l20b performance tips wanted!

[bilzbobaggins]

xanax not zanax.  good luck.

 

Jeff

[wayno]

Headers are just fine, I have been using them on my work truck for over 15 years, they just don't last very long(maybe 3 or 4 years before needing repaired), and are noisy, but I cannot hear them over the noise the dual SUs make.  :lol:

If your looking for more power along with reliability, there is no substitute for displacement.

 

The bigger the cam, the harder it is to haul weight.

[EricJB]

Is there any good headers out there?

 

I think there used to be. I've seen pictures. All I see anymore is that fits everything POS shorty. I ended up making one.

 

 

[datzenmike]

Is there any good headers out there?

 

 

stock manifold is the best IMO

I think the 'problem' is that Nissan made the stock manifolds so well that that a header isn't any improvement. This is not the case with some makers...

 

 

ANYTHING would be better.

[heretic]

WTF....that's 4 halves...way too much 'info'. 

 

HAHAHA he did say  "... the other half are bad at math"

[Stoffregen Motorsports]

There's no replacement for displacement, as the saying goes. Bore it, throw a cam in it and you can expect 130 HP with no real headwork. But the sky's the limit (as long as you have an open checkbook) all the way up to 220 streetable HP with dual carbs.

[banzai510(hainz)]

be honest youll be luck to get 100 to the round in most cases.

130@ wheel is a min of dual carbs cam head work

[h2oprint]

I am too working on my l20b, i hear aboutthe block off plate for the smog crap, can anyone show me a pic of that, as i want to remove that stuff.

[TENDRIL]

^^? on your intake manifold?

 

if so its just a piece of stock 1/4 alum. with a piece of gasket paper on mine?

 

with bolt holes drilled  on a w58 mani 

[Stoffregen Motorsports]

be honest youll be luck to get 100 to the round in most cases.

130@ wheel is a min of dual carbs cam head work

I'm speaking of flywheel horsepower. And I always assume that the right cam will be chosen and installed properly, the carb will be tweaked, the distributor will have the right curve, the exhaust will be maxed out with a good header/collector/tubing/muffler, etc.

 

When you say to be honest, are you asking me to dumb down to the "average build" level?

[banzai510(hainz)]

Honest?t I mean say the truth.

When it comes to Datsun making power you got to multiple by 4$$$$ then hit the 1/x (inverse key) on the calculator come out the HP increase.

 

there was a guy at Dave carrols(box 2dr box flair) with a LZ FI rail Rebello coil pack motor. He had 142 to the ground. paid 5k to have motor done at 1990s price.

 

Datsuns.com had a chart of peoples up grades and even with sidedraft it was hard getting to 110hp

 

I wish I had 110hp to the ground

[Stoffregen Motorsports]

Honest?t I mean say the truth.

When it comes to Datsun making power you got to multiple by 4$$$$ then hit the 1/x (inverse key) on the calculator come out the HP increase.

 

there was a guy at Dave carrols(box 2dr box flair) with a LZ FI rail Rebello coil pack motor. He had 142 to the ground. paid 5k to have motor done at 1990s price.

 

Datsuns.com had a chart of peoples up grades and even with sidedraft it was hard getting to 110hp

 

I wish I had 110hp to the ground

I've said it before, who said horsepower is cheap?

 

And it seems like you still think I'm talking about rear wheel horsepower, I'm not.

[datzenmike]

Here's Byron's (from The Realm) LZ22 with home made EFI. He (by his own admission) 'threw this motor together from spare parts' that he had. Nothing special about the head and a mystery cam, specs unknown. The previous year he had dual side drafts and it ran 134RWHP so it was dialed in pretty good.

 

[S13 b210]

One of the biggest differences I've felt on my l20b was putting on a Mallory dual point distributor, it was day and night difference. Just my thought

[RedBanner]

... huh?

[Sealik]

Build the bottom end bone stock. Maybe .040 for cylinder wall clean up. Find an exhaust manifold as DMike suggested and a compatible intake. Spend some time cleaning up the ports on the head. Don't hog them out, just straight and smooth. You can do this by hand. Gasket match the intake/head, and blend the carb adapter to the intake. Find a cam with a advertised duration less than 270-280 degrees, with accompanying springs. Run a 2" exhaust out the back with a good turbo muffler. 

 

Yes....here is the L4 intake port matched to the U67.....32/36..<...38 matched to IM

 

No specific order.....

 

 

 

 

 

 

 

 

 

 

If your looking for more power along with reliability, there is no substitute for displacement.

 

The bigger the cam, the harder it is to haul weight.

I think that is more relative to duration...not lift

 

 

I am too working on my l20b, i hear aboutthe block off plate for the smog crap, can anyone show me a pic of that, as i want to remove that stuff.

 

 

 

 

Eventually 'tossed' the Webers and went with 46 SUs....big improvement for the LZ23.

[h2oprint]

Awesome thanks, i thought it went somewhere else

[Sealik]

Note....

 

PCV valve was 're-located' to the center of IM

 

 

 

[RedBanner]

An egr block off plate is the most simple thing you can make your self.

.

.

...

 

 

 

 

 

 

But ive never made a egr block off plate...

 

 

 

I make egr cockoff plates.

 

 

[datzenmike]

One of the biggest differences I've felt on my l20b was putting on a Mallory dual point distributor, it was day and night difference. Just my thought

 

 

... huh?

.

Must have been something wrong with the dizzy if the Mallory made it better.

[Stoffregen Motorsports]

.

Must have been something wrong with the dizzy if the Mallory made it better.

I was thinking the same thing.

[bonvo]

i know im a little late to this but why all the header hate? sure they may not offer much performance gains but they look better and are easier to find ive been running a header since 2009 on a daily driven l20b there is some surface rust to clean up but no leaks to be heard its about getting a quality one 

[RedBanner]

Seasonaly driven. Wich is even harder on them. Ive seen some that are quality. Some one should mimick the l16 one in a heaveir tube, with a thicke flange. Id like one.

[EricJB]

The currently available header (shorty) doesn't have quality issues. The one I've had for 15 yrs is a pretty stout unit. Where they lack is in design. The primaries are way too short, and unequal lengths. With unequal primary lengths, the exhaust pulses don't hit the collector one at a time, in a timed sequence (firing order) At high RPM's they just crash into one another. The collector is not capable of assisting in scavenging. And going up against a very well designed stock manifold and downpipe ( that looks a lot like a tri Y header) it falls short.

 

Some say they look better, and you get to tell people that your car has a header. But that's about it. Looks and bragging rights. I really wish someone made a good header for Datsuns, even if they were $400 to $600, I would bite.  

 

 On a build with a budget, The money could be put to better use. Unless you want to buy mine, just kidding.   

 

This guy explains it pretty well.

 

[cruznude]

Yea, exactly I took the electronic out and installed a mallory dual point distributor and with my dual 40dcoe's, the p/u on the throttle response was amazing! So much better.  Have your block work done and a little bigger cam and you'll have a respectable build w/o putting your life savings into it.