Thread: making an intercooler?

Originally Posted by finallyrangie

hello clever people, I am hoping you will share your wisdom.

I saw some scrap at work and got to thinking, i could make a water to air intercooler the same size as the original item (2.8 tgv engine, think its 300tdi intercooler), then plumb it into a radiator out front and bobs your uncle,

2 questions,

question 1
I have calculated (be gently with me) that the 50mm input tube has a cross sectional area of approx 1900mm2, I can fit 26 tubes of 13mm internal diameter into the space which is approx 4500mm2, is that enough, or too much, I'm hoping its enough to slow the gas down to cool it without loosing pressure into the engine. Will this arrangement work better than the original?

question 2
am I mad?

will be fitting an egt gauge and checking what I have now before changing anything, then hopefully they will reduce after the new one is fitted, provided I can get it made.everything will be made form aluminium 2mm thick or less (scrap allowing)

Might not be worth the time and trouble. Have a look at Air to Water Intercooler. They have an enormous range of intercoolers, kits and components and are quite reasonably priced.

Interesting project.

Not sure I'd be bothered making up a intercooler from scratch. If you've got the equipment/ability to make one, I'd suggest getting some water to air core (maybe even a new IC from the likes of Air to Water Intercooler to use the core from) and using it to make a custom intercooler that would fit in the original space and connect using original intake plumbing.

In a previous life I worked with old British made aluminium air-air heat exchangers that had a core made from individual round tubes, probably about 5mm in diameter. Always had problems with leaks between hot and cold sides etc and were a real PITA.
I wouldn't want to risk a similar situation with a home made WTA and end up with coolant in my engine.

Steve

hell yeah go for it.

its not likely to work quite as well as you like due to the large diameter of the flow pipes (13mm) but to have a guestimation I'd say it would be marginally better than the OEM air-air unit

The idea is to slow the gas speed without dropping pressure, you need to increase the air volume in the cooler you also need to have a lot of surface area for maximum heat exchange.

It does sound like a lot of work given they have machines to do this stuff. But hey if you think you can do it you will get the satisfaction of having done it yourself.

Been there. Basically you'll struggle to get enough surface area in to get any significant heat transfer.

I got ~2.5m of 3/8" copper piping into the one I built, it took out ~15% of the heat when I got temperature probes into it. That said, it was still a noticable difference. Okay intercoolers take out ~50% of the heat, good intercoolers take out 60% or more.

Thought quite a bit about doing this. The best way i think would be to buy a core, and make the rest of the intercooler around it. This way you will get the best of both worlds!

I ended up buying a W2A as once I got into the maths of the design and the tools I'd need to shape the aly for the caps it was too much (didn't have proper tooling to shape it into something I'd be proud of)

these are the parts I got from the scrap bin, plus some lunch breaks with a hole saw!




this is everything assembled, more tig welding than you think



heat exchanger covered and tested, leak free after a couple of goes, the ends are nice and simple but hopefully functional




tacked together, the fully welded pictures came out blurry so will try again Monday.


quick question, can anyone tell me the size of the locating pins in the top and bottom of the standard intercooler, and the centers please, save me trying to measure mine in situ.

there will of course now be a massive stop, need an egt gauge, radiator and water pump before i can continue, and as you may all be able to tell, I've got more time than money!