Adjustable cam timing

T

Tenderoldwesty

been trawling the search option for what seems an eternity now trying to research adjustable standard camshaft timing. I'm looking to try and unleash a little extra lowdown grunt ( only use 1st and 2nd gear Around an oval ). Best talk through I've come across seems to be ebbs maxi micra blog , but alas the pics won't show and as always a picture speaks a thousand words.
Question is this is there anyway of getting the pics up or is there maybe another concise run through available somewhere so that a mere mortal like myself may just get my head round the process ??
Many thanks as always for any ideas/comments
 
i filed a flat on the dowels on mine westy, you dont need much, and advancing the inlet gives more lowdown grunt

PA140195.JPG
 
Thanks Frank
I gleamed that info from trawling ( about removing the dowels ). Being cheeky I don't suppose you have a pic of the amount to "adjust" the inlet please ? Or further info ? After my misfortune with the last rebuild I want to try and make this one last a little longer haha. I liken myself to a sponge lol soaking up info and hopefully retaining it
 
it just depends on how stretched your chains are really mate, you usually have to file 1 or 2 mm off to bring the cams back to factory spec, then an extra 1 or 2 mm on the inlet maybe ?
 
Oh I get the drift now I think. So the peg has been filed either side allowing for slight movement , I was under the impression that the pegs were removed completely. So firstly set the timing to tdc ( all marks and chain links set ) then just move the inlet slightly left or right for factory spec then more to advance ( left or right ? )
Is this just done by sight with the cam lobes as you showed me previously when setting tdc ? Or is there need for markers/angles etc.
Thanks as always
 
you only need to file the one side really mate, if you file about half way you can even twist the dowel round and use the next tooth :)
i never had one come loose, but always torqued them up pretty tight
 
I got reground camshafts off autosprint Birmingham. 272° with 3mm shims. I had to remove my dowels to advance timing to 110° starting point. With the use of a degree wheel and a dial gauge , its a very simple task
 
or you can check the opening/closing periods by turning the crank till the bucket becomes free from the lobe (i always used the little notch in the shim recess and spun the bucket with a small screwdriver
you can use that method for checking the overlap at tdc (when all 4 valves are slightly open)
 
So if I understand if I was to file/remove peg ( X ) that would allow me to adjust the sprocket and use link ( Y ) set on the timing dot , and thus be set ok ? Forgive my ignorance but just need to get it straight in my mind I presume like most things when I have done it ill think well that was straight forward hahahaha .
Thanks again guys micra cam timing modify.jpg
 
turn the cams clockwise to advance mate, and you need to advance them both if your chains are worn
but you need top-end power for the oval tho surely ?
 
Luvly thanks sir.
The tracks are only short ovals and in second gear they just start to top out at the braking point at the end of the straights. So really it's all about acceleration out of the bends because we are starting to slow 3/4 down the straight ready for the bend. In a nutshell we just need max performance in second gear at full throttle , so would you suggest a different setting then ?
Setup we will be running is 1.3 cams/crank/rods , 1 litre Pistons , lightened 1 litre fly , 1 litre box , lightened crank pulley , skimmed head , frank speed ( ish ) mani , and hopefully 1.6 Primera ecu and t/b
 
i personally would set the exhaust cam at factory spec, and retard the inlet 1 or 2 mm on the dowel :)
advancing the inlet should help the 1 to 4k powerband, but you should be running between 4 and 7k on an oval really
 
Thanks for your view sir much appreciated. Yes it makes sense that the optimum power is really required 4-7k because obviously any lower the possibility of spinning the wheels out the bends is heightened I suppose. So just a couple of mill would suffice or would I be better getting a degree wheel ? As judging "a couple of mill " isn't an exact science lol. Many thanks as always
 
Not sure if this falls into the same post but hey ho here we go anyway. Just fitted a pair of 1300 cams into a 1litre road car ( for future use racing to see how it performs ) and can't seem to get it running right. With the dizzy set as per standard the tickover is high ( 1500 ) and she hunts a little and is very flat when throttled. If we advance the dizzy to max advance then the tick over levels out nicely and stationary she revs nicely , but on driving it couldn't pull a sweet wrapper off. We have checked for manifold/pipes leaking and all clear , changed dizzy,plugs leads and still no better. Any advice / ideas welcomed as usual guys many thanks in advance
 
I will take the chain / rocker cover off in the morning and set it tdc and take / post a pic sir. If indeed it is out , is it simple enough to adjust with the engine in situ ??
Thanks for your time and advice again sir
 
Looking at the timing pic ( further up this thread ) should the dowels on the cams be 9 o'clock inlet and 12 o'clock exhaust ? If so then my inlet looks to be about 10 o'clock
 
Tried and tried nothing seems to be working
So in the pile she goes and just look about for a 1300 and go from there lol. Thanks for the ideas / comments guys much appreciated
 
Tenderoldwesty said:
No !! Didn't know you had to or indeed how to . Could you shed some light please
Click to expand...
You basically disconnect the tps, blip the throttle a bit the let the idle settle.
Adjust the idle speed to 650-700 then adjust the dizzy timing to 15btdc. This should sync the ECU to the dizzy.
The plug tps back in and adjust the idle speed to normal.
Good luck
 

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