Tyrone Posted May 9, 2005 Share Posted May 9, 2005 On Saturday my car was idling at 2000rpm after it had warmed up and popping and banging even more than usual. It would appear the Border blat had shaken a few screws on the carbs and thrown everything out. This was quickly sorted. However, whilst we were sorting this I noticed two things. 1. The breather pipe was throwing out visible oil vapours which it has never done before and 2. the coolant was overflowing out of the expansion tank. The car had been standing with the engine running at the high revs for 10 minutes at most and was hot, approaching 90oC. With the carbs retuned and balanced I drove home with no appreciable loss of power. The water level in the reservoir has returned to normal but the thermostat was dry due to the loss of coolant out of the reservoir previously, I topped up the coolant with less than a 1/4 of a pint. Firing up the car tonight, there was no visible oil vapour from the breather and the car ran for 15 minutes at idle (reset at 1000rpm), the temp gauge showed 70oC and visible vapour plumes came out of the coolant reservoir. I couldn't tell from the smell if they were combustion gases or not. There is no emulsion in the rocker cover and the coolant is blue. Am I worrying about nothing? Tomorrow I'll test the thermostat. Thoughts would be appreciated. Link to comment Share on other sites More sharing options...
Graham Sewell Posted May 10, 2005 Share Posted May 10, 2005 Do a compression test - that will soon tell you if the head gasket is blown! Low tech luddite - xflow and proud! Link to comment Share on other sites More sharing options...
Burt1969 Posted May 10, 2005 Share Posted May 10, 2005 Can't give any advice really just tell you what mine does. Mine sits at about 90oC most of the time. Idles at 700rpm, I'm assuming my breather pipe spits out oil as a)The bottom of the car is covered, not a bad thing! and b) I have to keep the oil topped up. The only thing I would say is that I have never had to top up the coolant! Regards, Phil. Our Kitty! Link to comment Share on other sites More sharing options...
Nigel Riches Posted May 10, 2005 Share Posted May 10, 2005 Tyrone my old x-flow puffs plumes of smoke out of the breather which is routed by a long pipe to down the tunnel too the outside world, it does this all the time, do I worry, only when it doesn't smoke. The over flowing coolant may simply be the fact that idling for so long caused the water to expand, more than usual, and overflow, if it only took 0.25 pints to top up I'd not be too worried, the thermo check is worthwhile, as if it did get cooked there is a strong chance it's roooted. Have you considered changing to a later sealed coolant system, so what is displaced by the heating of the engine is drawn back into the system as it returns to ambient, this precludes airlocks and so on. 1982. 5 speed, clamshells. B.R.G / Ali. The True Colours. Link to comment Share on other sites More sharing options...
Tyrone Posted May 11, 2005 Author Share Posted May 11, 2005 The thermostat is working fine, so it's a compression test at the weekend. I will be changing to a sealed system, anyone done it themselves, got pictures etc. Link to comment Share on other sites More sharing options...
Tyrone Posted May 11, 2005 Author Share Posted May 11, 2005 I've done a compression test and achieved the following results: Cylinder 1 57.5 lb/inch2 Cylinder 2 70 Cylinder 3 62.5 Cylinder 4 70 I borrowed the kit and it hadn't been used for a while so I can't vouch for its accuracy. How close do the results of each cylinder need to be? Edited by - Tyrone on 12 May 2005 00:07:04 Link to comment Share on other sites More sharing options...
Big Brother Posted May 11, 2005 Share Posted May 11, 2005 Taken from a post by Oilyhands A compression test should be carried out with the throttle cracked fully open and the engine hot. If there is a greater than 10% variance across any cylinders then this indicates a problem. If you did not perform the test in that manner then re-do it. Going by results I got from testing my Xflow ages ago, your results do seem rather low. I was getting readings in the region of 210 - 220psi Hope this helps Steve SE7EN-UP! Incorporating the Caterham Links Database Link to comment Share on other sites More sharing options...
Graham Perry Posted May 12, 2005 Share Posted May 12, 2005 Those numbers are very low. Edited by - Graham Perry on 12 May 2005 06:48:32 Link to comment Share on other sites More sharing options...
Tyrone Posted May 12, 2005 Author Share Posted May 12, 2005 The tester I borrowed only goes up to 150! I had kind of assumed that different testers would have there own 'resistance' and give different readings as a consequence. I expected to look for a uniform reading across the 4 pots. As it is the engine wasn't hot, so I'll do it again. Numpty question, what difference does cracking open the throttle make? Link to comment Share on other sites More sharing options...
Big Brother Posted May 12, 2005 Share Posted May 12, 2005 I *think* its because if you have a leaky inlet valve, it may not show up if the throttle butterflies are closed as they provide a slight seal. *arrowup*Could all be totally wrong but if it is, I'd like to know the reason as well Steve SE7EN-UP! Incorporating the Caterham Links Database Link to comment Share on other sites More sharing options...
Graham Sewell Posted May 12, 2005 Share Posted May 12, 2005 Another tip - so that the results are consistant the engine needs to turn over the same number of revolutions. So I typically count 10 compressions during the test for each cylinder. Note that the test result will rise for each compression. Low tech luddite - xflow and proud! Link to comment Share on other sites More sharing options...
Tyrone Posted May 13, 2005 Author Share Posted May 13, 2005 The car went in for its MOT today and passed with ease apparently. I'd mentioned the overheating problem to Carl at the Autocentre in Darlington, so that the boys wouldn't run it on idle too long. When I went to pick it up Carl reckoned it had been running on idle for 10 minutes with no sign of boiling over, he couldn't see any obvious signs of distress. Still going to do the compression test tomorrow and a few other bits and pieces. Link to comment Share on other sites More sharing options...
I.Mupferit Posted May 13, 2005 Share Posted May 13, 2005 If the throttle isn't open, the engine will struggle to pull sufficient air in to then compress and give a proper reading. Your low figures sound as though your throttle wasn't open. If you repeat the test with open throttle (ie free air inlet), I would expect to see figures similar to Steves on a healthy X/Flow. Brent 2.3 DURATEC SV NII OAW R 417.39 😬 Link to comment Share on other sites More sharing options...
Tyrone Posted May 16, 2005 Author Share Posted May 16, 2005 Well, where do I begin. The overheating problem turned out to be the poxy bracket holding the distributor in place wasn't doing its job. As a consequence the dizzy had been moving around. Iain A and I sorted that, set up the timing etc. and went for a shakedown blat. Dropped an exhaust valve and ****ed no. 2 piston *mad* anybody know where I can match 'Powermax' pistons? My head is nicely ported but it is also one of the older heads with the small combustion chambers which probably explains the low figures we got for the later correctly done compression tests (max 143psi). Anyone got a free x-flow they don't want 😬 Edited by - Tyrone on 16 May 2005 04:11:21 Link to comment Share on other sites More sharing options...
DaveMorris Posted May 16, 2005 Share Posted May 16, 2005 I've got a spare 1600 x-flow sitting in the garage that (touch wood) I won't need for some time. Regularly turned to keep springs in fine fettle. Have got webers etc and everything else to make it go. If you want to collect, and promise to look after it, then it'll keep you on the road whilst you decide what to do with your engine. If interested then mail me. Dave. Link to comment Share on other sites More sharing options...
Tyrone Posted May 16, 2005 Author Share Posted May 16, 2005 Dave, What can I say, that is considerably more generous than 'lending' me a packet of cigarettes!! Can I get back to you after I've worked out how much the repair is going to cost. It may be more cost effective to save up for a new engine in which case I will gladly take you up on your extremely generous offer. Cheers Bud Brian Link to comment Share on other sites More sharing options...
RossCarmichael Posted May 17, 2005 Share Posted May 17, 2005 Sorry to be the numpty here (see, I'm getting the lingo at least!), but what does dropping an exhaust valve mean? How/why does it happen, what are the consequences etc? I don't want to force Tyrone to relive the experience, but was just wondering... Cheers, Ross Link to comment Share on other sites More sharing options...
Petrolhead Posted May 17, 2005 Share Posted May 17, 2005 Crumbs, sorry to hear that Bri If you need a hand reming the engine let me know Yes the boiling over could have been because the fan belt was slack I would say, from what you have said, that you engine was probably ready for a refresh anyway. Like I say give me a bell if you need help NE7Club Web Site R5 no 65 😬 I am after low level tyre rack and jerry can box for Mino Link to comment Share on other sites More sharing options...
Tyrone Posted May 17, 2005 Author Share Posted May 17, 2005 Peter, Sorry, I've responded to your questions on the other thread. Waiting for prices from Burtons, Iain A has offered to help, he did some stirling work on Saturday until it all went horribly wrong (with absolutely no blame attached to him or me). However, if you are up for it, all offers of assistance are gratefully received, depending on when I get the bits I need to work the spanner sesh around the family social calendar, the atmosphere on Saturday was distinctly cool at times, Women!! Ross, No such thing as a numpty question if you don't know the answer. Dropping a valve is exactly as it sounds. The valve fell into the combustion chamber (the stem snapped in this instance), fortunately I didn't hear the noise it made 'cos of the aero, Iain enjoyed that aural pleasure!!! Link to comment Share on other sites More sharing options...
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