timing off one tooth..

[Boosted19]

I just bought a 95 talon TSi. It idles kinda rough and is only making about 13 or 14 inches of vacumm. So I looked at the timing on the car. the T belt looks new so I figured someone put the belt a tooth off by mistake. I belive it was the intake gear that was off one tooth lower then the exhaust. I think... I need to look at it again it was just getting late and dark out. Off one tooth is not going to hurt anything other then driveablitlity right? No bent valves? The car drives fine. Just trying to make sure im in no damage! Thanks!

 

[andymoraitis]

Sounds like the intake cam is advanced or the exhaust cam is retarded. It won't hurt anything but you'll want to correct it on stock cams where being that much out actually hurts performance. I actually have my intake cam advanced on purpose. The only time it would bend valves is if the head was decked enough. Since yours came this way and it's still running we know your valves aren't bent.

Hope that helps,

Andy

 

[perley03]

Sounds like the intake cam is advanced or the exhaust cam is retarded. It won't hurt anything but you'll want to correct it on stock cams where being that much out actually hurts performance. I actually have my intake cam advanced on purpose. The only time it would bend valves is if the head was decked enough. Since yours came this way and it's still running we know your valves aren't bent.

Hope that helps,

Andy

Andy,
May I ask why you have your intake cam advanced one tooth? Wouldn't you have too much valve overlap, as when the exhaust and intake valves are both open, and wouldn't that hurt in a forced induction engine?

 

[andymoraitis]

My cams are -2 degrees retard on a straight up install so it was hurting spool and low end performance despite the fact that I'm running a 2.3. This seems to be a common issue with some sets of Comp 200's. Advancing a whole tooth is actually around +5 advance. It's about 2 degrees too much but it provided massive gains in compression (from 170 to 190 across), helped the spool a bit and really made the low end come alive.

If you look at my mod list this setup logged 51 lbs/min at 27psi. While the cam advance is likely hurting a little bit, it's not enough to make me change it back although the gas mileage has suffered considerably. I'll be adding cam gears in the near future and dialing them in more accurately but for now it's much better than leaving them straight up.

 

[Boosted19]

alright good! also i saw in your reply you said it gives you massive gains in comp. it wont for me since mine is retarded? also i got the car with 87oct. i kniw there are knock sensors but i just got a little scared since you said your comp. raised alot....

 

[andymoraitis]

If you have stock cams, you'll hurt performance with the cams advanced or retarded that much. Set them back to stock and throw some 93 in it unless you want to lean out and knock all over the place.

 

[Boosted19]

alrighty! thanks for the reply and help!!!