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» Hello Spec Miata Community » Spec Miata Archives » Garage 2002-2009 » Can't set timing past 16 degrees (1.6)

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Author Topic: Can't set timing past 16 degrees (1.6)
David de Regt Verified Driver
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In my ongoing motor troubles, people have pointed out that it seems incredibly strange that I can't set my timing to more than 16/maybe 17 degrees on a 1.6 motor. This is a physical problem, i.e. I can't crank the CAS further, due to the setscrew. This seems strange to me too, but I don't know what can be causing it. I've tried swapping CAS out with a known good one, which had absolutely no effect. Any idea what this could mean?

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Steven Holloway Verified Driver Made Donation to Website
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You need to check the cam gears, as advised in the other thread. Maybe the "I" and "E" indexes are swapped.
I'd check those before I did anything else...

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David de Regt Verified Driver
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Yeah I'm going to check that tonight when I get home from work. Looking for other ideas while I'm stuck at work. [Smile]

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Keith in WA Verified Driver Made Donation to Website
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Could you get past 16* with the other motors?

I'm just thinking what are the chances that with the motor swaps and rebuilds and everything, they've all had the pulleys on the wrong sides or been off a tooth on the belt each time.

By all means check. I don't know if all the dyno pulls have looked the same way each time and you could have been cursed with different problems each time. Just trying to save you more dyno time if it's an issue you may have ruled out already.

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Keith Novak
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David de Regt Verified Driver
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I don't remember. The motors all came with their own pulleys though, so that's unlikely the issue. We've been swapping CAS and manifolds between motors, though.

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Jamie Tucker Series Champ

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If the I and Es are swapped it wont run. It wont even have compression. Having my own dyno I can't tell you how many 1.6s I have dynoed but it is a lot and they all get more than 17 degrees. In fact they go well past the timing mark; somewhere around 25 degrees or so. On one of my cars I had the same problem you are describing and found that my exhaust cam gear was off 2 teeth. Keeping digging you will find the problem!!! Good luck!

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Greg Bush Verified Driver
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The timing mark on the pulley can be off. The outer ring can rotate on the pulley.

Verify TDC is really TDC....

Keith in WA Verified Driver Made Donation to Website
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I thought he already checked that but maybe it was Mark...or a different motor. True enough though. My TDC mark was off 9* on a brand new reputable builder pro motor. The advice I got was don't pay attention to the factory marks. Make your own witness mark and use that.

When I called a very knowedgeable friend up for advice with my "what the hell" discovery he educated me that it's hard to find TDC with a few degrees rotation so rotate it about 20* on either side and find the middle that way. A small bit can make a big difference I hear.

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Mark de Regt Verified Driver Made Donation to Website
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It was Mark. We've had more than our share of problems this year, limiting us both to only three races this year, so far.

Continu'n' Saga Racing
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This very same issue happened to me this weekend.

I had the same problem with my motor after putting in a new water pump and timing belt. The problem is, you could have the two cam gears correct but the crank was retarded by half a tooth on the crank. Remember, the crank turns 2 complete turns for one turn of the cam. If you are off clockwise by half a tooth or about 10 degrees you will only get 14-16 degrees max on the timing. Basically, the cam was off by one tooth on the timing belt. The car still seemed to run fine on the street.

I had to remove the belt and re-align the marks on the cam gears to the block marks and made sure my crank was at TDC. Replace the belt... tighten the tensioner... and behold, I was able to get way pass the 20 degree location. The car still ran great on the street. We'll see on the track.

[ 10-14-2009, 08:22 AM: Message edited by: Continu'n' Saga Racing ]

David de Regt Verified Driver
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How are you half a tooth off? Won't the belt not work...?

I re-measured everything with the belt off and back on again, all at measured TDC (with a screwdriver in #1 and observing), and the belt appeared to be correct.

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Continu'n' Saga Racing
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At TDC, the Crank gear have the divot part of the gear centered with the arrow on face of the block. Somehow, while putting on the belt and giggling it in place the crank moved half a tooth clockwise. The pointer was at the edge of the left gear tooth. I didn't think anything of it at first but when I checked the timing, I got the same issue you had. The CAS was at the most advanced adjustment and I could only get actually 14 degrees.

I actually was talking to Karl Zimmerman(I was buying some longer wheel studs from him) and he pointed out that half a tooth off on the crank mark will be a whole tooth off on the cam gear part. Does that make sense?

David de Regt Verified Driver
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I get that the cams move at twice crank speed... But I think I see what you're saying now, that the crank moved half a tooth's worth while you were trying to set timing. I've verified that the crank was sitting at measured TDC while setting the belt on the cams, and it's exactly as it came from the builder, so I think it's a different problem. My balancer just is 5 degrees off for some reason.

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Continu'n' Saga Racing
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Oh well, just a thought. I was reading your post and had the same problem and didn't figure it out until I talked to Karl. Then the light came on because I remembered that even after putting the plastic face plate on with the Timing/TDC indicator, I remembered that TDC was really about 1/2" clockwise to the TDC mark on the plate. Anyway, when I solved the problem, I thought I would post and give you a possible solution. Sorry, I couldn't help.

cam Verified Driver
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quote:
Originally posted by Continu'n' Saga Racing:
... will only get 14-16 degrees max on the timing. Basically, the cam was off by one tooth on the timing belt. The car still seemed to run fine on the street.

I had to remove the belt and re-align the marks on the cam gears to the block marks and made sure my crank was at TDC. Replace the belt... tighten the tensioner... and behold, I was able to get way pass the 20 degree location. The car still ran great on the street. We'll see on the track.

Bring back an older thread, I think I have this problem as I can only get around 13* of advance timing. Car seems to run fine but a bit down on power. So was there a noticable differance when you got back on the track?

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David de Regt Verified Driver
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It's so cute how people in the southwest think that we can get on the track in october and november up here. [Smile]

I haven't actually figured out the problem yet. It looks like there's multiple problems at this point. Still no idea what's causing my weird A:F curves but I'm sending injectors away to get flow tested, gonna swap the engine wiring harness, etc. and try again.

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Glenn Verified Driver
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19 teeth between I and E. Check it!

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Glenn
Crew chief Meathead Racing, NE Region Sales Division Race Engineering, The GOLD standard in SM engines, Occasional race slave for OPM Autosports

David de Regt Verified Driver
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I checked the teeth between I and E, checked the crank pulley, checked TDC, timing belt looks fine, unfortunately.

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Glenn Verified Driver
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Call Bob Thornton at Race Engineering, he has a help line for just this type of problem. His number is in the Ad on the home page.

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Glenn
Crew chief Meathead Racing, NE Region Sales Division Race Engineering, The GOLD standard in SM engines, Occasional race slave for OPM Autosports

PedalFaster Verified Driver
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My understanding is that Bob's been very generous with his time on this issue, but even his help hasn't yet to a solution.

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Kent Carter Verified Driver Made Donation to Website
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what are the odds.... the timing light is wrong?

If it is a very simple, xenon tube strobe type it's nearly impossible. If it has the little advance adjustment knob.........

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cam Verified Driver
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update: First, thanks for the feedback. It turns out that I had 20 teeth between the I and E. It really looked correct but none the less, it was wrong. In order to check it, I had to take all of the front plastic timing belt covers off along with the H2O pump and crank pulleys. With everything exposed, I could clearly see TDC on the crank nose and line up the cam gears. I had to keep the passenger side idler (the adjustable one) tight and fully low tension on the timing belt. And I keep the drivers side belt idler bolt loose. Once lined up, adjusted and tightened according to the FSM. I can now advance the timing to the level I want to. Hope this brief write-up can help someone else.

Added: Went back and did some simple math. Being off one tooth advanced the cam timing 7.83 degrees. That can help explain why the car ran OK, just weak at the top end. This is on a 1.6.

Has anyone done a before and after dyno pull with the cam off a tooth?

[ 11-28-2009, 01:24 PM: Message edited by: cam ]

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