I am rebuilding my d16a6 and I might have to replace the crank (out of round) As I understand it the a6 and z6 cranks are similar if not the same. What about the d16y8 crank? HOw does it compare to an a6 or z6 crank? If its the same (strengthwise, journal diameters) I would be interested in it because its simply not as old. If anyone has some info I would appreciate it. thanks.

 

I just looked on hondaautomotiveparts, and they list the a6 and z6 cranks as having the same part number but the y8 and y7 cranks have different part numbers than the a6 and z6.

 

All the 1.6 dseries cranks work together. You just gotta make sure you get the right bearings.

 

the Y8 cranks dont have oil hole chamfers, which i think attributes directly to their tendency to spin bearings. havent had any problems with them after ive chamfered. i dont think the bearings matter, ive used all different D series bearings in various combos of block and crank. sometimes i enlarge the oil feed holes to match the oil passage diameter.

 

thanks--yeah I always heard of the y8 bottom ends tendency to chew bearings easier--didn't know if it was the girdle design, the actual shaft, or the oil pump. I think I am still going to stick to a6 or z6 shafts though. So in the y8 the oil holes aren't chamfered? Its just literally a hole in the journal? The z6 and a6 cranks share the same part number and are around $750 at hondaautomotiveparts, the y7 and y8 cranks (same part number) are around $550. I like the a6 bottom end because of the steel caps and seperate aluminum girdle.

 

I posted this in other post but got zero replies. What about grinding a Honda crank? My machinist said if it is out of round (over the 0.0012" total indicated runout spec) he would send it to a local crankshaft place to grind it. I explained to him that Honda doesn't even make undersize bearings and that there is that infamous nitride layer which I have heard only goes like 0.0005" down. Is that why crank grinding for Hondas seems to be such a taboo subject?

 

well, considering that an accurate crank grinding machine is like a hundred grand, the machinist who can get a .0001" runout/variance is $25 an hour plus taxes and insurance, and then the only undersize bearings are pro-topline..

... when you can get d16 blocks for free pretty frequently that still have good cranks, why bother? i must have gotten 6 of them this year for nothing.

the oilpump thing is a myth IMO, the ONLY difference in all the pumps is that the drilled intersect behind the main plug is a larger diameter in the Y8 pump and they have a CKF sensor boss. otherwise identical and a little epoxy/grinding will further improve all of them.

i enlarge all of the mainbearing feeds because they are cast with a taper that can be pretty closed off where it connects to the main feed.. most of the spun bearings i still think are from the lack of chamfer.

ive never spun a bearing with a Y8, and all of the ones i did had modded pump, oil feeds and chamfers so one of them solved the issue. ive seen 4 stock ones spit the number one connecting rod out of the block for no reason, not even being abused. rarely see any other D series with broken rods.

 

unless you hydrolock them

 

ACL makes undersize bearings 0.25mm (0.010"), and 0.50mm (0.020) I have a set of mains (ACL 0.25mm in good shape) from another build where apparently the crank was cut (bought the short block). Is ProTopline the same as King bearings?

 

i dont think so. topline is supposed to be cheap rebuilder **** but alot of it isnt any cheaper than ACL, and the quality isnt impressive IMO.