This saturday Dunc and I spent half the day clearing the garage of 1000 variable types of sh*… erm rubbish. Duncan felt that the occasion of my work bench being clear occurred so infrequently that it deserved recording for posterity. I do sometimes worry that my local dump will prevent me from getting rid of my rubbish assuming that I’m some sort of trader.
Anyway after the big tidy, we set about getting the car ready for the Snetterton meeting in a couple of weeks.
Number one on the agenda was cooling system. I’d bought this all aluminium radiator off ebay for the bargain price of 80 quid. You can see from the photo that the matrix is fully twice as thick as the original(although sadly it is not a double pass version) so it should help in the cooling stakes. After spending some time fitting the beast Duncan and I filled her with water and ran her up. Woomp instant overheat, Well not quite instant… but you get my drift. Airlocks Galore!
I know Tim had a pretty hard time getting the air out of his CBR, so I expected this. what i didn’t expect was that it was going to take two days of random fiddling, and a move of the expansion tank to clear the airlocks. Getting the expansion tank a full 18inches above the head before the airlocks cleared did seem a bit excessive.
I do have a plan using a different Thermostat housing to help though, and I’ll revisit the air bleeds around the system to try and bleed any inverted loops back to the header tank.
However once sorted out. The new rad plainly made a difference. i ran the engine up and the water temp climbed slowly to 96 deg C. I then switched in the fan, and the temp just dropped and dropped. Eventually it established a base temp idle at 72 degrees. And I could have left there all day and it wouldn’t have moved. Cool, considering the fan only covers about 20 percent of the matrix then I’m hopeful this will fix the water cooling problem. For the oil cooling Dave Turner suggested that I might need some turning vanes inside the side duct to direct the airflow up to cover all parts of the oil radiator. I’m told by Think Automotive, that oil is “funny stuff”, if a part of the cooler is shrouded from the airflow, then the oil here us hotter, and therefore thinner. What then happens is that the majority of the oil moves through the hot area and not through the cooler area that is in the airflow, but full of viscous,cooler, slower moving oil. Unsurprisingly the majority of oil is then not cooled by the cooler and the oil temps stay high. Nothing funny about that Sounds like physics to me. Anyway If I can’t fix this problem I’ll just stick another water rad in that side and move to a Laminova cooler.
Incidentally I was at Powertec today, in preparation for getting the car rolling roaded. Powertec are a spin off from, and share premises with Radical, and so in their yard was a fair stack of bent Radical bodywork… So I paid special attention to the air ducts. Radical use side mounted radiators too, with exits from the front wheel arches feeding the rear intakes. Just like mine. Except
1.The ducts are much deeper than mine, and never approach the main surface of the side pod between the exit from the front wheels and the entry to the radiator duct. They are always at least four inches deep. Therefore (I surmise) the cooling airflow doesn’t emerge beyond the main silhouette. Essentially the duct is closed, although it appears open.
2. Inside the front section behind the wheel is an aerodynamic vane, which separates the flow from the high pressure area behind the wheels, into two main flows. The inner flow is plainly intended to become laminar, and to move along the inner face of the duct, the outer turbulent flowis injected fairly rapidly into the exterior airflow.
3.The entry to the rear radiators is probably 30cm further forward from where mine is.
So I’m guessing the inner flow moves along the open duct, adhering to the surface profile, whereas the outflow generates turbulence beyond the face of the bodywork, which effectively seals the inner flow in place so that it move directly into the radiators.
Worth knocking up a moulding in the long term to test this idea.
In the short term I might just make some simple ali turning vanes and airscoops to see if this helps. keep the temps down.
Andy Bates over at AB Performance lent me a stock titanium exhaust Can from a superbike. He mentioned that another of his customers had found it quieter than a “Race” can from an aftermarket fabricator. I’m sure that must be the case as Mr Honda/Yamaha/Suziki has a much bigger budget to get these things right than anyone in the aftermarket. I’m also pretty sure they wouldn’t be giving power away in the ultra competitive BHP driven superbike market if they could help it… so it is worth testing.
So I made up a little adapter and a slip fitting that looks like this. And we ran up the engine for a back to back noise test. Following strict MSA test guidelines (well everything except the need to be in the middle of a playing field) so 7,500 Rpm, 0.5 Meters away and 45 deg from the center line of the exit, The stock can delivered 100dBa whereas my race can came it at 106. The stock can would mean I could pretty much get on every circuit in the country without worrying, whereas my race can needs to be repacked after every race. The stock can doesn’t need repacking as it’s internals are all steel.
So while the car is at Power Tec they are going to do a back – back test and If the stock can is not losing me power, or even if it is only marginal loss, I think I’ll take that for piece of mind. Last year I lost 2 test sessions and nearly one entire race weekend to failed noise tests. Besides it is very bling, even with a light dusting of Subaru World Rally Blue overspray 
Plus guess what… it’s lighter
The next thing we did, well actually it was the first, but i’ve only just remembered was Duncan swapped the cardboard intake shrouds for nice Ali plates which we bonded in place.
Lastly I finally took my life in my hands and drilled some large holes in the side of the Winnebago. These were to fit the new GH Awning onto the side. The Patio Awning by the main door is just slightly too small, and it doesn’t keep the car dry overnight, plus it rattles like nothing on earth and keeps me awake. So about 6 months ago I bought a second hand (although never fitted) awning from ebay, and this weekend I finally screwed up my courage and fitted the mounting plates. At 5m by 3m its pretty huge and heavy, therefore, so far I’ve only got the mounting plates fitted. Next weekend with the help of a few ladders and burly chums we’ll get the awning itself fitted. Assuming it doesn’t pull the sides off the bago, which seem to be made of 4mm ply and polystyrene.
Long Term I’ll get some sides for it, and then we can work on the car in the dry. Which is handy for places like Snett, Cadwell and Anglesey