How to F**k up a GSR block 101
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Joined: Dec 2002
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From: Tampa, Fl, US
How to F**k up a GSR block 101
give it to a machine shop that doesnt know wtf theyre doing!!!
to make a long story short the machine shop jacked up my first attempt at building this block by boring it way too much. they accidentally set the piston to wall clearance to .005 instead of the requested .0005...WOOPS!!! they also lost my bearings and machined the rods to fit the ITR pistons but they were cut on an angle and looked like ****. thankfully they fixed all these problems by getting me another GSR block and new oem honda bearings and fixed the rods....supposedly
i finally get the new machined block back and all the clearances are exactly what i asked for so i was happy and proceded to re-start and finish assembling this motor.
upon start up the motor ran perfectly fine for about the first 10-15 minutes then out of no where it started making a funny tapping noise and started to smoke. i decied to do a leakdown test for all the cylinders and this is what i got.....
cyl 1....2%
cyl 2....8%
cyl 3....3%
cyl 4....4%
then i decied to do it again with the pistons at the bottom of their stroke(the cams were out so everything was sealed as much as it coulda been
cyl 1....2%
cyl 2....75%
cyl 3....3%
cyl 4....4%
after hours and hours of trying to figure out what was wrong i decided to just get it over with and pull the damn head off a brand new friggin motor!!
and this is what i found after only about 30-45 minutes of total running time and rpm's no higher than 3000......
in case u cant figure out what happened the "press fit" wristpin managed to work its way out of its set spot and rub against the cylinder wall. this happened because when the rods were machined to fit the itr pistons the "machinist" felt the need to machine the inside ot the small end of the rod to probably clean up the left over metal from grinding away at the outsides of the rods earlier....which cannot be done on a press fit rod because they are heated for expansion so the wrist pin can fit thru and then it contracts once again when it cools and holds the rod and piston in place because it will never get as hot inside the motor as it does when it was heated therefore not allowing it to ever fall out of place after assembly...unless!!!...u machine enough of the small end of the rods away to the point where it takes very little heat to expand the rod enough that the wristpin can move out of place. and this makes perfect sense that the motor ran perfectly fine untill it warmed up and the internals reached probably a few hunderd degrees below the piston surface....
sorry just needed to let a little steam out as im pretty pissed because i put a lot of time and effort into making everything perfect in this motor.....
ill keep the name of the machine shop concealed unless they want to give me a hard time about fixing the problem
to make a long story short the machine shop jacked up my first attempt at building this block by boring it way too much. they accidentally set the piston to wall clearance to .005 instead of the requested .0005...WOOPS!!! they also lost my bearings and machined the rods to fit the ITR pistons but they were cut on an angle and looked like ****. thankfully they fixed all these problems by getting me another GSR block and new oem honda bearings and fixed the rods....supposedly
i finally get the new machined block back and all the clearances are exactly what i asked for so i was happy and proceded to re-start and finish assembling this motor.
upon start up the motor ran perfectly fine for about the first 10-15 minutes then out of no where it started making a funny tapping noise and started to smoke. i decied to do a leakdown test for all the cylinders and this is what i got.....
cyl 1....2%
cyl 2....8%
cyl 3....3%
cyl 4....4%
then i decied to do it again with the pistons at the bottom of their stroke(the cams were out so everything was sealed as much as it coulda been
cyl 1....2%
cyl 2....75%
cyl 3....3%
cyl 4....4%
after hours and hours of trying to figure out what was wrong i decided to just get it over with and pull the damn head off a brand new friggin motor!!
and this is what i found after only about 30-45 minutes of total running time and rpm's no higher than 3000......
in case u cant figure out what happened the "press fit" wristpin managed to work its way out of its set spot and rub against the cylinder wall. this happened because when the rods were machined to fit the itr pistons the "machinist" felt the need to machine the inside ot the small end of the rod to probably clean up the left over metal from grinding away at the outsides of the rods earlier....which cannot be done on a press fit rod because they are heated for expansion so the wrist pin can fit thru and then it contracts once again when it cools and holds the rod and piston in place because it will never get as hot inside the motor as it does when it was heated therefore not allowing it to ever fall out of place after assembly...unless!!!...u machine enough of the small end of the rods away to the point where it takes very little heat to expand the rod enough that the wristpin can move out of place. and this makes perfect sense that the motor ran perfectly fine untill it warmed up and the internals reached probably a few hunderd degrees below the piston surface....
sorry just needed to let a little steam out as im pretty pissed because i put a lot of time and effort into making everything perfect in this motor.....
ill keep the name of the machine shop concealed unless they want to give me a hard time about fixing the problem
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