Richard71 Posted April 17, 2018 Report Share Posted April 17, 2018 Hello All, Having exhausted all other possibilities of the cause of a mis-fire on #6 cyl on my TR6, I intend to carry out a compression test. Can anyone recommend a decent not overly expensive compression tester for the home mechanic? Richard. Quote Link to post Share on other sites
RogerH Posted April 17, 2018 Report Share Posted April 17, 2018 Hi Richard, I have one you can borrow unless you need one permanently Roger Quote Link to post Share on other sites
Richard71 Posted April 17, 2018 Author Report Share Posted April 17, 2018 Hi Richard, I have one you can borrow unless you need one permanently Roger Many thanks for the kind offer Roger, I may as well buy my own for future use, besides, I kinda need it right ASAP. I have a good universal compression tester for diesels, though none of the adaptors fit. Richard. Quote Link to post Share on other sites
RogerH Posted April 17, 2018 Report Share Posted April 17, 2018 Hi Richard, try this https://www.machinemart.co.uk/categories/?search=compression%20tester Or Ebay - I'm sure Sealy do one or Gunson I would steer clear of the Draper stuff. Roger Quote Link to post Share on other sites
Richard71 Posted April 17, 2018 Author Report Share Posted April 17, 2018 Hi Richard, try this https://www.machinemart.co.uk/categories/?search=compression%20tester Or Ebay - I'm sure Sealy do one or Gunson I would steer clear of the Draper stuff. Roger I've ordered the Gunson tool from the bay, should arrive by the weekend. Quote Link to post Share on other sites
Lebro Posted April 17, 2018 Report Share Posted April 17, 2018 Gunson one is good Bob. Quote Link to post Share on other sites
Nigel Triumph Posted April 17, 2018 Report Share Posted April 17, 2018 Gunson one is good Bob. +1. Used a Gunson compression tester for years. Nigel Quote Link to post Share on other sites
Ragtag Posted April 20, 2018 Report Share Posted April 20, 2018 Just done this on mine using a Gunson tester. I'm not sure what it is like for a 4 cylinder engine but I found it necessary to move the distributor in order to gain sufficient access to pots 4 & 5 Quote Link to post Share on other sites
BlueTR3A-5EKT Posted April 20, 2018 Report Share Posted April 20, 2018 Just done this on mine using a Gunson tester. I'm not sure what it is like for a 4 cylinder engine but I found it necessary to move the distributor in order to gain sufficient access to pots 4 & 5 One with a flexible tube is probably better. https://www.machinemart.co.uk/p/clarke-cht692-2-piece-compression-tester-kit/ Peter W Quote Link to post Share on other sites
Lebro Posted April 20, 2018 Report Share Posted April 20, 2018 This Gunson one has a flexible pipe https://www.ebay.co.uk/itm/Gunson-HI-GAUGE-COMPRESSION-TESTER/302704890128?epid=21017669463&hash=item467a9e1110:g:9K4AAOSwAJFa0h2d Bob. Quote Link to post Share on other sites
Ragtag Posted April 20, 2018 Report Share Posted April 20, 2018 This Gunson one has a flexible pipe https://www.ebay.co.uk/itm/Gunson-HI-GAUGE-COMPRESSION-TESTER/302704890128?epid=21017669463&hash=item467a9e1110:g:9K4AAOSwAJFa0h2d Bob. Yes, this is the one I have One with a flexible tube is probably better. https://www.machinemart.co.uk/p/clarke-cht692-2-piece-compression-tester-kit/ Peter W The issue is not the flexible hose, it is the length of the brass fitting that screws into the plug hole. The Clarke version you linked to would be better in this regard. Quote Link to post Share on other sites
Alec Pringle Posted April 22, 2018 Report Share Posted April 22, 2018 Bergen offer a range of decent quality budget testers, otherwise step up to Sykes Pickavant -anything in between is just marketing . . . . Cheers Alec Quote Link to post Share on other sites
TorontoTim Posted April 22, 2018 Report Share Posted April 22, 2018 *Off topic* Good god, it's nice to see that name at the bottom of a post Quote Link to post Share on other sites
Hamish Posted April 22, 2018 Report Share Posted April 22, 2018 *Off topic* Good god, it's nice to see that name at the bottom of a post +1 Nice to see you out and about on here Alec. Quote Link to post Share on other sites
Motorsport Mickey Posted April 22, 2018 Report Share Posted April 22, 2018 Good man Alec, keep making those posts and sharing the wisdom. Mick Richards Quote Link to post Share on other sites
greasemonkey Posted April 23, 2018 Report Share Posted April 23, 2018 Hi Richard, try this https://www.machinemart.co.uk/categories/?search=compression%20tester Or Ebay - I'm sure Sealy do one or Gunson I would steer clear of the Draper stuff. Roger I used to rate the Draper Expert stuff but have recently had a problem convincing them of my interpretation of their lifetime guarantee - so I won't be buying any more. Phil. Quote Link to post Share on other sites
Mr Gee Posted May 21, 2018 Report Share Posted May 21, 2018 Please advise what the cylinder compressions should be on a CR TR6 1973 is 110lb per cylinder ok !! ?? Quote Link to post Share on other sites
JochemsTR Posted May 21, 2018 Report Share Posted May 21, 2018 (edited) 110? that's not good....with these numbers on all 6.....?? Compression is checked with a hot engine, throttle open. (remove all plugs!) PI goes upto to 188... Carburator about 130.... Jochem Edited May 21, 2018 by JochemsTR Quote Link to post Share on other sites
barkerwilliams Posted May 21, 2018 Report Share Posted May 21, 2018 If accurate 110 would be low. Is the tester accurate'ish? (they are typically cheaply made and although give consistent readings may not be accurate) Did you test with wide-open-throttle and was it cranking until the reading stabilised? Unusual if all cylinders are similarly low, it is more common to have perhaps only one or two faulty cylinders lower than the rest. If all are similar perhaps you need to borrow a second tester for corroboration. If the car starts and runs well suspect the readings may not be accurate. Alan Quote Link to post Share on other sites
RogerH Posted May 21, 2018 Report Share Posted May 21, 2018 Hi Alan, PM sent. Roger Quote Link to post Share on other sites
stillp Posted May 21, 2018 Report Share Posted May 21, 2018 Try again with a squirt of oil in each cylinder. Pete Quote Link to post Share on other sites
PYU940F Posted May 21, 2018 Report Share Posted May 21, 2018 I recently bought a Clark compression tester, Looks good, various fittings with screw in and push in. I started to suspect its accuracy when my son's 2000 Alfa showed around 140 and my TR around the same. I checked my compressions with another tester and they were all + 20-25 psi. Probably good to check the gauge with an airline. Quote Link to post Share on other sites
oldtuckunder Posted May 24, 2018 Report Share Posted May 24, 2018 (edited) Did you test with wide-open-throttle and was it cranking until the reading stabilised? No good just cranking with the throttles opened, if its a carb'd car you need to have the air pistons held up also, bog roll centre tubes work well! Your looking for even readings across the set, not necessarily high readings, none of the non professional gauges are calibrated. If they are low, and another gauge confirms, then really only a leak down test will identify the problem. A wet test after the dry may help indicate if there is a bore problem. Alan Edited May 24, 2018 by oldtuckunder Quote Link to post Share on other sites
john.r.davies Posted May 25, 2018 Report Share Posted May 25, 2018 (edited) The pressure gauge on a compression tester is the same type as most tyre pressure gauges, a Bourdon guage. So how accurate are those? This Australian survey inflated a tyre at service station and other outlets, where by law they should be calibrated regularly, and then tested the pressure in the tyre on a calibrated gauge. "Tyre guage Survey - RACQ" https://www.google.co.uk/search?biw=1920&bih=949&ei=HLgHW5G6BarcgAbvl5LgAQ&q=Tyre+gauge+survey+-+RACQ&oq=Tyre+gauge+survey+-+RACQ&gs_l=psy-ab.12...379352.394268.0.396281.28.28.0.0.0.0.147.2012.27j1.28.0....0...1c.1.64.psy-ab..0.20.1510...0j0i67k1j0i131k1j0i131i67k1j0i10k1j0i13k1j0i22i10i30k1j0i22i30k1j0i13i30k1j0i13i5i30k1j0i8i13i30k1j33i160k1j33i21k1j33i22i29i30k1.0.QukQ81ecXrQ How did they do? 17 of the 52 sites tested were more than 5% inaccurate. The worst was 18% out. On, say, 150psi that would read 123 (or 177!) psi. And a compression test is more complex to do than a tyre pressure check An ordinary, uncalibrated compression tester can only be used to compare the pressures across the block, not to answer the question, "is my compression as hgh as it should be?" It could be used to compare two engines on the same day, at the same time, and if one is 'known-good' then a diagnosis made, but not at different times with diferent gauges. JOhn Edited May 25, 2018 by john.r.davies Quote Link to post Share on other sites
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