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Sat Jan 01, 2005 9:52 pm

rrebuild my motor going from a 1600 to a 1641 I was wondering is there some way to rebuild the connecting rods or have them reconditioned just trying to build on a budget.

Sun Jan 02, 2005 3:39 am

http://www.rimcovw.com/serv01.htm

Sun Jan 02, 2005 10:26 am

take your rods to a machinist... they can measure the big end stretch on their spindle hone guage. using the new housing bore spec. of 2.2760" as a base line, he can tell you how far it has stretched. my opinion is that anything less than a thousandth is not worth reconditioning.

most reconditioning jobs involve honing the big end (to 2.278") on a sunnen spindle hone till it is once again perfectly round. but doing so is a compromise, cuz you will be losing the metal that provides the bearing crush, as well as the factory specified clearance between the bearing and crankshaft (which effects oil pressure among other things). this practice is soooo common... despite its questionable value.

the only correct way to recondition a rod is to press the bolts out of the rod cap, grind the cap and beam mating surfaces, install ARP rod bolts, and hone to the original size of 2.2760".

regardless of the condition of the big end of the rod you will want to rebush the small end of the rod to extend your piston and ring life, and reduce operating noise.

when torquing rods always use a beam type torque wrench. the micrometer type is inherently inaccurate for this type of precise torquing. do not ever torque the VW rod bolt more than 24 ft/lbs... even momentarily. this will distress the bolt metallurgically- permanently, which can cause a future failure. always use straight 30W oil for assembly. there is a factory determined clamping force between the beam and cap that corresponds to and is a result of the torque value of 24 ft./ lbs., but only when 30W oil is used. if you use a synthetic oil the clamping force will be much higher for that torque spec., which would also distress your bolts and increase the likelyhood of failure.

clean threads with motor oil and a new toothbrush only. contaminants such as soap, gasoline, lacquer thinner will cause squeeky threads. this shows up on the torque wrench needle as a bouncy reading, rather than a smooth movement of the needle as the torque increases. if your threads are damaged, do not use a threading die to cut them clean. VW rod threads are rolled , not cut. cutting them introduces an undesirable metallurgical factor known as notch sensitivity, resulting in future cracks under stress.

Sun Jan 02, 2005 10:59 pm

thank you so much for the info so shuold I just go with new rods then?

Mon Jan 03, 2005 10:54 am

if your rods big end is too stretched you will have to do something. i personally will never buy the improperly "reconditioned rods", that are so common. but you will have to make that decision.

i personally would either find rods that arent stretched in the first place or i would have them properly reconditioned.