catch up. errr pt1
Ok, i'll have a go at the catch up post.
I have been doing a fair bit of brain work.
Where to start.
CARBS. I have been mucking about with 28 PCI carbs trying to work out how to set them up for twin carb use. I spent a while trying to find someone to machine up some 24mm venturies with no luck. The only person that would consider it is at the start of completely rebuilding his house so won't be able to get to it for 6+ months. In the mean time I have designed the tooling, mind you I don't have any of the tools to make the tooling or to use it. Still.
POWDERCOATING: At work on day I noticed that one of the taxi's next door was advertising “armidale powdercoating”. As you can imagine I was surprised but wrote down the number. A few minutes later I was making a personal call on the work phone. He he i'm so bad.
So back to the tale. After talking to the guy for a while and getting prices on powdercoating, that I thought were very good all things considered, he told me there was a guy in town who had just opened a soda blasting business.
SODA BLASTING: It turned out that he was 5 minutes walk from work. Next lunch time I was around there to suss it out. It turned out he is a nice guy who had just opened up and was in the process of trying to build his business. I have wanted to try soda blasting on carbs for a long time as I had heard that it was v.good at cleaning them, I was hoping that it would restore the outside finish, aka remove the tarnish that the alloy gets with age.
After several attempts to drop them in, I got him to blast some PCI bodies, tops and accellorator pump covers (all the alloy bits) plus a distributor points mount plate and an odd other few bits as a test. All in all it was a little more expensive than I was expecting ($60 or so) and the result wasn't as good as I was hoping, there was still some grot in the corners and detail. Having said that, the one body that was well cleaned turned out very nicely and the surface came up as I has hoping. So I will be back but have everything very clean to start with and use the blasting just to bring back the surface finish.
The soda blasting guy and a blacksmith I met at bunnings also gave me some leads on the best welders/fabricators in town... bound to be useful.
MOLASSES: I have also experimented a little with molasses to remove rust. Now that I have played on the net a lbit I now know what I did wrong, so hopefully i'll have some successful trials soon.
ADJUSTABLE PUMP RODS: A month or so ago I thought that i'd make a pair of adjustable accelerator pump rods (for 28 PCI's). it was supposed to be a quick easy and rather cheap project. So far it has taken about 2 months and about $60 and I have achieved basically nothing. Well i've bought some materiel I can't use and killed a $24 die but nothing positive. My first issue was trying to find 4mm steel rod. I could find it in titanium or stainless but neither is what I want. I want it to be as it would have been done back in the day. I didn't realize how hard it would be to find, so I went out and bought a 4mm die, 4mm tap and a die handle thingy and started to suss out nuts, washers and welding.
So after doing a few net searches and calling lots of suppliers, all with no luck. I posted a question on another vw website and today someone told me they had something suitable and they would post it to me... thanks Phat Bug, but that is getting ahead of myself. At the time no-one had any leads.
So I was trying to get my grubby hands on some 4mm rod. No luck, I was getting a bit stumped then I had a look in the box thingy with all of my stripped PCI's in it then lo and behold the linkage from the throttle shaft to the choke arm was the right size wire and was long enough. The two problems were that most were kinked (from the factory) and while I did have 2 straight links I didn't want to chop them up just in case they were something special. So that scrapped that idea.
Around this time I got distracted with some other carb stuff but more on that later.
While I had been hunting for 4mm steel rod I visited one of the local engineering shops and while trying to find someone I saw a conversion chart on the wall that showed that 4mm is damn close to 5/32”. I ignored this for a while but eventually decided to try searching for this as well.
A week or so ago I gave in and went into the local hobby store. To explain, a while back I went to the shop and the owner pissed me off I swore i'd never go there again (my other hobby is model railways). I foolishly as it later turned out went in there and bought 2 legnths of 5/32” piano wire. I was going to make up a mock up set to test the concept + make a few extra for friends with twin 28 set ups. So I got home dug out the stuff and waited until I could get out to the shed to play. I thought I had better try cutting a test thread as my thread cutting experience is about nil. I chuck the rod in the vice, dab on some oil and off I go... “damn this wire is a lot harder than I thought” in the back of my head alarm bells went off re the hardness of piano wire but I chose to ignore them. A while later and after lots of “am I using this tool correctly?” thoughts, I got about 6 or 7mm of thread badly cut onto the wire (err slightly tapered to the end) but the wire really didn't want to take more thread. I decided to quit while I was ahead but when I checked the die I noticed the the thread bits seemed to have tails that stuck out into the 3 holes in the die. I didn't notice these before I used the die so i'm assuming that in using so much force to try and cut a thread in what I now know is spring steel (high carbon content = v.hard) I deformed the die. Not happy. I guess that is khama for doing what I swore I wouldn't.
Now I have some rod being sent to me that will take a thread well. Thanks again Phat Bug so i'll need to get another die, or at least get mine checked out by someone who knows what they are looking at.
I have yet to source some 10mm AF hex rod to make the front adjuster screw out of. Or for that matter someone who can/will cut a slightly domed end on it etc. not that i'm up to that stage yet anyway.
All in all this has turned out to be far more complicated and expensive than I was expecting and it is far from over yet.
LH and RH PCI's: the distraction I had from the accelerator pump rods was trying to work out how to set up a pair of 28 PCI's as a Left and Right handed pair. Aka so that they would both have the linkage arm towards the middle of the engine when mounted (sitting in the same orientation as standard). I was hoping to work out some clever way to be able to convert them using only the stock parts that they come with (modified if necessary). Unfortunately I couldn't work out any arrangement that I was happy with. I then tried with some volvo 142S twin stromberg linkages I had but no luck there either. I think I will have to fabricate an stop arm for the lhs carb. I did a but of checking to see if anyone in town had a suitable punch to make the correct hole to fit over the throttle shaft but no luck so far. I could make a piece to slip over one of the washers and have it welded on but it would be a little clunky for my liking. I could also use a second arm off another carb but I want to work out how to do it without needing donor carbs. (yes eventually i'd love to make my own twin carb kit to sell, but i'm starting small aka my own set first).
enough for now. iguess i'll need to write a pt 2.
Comments 5
next time try glass/bead blasting, will clean it up a lot better, or acid clean??? never tried the acid cleaning but have had great results with glass blasting
matt
next time try glass/bead blasting, will clean it up a lot better, or acid clean??? never tried the acid cleaning but have had great results with glass blasting
matt
hi matt, i'm assuming you mean glass beading on the carbs? if i can find someone locally i'll give it a try. the local thing is a big issue to me as the nearest town that is bigger than mine is 110km away and i never go there. of late i've barely been getting ot sydney once a year. to me this kind of job is one where you need to be able to talk/see the guy doing the work.
i thought about using something acidic (i've used coke on 60's non bakealite (sp) fuse boxes with great success) but it made me a little nervous. i can't remember much about materials science but alloys so i'd be worried about how quickly they'd react and if it woud react with some parts of the alloy faster than others.
hi matt, i'm assuming you mean glass beading on the carbs? if i can find someone locally i'll give it a try. the local thing is a big issue to me as the nearest town that is bigger than mine is 110km away and i never go there. of late i've barely been getting ot sydney once a year. to me this kind of job is one where you need to be able to talk/see the guy doing the work.
i thought about using something acidic (i've used coke on 60's non bakealite (sp) fuse boxes with great success) but it made me a little nervous. i can't remember much about materials science but alloys so i'd be worried about how quickly they'd react and if it woud react with some parts of the alloy faster than others.
I've been thinking of doing the same thing for the 1600 single port I bought for the splitty. I do have a mate who has a 28 dual carb setup - one that he will not part with BTW - but one that I am sure I could borrow to copy the linkage parts.
I haven't even looked at the bus since buying it, so I am a little way off, but if you don't mind the wait, maybe we could pool resources.
The manifolds look pretty simple - just two flanges and some steel tube - I've already bought exactly the stuff to do this from an exhaust shop for making up the manifolds on the Type 4 - I'm pretty sure they're a standard size weld on flange / tube. Will have to check the sizes, but pretty confident that they will have "something" off of the shelf.
Will also be receiving a donation of a lathe when I get the garage finished, so might be able to help out with the venturi's - but this depends on how complex they are.
BTW - as I'm sure you now realise - piano wire is very very hard - have ruined more than a few pairs of side cutters when trimming my guitar strings - it's basically the same stuff.
Mick.
I've been thinking of doing the same thing for the 1600 single port I bought for the splitty. I do have a mate who has a 28 dual carb setup - one that he will not part with BTW :( - but one that I am sure I could borrow to copy the linkage parts.
I haven't even looked at the bus since buying it, so I am a little way off, but if you don't mind the wait, maybe we could pool resources.
The manifolds look pretty simple - just two flanges and some steel tube - I've already bought exactly the stuff to do this from an exhaust shop for making up the manifolds on the Type 4 - I'm pretty sure they're a standard size weld on flange / tube. Will have to check the sizes, but pretty confident that they will have "something" off of the shelf.
Will also be receiving a donation of a lathe when I get the garage finished, so might be able to help out with the venturi's - but this depends on how complex they are.
BTW - as I'm sure you now realise - piano wire is very very hard - have ruined more than a few pairs of side cutters when trimming my guitar strings - it's basically the same stuff.
Mick.
buy a small sand blasting cabnet or sand blaster and a bag of glass beads and do it yourself.
cheaper and you can go as hard or soft as you like
buy a small sand blasting cabnet or sand blaster and a bag of glass beads and do it yourself.
cheaper and you can go as hard or soft as you like
If you're feeling constructive, it's not too hard to make your own blasting cabinet - just need some mdf, perspex / glass for the window and some heavy duty rubber gloves. Basically make a box, with an angled top that hinges open (with the window in it), cut two holes in the front for the gloves (just big enough to get your hands in), and then cut two thin rings out that have the same inner diameter as the holes. you will need to seal the edges of the lid, but this is easily done with some draight excluder and a couple of catches to hold the lid down. Also - don;t forget to use some silicon or glue when assembling it - it needs to be air-tight.
Stretch the gloves through the hole and then screw them in place - voila - one blast cabinet - probably made from scrap bit's of stuff you had lying about.
You should be able to get bags of different media from a decent garage supplies place - the type of media you will need depends on the job + material. Soda is about the softest - good for removing paint without damaging metal, then you can get media such as walnut, glass, aluminium oxide, silica etc. You can buy it in tubs - and most likely get it delivered. The best thing about a cabinet is that you get to reuse it too.
Blasting guns are relatively cheap, and with the cabinet you can remove the container and replace it with a length of tube that sits in the bottom of the cabinet picking up the media - of course this works better if the bottom of the cabinet is an inverted pyramid shaped so the media flows to one point - then you will also need to add a mesh grid to stand your parts on.
One thing to remember - do not make the cabinet too small - the glass / perspex will get blasted and turn opaque pretty quickly.
Of course - this is fine and dandy if you have a compressor, and for blasting you will need a relatively large one as it takes a lot of air.
My dad made a cabinet like this which was great for small parts, and relatively inexpensive if made from scrap stuff.
If you're feeling constructive, it's not too hard to make your own blasting cabinet - just need some mdf, perspex / glass for the window and some heavy duty rubber gloves. Basically make a box, with an angled top that hinges open (with the window in it), cut two holes in the front for the gloves (just big enough to get your hands in), and then cut two thin rings out that have the same inner diameter as the holes. you will need to seal the edges of the lid, but this is easily done with some draight excluder and a couple of catches to hold the lid down. Also - don;t forget to use some silicon or glue when assembling it - it needs to be air-tight.
Stretch the gloves through the hole and then screw them in place - voila - one blast cabinet - probably made from scrap bit's of stuff you had lying about.
You should be able to get bags of different media from a decent garage supplies place - the type of media you will need depends on the job + material. Soda is about the softest - good for removing paint without damaging metal, then you can get media such as walnut, glass, aluminium oxide, silica etc. You can buy it in tubs - and most likely get it delivered. The best thing about a cabinet is that you get to reuse it too.
Blasting guns are relatively cheap, and with the cabinet you can remove the container and replace it with a length of tube that sits in the bottom of the cabinet picking up the media - of course this works better if the bottom of the cabinet is an inverted pyramid shaped so the media flows to one point - then you will also need to add a mesh grid to stand your parts on.
One thing to remember - do not make the cabinet too small - the glass / perspex will get blasted and turn opaque pretty quickly.
Of course - this is fine and dandy if you have a compressor, and for blasting you will need a relatively large one as it takes a lot of air.
My dad made a cabinet like this which was great for small parts, and relatively inexpensive if made from scrap stuff.