im looking to rebuild my h22a4 motor. it needs a new crankshaft due to the crank bolt being stripped. im in need of information on how to check if a crankshaft is good and reusable without machining and polishing. thanks any info is greatly appreciated.

 

Take it to a crankshaft specialty shop?
You can see obvious flaws-if the engine spun a bearing and wasted a journal, for instance.
More subtle problems require more precise measurement.

 

A micrometer, pencil, paper, eyeballs, and a idea of what to measure for.

 

magnaflux will also help to see if there are any hairline cracks

 

im picking one up. need some pointers into not getting a bad one i cant take it to the machine shop on the spot. my friend told me to check for scratches on the journals any other ideas?


BTW what is magnaflux?

 

is there anyway to check if the crankshaft is warped? without taking it to a machine shop

not jacking the thread but adding more to it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by egb18c5 &raquo;</TD></TR><TR><TD CLASS="quote">is there anyway to check if the crankshaft is warped? without taking it to a machine shop

not jacking the thread but adding more to it </TD></TR></TABLE>

no because a warp isn't noticeable to the normal eye. you would have to bring it to a machine shop.

first thing i would look for is any scratches on the journals. i would also look for any noticeable cracks or damages. if you see something that looks like a damaged part than odds are it is. but checking to see if its out of round isnt that easy if you dont know what your doing or have the necessary tools.

your best bet is to just take it to the machine shop and have them look at it.

if you buy it i would take it to a machine shop any way to have it rebalanced and have them check all the journals and make sure everything is within specs otherwise your either going to eat through bearings or your going to destroy things. you shouldnt re use used cranks without doing some kind of machine work prior to installing it.

 

thanks what do you think of a motor h22 that broke a timing belt. how would the crank be would having a broken timing belt affect or warp the crank, or breaking a timing belt cause a bent valve.

 

The Helm's manual outlines how to check for the crank being warped.

Basically you put the block on an engine stand, cylinder bores facing down. Install main bearings one and five and lube them up. Drop the crank in and set up a tenth's indicator (like this one) to check the runout of each main journal. This will represent itself as a "high spot" in the rotation of the crank.

If the crank is warped then journal number 3 will usually show the largest amount of runout. I think tha the max runout is like .002" IIRC.

If the crank is not bent then you would use some 1"-2" micrometers (with .0001" capability) to check each main and rod journal for cylindricity (make sure they're round and not tapered), and of proper diameter. If it's bent or out of round then it needs machining.

Pirate