ZCHondaCRX91

I got a DOHC ZC I just put some Delta 272 cams in and I was trying to degree the cams. The cam card says the centerline is 108.0, which I thought was 108 degrees which is where I put it on my degree wheel, but the valve isn't even close to being open all the way (the #2 cylinder exhuast valves are at peak lift). I've read up on degreeing cams, but just don't understand this completely. So, I put the crank degree at 108 at the exhaust centerline shouldn't the valve be at peak lift? Thanks in advance.

night

you have the wheel at 0* TDC on #1?
valve clearance at 0?
and dont forget the TDC / BDC

riceburner700

you have the ex and intake cams on the right side right

Natural Aspirations

Scan the cam card or take a picture.

You may be looking at the LSA.

Natural Aspirations

Found this on ZCR.

These are the Specs from the Delta 272 grinds.

Intake & Exhaust
Lobe Center Sep = .6 Cam Degrees
Valve Overlap = -520.5 Crank Degrees

Intake
Valve Opening = -260.3 'BTDC
Lobe Center = 352.2 'ATDC
Valve Closure = 281.1 'ABDC
Duration = 200.8 Crank Degrees
Max Cam Lift = .24795 IN.
Net Valve Lift = .44631 IN.
Lobe 'Area' = 19 In * Deg

Exhaust
Valve Opening = 280.2 'BBDC
Lobe Center = 368.9 'BTDC
Valve Closure = -260.3 'ATDC
Duration = 199.9 Crank Degrees
Max Cam Lift = .24772 IN
Net Valve Lift = .44589 IN
Lobe 'Area' = 18.94 IN * DEG

ZCHondaCRX91

Yes, have it all perfect. When I turn to 108 degrees ATDC the cam is just starting to open the valve and at BDC it is at peak lift. Is the centerline the peak lift or a certain lift value?

ZCHondaCRX91

Here is the cam card:

Natural Aspirations

Damn f0cking iPhone, I typed a book and it went to the wrong link....

#1 what cam gears are you using, b-series gears are not correct for the zc.
#2 record your 0.050 values and reort back with what you find.

ZCHondaCRX91

You can use the b-series cam gears, you just put the gears off one tooth (I've done it before and it's all good). If I remember correctly at 108 degrees ATDC it was at about 0.050, does centerline mean peak lift?

Natural Aspirations

Ok I wasn't sure if knew how to align them.

0.050@108 certainly is not correct.

Take your measurements with the gears at zero set your LSA to 108 (which sounds right) and let me know what you get.

ZCHondaCRX91

Are we talking about the #1 cylinder valves right? Because the #2 exhaust is at peak lift at 108 degrees. I ran out of time and decided to just put everything back together and set the gears at zero, but when I went to start it I got a code 9 (Cyl position) and was running like the timing was off, so I guess something must be wrong.

Natural Aspirations

Your timing events should be very close to these. All values are taken from cyl#1 and are in crank deg.

I had issues with the code 9 on my ZC years ago, it's completely irrelevant from your issues if you have the gears zeroed and the belt tight. It always ran fine even with the code, it's possible to run a SOHC dist and eliminate the sensor all together if needed, probably worth the effort when (if) you upgrade to obd-1.

ZCHondaCRX91

Okay, just want to make sure, the #1 cylinder at TDC is in the power stroke so after TDC the exhaust valve would start to open, right? What would -11 BTDC be, 11 crank degress before TDC or 11 degrees after? I will probably be taking everything apart and let you know what I get for everything.

night

I really don't wanna come across as treating you like you are stupid, but we have to make sure the basics are covered here. maybe you are twisting your terms, but it just doesn't sound like you have it straight in your head yet.

crank on mark, cam gears up, is TDC for number 1. which is the peak of compression before the power stroke.
#1 is all that matters when doing this. did/how did you find your 0* on the crank?


http://www.youtube.com/watch?v=V-z-R8Mv_HM

ZCHondaCRX91

It's okay, I just needed to make sure I understood everything 100%. I found TDC, by rotating the crank with a dial indicator hooked up to the piston, the peak value is TDC.

Natural Aspirations

It appears that Delta also has the rocker arm ratio wrong on their spec sheet.

I prefer using a piston stop to find TDC, but your way works fine.
Set cams gears to zero.
Set valve lash to zero.
Record what you find.

I'm willing to bet the Delta spec sheet is considerably off. No worries though they shouldn't be much of an issue being regrinds, I highly doubt delta has changed anything other than the base circle.

ZCHondaCRX91

>>UPDATE<<

Okay, I decided to just put the stock cam gears back on and reset the timing, but I still got a code 9 and ran like the timing was off. So, I took the valve cover off to see what's up, and I noticed that at TDC the timing marks on the cam gears lined up perfectly with the head as they should, but the dowel pin hole in the cam (to keep the cams at TDC when setting timing) wasn't lined up on the exhaust side, but it was on the intake side. I rotated it and when it actually lined up on the exhaust side it was 1 tooth off. I'm using the same cam gears, the only difference is that the cams are from another DOHC ZC and not my original ones. I would think that the exhaust cam was off one tooth, but the cam gear lines up and unless the cam is somehow different (it's the right R2 cams, and I have the Exh and In cams on the right sides). All of this would make sense that when I went to degree the cam it wasn't even close to 108 degrees and why only the Cylinder sensor is going off (on the exhaust cam)and not the TDC sensor. How many crank degrees is one tooth on the cam gear? 20 degrees?

night

360/teeth on gear

ZCHondaCRX91

360/34= 10.58 crank degrees?

I think that I should just set the timing on the exhaust cam based on the dowel hole and hope for the best.

ZCHondaCRX91

Okay, I found the centerline by the 50K method, but did it two ways and not sure which is right if any:

157 degrees ATDC open at 0.050" of lift, 32 degrees ATDC closed at 0.050" of lift.

157+32= 189 +180=369

369/2 - 157 = 27.5 Exhaust centerline?

2nd way

157 degrees ATDC open 0.050", 392 degrees ATDC close 0.050" of lift

157+392= 549 +180=729

729/2= 364.5 -157 = 204.75 exhaust centerline?

None of these are close to 108 degrees, it opens 0.050" at 157 degrees ATDC, and is 0.050" from the valve seat at 32 degrees (1 full 360 degree revolution and 32 more degrees on the crank). The valve lash was set to zero, and found TDC with a piston stop.

ZCHondaCRX91

I figured it out, I got it all degree in and the intake cam was just 1 degree off and the exhaust side was 10 crank degrees off, one whole tooth. I used some integra DOHC ZC cams for the regrind and since they use the 40 tooth cam gears the key way is slightly offset. It all worked out in the end, and runs alot better now with no CEL. Thanks guys.

Natural Aspirations

I was going to ask if they were d16a1 cams that you had ground. Good info!

ZCHondaCRX91

Well they were Integra DOHC ZC cams (basically the same design as the D16a1), but larger than the D16A1 and Civic DOHC ZC cams. Just glad it worked out in the end.