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Post by 1800heap on Apr 14, 2017 12:19:31 GMT
VVT so far.
Ok so having had a look at the cam gears and chain it is clear that only 2 ish degrees is possible with the original chain set up as I suspected.
Several problems arise from the original setup.
1- The space between the cam gear and crank gear is very limiting.
2- The lack of space between the double chain and the plate.
3- The lack of space under the original cover.
So the first problem can be solved by running the chain around idlers either side that retract into the space between the two gears. Then when cam timing adjustment is commanded it moves the chain out past its normally straight route and on the opposite side in, which compensates for chain length. I will draw it to give you a better idea what I mean but not today! So by moving one side out and one side in this will adjust the relative position of the cam and crank gears on the chain and thus the cam timing. This setup will also be able to set the tension and the oil fed device won't be required.
Second the lack of gap between chain and plate will either require adaptation of the plate, (likely required anyway) or by using a single chain. For the moment I would like to stick will double chain as I have only seen the vernier adjusters in the double chain. These I think will be required for setup!
Third the cover is going to need to be remaid no matter what I think, so the only posible mod is to shim the pullys for extra space.
I have descovered the chain is British Standard 06B-2 chain 3/8 pitch and removable links are available for it. A couple of which I have ordered from Mr E bay.
Next time a sketch I hope!
Nick
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Post by 1800heap on Apr 12, 2017 8:41:10 GMT
Apart from the ridge looks good which is why I didnt notice it at first.
Could it be something to do with the previous re-bore?
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Post by 1800heap on Apr 12, 2017 6:57:46 GMT
I thought it was odd. Just measured roughly with feeler gauge and the other cylinders are about 1.5 thou all round. Putting a 2 thou in I can still feel edge. Number 1 a 10 thou feeler is level with the untouched rim at the worst bit, which is center with the pump, so front edge. The opposite side is 2 though ish. Havent checked the rings on number 1 yet. Engine feels quite free. Rod 1 has about 10 thou of end float which is better than the others actually. Are you thinking some kind of side load? I wondered if it could be a cool/ hot spot causing it to do with the pump?
Nick
Ps I think the pistons are +40 so it has been rebored b4.
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Post by 1800heap on Apr 12, 2017 2:18:43 GMT
I have pulled apart my engine recently and had a look at the wear in the bores and thought it wasn't bad at all and was not going to bother with a re-bore. Looked a bit closer today and noticed on number 1 quite a big ridge but only half way round and on the water pump side. Must be to do with the pump but why?
Nick
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Post by 1800heap on Apr 10, 2017 9:19:57 GMT
I found out what I wanted to know, which was that the unit removed had developed a pathway to earth, which a new £3 Chinese fake condenser didn't. Chris. The Chinese condensor probably hasn't got anything inside it, thats why it passed! I wonder sometimes how many have a chuckle to themselves when the take our money! Its your megger tester you go for it!! Not trying to tell a sparky how to use or where to put his megga tester all good ha ha. You may be confusing killing someone with killing a cap though!! Nick
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Post by 1800heap on Apr 9, 2017 23:03:42 GMT
A quick search reveals insulation test ok at 500v and best not to test any highter as you may damage the condensor. Anything under 40 meg ohms the condensor is bad so it said.
Nick
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Post by 1800heap on Apr 9, 2017 22:33:45 GMT
Hi chris
Be a bit carefull what you use your insulation tester on. Caps have a rated voltage and you may damage them by zapping them with a 1000v insulation test. Not sure what condensors are rated at. David said they run at about 400 volts so may only be rated as an example at say 800v. If you insulation test to 1000v you could breakdown the insulation and cause premature failure! If the cap is rated at 2000v then no problem using a 1000v insulation test. Definitely don't test any electronic devices with it unless they are destined for the bin!!
Nick
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Post by 1800heap on Apr 9, 2017 9:52:12 GMT
All good David what I ment was I thought the primary function was RF didn't consider anything else. You have in fact enlightened me as I said. Happy to be enlightened I am far from an expert!
Nick
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Post by 1800heap on Apr 9, 2017 7:04:08 GMT
Unfortunately for you Chris David may well be right about your fault still being present. I have been enlightened about the main reason for the condensor thanks David. I have thought it was for reducing RF for about 20 years!! It probably helps with the service life of the contacts as well. Makes sence to use foil type caps for better service life. I thought for some reason the condensors had PCB's in them (Polychlorinated biphenyls. A nasty chemical!) not sure why! Bad memory strikes again! As David said they will still suffer in the heat. Incase you didn't realise the coil is powered with 12 volts but when the magnetic field colapses as the contacts open, voltage is induced in the opposite direction in the primary winding as well as the secondary. This voltage is quite high and is why you get a shock sometimes when playing around with the primary side of the coil. Also if you are a silly fellow like me and forget to ground your plug when testing for sparks a nasty shock from the secondary! Much higher voltage!
Nick
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Post by 1800heap on Apr 8, 2017 23:06:44 GMT
Now, the hard questiion is this: The car is using an ETi100 electronic ignition, which uses the contact breakers as a switch, so why would the condenser failing still cause the car to run badly? My brain hurts. Chris. Hi Chris Now I thought that the condensors job (basically a capacitor) was to prevent the car emitting nasty Radio frequency noises as you drive around. This RF is caused by the little spark from the contact breakers when they open l believe. You used to sometimes get it on the old AM radios as a nasty buzz that varys with engine speed! Capacitors depending on the type, only have a certain life even if you don't use them! This is because they have an electrolyte in them that drys out over time. Also high temperature shortens life. The higher the temp the shorter the life. This is usually factored in when smart fellows design electronic gear. It is also why smart IT people put air conditioning in communications cupboards! Sony elecyronic equipment of the 90's was notorious for bad caps! Caps can go two ways. They either change in Capacitance or develope internal resistance but usually both. They can develop an internal short circuit too. This can be seen in dead electronic equipment when they get hot and pop or get a big buldge on the top!! This resistance is bad as you have found out! If you still have the culprit condensor and you have a meter that measures resistance you can test it. Low resistance is bad. In fact anything except very high resistance is usually bad! What should happen on a good condensor when you connect your meter the resistance will climb well into the meg ohm range as the meter charges the cap. The faster it climbs the smaller the Capacitance. Bear in mind I haven't tested a good one to see, I am just going by general capacitor behavior. New old stock condensors are likley to have a short service life because of the above reasons! Nick
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Post by 1800heap on Apr 7, 2017 9:39:50 GMT
Thanks Wolseley1800
The skoda coil pack looks ok. Not sure I could live down having a Skoda part on my crab though!!
It looks like 4 pins on the connector which means it probably sparks on two at once and one spark is wasted. If the spark plug spacing was the same it would be a good option if the price was ok.
Only reason I picked the ford one was I have a ford with them on and knew I could make them fit before I bought one!!
Nick
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Post by 1800heap on Apr 6, 2017 11:39:34 GMT
Distributor so far and modified ford coil pack. Nick
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Post by 1800heap on Apr 6, 2017 7:54:15 GMT
I have a bit of experience with microcontrollers and have done a couple of projects that drive stepper motors. I was thinking of a stepper motor to operate the cam adjusters. I did make a start on turning a distributor into an crank angle sensor. I was going to use the ignition coil packs from a ford that go direct onto the spark plugs and do away with the coil and leads altogether. I haven't got very far with that though. This could just be intergrated with that. It is very time consuming unfortunately and all sorts of stuff comes up that gets in the way of me fiddling about in the shed with it!!
When I work out what on earth I did with the modified distributor I will post a picture!
Nick
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Post by 1800heap on Apr 5, 2017 5:57:10 GMT
Hi Nick Not sure whether 2-3 degrees would offer much noticeable advantage though on a standard engine, that's the sort of change to expect with "natural" chain stretch over time. David So I probably need to aim for more like 10 degrees? That makes it a bit trickier. I think the standard tensioner will have to go then. The adjustment will have to happen on both sides at the same time, with some way to maintain the overall tension. I will draw some pictures I think and have a look at the angles. Nick
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Post by 1800heap on Apr 4, 2017 21:17:33 GMT
Hi David
I think it would be doable to shift the cam position by up to a couple of degrees Maybe 3. I would use a tensionser on the opposite side to the normal position that shifts the chain across and thus adjusts by a small amount against a modified standard tensioner. The chain would run around a curve instead of straight as the tensioner shifts. Then use the vernier type set up as you said to get the base timing right. All depends on how much I would need to move it! I think if 3-4 degrees is enough that would be possible and might be worth a go. I will have a look at the tuning stuff. Like I said hypothetical at the moment. Im after a best of both worlds setup.
I got a set of roller rockers at a good price amongst some othe bits.
Nick
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