DelSolDon

First off a quick rundown on the build:

<U>D16Z6 block</U>
stock sleeves bored to 75.5mm
stock crank ground .010 under
hole thru block and girdle straight line bored
oversized clevite bearings
block notched for eagles
eagle rods
wiseco 8.5:1 pistons and wiseco rings
stock resurfaced flywheel
stock crank pulley
full rotating assembly balanced
surface decked for trueness
~175 miles on the rebuild

I recently got my car all prepped to go to the dyno for some tuning. Street tuning goes fine and a chip is burnt for ~9psi. Then the next day is dyno day. I get a call from my tuner saying that it will be going on the dyno soon, so I start to head over there to hopefully see some nice numbers, but when I finally get there my car is in the parking lot and he said that he had to pull it off the dyno due to a rod knocking under load. It started to knock on the 3rd pull when he bumped the boost up to ~12psi. The tuner took it back to his shop and ran a compression test which came back as 150 150 140 150 (3rd cyl. being low). So, I go up and tow the car back last night to my garage. I haven't gotten a chance to pull the oil pan, but will probably do that tonight.

Now the questions:
1. I was told by one of the guys at the shop where the tuning was done that I shouldn't have had the crank ground. Is it true that you should never regrind a Honda crank?

2. Since the block is line bored to that crank that is in there, can I swap in a different D16 crank, or not?

3. If I pull the rod caps and don't see any visual damage to the rod journals, can I just measure and re-install new rod bearings?

4. If it turns out that it would be best to locate a new block, crank, and girdle, when I swap over my pistons, would I need new rings? They are already seated since I have ~175 miles on the engine.

5. What about a new head gasket? It is a Cometic head gasket that is on there now with ~175 miles, no overheating, and both head and block surface were decked for trueness. ARP head studs installed also.

Thanks for any help, and please no opinions or hearsay. Just facts, and if possible, something to back up your facts.

Turbocivic94

I would change the crank. I do not recommend running under sized cranks.

DelSolDon

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Turbocivic94 &raquo;</TD></TR><TR><TD CLASS="quote">I would change the crank. I do not recommend running under sized cranks.</TD></TR></TABLE>

Since the block is line bored to that crank that is in there, can I just swap in a different OEM sized D16 crank, or not?

edit: according to honda parts lists, you can order a replacement crank, but not a block and girdle seperately. this makes me think that it would be fine to put a different crank in it. i would just have to measure for clearances.


Modified by DelSolDon at 11:46 AM 2/25/2006

redzcstandardhatch

you might be able to. why was the crank ground? i'd buy a different bottom end, and put the rods and pistons in it.

DelSolDon

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by redzcstandardhatch &raquo;</TD></TR><TR><TD CLASS="quote">you might be able to. why was the crank ground? i'd buy a different bottom end, and put the rods and pistons in it.
</TD></TR></TABLE>

crank was ground because it had a deeper scar than polishing could take out. also, i had never heard that you shouldn't regrind a honda crank, and my machine shop guy (who has done quite a few honda engines) didn't think twice about grinding it either.

would i need new piston rings if i swap to a different block?

coneheadsracing

I have a few honda building books, and they say you can use rings, but they really don't recommend it. Just find a used bottom end and rebuild it. Or tear it apart and see what was wrong, only 175 miles..... something should show up, and then you can go from there. I don't know about cometic head gaskets, but typically they aren't reuseable. I would just get a new one, however worse case you reuse it and use coolant and get to take it all back apart.

Turbocivic94

never use old headgasket. you should be able to just use another crank

sc4dr

The last time I thought I had a rod knock, turned out to be piston damage(skirts, and ring lands) from being to lean, and slight detonation, bearings did not look that bad. Your crank might be okay......tear it down and inspect everything

DelSolDon

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sc4dr &raquo;</TD></TR><TR><TD CLASS="quote">The last time I thought I had a rod knock, turned out to be piston damage(skirts, and ring lands) from being to lean, and slight detonation, bearings did not look that bad. Your crank might be okay......tear it down and inspect everything</TD></TR></TABLE>

hopefully not, and it seems that the knock is lower in the block than the piston. car was already street tuned and tuner was still being conservative with a slightly rich a/f ratio when the knock started. also, compression test came back OK, so that leads me to believe that the pistons and rings are OK.

DelSolDon

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Turbocivic94 &raquo;</TD></TR><TR><TD CLASS="quote">never use old headgasket. you should be able to just use another crank</TD></TR></TABLE>

yea, i've always been told that and have always told people that. but really, what could ~175 miles have done to it between two perfectly flat surfaces and torqed down in the right sequence with ARP head studs? i was told by someone else (on a local board) that i would be OK to reuse it and just to spray with copper spray for extra insurance.

sc4dr

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DelSolDon &raquo;</TD></TR><TR><TD CLASS="quote">

also, compression test came back OK, so that leads me to believe that the pistons and rings are OK.</TD></TR></TABLE>

Mine did too, and I didnt think mine was leaning out, but my pistons told otherwise. Just tear er down

earl

Your block was probably align bored back to stock dimenisions. You never regrind a Honda crank. Something always seems to go wrong.
Install the new crank with standard sized bearings. Rebuild the big end of what ever rods were knocking. Install standard rod bearings and put it back together. You can re use your current pistons and rings assuming they are not damaged.

DelSolDon

Your block was probably align bored back to stock dimenisions. yes

You never regrind a Honda crank. of all the pages and pages of info that i read when i was getting my short block together, i missed that. Something always seems to go wrong.

Install the new crank with standard sized bearings. Rebuild the big end of what ever rods were knocking. what exactly do you mean by "rebuild" the big end of the rods?

Install standard rod bearings and put it back together. You can re use your current pistons and rings assuming they are not damaged.

thanks

earl

Resize them back to oem and make sure they are round.
When you regrind a honda crank, you remove the factory heat treating.
Also you are at the mercy of the dis-interested crank grinder that does not care about your clearances.

non-VTEC

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by earl &raquo;</TD></TR><TR><TD CLASS="quote">Resize them back to oem and make sure they are round.
When you regrind a honda crank, you remove the factory heat treating.
Also you are at the mercy of the dis-interested crank grinder that does not care about your clearances.</TD></TR></TABLE>

how about having the journals polished? does that remove the heat treating?

DelSolDon

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by earl &raquo;</TD></TR><TR><TD CLASS="quote">Resize them back to oem and make sure they are round.
When you regrind a honda crank, you remove the factory heat treating.
Also you are at the mercy of the dis-interested crank grinder that does not care about your clearances.</TD></TR></TABLE>

huh, i really wish that i would have stumbled across this info earlier or the dozens of people telling me now would have told me before. i guess what gets me is that my machinist didn't think twice about grinding the crank. that is why i didn't even search on here or ask if it was common practice. all these f'in domestic machine shops around here.

hybrid_KJ

No, polishing is ok because there is no real material removal going on.

Honda carnks are either Nitrided or Carburized, I forget which method. That kind of metal hardening processes only effect the outer molecular layers or the crank and its effectiveness decreases the futher in you grind. A crank that is grinded to .010" is definitely past the harder outer layers and "softer" metal is exposed that is more likely to "grab" the bearing. A cank that is properly gound and radiused that is re-hardness treated should be ok to use but again like Earl said you are relying on a machinist that may not be as concerned with your engine that you are. Moral of the story run good un-gound Honda cranks. BTW material removal on a micropolish is somewhere around 0.00005".

DelSolDon

^^good info. i'm probably gonna start pulling everything apart today, and i have already located another D16 crank locally.

earl

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybrid_KJ &raquo;</TD></TR><TR><TD CLASS="quote"> BTW material removal on a micropolish is somewhere around 0.00005".</TD></TR></TABLE>I wish I had mic's that could read that good

DelSolDon

well, got around to pulling off the oil pan. some copper colored shavings in the pan. pulled the #2 and the #3 rod caps. the #2 rod cap was slightly discolored from heat and it of course had the thinnest bearings on it. all 4 rods had some side to side play (movement along the length of the crank), is that normal? will probably go out and pull the #1 and #4 rod caps tomorrow.

another note, for the first couple miles of the build, i had some distributor problems causing rough running/ misfiring. could this have caused the bearing failure, or added to the problems the crank was giving? oil pressure (at least at the gauge) was always good though. the engine also saw quite a lot of idle time trying to set the timing too. would this have also been a factor in it's bearing failure?


Modified by DelSolDon at 9:09 PM 2/26/2006

h22 civic

never regrind a honda crank better off buy new or find used you take off the temp coating

DelSolDon

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by h22 civic &raquo;</TD></TR><TR><TD CLASS="quote">never regrind a honda crank better off buy new or find used you take off the temp coating </TD></TR></TABLE>

thanks, but already figured that one out.

DelSolDon

what is the OEM size of the main and rod journals, so that i can measure to make sure that i don't just buy another ground crank?

DelSolDon

just picked up another Z6 block, crank, and girdle for $25. i just threw the crank in the bathtub to clean it up and it has 10/13-19 written in permanent marker on the first counterweight next to the crank pulley side. i doubt it, but is this a honda marking? i'm guessing it is a marking from a machine shop and hoping that it was only there to be micropolished.

can anyone tell me the OEM sizes of the journals so i can check to see if this crank has been ground before i take it to get it polished?

also the stampings next to the rod journals read:
#1-B1 #2-B2 #3-B1 #4-A2

would a machine shop grind these stampings off if they were incorrect due to grinding?

DelSolDon

bump to find out OEM journal sizes. i've searched on here with no luck, and i don't want to rely on the machine shop's info and measurements.