Robert, You da man! Thanks for the great feedback. Yes, the oversized Gude cam did have an obnoxious idle for a while there, but after putting in the MSD ignition and later the timing controller knob (for fine tuning), that problem went away. Idle is solid, but I do keep it higher than spec, around 1000-1200rpm.
The issue is this, on any particular day hot or cold, the engine's acceleration is ferocious (especially on cold days!) but after 5-10 minutes, the power fades and in heavy traffic acceleration noticeably sags. I'm still getting an average of 28mpg, so I know the tune is good. I'm thinking of trying your suggestion of a lower temperature thermostat and combining with Purple Ice coolant additive- Lisa Kubo uses it on her turbo Civic. See: http://coximport.com/royalpurple/purpleice.html George '89 DX-Hybrid-D16Z6, 127k miles "Seats, Suspension, Engine, MSD, needs to cool off!" -----Original Message----- From: Robert K. Kuhn [mailto:[EMAIL PROTECTED]] Sent: Wednesday, December 18, 2002 8:26 PM To: George Freeman Cc: The Rex list Subject: Re: CRX: Heat soaked intake On 07:46 PM 12/15/02 -0500, George Freeman said... >Okay gurus, > > >I've got an issue that turns up during heavy traffic (sitting idle for >long periods)- the engine loses a few horses and it's annoying. I >understand the cold air intake may be heat soaking and was curious if >"water wetting" the cooling system may help? I understand there are >insulating "socks" you can buy to cover the cold air intake pipe. >Anyone seen or heard whether this works? > > >George >'89 DX-Hybrid-D16Z6, 126k miles >"Seats, Suspension, Engine, MSD, next=dyno" Most of the CAI have some sort of heat insulation (i.e. Ceramic coating) which does a pretty good, IMHO. I have heard of some people using materials such as tin-foil and attic insulation around the intake tube to help reflect heat from the engine. I knew one guy who used header wrap. I must also say that of all the homemade insulating setups that I've seen, none have been scientifically proven to work. If they did, it was subtle at best and perhaps mostly psychologically if anything. Some things you may consider doing include: - Replace the cooling fan switch with one that kicks on at a lower temp. Perma-Cool use to sell a universal fan switch that was adjustable (you set the temp). It's universal in that it "clips" to the radiator fins. This will, of course, effect your heater's performance. - Use a header wrap. There are mixed feelings about this. The only thing you have to remember is not to wrap it up all the way to the flange/welds. Or you can try using the header wrap on your intake pipe. It will look kinda odd and it may even void the warranty (if that is a concern). - Use a lower temp thermostat. This will, of course, effect your heater's performance. - Rig up another electric cooling fan under the hood. I have actually seen some mounted on the underside of the stock hood on a Civic. Or replace the stock fans with a higher volume fan. I replaced my stock fan (which has a 9 inch blade) with a Hayden 10 inch fan. It's thinner, draws less power than the stock, runs whisper quiet (I'm thinking about rigging up an LED to let me know when it comes on it's that quiet) and it pulls A LOT OF AIR. I paid about $70 (USD) for mine. Keep in mind that a *hot* engine usually means a cleaner burning engine. German engine, for example, runs on the hot side (usually in the 230F and 280F). You do give up some performance, however, but not a lot when talking about a daily driver. In fact, my last GTi ran better and stronger when it had finally come up to temp (which was 250F). When it was "cold", it just didn't feel as if it was all there (for a lack of a better description). If this is the same engine that has those performance cams, the problem is most likely the duration. As I mentioned to you in an earlier message, I once ran a high performance cam in one of my previous cars which gave me the bottom end torque I was looking for but it idled so bad once it got up to temp that I would sometimes have to feather the throttle when at a stop. Part of the reason was the lack of vacuum from the cam duration. They sell a vacuum reservoir which helps with this condition (of course it wasn't around back then... bastards!). Perhaps the easiest and quickest thing to try is to wrap some tin foil around the intake tube (shiny side out) and see if that makes a difference. Robert K. Kuhn CRX Owners Group President (http://www.crx.org/southcal) 1990 Honda CRXsi (http://www.hooligan.cc) ICQ # 3714283 (nickname: godzilla)
