camgear and timing with Y8 cam

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iketani
Posts: 4
Joined: Fri Aug 26, 2016 2:23 pm

camgear and timing with Y8 cam

Post by iketani »

Despite lots of research i'm still confused with camgear and timing with an Y8 cam on a D14.
Which camgear should be used, PM3B or Y8? Is it possible to get the timing right at all without an adjustable camgear?

Edit:
If i understand correctly, the Y8 cam is retarded by half a teeth or 4.75° compared to a Z6 cam because the keyway is not at the same angle. But the Y8 camgear advance the cam by 4.75° compared to a Z6 camgear, which correct the cam angle. This is why on a D16Y8 with adjustable Z6 camgear, you need to advance it 4.75° to have the cam at 0.

Now due to the lower deck height on the D14 block, and since the camgear has 2 times less tooth than the crank pulley, a D16 cam needs to be advanced by 9.5/2 = 4.75°. That's what i keep seeing online for the D15 mini-me and milled heads, but i don't understand why the timing needs to be advanced if the belt is shorter to compensate for the smaller deck height. I'm guessing the people who say this use the 104 thooth belt instead of the 103 one, hence the half teeth error due to the shorter distance with the crank.
So with an Y8 cam, the camgear actualy needs to be advanced by 9.5° relative to the keyway? So 9.5° with a Z6 gear, 4.75° with an Y8 Gear.

The only way i see to set an Y8 cam correctly like that in a D14 with a stock gear, is to use a Z6/D14 PM3 camgear which makes the Y8 cam 4.75 retarded, then put the camgear one teeth advanced relative to the belt. Which makes the cam 4.75 advanced as it should be according to US forums.

If the cam doesn't need to be advanced due to the lower deck height like they say, then simply using the Y8 camgear should be correct.

Which one is right? There's more misinformation than not online on how to compensate for the deck height difference that i'm confused.
Any advice will be greatly appreciated!

Edit2: i think the 103 tooth belt correct the difference in deck height, so i'm going to try the D16Y8 camgear.

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Dodo Bizar
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Posts: 2009
Joined: Mon Jun 22, 2009 10:36 pm

Re: camgear and timing with Y8 cam

Post by Dodo Bizar »

Hey man, nobody is right hehehe.

Truth is, cam gear is highly advisable since the best setting is to be tuned. Normally I'd say go for retarded 0.5 tooth if there is doubt, never advance. Always when I started on the dyno with a 'proper' timed cam, we ended up retarding the camshaft (note that you need to advance the distribution equally to not alter ignition timing!).

Compared to PM3 I now am at 1 full tooth retarded, about 9 deg cam!!! For my max power which is around the 140 bhp mark. My distribution could not reach so far btw hence I had my stock ignition tables advanced 10 deg (crank 10 deg I believe, so cam 5 deg).

The thing about deck height is only mattering for odd vs even number of belt teeth, but even within the same engine type I have seen large differences up to half a tooth, probably due to quality / age of the timing belt. I once had a stock D14A3 in my hands were the timing marks were not aligning at all to half a tooth.

Bottomline: dynotest an adjustable cam gear (I am not in the class of people who ever destroyed a cam gear, hence I feel safe). If that's not an option, both PM3 and Y8 get you ballpark right, testfit, and either timing marks do line up or the stuff is off by 0.5 tooth... in the latter case, choose the position in which the cam is retarded 0.5 tooth. Generally that gives you more power anyway. No fuzz in keeping it perfectly 'Honda OEM aligned'.

iketani
Posts: 4
Joined: Fri Aug 26, 2016 2:23 pm

Re: camgear and timing with Y8 cam

Post by iketani »

Thanks for the reply!

Well i can't dyno the car sadly. So i won't be able to do much with an adjustable cam gear other than setting it arbitrarily. I have a Brian Crower cam which is probably not indexed like a stock cam and won't make maximum power at the same angle.

I just tried to install the D16Y8 head and set the timing to clay the engine.
The PM3 Gear timed with the 7 o'clock mark is off by half a teeth.
The Y8 gear align perfectly with the 3 and 9 o'clock marks on the D14/Y8 belt cover.

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