Hey everyone

I am assembling my b16a bottom end

I put in standard sized ACL bearings in the mains.

The clearance is as follows according to plastigauge.

#1 .002
#2 .015
#3 .015
#4 .015
#5 .002

How 'free' is the crank supposed to spin with the main caps torqued?

Thanks in advance for your help.

 

It should spin with very little to almost no resistance.
You should feel a difference in the "break-away" torque and the "maintained/turning torque" when turning the crank.
Dont forget lots of assembly lube!
As you torque down the mains, measure the turning torque. It should be consistent.
After you install the pistons is when youll start to feel it change too.
Crank been checked for straightness?

 

When i torque the last cap #5, the spinning force changes...

it stops a bit when the crank is 180* horizontal

 

Each main should have very close to the same effort to turn the whole crank.
I wouldnt rely on plasti-guage 100%. You are measuring a very precise dimension.
Id re-measure your mains just to be safe.

 

for 1 and 5 order honda bearings that'll give your a .015 clearance

 

is the .015 really necessary?
or is the .020 pushing it?


also any idea why the crank might turn like that?
i would suspect a tighter clearance may cause the little bit of binding, but a looser clearance confuses me

 

my motor has been going strong for 12k+ miles and it took > 10 ft lbs to get the crank moving

 

the OP is talking about his mains and crank alone

your probably talking about the whole bottom end, with the pistons and rods installed.

i would take the block and the crank to a machine shop and have them check it out.

 

i would say the crank might be bent.....check out the crank and or align hone the block

 

was the cranjk laying on its side for any time? i have always been told to like bolt the flywheel to it and stand it straight up. but thats also why i always do the eagle crank,lol i have one for sale right now but its a package deal rods and crank for b16a.

 

OP, get some OEM bearings and even up you clearances. You should fix number 1 and number 5.

As far as your original question, when I rebuilt my current engine, my then 4 year son could spin the crank with fly wheel on easily.

 

This is 100% correct.

 

is the block sleeved? I've seen and heard of shotty sleeve jobs where they didn't hit correct sizes on the bores, and just forced the sleeves in which will distort the mains. If you have standard bearings, I guess we can't point the finger at the guy that ground the crank. But there is an idea, maybe just polish the main journals on #1 and #5 to get that .05 you want to see (have a machine shop do it).

 

Im not sure if i am thinking this correct, but if i polish the crank, wont i get a wider clearance?
like from .002 to.003

 

What's your actual clearance, .002 or .02? that's a big difference.

 

Its the one on the plastiguage green chart...

 

Lol, post up the letters on the crank (starting from the pulley) and the numbers from the rods and I will tell you what color you need for stock honda clearance, 0.0015".

 

those clearence arent to bad, but u shouldn't have a loose clearence on the ends of the crank! the crank should not have a drag at any point while turning, best thing to do is bring the crank and block in to see if there's anything wrong with it, could be a bent crank or a wrap housing!

 

You should check to see if your crank is straight as another person posted. As a matter of fact, on any build you should check to see if the crank is bent just before you drop it in. You can just put in the first and last main bearings and check with a dial indicator on the center journal.

 

i did have the crank on its side for about 2 months

 

And remember your clearances can come out OK even if your crank is bent.

 

is this a b20 block? I read in another post, that omniman stated, every b20 block he's delt with needed a line hone. I have personally never delt with b20's, but you should have a machine shop check it out

 

Did he say "b20 block"?

 

whenever i do a rebuild i always use a micrometer on the crank journals( all the way around and from side to side) and also check the ID on the main caps after torquing them down to spec. get the difference from those two and then compare it with your numbers you got from the plastigauge results. im not a big fan of only relying on a plastigauge(not many are). had a buddy that relied on the plastigauge method alone without having his block aligned honed( not always needed) but i also remember him getting his block decked before he had it bored and honed so there was a couple things he didnt do in the right order. anyways he had the same problem as you, when he torqued everything down it wouldnt spin freely. he took the block to a different machinist and the guy recommended having the cylinders re-bored and honed but with a torque plate this time (the first shop he took it to wasn't up to par) last but least the guy aligned honed his block and gave my friend a different spec of bearings to use and the problem was solved. if i was you i would take it to a reputable machinist. might not be straight like someone else mentioned, ya never know

 

Block and Crank Numbers
DCDCD
43322

Looks like #5 is supposed to use a Brown Bearing.
Brown 2.007-2.004 mm 0.0790”- 0.0789”

Acl Std Is
Green 2.004-2.001 mm 0.0789”- 0.0788”

Why would i be measuring .001" On #5?