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Post by gordo on Dec 9, 2007 20:59:09 GMT 12
yup, they are tapered to enhance sealing - probably a pipe thread.
Personally, I'd run without the booster being hooked up - just got to push a bit harder on the brake...
One of the reasons the engine is running rough would be if the carb's aren't balanced, the best way to ensure they're drawing an equal amount of air is by using a flow meter - I've got one somewhere, if you aren't too far away I could fish it out and call in, sometime.
I presume you've got the float levels correctly set and the idle mixture has been set correctly? IIRC, it should be around 2 turns back from fully in.
Needles and diaphram springs, as such, shouldn't be affecting the idle as they should be adjustable out.
However, anything off idle will be affected by the needles, and to a lesser extent, by the springs. Any modifications you make will also affect the needles required. As for setting them up, I'd suggest you see if you can find some older carbie guys as I doubt youngsters'll have much experience on modified CDs.
What sort of filters are you using? I would expect you'll be able to pick up some SU ram pipes that can be modified easily to fit the CDs. Back in the day, I machined one up for a Chevette from solid - took quite a bit of time and I wish I'd thought of the SU option first....
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Post by bulldog on Dec 9, 2007 21:12:00 GMT 12
So i was thinking after a little reading on the net to have more of a go at tuning these things. I was thinking of trying the mixture screws on the bottom first, making sure they're both at the same setting etc. I have checked the float levels at all. I can pop the bottom off both but what are you measuring?
What's the reason for getting rid of the brake booster? Does it steal intake pressure or something?
I was going to ring Murray at weber specs, he's been around for ever but I'll hold off.
Where abouts are you gordo? I'm in west auckland (west harbour) but I'm happy to come and see you if you're willing to put in some time for me.
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Post by zep on Dec 10, 2007 7:03:12 GMT 12
I would ring somewhere like EFI and Carburetter Specialists in Grafton before you ring Murray at Webber Specs. That man is grumpy and not much help a lot of the time! Well my experience with him was not that good anyway.
I was building up a carby turbo and it wasn't working that well, so he told me to get this other carb (rare as hell and expensive) and it ended up too small!!! Very annoying.
He's probably better with the N/A stuff tho. meh i dunno, is there not an SU specialist somewhere?
/end off topic
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Post by bulldog on Dec 10, 2007 9:14:26 GMT 12
Yeah I've certainly found Murray can be a grumpy old man but he's got a huge amount of experience with vauxhalls. He's expensive though. I guess you get what you pay for these days.
I have already met with carby specialists in grafton. The head guy seems pretty good.
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Post by gordo on Dec 10, 2007 19:05:18 GMT 12
So i was thinking after a little reading on the net to have more of a go at tuning these things. I was thinking of trying the mixture screws on the bottom first, making sure they're both at the same setting etc. I have checked the float levels at all. I can pop the bottom off both but what are you measuring? What's the reason for getting rid of the brake booster? Does it steal intake pressure or something? I was going to ring Murray at weber specs, he's been around for ever but I'll hold off. Where abouts are you gordo? I'm in west auckland (west harbour) but I'm happy to come and see you if you're willing to put in some time for me. IMO, first thing would be to set the float levels correctly, if you get a couple of service kits, they'll come with instructions and new float needles. Whilst doing this the condition of the rest of the carbies can be checked - I'd look at replacing the diaphrams as well, only a couple of bucks. Next thing would be to set initial mixture, around two turns out from fully in. Note, this part of the carbies looks like a very old model - possibly from the old Viva engines tuners. I'm usually a bit cautious about vacuum take offs on dual carbs but it would seem the booster it taken off the balance tube, so that should be fine. Reason is, it can cause slight leaning out if the brakes are used a lot between light throttle openings. At the moment I'm also a Westie - Te Atatu South but would prefer to catch up at your place - rather messy here. Could call round in the evening this weekend or perhaps Thursday - PM me if it suits? BTW, what are you going to be using for tyres? [edit] Any particular reason for using the twin carbies, you'd get close to the same performance out of a 1 3/4 on a modified manifold and it'd be much easier to set up - only one carbie to worry about. |
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Post by bulldog on Dec 10, 2007 20:24:06 GMT 12
Hey Gordo, used to live in te atatu south before here. Coniston ave.
Anyhoo. so I got a call from mainfreight that my trademe wheels and tyres were ready to be picked up from Otahuhu so i simpy had to try and get these things going better today to go and pick up my wheels! Only thing I did was mess with the bottom mixture screws and found that winding them right in then out about 5-6 complete turns the motor started to idle albeit a bit fast but there's no longer the need for the choke to be on and it seems to go ok. I'm thinking it may not be too far away from a good mixture although without some sort of O2 etc sensor it's a bit beyond me besides sound and performance tuning.
Reason for the twin strombergs was purely that I bought them relatively cheap for $130 including manifold, compare that to being quoted $700 for new twin choke weber and inlet + tuning this seemed like a good case of lets have a crack and see how we get on. Ultimately I would have loved to take Murray up on his offer but I simply don't have $700 lying around at present. Don't get me wrong...I earn a good wack but with baby 3 weeks away and the mrs on leave for almost a year...you get the picture.
Hey if I could modify my existing and find a bigger stromberg somwhere for I'd do it. I'd just like to get these bad boys up and running and see how they go. If they end up being a pain in the ass, I'll flog them for something else. Remembering the end goal is also to repower to thing and drive train etc so it's not worth spending heaps of $$ on it.
I'll PM you a night if you're up for a visit. I can get away from work most times also as I've got a really flexible job.
How does tomorrow night or wednesday sound? Have mother in law coming over to stay from OZ on thursday for almost a month (god help me) otherwise the weekend is ok.
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Post by zep on Dec 11, 2007 7:10:21 GMT 12
Should have GM/T meet at your house while mother in law is over  |
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Post by bulldog on Dec 11, 2007 10:20:35 GMT 12
That's a great idea! I'll send them shopping with e credit card outta shut em up for atleast half hour  |
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Post by gordo on Dec 11, 2007 18:16:25 GMT 12
Haha, I was also thinking it would be a better reason for catching up with you on Thursday. they may even leave WITHOUT the credit card...
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Post by bulldog on Dec 11, 2007 18:51:59 GMT 12
SO wednesday is good or weekend really as I know I'll have to do the 'meet and greet' on thursday night  Anytime you're up for it really, afterall you're doing me a big favour. |
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Post by gordo on Dec 11, 2007 19:10:16 GMT 12
Wednesday is TOP GEAR night! Don't the womenfolk realise that?
Weekend it'll be, then. Unless it's pissing down it'll be in the evening and I may still be a bit grubby - car stuff, hopefully.
If that suits, give me a PM, unless you're happy broadcasting it here.
BTW, I noticed Mikuni has enquired about your Chevette.com membership.
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Post by bulldog on Dec 12, 2007 18:07:16 GMT 12
ok guys, I'm thinking about buying the whole 2.3 slant 4 rally motor (s), w50 gearbox(s) piazza lock diff with axles etc from that guy on trademe. The motor needs a replacement big end bearing but that shouldn't be too hard although does raise the questions as to why it happened in the first place.
So anywho....what's everyone's thoughts? Should I go for this package and slowly work my way through installing and modifying to fit it all or should I hit the jappa route?
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Post by gordo on Dec 12, 2007 19:15:28 GMT 12
It's going to be a fair bit of work, but more in keeping with the "period modification" thing.
I've rebuilt a shed load of CF engines when I was with Telecom, not that much to do with modded ones, though.
As I said, it's a heavy lump but can be built to produce a torquey 190hp or so - a mate a few years back had one in his Chevette and was quite a beast.
However, if you're not too fussed about these things, you can use a Japanese or other engine which should give at least as much power, be smaller and much lighter.
Depending on exactly what your driving style is, and the events you're looking at, less weight and better handling may be a lot better than more power.
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Post by bulldog on Dec 12, 2007 19:32:38 GMT 12
i was thinking more about it being easier to install than say a jappa motor? this guy has all the engine mounts etc as well.
How much heavier are we talking tho? Are we talking 20 kilos or 100kilos heavier?
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Post by gordo on Dec 12, 2007 19:48:57 GMT 12
IIRC, the 2.3 was around 350lbs for the long engine, that's around 160kg - not positive though - been a while.
If the guy is selling everything, such as radiator, hoses, throttle linkages, proper exhaust manifold, gearbox, driveshafts, diff' etc, it makes the whole thing feasable. It's the little things that take the time and hassles.
I've seen Chevette club rally cars with a 13B, a P76 V8 (4.4 litre), Oldsmobile/Rover V8 (3.5 litre) and a Ford V8 (302 Windsor but recessed into the firewall) as well as the 2.3 slant four. It's quite a big engine bay and will take quite a few options.
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