altezzaclub

The video starts at idle, you can see the slide moving up and down with the grumpy cam, moves off through 1st and 2nd, and I booted it when in 3rd at about 20seconds. That's the only time the throttle plate is horizontal. The mist around the needle is raw fuel being sucked up out of the jet. You can also see the giant torque of the 4K tilting the motor away fom the camera! The slide drops down & up as we change gear. In 4th you can see the throttle plate isn't wide open as it holds 100kph, then it slams shut as I lift off and flips up each time I blip the throttle to change down at that side road where it stops. The piston never quite goes right up, which is how the HS2 carbs were made. No mighty roar I'm afraid, I think that's why the son threw the camera out... Nope- Imageshack threw it away.. sorry about that.

First up was to see if the needles were coming right out of the jet at full throttle. This needed a webcam bracket making up, which took 10minutes and some black tape. It was too dark with the bonnet down, so I had to tape a torch on as well!

It still had a leaning effect, which didn't worry me as I am using needles that were made for a 1000cc Austin Healey Sprite and I've sanded the mid-range to get it as rich as I wanted. I'd never touched the top end, I knew it leaned out above 4000rpm but I wasn't sure what part of the needle was working there. So I took an old webcam my son had tossed, and an old laptop we have, and went out to the hill coming in from Dubbo. In the photo the hill goes up a long constant grade that the Rolla will just hold 100kph on if you start at that speed. There is no way it will accelerate up there. Where the blue line is there is a road to left which is the end of our climbing tests, and the road undulates a bit to the green line, where there is a traffic island we turn left at. So we get a long hard climb, a cruise up and down, an island to stop at and then accelerate away from.

OK, the cardboard intake works superbly.. too superbly at high speed, where it leans the carbs out!! We disconnected the intake tube in Wyalong, moved it away from the airbox a bit and taped it into place with the odd spanner... A couple of tries and we knew what size hole released the pressure at 100kph. Then I cut a hole in the top of the airbox and put a plastic flap over it. It closes below 60kph (in theory!) and the motor sucks in cold air, and can flap up at 100kph to let out excess pressure.

Go to a racetrack when clubmans racing is on and chat to guys there about who is a good tuner locally. If not, chase some mad old Italian backyard garage who does old Fiats/Lancias etc as they will know Weber tuning backwards and have a shitload of jets to try. It should end up smooth and sweet with no flat spots, but roar when your foot is flat. Round-town should turn in 8.5-9L/100km. You can make Webers very fuel-efficient. If you pop the little round top off you can take the jets out and look at the sizes. The top one is the air jet, should be around 180, the middle tube is the emulsion tube, say an F9 or F6 or F15, and the bottom one is the main fuel jet, should be around 115. All 4 sets will be the same. (well, the certainly should be!)

ROFLMAO !! I read "I'm lucky to get 250Km" and thought - "Gee that's bad!" then I read the rest and cracked up! There's nothing worse that DCOEs for using fuel, but that power and noise is soo addictive! Have you had the jets changed to suit the motor? Slap an oxygen sensor on it and you'll probably find it running rich 80% of the time. You've got main jets, air jets, emulsion tubes, idle jets, pump jets... and they all need to be right for that motor. Don't forget the float levels too.

err.. well, yes it is OT, but its all good education! All the IRS cars squat under acceleration, so your -3deg on the rear becomes -somethingodawful deg when you nail it and you're running on the very last inside tread with full power.... ..and they probably don't get enough bodyroll to put a -3deg tyre flat on the ground! There's a lot to be said for a live rear axle, its just that great weight banging up and down in the back and jumping off the road! Sorry Mat10e... carry on...

I used the holes in the tappet cover to mount a bracket. I already had a little alloy bracket holding the heater pipe off the dizzy, so I just added a right-angled bracket. You might have to have the cable in a different place with the Weber, but those are the holes to use.

This sort of thing- soft to start with then stiffens up. http://www.fatcatmotorsports.com/FCMstops_comp.htm

Softer bumps stops are probably the best bet. You can't rely on the shocks to limit bump as you will bend the shaft or smash the piston. Cutting the bump stop shorter makes them really hard when you finally hit them, but the new-style plastic bump stops are designed to give more so they're not so harsh at first. If you it a bump stop halfway through a corner the tail snaps out instantly, as you've probably found out...

I run the Altezza at that. Plenty of young guys are hanging their wheels out at -2.5deg, but plenty of young guys are also suddenly finding the inner treads are through to the canvas and the tyres are only three months old!! I think the IS200 chassis is prone to inner tread wear if the wheel alignment guy uses the toe-out side of the specs. The KE70 seems really light on tyres, the Corona LCAs give it basically zero camber on slightly lowered springs. -13minutes and -18minutes, with 1.2mm toein. I am forever amazed at how little a lot of techs know about cars at all, yet here they are doing wheel alignments that affect tyre wear and handling every day... "if its got a green tick that will do- get me the next car.." I always find a guy who does racing cars.

Running OK when cold then not running when warmed up suggests its too rich at idle. Re-setting the idle mixture screw might fix it straight away. That's just screwing the mixture screw in and out again to get the highest, smoothest idle and then re-setting the idle speed screw to the idle speed you want. Must be done warm. Another one would be float height too high, but that is less likely. Have you measured how much fuel it uses? It should use less than 8L/100km around town. Go over it as KE70dave said, a general tune that you can do at home yourself. These are dead simple cars.

It amazes me how bad other forums can get. If you read the posting rules on Toymods it seems like a legal dictionary!

LOL! Done that! Has anyone looked into tyre wear and camber ratios?? You will need to run more toe-in to stop the inside edges blowing away, so although that helps to equalise the tyre wear across the tread they still wear faster for every degree of camber added. ...and if you're looking for front grip you will be running very expensive tyres...

Ah- get a Celica rear sway bar in there, and Corona front LCAs. Cheap to buy and quick to fit. They take out a lot of the understeer and make wet drifting quite easy.

...and these are 'yous'

Well, true its about twice what a 4K puts out, but that jump from 70KW to 90 is still a lot. I suppose being stuck with 2valves per cylinder is most of that, you don't get screaming power without twincams it seems. I think if I fitted a 3T I'd want a cam in it and then twin sidies and an exhaust and a head job and damm I've spent all my money...

Well done! Its nice to solve a problem and let us all find out what the symptoms mean.

lol! Ive done it plenty of times back when I was collecting Datsuns. I own an absolutely overrated Datsun 1600 at the moment that I chased a guy down for, took him a year before he phoned me up and sold it to me. No-one had mobile phones then and texting didn't exist so it wasn't a problem. I like this idea... You might get an offer you can't refuse!

Windscreen washers squirting detergent onto the rear wheels! :laff: Forget the 4K! They didn't do drifting in 1960 when they designed it. Side cam with pushrods, non-crossflow, two valves per cylinder, pathetic 40odd BHP... everything is against it. You can get it up to 50something bhp, maybe 60-odd, and its fun to drive, especially in the wet, but there's no way in hell you will go drifting on dry tarmac without everyone laughing at you. Look up the Tasmanian drift KE70, an excellent job with a 1UZ v8 in it. The 4AGs will do OK, look at this- That's a bigger motor, twin overhead cam, 4valves/cyl, crossflow head... you get the drift... If you're really keen, put up $4000 minimum but really $6k, and go for it.. 40DCOE Webers, forged bottom end, massive head job, exhaust, fancy oil pump & ignition and you'll get at least a blown gearbox, maybe diff as well... :laff:

Is anyone running more max advance than stock??

Jono do they feed more voltage into the coil for a bigger spark? or do they just replace the points as a timing device and leave the coil to run on the same voltage??

I'm looking at CDi ignition vaguely, the Jaycar website is down today so I'm surfing all sorts... I came across a well-written piece here and wondered if anyone has modified the advance curve inside their dizzy. As the author notes, the stock curve is for reliability and lack of warranty claims rather than performance, so there might be some gains to be made. http://www.jcna.com/library/tech/tech0015.html

Bubble test works best with a thermostat in and cold from overnight. Start it in the morning with the rad cap off and the throat filled to overflowing, and just let it idle while you watch. If its bad, bubbles push the water over the rad throat then suddenly go 'bloop' and air comes out. If it not so bad a stream of tiny bubbles comes out all the time after a few minutes. Once warm water comes through the test has ended.

Ah- things must have come ahead. You wouldn't get much extra pressure from the Datsun 1600's inner spring, it did almost no work at all, and valve lift was not a big deal in the 1970s.