M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine + Driveline => Topic started by: JiXer on June 23, 2007, 01:24:16 AM
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So, I had to overhaul my timing system and I have most of it complete, but I am nor paranoid that I am not at TDC. I have an aluminum flywheel which does not have the convenient little 8mm whole for setting TDC.
So I had to guess.
Is there another way to make sure that I am right on TDC?
I also want to set my intake cam to 5^ advanced, but I am not sure how to be sure that I am right on 5^.
Help is greatly appreciated as I need this car for Monday morning.
Thanks in advance.
J.
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the crank pulley should have a mark for tdc. search for a thread regarding the timing chain procedure. that should help
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the crank pulley should have a mark for tdc. search for a thread regarding the timing chain procedure. that should help
Unfortunately, I don't think it does.
And I have searched and searched, but everyone just uses the flywheel.
J.
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Unfortunately, I don't think it does.
And I have searched and searched, but everyone just uses the flywheel.
J.
Are you sure? I'm willing to bet there's one at the front of the engine somewhere.
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Are you sure? I'm willing to bet there's one at the front of the engine somewhere.
What exactly are you willing to bet?
J.
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When the woodruff key is straight up. Like in photo, also observe cam position.
(http://i93.photobucket.com/albums/l59/nobrakese28/DSC_0026.jpg)
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When the woodruff key is straight up. Like in photo, also observe cam position.
(http://i93.photobucket.com/albums/l59/nobrakese28/DSC_0026.jpg)
i rest my case. thanks nobrakes, ive been trying to figure out the name of that damn key for about 2 weeks now. i recently did a head swap on my friends integra gsr and those keys are important pieces on the cam gears. for the longest time i couldnt remember that one word before key, but i KNEW it started with a "w"
damn WOODRUFF key lol
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Woodruff key? What's that?
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Yes, an explanation would be nice, as I am gearing up for the same overhaul.
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the best way is to measure real TDC through spark plug hole.
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the best way is to measure real TDC through spark plug hole.
This does you know good.
There is at leat 10^ of rotation in the crank while the piston is in the top position. Top DEAD center is when the piston is at the top and the crank is at the very center of the rotation. There are 36 points on the cam sprocket which means each tooth is ten degrees. So this is not a sufficient method of finding TDC.
The stock flywheel is the ONLY way to be totally sure. You can all but garauntee you will be with in a tooth, but that will still prevent the motor from turning over.
The best way to do this job is to actually take the outer timing covers off and scribe points on the end of the crank and and the oil pump cover and then do the same to the cam sprockets and the head. Don't use a grease pencil. It will wash off. Actually scribe it with a file or something.
I finished mine today and had everything set up with the intake cam about 6^ advanced and the exhaust cam at zero. It made a very horrible clacking noise. I had to back the intake cam off to maybe 2^ or 3^ advance for it to run properly. It pulls strong, but when it comes off throttle, I still have a little rattle that I can't figure out. It might be somewhere else in the motor or might just be the way that motor sounds?
It also GROWLS when its approaching 7,000 RPMs. I don't remember it sounding like that before. Not sure of thats a bad thing or not?
J.
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Thi
s does you know good.
There is at leat 10^ of rotation in the crank while the piston is in the top position. Top DEAD center is when the piston is at the top and the crank is at the very center of the rotation. There are 36 points on the cam sprocket which means each tooth is ten degrees. So this is not a sufficient method of finding TDC.
It depends what accuracy you have. You can mark the middle of these 10deg, right? ;)
The stock flywheel is the ONLY way to be totally sure. You can all but garauntee you will be with in a tooth, but that will still prevent the motor from turning over.
The best way to do this job is to actually take the outer timing covers off and scribe points on the end of the crank and and the oil pump cover and then do the same to the cam sprockets and the head. Don't use a grease pencil. It will wash off. Actually scribe it with a file or something.
Totaly agree.
I finished mine today and had everything set up with the intake cam about 6^ advanced and the exhaust cam at zero. It made a very horrible clacking noise. I had to back the intake cam off to maybe 2^ or 3^ advance for it to run properly. It pulls strong, but when it comes off throttle, I still have a little rattle that I can't figure out. It might be somewhere else in the motor or might just be the way that motor sounds?
It also GROWLS when its approaching 7,000 RPMs. I don't remember it sounding like that before. Not sure of thats a bad thing or not?
I had the same problem. If you want better top end you should advance cam, but I had terible noice when intake cam was retarded. Are you shure that you advanced it?
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I had the same problem. If you want better top end you should advance cam, but I had terible noice when intake cam was retarded. Are you shure that you advanced it?
Well, if I am correct in saying that the M42 turns clock wise (when standing in front of the car, looking down at the motor), then I definitely had the intake cam advanced and less than the max, but something was not happy.
I am still slightly advanced, but not nearly as far as I could go.
Which begs the question, why would BMW build in adjustability to the point of near catastrpohic failure in an interference motor?
J.
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I had the same issue when I rebuilt my timing case on a lighter flywheel. Using some welding rod we got it about as good as it can get. It does not take anywhere hear 10 degrees of error to get valves hitting postons (ask me how I know). It runs strong up to redline. Maybe your growling noise is something that timing case noise was masking before? If the timing was way off, you would definitely know, and it would not be terribly willing to redline or idle nicely. Good luck.
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Well, if I am correct in saying that the M42 turns clock wise (when standing in front of the car, looking down at the motor), then I definitely had the intake cam advanced and less than the max, but something was not happy.
I am still slightly advanced, but not nearly as far as I could go.
Which begs the question, why would BMW build in adjustability to the point of near catastrpohic failure in an interference motor?
J.
Sorry for my mistake, you should retard intake camshaft for better top end. The valve shoud be opened later and closed later. My first atempt was to advance intake, after that I got terible noise and weak top end. After I retarded intake camshaft at max posible position. And after this I lost low end torq, but top end was much better. Limiter is 7200rpm.
You can try to simulate it on the DynoSim 2003.
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Sorry for my mistake, you should retard intake camshaft for better top end. The valve shoud be opened later and closed later. My first atempt was to advance intake, after that I got terible noise and weak top end. After I retarded intake camshaft at max posible position. And after this I lost low end torq, but top end was much better. Limiter is 7200rpm.
You can try to simulate it on the DynoSim 2003.
You have it backwards.
J.
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This is what I do to get TDC.
After installing your flywheel and clutch set it as close to TDC as you can. Then remove the timing chain and set the cams to TDC. The flat ends of the cam should be straight across. Then set the crank to TDC (I use the long screw driver in the spark plug hole trick). Then install the timing chain.
It's worked for me everytime.
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Cam should be advanced, not retarded, according to everything I've heard. Anyone know for sure which? Advanced makes the most sense to me.
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Cam should be advanced, not retarded, according to everything I've heard. Anyone know for sure which? Advanced makes the most sense to me.
Why do think so? I'm saying you how I did that and what results were after adjustment. Do what you want... ;)
This setup was shit and inverted is wich I'm driving now.
(http://img74.imageshack.us/img74/7769/detalewm7.jpg)
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That is a full 10 degrees advanced, you should only be 5 to 6. Advancing helps top end HP and hurt low end torque, which if you drive down low (around town) would feel worse.
Retarding helps torque. So when you drive around town it will feel alot better. But if you are racing (not necessarily atuo-x) then you would want it advanced.
Secondly you need to replace your cam sprockets. They are beat. I'd recommend replacing your chain also.
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Advancing helps top end HP and hurt low end torque, which if you drive down low (around town) would feel worse.
You are totaly wrong. Try some simulation software.
Retarding helps torque. So when you drive around town it will feel alot better. But if you are racing (not necessarily atuo-x) then you would want it advanced.
Wrong, all is vice versa...
Secondly you need to replace your cam sprockets. They are beat. I'd recommend replacing your chain also.
Sprockets was inspected during engine rebuild. They are good enough to be used. As I said before in one thread it coud be that diferent manufacturers use diferent tooth profile, or diferent tooth profile height. Worn places are always fully polished and places which are worn litlle bit still have mashining patern.
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I will respectfully disagree.
However I feel obligated to tell you that your cam gears are done. They should not be sharp like that (should have a flat top roughly 1.5mm long) and they should not have those deep grooves and pits in them.
Now I have to say that while I am also a stubborn and prideful person, when numerous people who have lots of PERSONAL experience with something tell me something that may be contrary to what I know, I will certainly look it up. Before I started doing things myself I had many mechanics who told me something that was totally wrong. They didn't know any better at that time.
I've tuned many cars and advancing the timing in conjunction with added fuel is one of the easiest ways to get some HP up top. When you retard the ignition it helps down low. This is of course all to a point. At a certain point you start to lose horsepower or torque when you go beyond that peak.
If you are beyond the point especially with timing you can lose power really fast. Two years ago I was tuning a Honda and this guy wanted to use a certain chip, it had timing advanced way too far. I had to convince him that the timing up top need to be retarded back to a certain point. The timing was still advanced but not to that point that the chip values started at. But it was a gain of 8 horsepower for 7 degrees (35 degrees vs. 42) in one small change. That combined with 3 degrees advanced intake and 2 degrees retard exhaust, combined with fuel mapping, and it came out to 12 hp gain for that tune, the engine as a whole gained 60hp. I built and tuned that motor.
I hope you don’t take this as a personal attack, yet as a learning experience. It’s hard a prideful person to accept that you are wrong, believe me I know (ask my wife). However if you continue to “know” you are correct, in the face of data that suggest otherwise, you’ll end up with a ½ ton paperweight.
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best is 7 degress retarded setup, exaust stock.
(http://img237.imageshack.us/img237/7026/grafikasjn3.jpg)
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check Catcams.com