aircobra Posted January 31, 2016 Posted January 31, 2016 my rebuild is going along nicely this w.end, got the crank, pistons and the head done https://www.flickr.com/photos/62957688@N08/24097470454/in/datetaken/ (that color is NOT green, its the chrysler pale blue - close match to the datsun) now for the cruicial task - valve timing i understand the the L engines ( unlike toyotas) are interference engines, which means get the timing wrong and say good bye to all your new shiny bits 1. no#1 piston TDC, evidenced by the keys pointing straight up 2. cam dowell against the mark just to the left of the top cam plate bolt 3. shiny chain link on the timing mark https://www.flickr.com/photos/62957688@N08/24699423266/in/datetaken/ ( my chain came only with one shiny link 4. v mark on the plate mark. https://www.flickr.com/photos/62957688@N08/24632105851/in/datetaken/ there are some comments on a bit to the left, bit to the right - this one is spot on 5. now just bolt on the chain kit and the sprocket bolt? after that i was just going to spin it by hand a few revolutions. if it all moves freely, i take it i'm in the clear Quote
aircobra Posted January 31, 2016 Author Posted January 31, 2016 thanks, ignition timing yet to come does it have the be slightly to the left? Quote
Enzo Posted January 31, 2016 Posted January 31, 2016 Hi, Looking at the first picture the block has been decked. It looks like the piston is sticking out of the top of the block. Is the piston flush with the deck or as the picture seems to indicate that it is sticking out a bit. Curious. David Quote
Administrators gav240z Posted January 31, 2016 Administrators Posted January 31, 2016 does it have the be slightly to the left? Yes if memory serves correct that is the firing position for #1 at TDC. Quote
C.A.R. Posted January 31, 2016 Posted January 31, 2016 For heavens sake Andrew, buy a workshop manual or "How to Rebuild Your Nissan/Datsun OHC Engine". Setting up cam timing is described in both. Quote
aircobra Posted January 31, 2016 Author Posted January 31, 2016 got the book. that's why the title says "double checking". its my first L rebuild, so slow is good on this one dave, you're right about the piston, i'll need to spin in over Andrew_L26 1 Quote
Linton Posted February 1, 2016 Posted February 1, 2016 dave, you're right about the piston, i'll need to spin in over he means if the piston is protruding you have a problem!! and before you ask no you can't put the head on if they are, without further head gasket alterations. Quote
aircobra Posted February 17, 2016 Author Posted February 17, 2016 progress update - its pure rock and roll, all orig except for the fan, and the pulley which are l28 on purpose just one remaining problem, left carb piston is sticking at the bottom. I think either the needle or the tube is slightly bent also missing one of the small heater hoses and waiting for some parts to come back from plating its the most new parts i've ever put into an engine, including alternator, oil pump, https://www.flickr.com/photos/62957688@N08/24969142771/in/datetaken/ https://www.flickr.com/photos/62957688@N08/24944342272/in/datetaken/ https://www.flickr.com/photos/62957688@N08/24969175661/in/datetaken/ https://www.flickr.com/photos/62957688@N08/24435631663/in/datetaken/ https://www.flickr.com/photos/62957688@N08/24766898570/in/datetaken/ thanks everyone for all your help gav240z and mother240 2 Quote
Administrators gav240z Posted February 17, 2016 Administrators Posted February 17, 2016 Well done it's looking great. I see you have the OEM braided hoses did you source them new? Quote
aircobra Posted February 17, 2016 Author Posted February 17, 2016 the only one braided hose on the breather, the rest are standard rubber but i was able to source the OEM looking hose clamps for a $1 each. that's a bargain apparently the plastic fan does a better job of the cooling Quote
aircobra Posted April 5, 2017 Author Posted April 5, 2017 ok, a year later its all connected, fuel's up and it doesn;t work spark is there, but it just backfires on the last 2 cylinders. i'll have to take the covers off and check it all again Quote
Enzo Posted April 5, 2017 Posted April 5, 2017 (edited) Hi, If it's back firing through the exhaust, check that you have the plug leads on correctly in the distributor cap and that the direction of rotation is correct (anti-clockwise). Firing order 153624. Just noticed on your pictures from Feb 2016 that the distributor button is 180 degrees out. Should be facing to the front. I presume that the engine is on top dead centre. Edited April 5, 2017 by Enzo Quote
aircobra Posted April 5, 2017 Author Posted April 5, 2017 ok, engine TDC (#1 piston, you can jsut see it) https://www.flickr.com/photos/62957688@N08/33004383124/in/dateposted-public/ check sprocket https://www.flickr.com/photos/62957688@N08/33806777606/in/dateposted-public/ check pulley https://www.flickr.com/photos/62957688@N08/33463346350/in/dateposted-public/ check but goddamit, you're right, the distributor is 180 deg out https://www.flickr.com/photos/62957688@N08/33806750906/in/dateposted-public/ tang https://www.flickr.com/photos/62957688@N08/33806689226/in/dateposted-public/ close enough - and the small half moon is facing the front - as per fsm i think i have a L28 distributor and the long shaft, but its supposed to be identical what is going on? i had a look at the distributor and you can't really assemble it incorrectly - the slot is cur directly onto the shaft as is the arm notch no wonder it was backfiring ! Quote
aircobra Posted April 5, 2017 Author Posted April 5, 2017 you can just see black texta mark on the distributor photo. so its out 160 deg Quote
Enzo Posted April 5, 2017 Posted April 5, 2017 Ok. The crank appears to be about 5 degrees off TDC, which means that the pulley should not be aligned at the notch. Which hole is the sprocket fitted to. Should be on No1 if your chain is new. Other holes are for stretched chains to bring everything back into alignment. Start from scratch. Rotate the engine by hand to align the pulley at TDC. While doing this insert your finger into the No1 spark plug hole to feel the compression as you approach TDC. This will ensure that you are on the compression stroke. (Not 180 degrees out). If you have the valve cover off make sure the inlet and exhaust lobes of the cam on the No1 cylinder are pointing up at 10 and 2 o'clock.(Away from the piston). If the cam is correct and the Crank is correct, look to see were the distributor button is pointing. It should point to the front slightly to the left of the cap hold down clamp. If it is still 180 degrees out (facing to the rear) drop the oil pump and rotate the spindle and reinsert. You may have to do this a couple of times till the shaft looks like the picture you have with the small half moon to the front. Once aligned refit the distributor and all should line up. Rotate the engine by hand and double check. If all is good, fire it up and set your timing. Good Luck and double check everything. David. Quote
aircobra Posted April 5, 2017 Author Posted April 5, 2017 all the photos above are from my car right now 1. crank is spot on - its just the photo because the plate wth he degrees is slightly to the left of where i stuck in the camera when i took the shot 2. i stuck a screw driver in the plug hole to make sure its TDC 3. the cam lobes are up 4. half moon is exactly how it is the photo - eg small side of the half moon to the front . the photo is from my car 5. the button definitely points to the right - as per photo the only to fix as far as i can tell is to drop the oil pump and rotate the shaft 180 so the big side of the halfmoon is facing the front, but that would be contrary to every manual and doesn;t strike me as a good idea i'm enclosing a photo of the rotor, just in case - it only goes on one way both the distributor and the shaft came from a non-running L28 ( which is why i'm suspicious), the pump is brand new do you have a spare dizzy to see how the rotor aligns to the slot in the shaft Quote
aircobra Posted April 5, 2017 Author Posted April 5, 2017 point is - regardless of whether the timing is right or wrong, if the small halfmoon is facing the front, the bloody rotor should do the same - both slots are machined onto the same shaft !!! and this is my problem Quote
RLY240 Posted April 5, 2017 Posted April 5, 2017 There's nothing stopping you just relocating the leads on the cap 180 degrees. Quote
aircobra Posted April 5, 2017 Author Posted April 5, 2017 i could - but i want to know where i f,,,ked up or if i have the wrong parts here's pics of the distributor https://www.flickr.com/photos/62957688@N08/33811880656/in/dateposted-public/ https://www.flickr.com/photos/62957688@N08/33723258511/in/dateposted-public/ https://www.flickr.com/photos/62957688@N08/33811839986/in/dateposted-public/ https://www.flickr.com/photos/62957688@N08/33468282260/in/dateposted-public/ https://www.flickr.com/photos/62957688@N08/33009362814/in/dateposted-public/ and here's lobes proving TDC https://www.flickr.com/photos/62957688@N08/33009400924/in/dateposted-public/ Quote
Moderators PB260Z Posted April 5, 2017 Moderators Posted April 5, 2017 Check..... direction of rotation is correct (anti-clockwise). Firing order 153624. Great advice - very easy mistake to make Quote
Enzo Posted April 5, 2017 Posted April 5, 2017 (edited) Ok, The picture of the underside of the rotor button shows only a piece of metal on one side. The rotors usually have a metal section that presses into the button with a piece coming up on both sides and this locks the button in place. Does yours fit on facing either direction. The side with the missing piece should line up with the flat on the shaft. If it goes on both ways it should be replaced. I will post a picture shortly. Edited April 5, 2017 by Enzo Quote
Cozza Posted April 5, 2017 Posted April 5, 2017 Haven't pulled a dizzy apart for a couple years but is it possible to assemble the inner and outer shaft (mechanical advance area) of the dizzy 180' out?? Quote
aircobra Posted April 5, 2017 Author Posted April 5, 2017 same design - and the same brand as on my photos 1. the shaft has a bevel on it - so it looks like the letter "D" from the top 2. the metal spring in the photo simply keeps the rotor against the shaft. the flat protrusion then slides into the bevelled section of the shaft. only goes on one way. i went to burson and the bosch replacement has a different design, but also goes one way . the same way can anyone identify the distributor ? the only difference between stock 240 and my one seems to be that the condenser is on the inside, not outside the only remaining questions is - what side of the shaft is the bottom slot cut? there are only 2 options as you look at the bottom of the shaft a. the small halfmoon is on the SAME side as the bevel eg the flat side of the "D" b. it is on the OPPOSITE side Quote
aircobra Posted April 5, 2017 Author Posted April 5, 2017 i don;t think so - see comments above. the shaft is one piece with the slots and bevels cut it into it. or at least that's what i remember Quote
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