Hey guys,

I'm sure this has been covered before somewhere, but I've searched and couldn't find a similar enough story. Thanks in advance for reading this:


My buddy just bought himself an Evo 9 with 50,000 miles. It has several bolt-on's, but it has stock cams and stock turbo.

One week after buying it he had it tuned and it made around 320hp/300 tq on 91 and 410hp/414tq on e85.

Since the 60k maintenance service was approaching, we decided to change his timing belt and components and found that even though his cams were at perfect TDC ( notches lined up on intake and exhaust side) his crank gear was about a centimeter off of the T from TDC in the clockwise direction.

The car runs and drives fine, but does have occasional starting issues and reads 4 psi less vacuum than my car does.

My questions are then:

1. If I fix his crank gear timing so that it is at TDC with the camshafts, would it screw up the tune so bad that it wouldn't even get him to work?

2. How safe is this mechanically on the Mivec side ? I know that the exhaust cam gear is bolted in place and can't make adjustments to mechanical timing like the intake CAM gear can. Knowing this, would there be a chance that Mivec could cause the valves to hit pistons due to the setting of ATDC on the crank gear?

3. Now that he is tuned with this setting, does that make this ok at all?

4. Could this be the reason why he is reading less vacuum than me? We found no boost leaks.



I'm just trying to gauge if I should tell him to stop driving and rent another car or just drive it easy for a while. It literally drives and idles just fine.

Thanks guys

-pal215

 

Correct the timing, have the tuner double check the tune.

 

http://www.evomoto.com/tech_info.php?tech_id=18

number 15 on the post.

 

Thanks for the info guys!

Looks like the danger is not as imminent as I first thought. We will continue with the timing belt change and see if there are any adverse effects. Hopefully the car just runs as well as it did before, although I am predicting a loss in power.

When rotating the crank gear counter clock wise, isn't that the same as retarding cam timing?


-pal215

 

1 whole centimeter sounds like the crank is a tooth off. Step 15 in that evomoto article indicates a few degrees, not a centimeter..

 

Yes, that's what I'm afraid of. I don't know how the car is even driving as well as it is. My friend is telling me that he doesn't even have a check engine light on.

One tooth sounds like 15 degrees on the crank gear doesn't it ?

-pal215

 

Yes, I think that's about right.

 

Ok guys,

Today we went ahead and corrected the timing on the engine. The crank is now at TDC with the cams, oil pump, and balance shafts.

The results were positive.

The vacuum returned to about -19 (+-1) and the idle went up from 800rpm to 1000rpm.


The car is drivable with some knock above 23 psi, but 15psi is more than enough for him to drive around until he can go in for a retune.


So for the future, if you ever find yourself in a position where your crank gear jumped 15 to 30 degrees, you will not blow up.

-pal215

 

i cant imagine the car made good power being that far off with the timing

 

Glad to hear it's fixed It should make batter power with a retune. It's knocking because it's keeping more air in the cylinder (more cylinder pressure). Probably running a bit lean due to more air also, and the lean condition is probably also contributing to knock.

 

That's why it was so strange, it made excellent power with the crank gear being at least 15 degrees or more off. What upset us the most was that the tuner didn't catch that while he was tuning the car. Wouldn't he have seen something a little off ?


-pal215

 

Thanks man,

He can finally rest easy tonight. And yes, I would have to agree with you.

The only question that remains is, with respect to cam timing, did setting the crank gear back 2 teeth effectively retard timing?

-pal215

 

If the crank gear was off in the counter clockwise direction (timing mark to the "left" of the mark in the case), the cams were advanced. Retarded in the other direction.

 

without being a "tuner" i would imagine that they would have had to run significantly less or more timing that most cars

 

My thoughts exactly and with that being the case, the tuner should have noticed that one of the gears were off.

We would have fixed the problem and rescheduled the tune.

-pal215