UK Lakester build G/GL

[Seldom Seen Slim]

You'll have to speak up if you want her to hear you.  Remember, Alice is ten feet tall.

[rgdavid]

Its all gone wierd again  

What is a "clear steer " ?

[jdincau]

http://wizardsteerclear.com/

[kiwi belly tank]

Wizzbang name for an old idea! I built my first "ratio chain drive" in 1969 for my oval track Jag.
  Sid.

[Lemming Motors]

QUESTION.  I am waiting for parts and waiting for a radiator shop to give me a quote on a simple rad to go in a tank - they get interested, get all excited and start proposing clever solutions and then it all goes quiet. So, planning ahead to my next special construction challenge ......

Could someone running a naturally aspirated engine comment on cooling the induction air please. I had orignally assumed some aluminium tubes running through an ice bath with the induction air feeding from the NACA inlet to a collector that feeds the tubes, through the cold tubes, collected, to the ITB airbox via a 5" duct. Since I can't weld aluminium* and the local fabricators seem to want a kings ransom for things like this what clever solutions have people arrived at and how did you measure success?

I have considered using metal epoxy to bond the alloy tubes to drilled end plates then wrapping that in a fibeglass tank. I have also considered thin wall fibreglass tubes all fibreglassed together.

If I calculate for a 5" induction duct that surface area is ~ equivalent to fifteen 1.25" ID tubes in three rows of five with space for ice and water around them. Each tube would be around 14" long in my most ideal packaging configuration. Will this work? Will the tubes strangle the free flow of air? etc. Is there a smarter way to do it?

*some days I can't weld mild steel.

Thanks, John

[comet]

John would it be possible to silver solder the joins? I might be miles off track here but thought I'd throw it out there anyway. Ally can be silver soldered according to my mate Google.

Cheers
John

[Lemming Motors]

Ooh John, you comment about (silver) solder triggered a brain cell and I dont know why I didnt consider it - instead of ally make it in copper / brass and solder it.
Silver solder ally is interesting too.

In the UK the larger size (home) copper pipe on the boiler, gas mains and hot water cylinder circuits is 28mm (1.1 inch) - a bit narrow but if some is good more might be better and too many will be just right. I bet there is a larger diameter out there too.

Great thermal conductivity and would look great polished 

[kiwi belly tank]

Get some ally soldering rods & see what you can do with that John!
  Sid.

[Rex Schimmer]

John,
I like the copper tube thinking! Look at the area of all of the tubes and then calculate the air velocity through them at max engine speed. It needs to be fast enough so that it is turbulent which will provide maximum exchange of heat. I think I would have the exchange tubes between the NACA duct and what ever you are going to use for an air box over the engine inlet. Remember you need to slow the air down before the engine inlets to recover pressure and take advantage of some velocity charging.

I have always thought of just taking a bottle of compressed air, like a scuba bottle, and discharge it into the engine air inlet. I would not seal it so that it would not be considered a type of supercharging but the air escaping from the bottle at high velocity comes out at a very low temperature and mixed with the air coming in through the scoop it should cool it. (Maybe!?)

One more idea, buy that Harrison heat exchanger that I have ($50 to you) make your inlet so that it seals around the exchanger and then pump ice water through it you are sure to get some good temp drop. (I am going to sell you that thing yet!!!)

Rex

[Jack Gifford]

The original solder for aluminum was patented in about 1955 and named Chemalloy. Its chemistry was quite complex and it achieved a true soldered joint with strength equal to the aluminum alloy being soldered. I don't find "Chemalloy" available now, and don't know if modern "aluminum solders" are just gimmicks.

Sheet copper is a good idea. Brass also solders well and could be a little thinner than copper. In fact, thin mild steel is also easy to solder.

[comet]

John larger sizes are available. 28mm, 35mm, 42mm, 54mm. The larger sizes get pretty pricey though. You may find a local industrial plumbers outlet ( Pipe Center Wolseley, BSS or one of those would be the ones to try) can help you out especially if they have some damaged copper. It is sometimes reduced in price it it is bent or has a ding in it.

[Peter Jack]

The original solder for aluminum was patented in about 1955 and named Chemalloy. Its chemistry was quite complex and it achieved a true soldered joint with strength equal to the aluminum alloy being soldered. I don't find "Chemalloy" available now, and don't know if modern "aluminum solders" are just gimmicks.

Sheet copper is a good idea. Brass also solders well and could be a little thinner than copper. In fact, thin mild steel is also easy to solder.

If you google aluminum brazing rod you'll find an assortment of options. I use a rod called "Aladdin 3 in 1" myself. I have tried brazing aluminum sheet with it and it works really well although I don't normally use it for that purpose as I have tig which is easier and superior. I use the rod for welding pot metal castings. It does a really neat job for that.

I pick it up at my welding supplier.

Pete

[Lemming Motors]

Thanks guys, I appreciate the leads wrt aluminium soldering and brazing.

The reference to a scuba bottle made me think a 50% O2 mix (deco gas mix we used to dive on) might improve the induction air 

No one has said the overall concept is flawed (yet) which is encouraging.

I have been discussing combustion chamber shapes (and pistons) with my top-end man this morning: exciting and scary in equal measure.

[Lemming Motors]

I have reinstated the inner panel with some slight beating to fit the shifter.
I have also moved the firewall UJ to the engine side of the firewall through bush (it was mocked up on the cockpit side) in the hope that will better accommodate slight engine movement without binding the shifter rod. That seems to have the added benefit of removing some of the play from the cardan bush / slide and it might work as mocked up - plan b is to hack a DD steering shaft and tube. I am now replacing the UJs to a higher spec (from Racetech); 3 mid spec UJs added up to around 10mm of side to side movement over the length of the shift rod assembly which feels like excessive play when seated and 'changing gear whilst making vroom vroom noises'.

As I am also exploring the rad and tank (what a saga) I need to know where things are passing through the firewall (ideally not positioned to pass through the rad) so a first crude mockup of the firewall in 1/4" mdf allows me to drill holes and then plan the tank out on the mdf.

[Lemming Motors]

Arrggh - I rotated and saved that pic of the firewall.