Cam timing

[rammstein]

I have an M52B28, and the previous owner(s) put an S52 camshaft in it at some point. I always felt like something was a bit off in the power delivery and I took it to a dyno recently, and the chart showed some serious funkiness.

So I took the car in to a place that does software, as I assumed the chip in my car was not doing its job properly. They called me and informed me that the chart seemed to indicate a problem with the cam timing and asked if I wanted them to have a look. I ok'd it, and 2 hours later they call and tell me that it was WAY off. So they fixed this instead of replacing the chip. I picked up the car, and WOW. Wow. Its like a new freakin car. Pulls like a champ, no hesitations anywhere. I bet I gained 20hp.

Anyhow- I did some searching, and apparently to install cams properly you need special tools. Some people claim you can get away with it without the tools, so I wonder if that is how my car got to such a state.

But here is my NOOB question- is it possible for the cam timing to 'slip', so to speak? I would assume not, seeing as how there is a chain involved and all, but could someone confirm.

[Sagaris]

Stretched timing chain perhaps?

[FredK]

I don't think the timing chain could "slip" unless something was very very wrong.

I think the issue is that maybe the Vanos was improperly installed at first, which can limit its travel and therefore performance.

[matt]

Nobody ever believes me when I tell them this.

You can NOT get away without using the tools. I don't care who you are or how many of these you've done. Period.

[etxxz]

Nobody ever believes me when I tell them this.

You can NOT get away without using the tools. I don't care who you are or how many of these you've done. Period.

+1 learned from personal experience!

[rammstein]

I am assuming that whoever did the original swap didn't use the tools. That's the only explanation. According to my mechanic it was off by a considerable margin. I was just wondering if it was possible that it was EVER correct... but like I said and others have echoed, it seems unlikely.

ANywhoo, with this problem now corrected, my car feels a zillion times better. I can't wait for the track on saturday. It shall be epic. :D

[xwill112x]

your lucky the pistons didnt smack the valves! i would be scared to find out what else had been done ghetto...

[rammstein]

Its funny, because most everything else has been done very well.

[graphikg]

Hmmmmmm.... My timing seems to be off as stated by my mechanic and my car cant even go past 3500 rpm under load. It just shuts off.

[Dj Buttchug]

^ yup tell tail signs of timing off. especially at higher rev. My timings off too haha

good thing i got easy adjustable cam gears ftw

[graphikg]

Wish I new that earlier. I had the head resurfaced, installed it my self with a friend. I even did my own clutch, flywheel, and oil pan gasket replacement myself --- but couldn't time the darn thing right - even with the tools. Now it is costing 400 bucks to get it timed properly by a shop. AGGHH!!! I atleast dont have bent valves or anything though as far as I know.

[rammstein]

Well, mine was not off by nearly as much, at least based on the severity of symptoms you are describing. I just know that all of the rough idling and weird bucking issues under full-throttle at low-rpms that I was getting were completely eradicated by the adjustment of the cam timing.

I wish you luck in getting your car sorted out. I was seriously happy when I got the car back from the mechanic back when I posted this- it turned out I had a better car than I thought :D

[graphikg]

I hope the same for myself... How much was it to get yours timed? Hopefully the shop doesnt charge me higher since my flywheel is aftermarket and has no flywheel lock hole; just to make things more difficult.

[ForcedFirebird]

I hope the same for myself... How much was it to get yours timed? Hopefully the shop doesnt charge me higher since my flywheel is aftermarket and has no flywheel lock hole; just to make things more difficult.

Doh! $400 doesn't sound too bad, will take them a few hours, and make sure you let them know that you have an aftermarket flywheel, they can use a piston stop. If they didn't know, might take them a bit to even realize.

[graphikg]

Ya, I let them know... They said they will use a tool they thread through (I am guessing where the spark plug goes) to read where the piston is sitting, then adjust the crank pully TDC line, and time the cams from there. I guess 400 shouldnt be too bad then. I already told them about there being no flywheel hole.