After a guy I work with came to watch the racing on Saturday his heart got set on the good old datto's... today he purchased a MINT condition 1979 Datto 1800J SSS which I think was fairly unique to SA as I dont pick up much by google,,,

Has a semi tired L18 in it with the twin SU's, motor runs like a clock but has some blowby after her 180 000km's.

I am gong to help him spice it up a touch to get her to perform nice in Marque class so I have a right hand man to help me fend off the Alfa's but I have never paid any attention at all the the L series motor so here I am asking for some help...

Nothing crazy needed, but I will change pistons and obviously do head work while I do the motor, anyone know of some slightly higher comp pistons the swap in easy? also what is a good size cam if one keeps the SU's (they work 100% so it would be a bit sad to loose them).

Last of all, what sort of power gains do the L18's make with a nice exhaust manifold, exhaust, cam, head work, bump in comp etc?

And yes the first thing we do will be to put new springs in and raize it a bit!

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Don't know about the L18 (I'm learning about em these days too) but I do think that the car looks great right now...please don't raise it. :)

Yeah i second that unless its scrubbing or bottoming out which can be fixed as you would know without raising it Leave it as is. It looks really tidy and has a nice stance.

you probably will have to raise it for circut racing but as a tidy street car looks good, you can search ozdat.com for heaps of useful l series info too.

This looks like what we always refer to as a Stanza, but we had them stock with l16 not l18.

Its wayyyy to low at the moment bumps and rubs all over and is super soft, needs at least twice the spring rate especialy in the rear,

Will start the search on Ozdat,

ya thanks for that ozdat tip.

those were called Stanza in aust with L16 and different grill and headlight, and were successful factory rally. sort out the ride height for the best handling for what u use it for. no point rattling your fillings out just to ride on the bumpstops for the look.

The L18 responds nicely to all the usual mods,like more compression, webers & extractors, good spark, balancing, bigger camshafts, etc. Talk to some people here in Australia like Stewart Wilkins & Arther Jackson at Stewart Wilkins Rallying, Baz at Datsports, & if you sign on to the Brindabella Motor sport Club (a large rally based club in Canberra) there's somebody by the last name of Munyard on the NSW Central Coast who is their L series God.
You should be able use the 4.11:1 diff ratio from a Bakkie (h165) in this car. The brakes are the same as B310 Sunny's so any S13 disc & rotor conversions should work the same. The biggest problem might be finding a strong enough gearbox, as I've broken a stock Stanza 5 speed behind a stock L18, & I don't know if you could get any of the larger 5 speeds in South Africa. If you can, you might have to enlargen/move the hole for the gearstick.

Rezlo on the cam side of things. Do not go to mad with the SU's especially if you are going to run something as thin as ATF oil in them. Currently I'm running a 268, nice bottom down torque, but would like to go one or even to steps up, but that will be the limit.

In a previous A12 motor my brother ran a serious wild cam with a set of SU's, this resulted in the pistons jumping up and down and tunning was a nightmare on ATF, he had to revert to normal 20W50 car oil to keep the pistons from jumping.

Hi Rezlo my brother is in Jozi and has a PG720 with a bone stock fuel injected L28.This motor came in what we here in Zim know as the Skyline GTX.He is running the motor with it's stock box but the diff is a stock PG720 item.As far as pistons go if my memory serves me well he used Ford pistons for his rebuild not sure exactly which ones though.I could give you his number if you would like to talk to him.Oh and that PG720 of his goes like stink.