Sealik Posted October 29, 2011 Report Share Posted October 29, 2011 Just came to the conclusion that the Z22 connecting rods are about 2mm wider than the Z24s. Actually...took a piston to a local mechanic and he noticed it right away, the lack of movement of the rod in the piston that is. This should be of concern when mounting Z24 pistons to Z22 rods...(?) The Z24 rod/piston has about 3 mill clearance. The Z22 rod/Z24 piston has about .012 clearance....not much at all. He figures that maybe with a bore that isn't 100 percent true....or if the block wasn't bored with a torque plate(?)..rods incorrectly resized etc,etc...combined with the minimal amount the piston can move relative to the rod, could lead to the wear on the side of the rod, in pic above....(where the pen is pointing). Many possibilities...but Contributing factors for blow by, rings not seating, bearing wear...etc. Quote Link to comment
datzenmike Posted October 29, 2011 Report Share Posted October 29, 2011 Doug I confirm this. The Z24 are 0.853" while the Z22/L20B are about 2mm wider (just slightly narrower than the KA rods which are 0.980 / 3.175mm) Put the belt sander to them, new rings and hone the cylinders. Quote Link to comment
Sealik Posted October 29, 2011 Author Report Share Posted October 29, 2011 A bit of a bitch to get my belt sander in there.... :D Would of assumed the machinist should of noticed this.... :blink: Guess where all that metal went......?....noticed I lost a little oil pressure since day 1. New bearings also. Quote Link to comment
MicroMachinery Posted October 29, 2011 Report Share Posted October 29, 2011 B'oh :( Atleast you found the problem(or a good candidate) Quote Link to comment
Sealik Posted October 29, 2011 Author Report Share Posted October 29, 2011 B'oh :( Atleast you found the problem(or a good candidate) Yeah....most likely a large contributor. Wondering if anyone else had their Z22 rods shaved....or....could be some possible problemos down the road. Should be a given for a competent machinist though. Quote Link to comment
wayno Posted October 30, 2011 Report Share Posted October 30, 2011 Just came to the conclusion that the Z22 connecting rods are about 2mm wider than the Z24s. Actually...took a piston to a local mechanic and he noticed it right away, the lack of movement of the rod in the piston that is. This should be of concern when mounting Z24 pistons to Z22 rods...(?) The Z24 rod/piston has about 3 mill clearance. The Z22 rod/Z24 piston has about .012 clearance....not much at all. He figures that maybe with a bore that isn't 100 percent true....or if the block wasn't bored with a torque plate(?)..rods incorrectly resized etc,etc...combined with the minimal amount the piston can move relative to the rod, could lead to the wear on the side of the rod, in pic above....(where the pen is pointing). Many possibilities...but Contributing factors for blow by, rings not seating, bearing wear...etc. I put Z24 pistons on to Z22 rods with no issues at all that I know of, when I changed the break-in oil, I was very unhappy about throwing away perfectly clean oil. The only thing I have had happen is the stripped out headbolt, I had to change the L16 thermostat housing out for a L20b housing with the bypass hose, and the miss that happens when hot out, when I sit waiting for the signal to change to green, I have an uneven miss for about 10 or 15 seconds, by the time I hit 3rd it is usually gone, till the next light. :( My machinist put this block together, when I asked about breaking it in, he just said drive it normally, as the products out there are so good, they are almost broke-in before you start it(these are his exact words). I am very happy with the machine shop I use, the only drawback is I have to wait for him to find time for my stuff, as he has race cars to keep in running condition for other customers. Quote Link to comment
albyneau Posted October 30, 2011 Report Share Posted October 30, 2011 I put Z24 pistons on to Z22 rods with no issues at all that I know of, when I changed the break-in oil, I was very unhappy about throwing away perfectly clean oil. The only thing I have had happen is the stripped out headbolt, I had to change the L16 thermostat housing out for a L20b housing with the bypass hose, and the miss that happens when hot out, when I sit waiting for the signal to change to green, I have an uneven miss for about 10 or 15 seconds, by the time I hit 3rd it is usually gone, till the next light. :( My machinist put this block together, when I asked about breaking it in, he just said drive it normally, as the products out there are so good, they are almost broke-in before you start it(these are his exact words). I am very happy with the machine shop I use, the only drawback is I have to wait for him to find time for my stuff, as he has race cars to keep in running condition for other customers. I'm sorry~ did I just read this wrong? You're happy with your machinist.... that stripped out a headbolt thread? Quote Link to comment
Sealik Posted October 30, 2011 Author Report Share Posted October 30, 2011 I put Z24 pistons on to Z22 rods with no issues at all that I know of, when I changed the break-in oil, I was very unhappy about throwing away perfectly clean oil. The only thing I have had happen is the stripped out headbolt, I had to change the L16 thermostat housing out for a L20b housing with the bypass hose, and the miss that happens when hot out, when I sit waiting for the signal to change to green, I have an uneven miss for about 10 or 15 seconds, by the time I hit 3rd it is usually gone, till the next light. :( My machinist put this block together, when I asked about breaking it in, he just said drive it normally, as the products out there are so good, they are almost broke-in before you start it(these are his exact words). I am very happy with the machine shop I use, the only drawback is I have to wait for him to find time for my stuff, as he has race cars to keep in running condition for other customers. Got a miss..?.....that sucks Hmmmmmm..never did locate mine. I'm assuming there is a reason for the large gap (3mm) between the piston and rod. The Z22/Z24 combo only leaves approx .012 If the crank end play exceeds .012.... or if the new bore is not perfect , or if the piston is too tight/loose in the cylinder, or if the con rods have been improperly re-sized....etc...etc. Many variables.... I changed my oil and filter 3 times before I hit 500 miles....looked exceptionally clean. I even filtered the old oil checking for metal deposits....zippo But....as the 1 bearing shows....something got in there EDIT My miss was bad at idle....not noticeable under load....was reminded at the next stoplight though. Quote Link to comment
Sealik Posted October 30, 2011 Author Report Share Posted October 30, 2011 Did some more measuring.....before I take the block back. Pulled No 3 crank cap Looks a little wider than .051mm (.002)....so...lets say .045. FSM suggests... 0.020 - .062mm (.0008 - .0024) Limit...012 (.0047) Not bad I guess....but Con rods Looks like .051mm FSM .012 - .054 (.0005 - .0021) Limit... .12 (.0047) That's pretty much max clearance...? Checked the crank end play......Zero clearance???? Pried the crank both ways...no movement Quote Link to comment
sinner720st Posted October 31, 2011 Report Share Posted October 31, 2011 maybe there was no crank endplay because your con rod to piston clearance @wrist pin is too tight... Quote Link to comment
Sealik Posted November 2, 2011 Author Report Share Posted November 2, 2011 maybe there was no crank end play because your con rod to piston clearance @wrist pin is too tight... Took the block in...(240km road trip).... and the machinist checked for end play... ect. Was around .005....pretty good Checked the clearances (visual) from the bottom of the engine, looking up below the piston. Could see all the con rods were hard up against the front of the piston.....obviously not enough clearance between the piston and rod. The clearances were good at the crank/con rod.....had movement...around .012 Sooooo...he managed to break No 1 piston while pressing the pin out.... :blink: Stated that the rings were too hard.....compounding the issues???? My NPR pistons have..."Premium Steel Material chromed Piston Rings " Too hard???? What's everyone else running? Suggests I find some rings that are moly or cast?????.... And of course new pistons................ Getting charged for shaving the sides of the rods......re and re the block for 'free' Seems I have a massive headache.... :unsure: ..... :D Quote Link to comment
Jester Posted November 2, 2011 Report Share Posted November 2, 2011 Doesn't make sense; with .005 crank end play and .012 clearance on the rod/piston, WHY ARE THEY FAVORING THE LEADING SURFACE?!?!?!? Did he re size the rod journals properly? Out of square? What did the small journal at the rods do when he checked end play? Did they move back with the crank? Makes me wonder what your crank end play would look like with out the rods/pistons connected. Or if the lack of gap at the piston/rod would increase upon rotation. Quote Link to comment
Jester Posted November 2, 2011 Report Share Posted November 2, 2011 It's hard to tell with the lighting in this pic, but, does the wear mark go ALL THE WAY AROUND or just one half? And which direction was the wear facing? Quote Link to comment
Sealik Posted November 2, 2011 Author Report Share Posted November 2, 2011 It's hard to tell with the lighting in this pic, but, does the wear mark go ALL THE WAY AROUND or just one half? And which direction was the wear facing? Jes...there is wear on the opposite side of the rod...just not as much Doesn't go all the way around. Nothing of notice on the other side. But.....I did notice the upper half of the rod bearing is worn at the backside of engine....whereas the lower half of the bearing is worn at the front. I wasn't watching him when he checked the end play. The rods were re-sized.... then could of been bored on a bit of an angle and or..?....which could lead to that wear on rod bearings and place the con rod towards the front of the engine...? He measured the crank and rod (with cap on)...and said there wasn't too much clearance between the 2. Explained that my method of using plastigage was not acceptable, being... that if it's not 'fresh' it will compromise the readings. :blink: I got .051mm....which reflects my lower than norm oil pressure. Max is .054 Quote Link to comment
Jester Posted November 2, 2011 Report Share Posted November 2, 2011 Tell tha SOB that if he did his job right the first time you wouldn't have to use secondary measures to check his shitty work. Surely that would get you some free machine work. Sounds to me like he needs to check his machine for being true. No reason for you to have to pay for his screw up. Quote Link to comment
merlin Posted November 2, 2011 Report Share Posted November 2, 2011 you can buy that set of pistons back from me if you want the same ones... Quote Link to comment
wayno Posted November 5, 2011 Report Share Posted November 5, 2011 I'm sorry~ did I just read this wrong? You're happy with your machinist.... that stripped out a headbolt thread? I guess I don't check the threads I post to often enough, the shop that did my block did not put the head on, I did. I had to drill the holes in the Z22 block to match the holes in the head before I put the head on, so I am the one that put the short head bolt into the long head bolt hole, that hole has one of the alingment dowels, so the bolt has to go in deeper to get to threads, and there were two bolts that were a 1/4 inch longer than the others for them holes, my screw up. Quote Link to comment
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