J series timing

[Gary]

yyyyyyyyyyyeo,

 

i have a J15, and when trying to set timing today, the light suggested it was about 50deg BTDC :blink: the timing scale wasnt near the stationary point you measure from

 

it starts and runs ok once warm, and when i drove it last i did so for a fair trip and it didnt feel like timing was bad

 

on another car ive got, ive skipped a tooth on one of the cam pulleys before and the car drove and revved up fine, just lacked in power. its possible ive skipped a tooth on the cam sprocket when i did the bottom end bearings for the J... maybe i cant remember now

 

could the J still run decent with such a misalignment? or is it perhaps something else? i dont think the dizzy has adjustment enough to pull timing back that far is all

[metalmonkey47]

I ran my A15 like that for a while without problems. I didn't really know until I had installed a multi spark ignition where timing was critical.

 

You can rotate the distributor back a tooth, and that should give you more adjust ability.

 

on another car ive got, ive skipped a tooth on one of the cam pulleys before and the car drove and revved up fine, just lacked in power. its possible ive skipped a tooth on the cam sprocket when i did the bottom end bearings for the J... maybe i cant remember now

 

 

Not likely, since that's valve timing, not ignition timing.

 

 

 

 

But lets see what Mike has to say i know nothing about the J engines.

Edited March 16, 2011 by metalmonkey47

[Gary]

ah yes good point :lol:

 

im used to engines with dizzys ran off one of the cams, i didnt even consider that the J's one runs off the crank

 

saves me pulling the timing cover off again, excellent work! ill mess about with it today see if i can fix

[datzenmike]

Edit: Sorry thought this was an L motor.

 

You may have a pulley from a J13 or something and the timing mark is in a different location.

 

The timing scale or front cover may be from a J13 or something and is in a different location.

 

If you cannot rectify this, just keep advancing it and driving it until there is definite pinging under load, then retard slightly to get rid of it. Engine is timed.

[Gary]

just pulled it apart a bit, the manual suggests the dizzy is driven from the cam :\ would have to reach from one side of the engine to the other to do that but it expressly states the dizzy needs to be removed before removing the cam. i just finished sealing the sump for the 3rd time i dont really want to do it again. spose i will if i have to

 

the bits pictured in the 520 manual dont match mine either, ive got a bolt with a cam sorta head on it for adjustment that sits on a plate and looks like it wont enjoy being seperated from the block :\ dizzy looks same though

 

so it would appear mine is different from J13's :( mike it could have timing covers from various J series cos i dunno anything of its history. the intake manifold is strange, so other bits could certainly have been swapped over too

 

ill remove the shaft see what its doing, i found mikes thread from a link posted on olddatsuns, mine is identical to his

http://community.ratsun.net/index.php?showtopic=393

[MikeRL411]

just pulled it apart a bit, the manual suggests the dizzy is driven from the cam :\ would have to reach from one side of the engine to the other to do that but it expressly states the dizzy needs to be removed before removing the cam. i just finished sealing the sump for the 3rd time i dont really want to do it again. spose i will if i have to

 

the bits pictured in the 520 manual dont match mine either, ive got a bolt with a cam sorta head on it for adjustment that sits on a plate and looks like it wont enjoy being seperated from the block :\ dizzy looks same though

 

 

I think that what you are describing is the "vernier" adjust assembly for fine tuning the timing. You do a gross setting by the front index tab and fine tune by tweaking the "cam" screw against he slotted part of the distributor assembly. There should be a plate on the block side with + and - markings to guide you in the final setting of the timing. Possibly missing?

[Gary]

just pulled the whole assembly out then :D

 

was covered in grease thick enough to obscure the measurements on the plate there, but thats what looks to be, vernier sort of adjustment moved about by the little cam screw. the way it was set before i started was 0deg adjustment

 

it looks like distributor is driven from the cam after all, doesnt seem to reach down far enough to hit the crank, and from pictures it looks like the cam has the appropriate helical teeth to mesh with the dizzy driveshaft

 

i think ive got my head around it now, might have to check sprocket alignment after all :( im not completely sure what angle to align the driveshaft at though, any hints?

[datzenmike]

Sorry not that up on the J series. I wouldn't worry about the timing mark lining up. The motor needs as much advance as it can handle without pinging under load. Take for a drive with the dizzy just barely snugged down so you can twist it to adjust the timing. If it runs ok add some advance and drive it under load. Keep adding advance until you can hear it pinging and retard slightly. This will give the best economy and performance.

[Gary]

its cool man :) sorta wish it was an L series :( gotta make do for now though to keep the Man happy. sorta keen to get it aligned as per factory so i can work from there once i can drive it about, ive got a little carb tuning to do too

 

with L series, when you're aligning the dizzy shaft, what position does the crank have to be in?

 

im going by the 520 manual, it tells me it should be at TDC on the crank pulley, but that the stationary point means its 10deg BTDC (maybe there was more than one stationary point on the J13?). i dunno what it means, i thiiinnkk its trying to suggest you align dizzy shaft to about 10deg BTDC, put it all back together, then fine tune with the dizzy until its bang on what j00 need

 

is that how is it done for L series? or do you align dizzy shaft to TDC, put it all together then adjust dizzy from there?

[Zendar]

This might help you Gary.

Figures 1.74 and 1.75 are upside down. J15 initial advance is 8deg BTDC at 600rpm.

 

[Gary]

nice one thanks man :)

 

i sorted it using the stuff for a J13, not sure what was wrong before but seems to be aligning itself good now. starts again which is plus, and much easier, and doesnt choke as easy like it used to under WOT

 

i think my problem in the end was dizzy shaft was misaligned, i also cleaned the breaker points and regapped, regreased the cam and gave it a good clean inside. might have had something to do with dramas but i dunno. also fiddled about with the base plate for the dizzy for a little more adjustment which helped out too

 

i got a few pics i might put em here if anyone else had similar dramas

[Zendar]

I had the same problem and the dist. driveshaft was misaligned. Easy to fix with a long bolt :P.

Now I have a L18 in my truck.

 

Gary can you get J15 valves in Australia?

[Gary]

true that! i used an allen key socket i had, i think was 11mm, fit perfectly :D tight enough to hold it as long as i needed, then with a twist it'd come out no dramas

 

when i had the head machined and checked i got new J15 valve guides and one or two exhaust valves cos they werent in good condition, so we can get em here. pretty sure the machine shop just matched a generic size to suit though, if you cant find em i can visit again. it might have details on my invoice someplace come to think of it

[Zendar]

Can't get valves here in Finland anymore, any info on the valve would help out :)

[banzai510(hainz)]

Maybe datman in the UK can get soeme

[Zendar]

Maybe datman in the UK can get soeme

Thanks Hainz

 

This is the reason why I did the L18 swap

[Gary]

did a good job of it thats for sure :D

 

ill swing into the shop on monday, they're closed weekends

[Gary]

a couple pics and a basic howto:

its fair simple, the bits to the distributor side of things are;
the distributor cap, the distributor itself, its mounting plate on the engine, and the shaft that drives the dizzy. im sure you'll find it elementary to remove these things, but the shaft for the dizzy can be a little tricky. the easiest way i found was to use something that fit tight down the center of it, then gently twist it clockwise (i think) while pulling it out. provided the shaft fit snug against whatever you used to remove it, it shouldnt fall down and into the sump. for me, an 11mm (i think) allen key socket was perfect for the job.

provided the cam and crank sprockets are aligned (they dont slip, but if you've done a cam or something just make sure theyre aligned good), now youve just gotta put it all back together

the first thing to do is check/set point gap on the distributor. there's two screws to use to do this, the one to loosen the arm so you might adjust it is a phillips/flat head screw (mine was anyway) and the other one is to gently adjust the gap, and is a plain shallow flat head. its a good idea to clean the points good, they should look even and not pitted severely or chunked up. the correct gap is between 0.45mm and 0.55mm, the feeler guage you use should pass between the gap easily. when you tighten it all back up after setting the gap, check the gap again and adjust again if necessary. would be a good idea to clean the cam surface the points rely on, and lightly regrease it while you're there (i used a tiny bit of wheel bearing grease). careful to make sure the points are clean after you regrease. should probably clean up the points on the dizzy cap, and the rotor too while you're there, and replace the dizzy o ring unless done not long ago.

now get the crank to 10deg BTDC, just after the compression stroke. the easy way to get there is to remove the spark plug, stick your pinky finger in the hole and slowly turn the engine manually. on the compression stroke you'll feel pressure trying to escape out of where your finger is. once you feel that, align the timing mark on the pulley (with the stationary point on the timing cover) to the 10deg BTDC mark, which is the second mark from the left (1st is TDC, second is 10deg BTDC, third is 15deg BTDC, fourth is 20deg BTDC)

now its time to align the shaft for the dizzy. the dizzy runs off the camshaft via a helical gear, it's important this shaft is aligned properly on the cam, otherwise timing will be out by enough to cause dramas. first have a good look at the shaft face, you'll see that the slot cut out of it isnt centered, its offset toward one side. if you imagine the face of the shaft to be made up of two C's or semi-circles, you'll notice that one side is smaller than the other because of the offset slot. the trick is to make sure the smaller of the semi circles is toward the front of the engine (ie say toward the crank pulley), and the groove is to lean back a touch just like a backslash. here's a pic to give you an idea:


so with the crank set at 10deg BTDC, and using your tool of choice that fits snug inside the shaft, carefully insert the shaft into the hole whilst feeling for its seat inside. remember the gear teeth you're attaching to are helical so it'll take a try or two to make sure its aligned properly. some pics to help out a bit, for reference ive shown you the two surrounding alignments that ARENT correct, so its the middle one of these pics that j00 need:
NOT this:


this


NOT this:


with that done, you can install the mounting plate for the dizzy (with appropriate gasket/RTV), then with the rotor fitted and pointing toward the top right (say at 1:30 o clock) put the distributor back into its hole. while gently pushing it in, wiggle the rotor carefully so the the dizzy shaft aligns with the slot in the shaft that goes to the cam. it'll eventually pop in ready to go

now just replace the dizzy cap, and refit the spark leads as per this poorly represented diagram:

3    1
             ----> front of engine
4    2

it should start fair easy now, if it doesnt then set it to as much advance as you can and try again. if you need more adjustment, the dizzy itself can rotate on its own small mounting plate by loosening a screw and shifting it forward or back. the static timing should be set at either 8deg or 10deg BTDC (i did 10deg for my J15, some books recommend 8 though, doesnt make a lot of difference i think). when the engine is running and you're using a timing light, it should be about 15deg BTDC. ive got some more advance dialed in at present but i think the simplest way to set appropriate advance is trial and error. set advance slowly each time you test, you dont want it be pinging under high load so careful

[boomwalker]

Hi Gary,

the photobucket is not working and its driving me crazy..cud u please email it to me at mohdamin@feseq.com

TQs

[]2eDeYe]

If you go to the direct link the images should work for you. Links in order per post #18

 

http://img.photobucket.com/albums/v471/v3ctourist/datto/timing4.jpg

 

http://img.photobucket.com/albums/v471/v3ctourist/datto/timing3.jpg

 

http://img.photobucket.com/albums/v471/v3ctourist/datto/timing1.jpg

 

http://img.photobucket.com/albums/v471/v3ctourist/datto/timing2.jpg

[boomwalker]

thank you...but it is doesn't work huhuhuhu

[Gary]

shit sorry dude, haven't checked ratsun in a while. i just finished going through backing up photobucket images since they went and did what they did. i'll update my post with imgur links for now for you

edit; looks like img tags arent allowed now so i can't give you image previews in the post. i've uploaded the images anywho so but ill try work out how to display images again.

edit: ahaaa fixed. i was trying to image tag a url :huh: