daymkimchee

Alright i had a d16y8 with 150k and was running it and spun a bearing on it.Replaced it with a y7 block with only 100 k on it.After 500 miles of letting everything settle in i pushed it in 3rd gear to 6000 rpm n now it spun another bearing also.I had just checked the oil levels and everything.WHATS GOING ON?I was babying it for the first 500 miles to be safe...Ive read that the y7 y8s have a shitty oil pump is this TRUE?

newtron63h

no idea about the pumps. sure the clearances are right?

sp00ledbseries

Just buy a b series lol

jdm602

your missing a cam.

well the fact that your replaced the 150k block with a 100k block prolly wasnt the best route either. im sure it was something you could get your hands on for a quick fix but 100k is a lot of miles and could have been beaten to ****. prolly just a coinicidence imo. and oil pumps are fine.

trustdestruction

Y8 has a horrible oil pump design but if you're not boosted or anything then you shouldn't be spinning bearings like that.

daymkimchee

i dont know it just really frustrating especailly when i have no answers my z6 lasted 180 k with no problems beatin or watever n is still running today

Kista20

did you do anything to the y7 such as pull the pan before you swapped it in? With a used engine of that nature at the very least I would have done that and installed a new oil pump and pickup. My y5 w/ 179k puts out 25-30psi at idle and 50-60psi when going down the road.

Jimster480

No.

@ the guy for B series. STFU, b is overrated.

newtron63h

when you swapped blocks was that it? you swapped a bare y7 block for the y8 block?

Hanmin

I've seen alot of y8 spin a bearing.... That's why theres so many available vtec heads out there. I'm not sure why though

D series is overrated.

SmellsLikeMustand

how about the 88-91 si motors they seem to last forever mine has 322k
swap a zc motor or something..

newtron63h

my guess is that they spin bearings not because bad design but because of pushing a stock engine beyond what is desgned for(throwing boost to a stock bottom end without at the very minimum checking bearing clearances.) there is a huge list of things that should be checked, measured and fine tuned before significantly increasing compression and combustion pressures.

for instance one of the things that helps an engine turn high rpm AND last for decades(hondas in general) is the use of lighter tension rings, this reduces wear on the rings and cylinder walls and reduces friction. but light tension rings wont seal as well when the pressure is increased.

in case some of you dont know pretty much the only reason an engine will spin a bearing is that the oil pressure holding the journal away from the bearing somehow is overcome(either by a drop in oil pressure or too much force on the rotating components) and the journal contacts the bearing.

so for a bearing to spin on a stock engine then the oil pressure dropped or the bearing clearance was too big.

of course there are other MUCH less likely scenarios, but its a pretty good bet its either a pressure problem or a clearance problem.

hondamark35

well put.

of course this is assuming correct oil viscosity. oil that is too thick will not flow as easily into the bearings. under high load, the bearings are starved. on the other hand, too thin will not resist the "force on rotating components."

OP: were you using the correct oil?

thumper64

The D16Y7/8 had fewer oil journals if I'm not mistaken. Find a Z6 or A6 block to rebuild. I've seen Z6s run down around $200 occassionally if they have high miles.

foxdecoy

y7 and y8s do have fewer oil journals the cranks on ys have one oil journal where the rod bearing sits while z6s have two
the ys oil pump is also about 30 percent less effecient than the z6 oil pumps

did you run low on oil because that is a pretty common mistake

Cortez_h

I've read that y7 & y8's stroke ratio isn't so great hence how easy it is to spin a bearing. Anybody else ever hear this?

1992Si

Boy I guess some of you have never heard of the problems with y8's.

OP go to d-series.org the guy's there will give you more help then the single cam haters here. You need to do mod's to the oil pumps and cranks to make them survive. It's all general knowledge there.

turbod16.com is another good site.

Jimster480

no, thats not really why it happens. Thats only if you over-rev it. But the R/S ratio makes the rings degenerate prematurely if you rev it high.

JDM_SOHC

yeah just buy a b series, so u can throw a rod into ur oil pan instead next time and be out over $1k lol... or u could just build the y8 for half the cost of a b-series swap alone an call it a day...

TravisCadello

Dam, that would suck! you should had put new rod and main bearings in before you put on the block. and my z6 block took a beating everyday and had fried rings and as long as theirs oil in it that sucker would never brake or come apart. as for the b7 and y8 they suck.

I think the z6 is the best block you can buy for a d series.

SiREJ8

So what was used to clean the head mating surface??? those lil roloc disc can be death to an engine!

I had my y8 all the way up to 190k before it gave out, that was even 30k with a stage 2 comp cam and valvetrain... My current setup is a y8 block with modded pump and a6 rotating assembly that I put together myself, running great even on stock ecu!

TravisCadello

I got my z6 block still and plan on changing the crank out and getting ZC pistons. and have it siting their just in case this JDM D15B Blows lol. I blew 2 b7 blocks but i dont know if theirs a difference in the JDM or not.

Jimster480

i dont think there is.

SOHC_4dr

man i had 223,xxx miles on my Y8 and my oil pump seized up. toasted the motor and replaced it with a 14,xxx mile engine lol

trustdestruction

There is. The JDM D15B block is kinda a freak engine.

semi-externally:
-D15Z1 Water pump
-D15Z1 timing belt
-unique timing belt tensioner but a D16Z6/D15Z1 one will work; D15B7 will not.

http://www.d-series.org/forums/gener...-vtec-faq.html

internally:
-block is a unique casting (if that's the correct word) but is similar to the D15Z1.
-unique pistons
-unique crank
-idk about rods... only know the part number


http://d-series.org/forums/naturally...-official.html