TomGaval Posted June 5, 2015 Author Share Posted June 5, 2015 I'm still using the Evans coolant. I was hoping for coolant temps of around 212-215F max. Or al least below 220F. I'll try another exhaust gas test now that the expanison tank is up closer to the back of the head. I'm probably still in the denial phase re: the head gasket failure. Having a K series that had a silmilar problem, I'm familiar with the symptoms. Just hoping to avoid telling the wife I need to spend more on this one now. Having two catermams in the garage seems to draw her attention to them much more than when I only had one. I just hope there is nothing wrong with the Cosworth head. Those puppies are expensive!Thanks for listening and the suggestions. Keep em coming. Tom Link to comment Share on other sites More sharing options...
Paul McKenzie Posted June 6, 2015 Share Posted June 6, 2015 Tom, Like ECR I've also experienced head gasket failures on VX's for a variety of reasons. Don't know much about Duratecs, but judging from the symptoms, I would amost guarantee that's your problem. Link to comment Share on other sites More sharing options...
Rob Walker Posted June 9, 2015 Share Posted June 9, 2015 Is the engine wet sumped? Slightly overfilled would give the same problems that you are experiencing as the wet sump suffers badly with windage. Link to comment Share on other sites More sharing options...
TomGaval Posted June 10, 2015 Author Share Posted June 10, 2015 Rob, the engine is Dry Sumped and I have a catch tank that any overfill usually pukes into. I just went out and warmed up the car, brought the coolant up to 195F-200F, and performed another exhaust gas test, since I recently moved the expansion tank up onto the firewall. Revved the engine, did the test for several minutes, more idling and revving and once again, no color change in the test fluid, so Negative for exhaust gases in the coolant system. Frustrating. Link to comment Share on other sites More sharing options...
Pendennis Posted June 10, 2015 Share Posted June 10, 2015 Does this engine use a water rail Link to comment Share on other sites More sharing options...
TomGaval Posted June 10, 2015 Author Share Posted June 10, 2015 No, hose from back of the head goes to the top of the radiator on the intake side with no water rail. Link to comment Share on other sites More sharing options...
Pendennis Posted June 10, 2015 Share Posted June 10, 2015 Why has it a catch tank? Link to comment Share on other sites More sharing options...
TomGaval Posted June 10, 2015 Author Share Posted June 10, 2015 OIl catch tank? I have one on my Dry Sumped RoverK with the Caterham bellhousing tank too. Link to comment Share on other sites More sharing options...
Pendennis Posted June 10, 2015 Share Posted June 10, 2015 Ah not relevant to your coolant issue, presume you've checked water pump rotation? Link to comment Share on other sites More sharing options...
TomGaval Posted June 10, 2015 Author Share Posted June 10, 2015 Water pump is functioning, but I'm planning on converting to the SBD electric water pump set up as another thing to try before conceeding to a head gasket failure. The thinking being that the electric pump will not be rev dependent in pumping the coolant around, where as the mechanical one is, even though most duratecs run with the mechanical pump with no issues. Link to comment Share on other sites More sharing options...
Pendennis Posted June 10, 2015 Share Posted June 10, 2015 Have you checked pump is being driven clockwise Link to comment Share on other sites More sharing options...
7 wonders of the world Posted June 11, 2015 Share Posted June 11, 2015 Duratec waterpumps run ANTI clockwise,Might of asked before but are you running the oversise waterpump pulley, or alternatively the undersise crank pulley to slow the pump speed at high RPM? Link to comment Share on other sites More sharing options...
TomGaval Posted June 11, 2015 Author Share Posted June 11, 2015 Yes, I have the Cosworth larger waterpump pulley. Link to comment Share on other sites More sharing options...
Pendennis Posted June 11, 2015 Share Posted June 11, 2015 Oops, so they do! That's the second thing I've guessed wrong in two days.....i wonder whether something in the coolant is over pressurising as it warms up? Link to comment Share on other sites More sharing options...
7 wonders of the world Posted June 11, 2015 Share Posted June 11, 2015 Hi Tom, Did you check to see if there a restrictor in the inlet to the expansion bottle in the bled hose from the back of the head - the 8mm hose, might of mentioned it before. by restricting this feed you can prevent it over filling the bottle, use a roll pin tapped into the bottle, might have been missed when the bottle was made. Link to comment Share on other sites More sharing options...
TomGaval Posted June 11, 2015 Author Share Posted June 11, 2015 That's one thing that I have not done! I know that there is no restriction in the line coming from the head to the expansion tank. And I know that if I sqeeze the lower radiator hose that coolant will squirt in to the tank from the small hose coming from the head. Off to the hardward store in the morning. Thanks! Link to comment Share on other sites More sharing options...
TomGaval Posted June 22, 2015 Author Share Posted June 22, 2015 I'm happy to report that I finally had a full day of full sessions on track with no issues!!! I had a small .040 hole bleed nipple made for the top bleed bolt on the radiator that I plumbed up to the expansion tank, which I moved up to the highest point on the scuttle/firewall. I replaced that one with an 1/8 inch fitting which allowed a little better flow potential.I had been running the expansion tank level at just below the MIN line as it allowed for expansion without puking at least for the first session on track. A friend and fellow Caterham owner suggested that on track that might be the cause of my issue as the air could be sucked in on high g cornering or just due to sloshing that left the bottom hose uncovered.I filled the tank to the max line and after the first 25 minute session, with air temps at 95F the car ran great with Coolant temps maxing out at 210F. Coolant rose to about the 3/4 full level, but no puking. So it looks like it was able to self bleed itself. Coolant level dropped back to the 1/2 full mark before the next session, so still above the Max line, but the second session also was a success. Max coolant level 212F.After the third and fourth sessions the coolant level seemed to stay pretty stable, as did the coolant temps. So At this point, I'm going to call it resolved. Seemed to be air in the system due to my stupidity. OH, bonus of the day was we had special guests on track with us. Andy Lalli, 4 time Rolex Daytona 24 hour winner, and Katherine Legge, from your side of the pond. She was awesome. What a nice person. She said she may be running the Indy500 in 2016. Send over a few more like her please. Thanks again for all your suggestions. Gotta love Blatchat!!! Tom Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted June 22, 2015 Member Share Posted June 22, 2015 Glad it's working better.Please can someone explain about the restriction bit.But here's the tough one... how about keeping the position of the tank and the filling level, and changing just one thing: the presence of the restrictor. That could add a lot of information.Jonathan Link to comment Share on other sites More sharing options...
ECR Posted June 22, 2015 Share Posted June 22, 2015 Glad it's solved, now you can really enjoy the car ! Link to comment Share on other sites More sharing options...
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