parts shelf....been trying to figure out how to make an anti-reversion chamber for a long while and this looks like it will work....parts from 'Nickson'. Now to get them welded up.
This is for a 2" exhaust, other sizes available. should be able to get parts for 2.25" or 2.5" if that's what you're running.
Will be placing this just after the first frame pass thru.

1) 2" id x 2.5" od part #17566
2) 2.5" od x 2" od part #17568
3) 2" od exhaust piece to match my car.

Who's parts shelf? Thank you.

Got these @ Canadian Tire.......
Nickson is a US company, so likely Napa and other parts stores should carry them....maybe Rock Auto?
http://www.nickson.com/