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Jun 10, 2011 21:10:12 GMT
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This is a little rule that I know that works on all pushrod 8v 4 cyl engines which I'm sure their are a fair few of on this site.
Rule of 9
i.e if 1 is down adjust 8 if 2 is down adjust 7 if 3 is down adjust 6 and so on so that the two numbers always add to nine.
Rocker number is done from the front to back of the engine.
Hope this is helpfull to someone
Paul
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On that subject, my grandpa said if you have nothing to measure the clearance with, adjust the screw in as tight as you can between finger and thumb then back it off so you could click the rocker a bit. Not scientific but in this case a noisy tappet is a happy tappet. From the perspective that it is easier to set them loose and adjust them when you can rather than adjust them tight and have to pull the head to regrind burned valve seats. --Phil
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djefk
Part of things
Posts: 844
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Or another way is to use a long piece of heater hose: with the rocker cover off and the engine ticking over slowly, point the hose at each tappet and listen to the noise it makes. Adjust each one to just at the point where any tighter and it'll go quiet (you do NOT want it to be quiet or you risk valve burning). Repeat this for all valves.
This will be handy for any noisy high mileage Rootes 1500 / 1725 or ford crossflow car owners - I once sorted the horribly noisy tappets on my ex's 1300 mk4 Escort after repeatedly trying the correct feeler guages (no good as the wearing faces on the rockers were so worn) and one of those clik-adjust things (which broke almost immediately).
Again it's not scientific but when you have no other option it's surprising how accurate this method can be: the car felt 60,000 miles younger afterwards as the valves were now opening further (the tappets really were that bad!), with no valve burning problems.
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My method is; I imagine a mirror in the mittle of the rockers. For each valve that's down, adjust it's 'mirror image'. Saves you the complicated math ;D I've never tried, but I was told a strip of coke can gives adequate rocker gaps if no feeler gauge is at hand If you have no data to set the gaps for; set a minor gap, run the engine realy hot. Adjust the rockers to no play. Let it cool over night. Measure the gap. Add a wee bit for security reasons and you have the value you need to set the rocker gaps to Cheers, Jan
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Jun 11, 2011 12:29:15 GMT
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you'd be surprised how much of a difference a thou or so can make!!
when I had the x-flow I used to set them with the rule of nine but it was less turns of the engine to do them out of numerical order ;D
I had a piper 270 cam in that but I remember the gap was .0014 thou & alhough it used to run quiet there were times it would only idle on 3 cylinders. this was low compression due to the tappets being too tight & I think I ended up running the inlet 14 & the exhaust 15 thou & it cured it.
i also had to help a mate get his excort running that he bought too. set the plug gaps, points, static timing etc but still wasn't right. turned out that had a kent cam in it & the previous owner had set the clearances to .0018in/.0022ex as standard when the kent cam was something like .0012 thou!!!
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Last Edit: Jun 11, 2011 12:31:58 GMT by Ratters
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Jun 11, 2011 13:02:01 GMT
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Valve clearances are an essential check and do make a huge difference to how well an engine runs. Rule of nine and a set of feeler gauges is the best way to do it. Also to turn the engine if you cant get a spanner on a pulley, put the car in third and gently rock it forward
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Jun 11, 2011 13:38:31 GMT
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This will be handy for any noisy high mileage Rootes 1500 / 1725 or ford crossflow car owners - ..... Again it's not scientific but when you have no other option it's surprising how accurate this method can be: the car felt 60,000 miles younger afterwards as the valves were now opening further (the tappets really were that bad!), with no valve burning problems. True. The method I used to employ on my Super Minx was to go out for an enthusiastic drive for 30 mins, come back, set the idle as low as it would run smoothly-about 450 rpm, whip the rocker cover off, slack off a lockout at a time and adjust by feel and sound. The engine ran its best with just a gentle tic-tic-tic from each. Set the idle mix and speed by ear and nose, set the points by eye, set the timing for the highest idle then advance it slightly and readjust the idle speed so the dynamo would just disengage. No tools required other than a 1/2" ring and a flatblade screwdriver. Wish getting a modern to run well with 30 minutes fettling was that easy. --Phil
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Jun 11, 2011 13:56:44 GMT
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Wish getting a modern to run well with 30 minutes fettling was that easy. --Phil Now this is something that really bugs me. Running problems on computerised engines really aren't that hard to diagnose. 1. If the engine is not running at all! You have a failed sensor on a critical system, I.e. crank position sensor not sending a signal as to when to send a spark. Things like a failed mass airflow or lambda sensor will put the car into limp mode but are unlikely to kill it completly. 2. The poor starter rough idler. This is nearly always ignition related. A failing crank position sensor or dodgy coil pack is the most likely culprit. 3. The high emissions. Lambda sensors if they aren't sending a signal then the ECU will increase the mixture as it thinks the car is running overly lean. 4. Down on power. This ones the most difficult as any failing sensor can put the car into limp mode, but my first check would always be the MAF sensor which will be located behind the air filter. Again if the computer is unsure of how much air is coming in it wont have any idea what mixture it should set so will make an eductated guess to keep the engine running. The easiest way to check is to just pull the wires off your suspect sensor if the engine doesn't run noticeably worse or cut out then that sensor is not working properly. Alternatively you can plug in a laptop but that will only say something like No signal from speed sensor. It wont tell you where it is or whether the sensor is faulty or if its just a broken wire. Personally I only use one if I'm really stuck
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Jun 11, 2011 17:07:54 GMT
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Wish getting a modern to run well with 30 minutes fettling was that easy. --Phil Now this is something that really bugs me. Running problems on computerised engines really aren't that hard to diagnose. At the side of the road, in the dark, in the howling wind and pouring rain with only a pair of worn out pliers and a screwdriver? With the GTA I could fix it but I'd be walking home and fetching it the following day; with the Hillman, the Victor and the Transit I got myself fixed there and then and got home. Albeit in one instance only firing on 3 cylinders, but I got home...
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Jun 13, 2011 10:52:35 GMT
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...to turn the engine if you cant get a spanner on a pulley, put the car in third and gently rock it forward This tip is excellent. I used to always do my tappets by turning the engine with a socket, but after watching a mate of mine roll his car around by hand in fourth gear I was impressed. In a high gear it only takes a few centimetres of car movement to bring the engine to the next position for adjustment. The bloke I was watching works mostly on Minis and air-cooled Fiats so they're light cars and easy to roll, which means you can do it with one hand.
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Jun 13, 2011 11:56:18 GMT
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valve clearances on my van are simple they don't have clearances so you just wind the rocker down till there is very slight resistance on turning the push rod the beauty of a hydraulic roller cam and roller rockers
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dw1603
Part of things
Posts: 591
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Oct 17, 2011 22:19:53 GMT
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...to turn the engine if you cant get a spanner on a pulley, put the car in third and gently rock it forward This tip is excellent. I used to always do my tappets by turning the engine with a socket, but after watching a mate of mine roll his car around by hand in fourth gear I was impressed. In a high gear it only takes a few centimetres of car movement to bring the engine to the next position for adjustment. The bloke I was watching works mostly on Minis and air-cooled Fiats so they're light cars and easy to roll, which means you can do it with one hand. And you don't get a ratchet through your rad if you forget to remove it before firing up!
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Oct 18, 2011 19:21:45 GMT
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Standard Pushrod valve clearances cast iron head 10 and 20 thou cheers
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Oct 18, 2011 19:23:18 GMT
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or .25mm and .50mm to the late person
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Oct 18, 2011 22:09:21 GMT
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If you are lazy or you have a very heavy car which doesn't like to roll (read, Citroen DS with deflated hydraulics) you can also turn the crank over with the starter, if you time it right, you can get it exactly in the right position and do the valves in 1 go
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Oct 18, 2011 22:24:08 GMT
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Standard Pushrod valve clearances cast iron head 10 and 20 thou cheers or .25mm and .50mm to the late person What a complete load of bull. Valve clarances depend on many, many things, including pushrod length, valve length, rocker arm ratio, cam profile, expected engine temperatures, etc. Manufacturers give specific values for a reason - not for the good of their health. Just using a Haynes book that is to hand: Mini 850/1000/1100: 0.012" in and exh Mini 1275 Cooper S: 0.015" in and exh Late 1275 Cooper: 0.013-0.015" in and exh. Ok, so they are not massive differences between engines, but with your figures you'd be setting the inlet tight and the exhaust loose. Yes, so yours are in the ballpark, but so is setting them by ear so they *just* make a noise. If you're going to go to the bother of setting them using feeler gauges then at least use the correct feeler gauges - how difficult is it to look up the manufacturer's figure in a Haynes book?
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bl1300
Posted a lot
Posts: 1,678
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Oct 19, 2011 16:36:34 GMT
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jevillug.
My Autodata software supports what your saying different valve clearance setting for nigh on every engine. Also worth looking up is whether or not your manual says to set clearances with a cold or hot engine.
Every car ive owned has been cold set but id still check the manual or autodata first cause the figures will be very different if you do the wrong one
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Current fleet.
1967 DAF 44 1974 VW Beetle 1303s 1975 Triumph Spitfire MkIV 1988 VW LT45 Beavertail 1998 Volvo V70 2.5 1959 Fordson Dexta
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Oct 19, 2011 19:32:45 GMT
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hehe, check the specs for a vauxhall 1256 (viva/chevette) engine - that says to set them to 12 thou with the engine running
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To get a standard A40 this low, you'd have to dig a hole to put it in
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bl1300
Posted a lot
Posts: 1,678
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Oct 19, 2011 20:04:19 GMT
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hehe, check the specs for a vauxhall 1256 (viva/chevette) engine - that says to set them to 12 thou with the engine running I'm sorry but how the heck do you do that
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Current fleet.
1967 DAF 44 1974 VW Beetle 1303s 1975 Triumph Spitfire MkIV 1988 VW LT45 Beavertail 1998 Volvo V70 2.5 1959 Fordson Dexta
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spiny
Club Retro Rides Member
Wiki Admin
I am abivalent towards car electrics ...
Posts: 1,331
Club RR Member Number: 167
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Oct 19, 2011 20:27:44 GMT
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i did the MG a few weeks ago, the haynes for that says it can be done with the engine running - how is this done ? I wouldn't like to drop a spanner trying to get the ring end on the nut.
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