Myles Posted April 16, 2006 Share Posted April 16, 2006 The thermostat failed during the trackday on Friday - so I removed it completely on Saturday morning for the drive back home (not having a spare). All well and good. Today - during the solitary session when the engine actually fired - I let it warm up on idle for several minutes. The SPA coolant gauge was showing around 60 degC - as was the readout from the Emerald (give or take a couple of degrees) - and then the fan kicked in (controlled by the switch in the rad - no ECU control)... The fan switch is an R500 spec item - should be cycling around 80 degrees IIRC. What gives? Why is the top of the rad apparently getting hotter than the circuit through the engine? Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Rob Walker Posted April 16, 2006 Share Posted April 16, 2006 Airlocked, no flow through the rad. Link to comment Share on other sites More sharing options...
Myles Posted April 16, 2006 Author Share Posted April 16, 2006 Hmm - the rad certainly seemed hot - and with no stat, there should have been flow everywhere. How would the top of the rad get 20 degrees (ish) warmer than the rest of the system anyway? The coolant level had dropped on the trip back from Anglesey - I couldn't see any signs of leakage, so it's either an airlock that has sorted itself out or a HGF (no spitting from the zorst or mayo, so I don't think that's the case). Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Johnty Lyons Posted April 16, 2006 Share Posted April 16, 2006 Oh come on Miles think about yourr coolant flow direction on a K the penny will drop I know your not that stupid 😬 jj N.I. L7C AO. Membership No.3927. Se7en Services.N.I. Caterham Service Agents. www.onthelimiter.com Link to comment Share on other sites More sharing options...
Myles Posted April 16, 2006 Author Share Posted April 16, 2006 Mmmmmm. The rad has big hoses, the heater bypass has thin ones. Without a stat, the rad will provide an easier route than the heater bypass (where the temp sensor is), so yup, guess it's fine. Thanks JJ. Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Adrian M Posted April 18, 2006 Share Posted April 18, 2006 Myles my thermostat was playing up and Anglesey on Friday. I found that it wasn’t opening while I was out on track, however the engine wasn’t running hot. When I came into the paddock the engine temp would rise but the thermostat still wouldn’t open. I’ve since had it opening while the engine has been idling but decided to do away with it and use the MBE ECU relay switch rather than the original one in the rad. Ade Link to comment Share on other sites More sharing options...
Myles Posted April 18, 2006 Author Share Posted April 18, 2006 I’ve since had it opening while the engine has been idling but decided to do away with it and use the MBE ECU relay switch rather than the original one in the rad. Forgive me, but that sounds potentially confusing. Have you taken out the waxstat (as I did) *and* bypassed the passive fan switch in the rad? I think that could be asking for trouble if my experience is anything to go by - the MBE (or my SPA gauge in this case) are reading a tepid 60-odd degrees in the heater/bypass circuit (small-bore pipes round the back of the engine) while the rad etc. are running a good 20-degrees hotter. The MBE would probably turn the fan on waaaay too late, wouldn't it? There's nothing to stop you using both switches though - same as using manual fan override switch. Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Adrian M Posted April 18, 2006 Share Posted April 18, 2006 I’m planning to remove the stat and the fan switch from the rad and use the MBE ECU/relay to trigger the fan. This is the R400 race set up and I believe the fan trips much lower than 80. I already have an override switch wired up but this won’t help with my thermostat not opening which is why I plan to ditch it. Admittedly on a cool day the engine may struggle to get up to temperature but I can always cure this with tape on the nosecone. Ade Link to comment Share on other sites More sharing options...
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