pogonophobia

I'm swapping the head from a d15b7 to a d16y7 head. I'm sure I need to use the y7 cam gear and the y7 belt. My question is how to time the two together. I've read that one belt is shorter than the other and the cam gear needs to be set different. But I haven't found anything that was exact how to. Is there anyone who can shed some light to timming a y7 head on a b7 block

TomCat39

The key here is not to expect the UP and side markers of the cam gear to line up like factory.

You first put the cam TDC with the Y7 gear with the up and the side markers like you normally would via the FSM. I would do this without the cam bolt installed so that you can take the Y7 gear off without turning the camshaft at all.

Now you can slide the B7 gear on and I would probably add my own side markers on the B7 gear so that I had some sort of TDC marks on the B7 gear that correlate to your custom setup.

Tighten the cam bolt and you have the B7 gear on the camshaft in TDC position.

pogonophobia

So what your saying is a b7 gear will work on a y7 head. And if I use the b7 gear should I use the b7 belt as well

TomCat39

I am not saying the B7 gear will be your fix.

I, like you, am assuming the half tooth variance from the deck height will also be present in your setup like it is on the mini-me setups. It just may be on the opposite side (retarded vs advanced).

The fix for the half tooth is normally using the opposite gear to the head (obd2 gear on obd1 head and vice versa).

You will know for sure once the head is on and you run either belt from the crank gear up to the cam gear. If the teeth mesh, then you are not off. If it's half a tooth off, then the opposite gear should compensate.

As for which belt, you want the belt that is not too tight. I don't actually know how many teeth are on the Y7 belt. And I'm foggy on the B7 belt but I think it's 106 teeth but could be mistaken. Really, the teeth distance is the same between belts so changing teeth count won't affect timing, it only effects tightness and looseness of the belt. Too loose and it can skip teeth, too tight and it puts added stress on bearings and such. I think the tensioner can make up for some slack but not sure how loose is too loose.

You are going a direction a bit different than the typical tried and true methods. I have not seen much documentation of any of putting the non-vtec obd1 head on an obd2 block.

pogonophobia

From my understanding both the y7 head and the b7 block are both obd1 I know the b7 block is for sure correct me if I'm wrong

eghatch9295

iTrader: (1)

y7 head is obd-2, but will work on your engine. use the y7 gear and y7 belt. y7 belt= y5,8,z6

TomCat39

How come when you put a Y8 head on the B7 block there is a half tooth variance from deck height, but the same is not true when you put a Y7 head on the B7 block?

I've always read that the Y7 and Y8 blocks are nearly identical, and you even state the Y7 belt is the same as the Y8 belt which would also indicate the same thing to be true.

eghatch9295

iTrader: (1)

you were right on the gear. caught me mid-day sleeping. the blocks are nearly identical, the gears and belts are. (y7/8)

TomCat39

Here is some additional information on timing belt options quoted from this post:
https://honda-tech.com/honda-civic-d.../#post12322998

What is interesting about this is the D15B7 has a shorter deck height of 10MM ovedr the D16's. And yet, the timing belt is 2 teeth longer over the D16's.

Now quoting this post on D-series:
How to mechanically time a mini me swap/ other mini me info - D-series.org

Seeing the tooth count difference between the D16's and the B7 of 2 teeth even though the deck height is taller by 10mm on the D16's makes me think the water pump is laterally out farther requiring the longer belt.

The deck is only dropping 10mm so I suspect the ideal belt would have 105 teeth.

Now is it better to be 10mm tighter on the belt than ideal or 10mm looser on the belt?

Or am I just waaaaay over thinking this?

24TEN

iTrader: (2)

212mm - 207mm = 5mm

eghatch9295

iTrader: (1)

every one of these i've done tension properly with the 104 tooth belt. back in the day of mini me's being on the cutting edge, a lot of guys went with the vx 103 tooth belt, only to find it was too tight. 106/7 is too slack, 104 works perfectly.

TomCat39

yeah, ooops.

Yeah, I've seen a few people say they VX belt (103 tooth) was too tight. And also seen everyone seems to run the 104 tooth belt.

Was just looking at it mathematically and couldn't even do simple subtraction. 20mm (2 teeth) - 5mm (deck height variance) ends up being 15mm tighter belt using the 104 tooth belt on the B7 block D16 head.

Thinking about that and everyone's experiences. If 5mm looser makes the belt too loose, then it sounds like the stock B7 is a bit looser of a belt to begin with.

I still think ideally a 105 tooth belt would be the near perfect fit but that's not the typical options in the 92-95 era if at all. And since the 104 belt works well there's no need to go digging any further really, except for fun.

eghatch9295

iTrader: (1)

it could be found with digging, im sure. iirc, d series belt width is 24mm. annnnd go!

TomCat39

LoL

I went..... and pretty much a bust if you wanna stick to Honda.

Hyundai Accent seemed to have a 105 tooth belt with proper pitched round tooth but it's thinner and suspected not as strong.

How ever in that read, another interesting piece is the tensioner being swapped out has an effect on belt tightness.

Seems on the A6 block with the Z6 head, you use the Z6 belt but you have to also use the Z6 tensioner or it's waaaay to tight with the A6 tensioner.

That being said, the A6 tensioner may take up the slack on the B7 belt if required.....

Dunno, might be something to try sometime.

eghatch9295

iTrader: (1)

ive been after a decent a6 block for awhile, and that is the head i would use. if i can ever get my hands on one, ill let you know.

24TEN

iTrader: (2)

I already knew about that Hyundai option but does that thread actually show that the tensioner is interchangeable? In my experience they are not, at least not on a Z6 block utilizing an A6 tensioner (B2/7/8/etc is the same).

TomCat39

Ya know, I have no idea really. The way it's written it appeared as that was the fix in their situation.

It does seem odd that a Z6 tensioner would fit an A6 block but not the other way around.

This is the thread, that tidbit is in post #9 the Hyundai belt is in post #2 and then the follow up about strength being questionable is post #15:

a6/z6 timing belt? where to find 105 tooth? - D-series.org