Honda D Series Forum banner

1 - 20 of 60 Posts

·
Registered
Joined
·
504 Posts
Discussion Starter #1
So I have been tuning this car and everything was great. Went out today to tune some more, and less than a block away I heard it knocking. No loads were even put on the engine, it warmed up for 10 mins in my driveway before leaving. I brought it back, dropped the pan and found the # 2 bearing was eaten. Crank is fine, haven't pulled the rest yet. I think this is due to oiling issues, but I want some opinions. I took pics of the mains as well. Motor has less than 1000 miles on it.

Z6 p2p0 rods vitara pistons, oem mains, acl race rod bearings

 

·
Registered
Sloppy Jalopy
Joined
·
977 Posts
what clearances were used on the bearings?

what do the plugs look like .

timing map

boost level
 

·
Registered
Joined
·
504 Posts
Discussion Starter #3
I didn't build the engine, I don't know, I'm just the tuner. I'm pretty conservative on timing. I think I'm at 17° @ 8.5 psi. Plugs look fine, they are gapped at .030 when it started cutting out up top. 93 octane gas. Turbo is a turbonetics 5755
 

·
DIY Guru
96 Ranger-stock
Joined
·
637 Posts
What weight oil was used?

Was the crank ground undersized, or just polished?

Looks like the mains have a bit of taper to the journal, or the crank could be slightly bent.
 

·
Registered
ej8
Joined
·
104 Posts
Do you see guys?

z6 engine bearings also go wrong not only y8 fails

this is second motor z6 failure like in 30 days period on the forum
 

·
Registered
Joined
·
504 Posts
Discussion Starter #7
Do you see guys?

z6 engine bearings also go wrong not only y8 fails

this is second motor z6 failure like in 30 days period on the forum
What is your point? If your oil pump fails on a y8 or z6, I'm sure the carnage would be the same. My whole question here is not that it failed, but why. I see no signs of detonation and if you look at the side view of my bearings, you can see they were not smashed which is common with knock. I want other to confirm if this looks like poor oiling.
 

·
the artist formerly known as drexelstudent11
Joined
·
3,983 Posts
that's pretty conservative timing for the lowered compression - I ran 19 degrees at 10 psi on my bone stock Z6 on 93 with no issues
 

·
Premium Member
95 civic coupe
Joined
·
1,358 Posts
Yeah seem conservative has to be the something else. I ran 17 degrees at 20psi
 

·
Premium Member
95 civic coupe
Joined
·
1,358 Posts
What fuel?
E85 now.. I've run 21 degrees at 20psi before on pump believe it or not, it eventually spun a bearing but it worked. I'm thinking maybe the clearance was tight on your motor
 

·
the artist formerly known as drexelstudent11
Joined
·
3,983 Posts
yeah, it's possible the OE bearings were wacky sizes for wacky journals and the ACL races didn't give enough clearance on that journal
 

·
Registered
Joined
·
504 Posts
Discussion Starter #13
yeah, it's possible the OE bearings were wacky sizes for wacky journals and the ACL races didn't give enough clearance on that journal
If you look close enough at all the mains, it looks like the coating is almost gone on some of them. I have a ls motor torn down that has 200k on it and that coating is still there
 

·
Registered
See above...
Joined
·
13,322 Posts
Here's a story of what I went through that perhaps can be given to the vehicle's owner for some insight on what to do from here. I too had a Z6 spin a #4 rod bearing on <1k mileage motor. I was meticulous with the install AND the parts used. Factory matching OE crank to block with ACL standard bearings with a .002 oil bearing clearance all-around. Ended up re-using the same block, but used one of four different Z6 cranks I had sitting around at the time. Used the one that looked the best and had the least amount of the rear main seal groove wear on it. THIS TIME AROUND I had my machinist polish the journals AND I used King bearings this time...still standard size with a .002 oil bearing clearance all-around. Reassembled with the same steps, procedures, and care used on the first build. Block was perfect, and netted me 400whp on the dyno that same year without a hint of knock or even oil burning. :)
 

·
Registered
Joined
·
504 Posts
Discussion Starter #15
So are you assuming you had crank issues the first time? If everything measured correctly how can you blame it on the crank?
 

·
Registered
ej8
Joined
·
104 Posts
my point was on next thing -

many guys telling it not worth to turbo y8 engines because very ofter spun bearing happens concern on many engines fails after 150 miles

and many guys telling the Z6 cranks only the right way to go.

I'm just told that here is another your Z6 with spun bearings.

In my personal opinion there is no difference between both just need to check all clearances and relapse the bearings and pay attention to oil pump, specially If rich high mileage or planing to go turbo way.

sorry for my English!
 

·
Registered
Joined
·
504 Posts
Discussion Starter #19
my point was on next thing -

many guys telling it not worth to turbo y8 engines because very ofter spun bearing happens concern on many engines fails after 150 miles

and many guys telling the Z6 cranks only the right way to go.

I'm just told that here is another your Z6 with spun bearings.

In my personal opinion there is no difference between both just need to check all clearances and relapse the bearings and pay attention to oil pump, specially If rich high mileage or planing to go turbo way.

sorry for my English!
There is a difference. This bearing did not spin, it was safely secured in the rod, and there is 0 heat makes on the rods. People tend to assume rod knock always means spun bearings and that is a common misconception. If not shut down soon enough, rod know leads to spun bearings. Most bearings when a failure from detonation first start as a smashed bearing, creating a large gap, and if shut down, can easily be swapped out by just dropping the oil pan.

Z6 cranks are better than y8, peroid. Besides that, the motors are the same imo. You can boost a y8 crank safely, it's just not as good as a z6.
 

·
Registered
Joined
·
504 Posts
Discussion Starter #20
what you planing to do next?
Crank is fine, new bearings were ordered and on their way. Oil pressure seems low to me, however owner states it was that way with another motor as well and he believes there is a kink in the line. Oil pump was ported. My hope is to find another oil pump and swap it out. Also, the car will not leave my garage again under its own power until I ensure it had adequate oil pressure. I'm replacing the pressure line so that can't be a factor.
 
1 - 20 of 60 Posts
Top