So your auto made 79rwHP? or 58rwkW?

It's stock?

I reckon all the stuff my Dad has done has only moved the powerband up the rev range, not given it more power.

The air/fuel at peak power was only 12:1 so there's a bit more power to be had. At least the graph now for a/f is relatively flat. Need more needles to try and get a better a/f graph. Then his should get a little more power. Plus we haven't playing with timing yet either.

_________________
END TRANSMISSION

hehe. That's another thing i don't really understand. The different jargon used to describe a cam. I understand the duration ie 270', but some people say: mild, warm, 25/65, stage 1/2/3, or even 72 degree. I find this confusing
And when i ring a place and ask what they recommend, i get all this jargon which could be describing the same thing for all i know. When i say "What's its duration. What's its lift?" They say "I don't know, it's a stage 2 cam"

Bout the only common thing is its intended use. Everyone seems to know what it'll be used for...

_________________
END TRANSMISSION

all that stage stuff is only for crow/crane cams!! ignore them.

Not stock but close. 25/65 cam matchported head and 1 3/4inch SU's.
Same bottom end that came with the car, so only bolt-on stuff really.
Standard exhaust manifold and 2 inch system

with the 25/65 "i think" the 25 is degrees of overlap and the 65 is degrees of lobe seperation. I would ask Baz about that , as he supplied the cam and will know all its specks.

fr3ak wrote "So your auto made 79rwHP? or 58rwkW"

-yes it made both.
oh and dont forget the .8 wrhp (79.8 rwhp)

That's good.
What did your a/f graph look like? Where was the peak power made?

_________________
END TRANSMISSION

a/f ratio was 11.9 ! so it needs adjusting (13 -14 is about right)
Peak power was all in @ 6000 rpm
and max torque was in @ 2800 rpm ( torque was 137 Nm )

A problem we had was finding a safe and good needle. As we went up in the needle size (to lean it out) we had dangerous a/f for light throttle/ cruising. Finding a suitable trade-off needle size could be time consuming.

Solution is to have 2 sets of needles: one for cruise, one for race.
I thought 12.5-13.5 a/f was right. But i guess it depend on each application. Dad's peak power made at 5750 RPM and torque was 210Nm. Don't know how accurate that torque fiqure is...

_________________
END TRANSMISSION

Freak,
You can rev your L18 as hard as you want. Just don't expect it to last unless the crank is suitably prepared when it is machined. You need to explain to whoever is doing your machining what you plan on doing with the car. Also with 40mm Delortos you wont flow enough air to make power at high rpm so there is very little point revving it much past the point you make maximum power at. If you are still running std valves I would be surprised if it makes max power above 6000rpm.
As for suspension rates, what works for racing (ie grip) will not work for drifting (ie hard as a rock-no grip) so again you need to decide what you want to use the car for and set it up to suit.
Unfortuneately how fast you go is directly related to the size of your wallet.
Jake

What ever happened to the people that know about L18's....

If you have have asked this question 6 months ago you'd have about 5 people swearing on their mothers grave L18's will rev to 8000 all day every day....

Now i dont have much exp with this, but MY L18 has no trouble at all dipping into 7,500+ rpm the only trouble is with the L gearbox making ear piercing noise at and after 6,200rpm.

I wouldn't be worried too much about the rpm... set your engine up, get it tuned, and use the powerband correctly.

the racer brown guide on the datsport site is a good read if you want to know about L series engines and cams
http://www.datsport.com/Racer_Brown_Menu.html

Yes. That text is slightly similar to the camshaft section part in "how to hodrod and race your datsun". I wonder who copied who? hehe
Is it stock, or has it been worked on?

And yeah, i'll just get mine tuned the best i can and be happy with that.

Thanks for the help guys!

_________________
END TRANSMISSION

its slightly worked... its had head.... and has a decent cam

Fr3ak,

I built an L18 using L16 rods and Mitsubishi Starwagon 87.5mm pistons. They are flat top and the Stanza rods are slightly longer giving better ro/stroke ratio. Head is modified with 44/38 valves. Carburation is twin 40 dellortos. Cam is a Tighe 359/517A which is a 72 deg exhaust side and 74 deg intake. Lift is 495. Go to Tighecams.com.au for full specs. Bottom end is balanced. Rods from Stanza apparantly have larger rod bolts than 1600 rods, and L24 rods also have larger bolts. Engine is revving to 7500, only drama has been a big end that went after a big spin. I think I left foot on go pedal whilst grabbing first to execute a perfect 360. Well it felt perfect until the noise started!!!. Use in autocross and hillclimbs so far and have been pretty happy with this combo. 37cc head gives around 11:1 comp running on PULP. Not dynoed but goes pretty well.

_________________
Bondy

That's some good stuff What does the engine 'feel' like to rev out?

How much $$$ was the cam?

If you ever get it dyno'd, please e-mail me the results.

Thanks for the input, welcome to OZDAT

_________________
END TRANSMISSION

I just went and had a look at an l18, l20b and an l16. The l18 and l20b both have the same counterweights. the l16 doesn't have as many. The l20b was out of a series 1 bluebird. Is a series 2 crank different?



Thomas.

There are a few 6 bolt fully counterweighted works L18 cranks lurking about in a few garages. No idea what the $ would be, though. But this'd be an excellent starting point for an L18 hottie.

Cheers,

_________________
Chris [;-{)>