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Discussion Starter · #1 ·
I am in the midst of a timing

I am in the midst of a timing belt change on my ’87 328 and a few questions have come-up that I would appreciate some input on.

1) So far, I have removed almost all the required items, however, I got tired and hungry after only removing the rear valve cover (the front valve cover is still on). The timing marks on the rear cams are off equally about 1/8” toward the front of the car (I did not note for sure which way the cams rotate, but I think this would indicate that the cams are advanced). At one time I remember somebody saying that the cams could be set slightly differently, but as long as they were identical they said to remark them and put them the way they were (assuming the car runs good). It seems that this situation may advance the cams about 12 degrees (one tooth on the cam gear). My thoughts are that either A) the timing is off (crankshaft gear moved a tooth) B) the cars run better with this situation, C) when I put the new belts on, the marks will line-up (belt stretch). When the front valve cover is removed I will be able to tell if this is unique to the rear bank. Additionally, a very reputable garage did the previous 30K service. Ric Rainbolt wrote a well written procedure and he indicated that the cams might move when you release the tensioners and run the belt around the one time.
My question is what does everybody think about how to proceed with the cam timing if the scenario ends-up that the front cams and the rear cams are off the same amount?

2) If I decide to remove the pulley and move it to center the mark-up is it okay to tighten the pulley bolt with the new belt on or should I try to hold the cam with a vise grip or something.

3) On the valves that I checked, the clearances are at the high limit of .014” am I correct in assuming that this condition would tend to indicate that there is little or no wear because when the valve seats wear the valve clearance gets tighter?

4) There is no evidence of any oil leaking from the seals. Would any readers recommend putting the new cam seals in? I have heard that it is sometimes difficult to get the cam seals/O-rings/gaskets to seal-up real well. The car has about 20K miles and 7 years on the seals. Originally I was going to put the seals, etc in, but my thoughts are moving towards leaving well enough alone.

5) After completing the belt installation is it recommended to fire the engine-up (before completing installation of all accessories, etc) to check belt tracking leakage or anything else.

I’m sorry for rambling on and thanks in advance all your thoughts. I always enjoy reading all the dialog so I thought I would contribute by asking these vexing (to me) questions.

Mark
 
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Discussion Starter · #2 ·
Hi Mark,


>My question


Hi Mark,


>My question is what does everybody think about how to proceed with the cam timing if the scenario ends-up that the front cams and the rear cams are off the same amount? <<

Let's assume the Cams were not off from the Factory. So, the more likely guess is that the crank moved or was never on TDC when you began. A second possibility although it seems remote, is that someone set the cams to the wrong positions at some point in the cars history.

Before proceeding further you REALLY need to familarize yourself with ALL the marks and insure all alignment questions have answers before you take the old belts off.

Keep in mind that THE MOST IMPORTANT Mark is on the Flywheel, that being TDC. The Cam marks follow TDC in importance.


As to the seals & orings. Personally I feel the seals & orings should be changed whenever the valve covers come off. After about 15K miles of use the potential for cam seal leaks goes way up.

Regards, JRV
 
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Discussion Starter · #3 ·
JRV:
Thanks for the quick res


JRV:
Thanks for the quick response.
As it turns-out I was looking at the 6 Deg Advanced mark. When I lined the mark on the cams up; the flywheel pointer was at the PM 1-4 mark. After a couple of trys I was able to get the TDC mark to line-up on the flywheel and then the cams lined-up perfectly too.
I took your advice on the seals and have removed the cams to install the seals. I just started to clean things up so it will take a while to get it back together.
Thanks Again
, Mark
 
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Discussion Starter · #4 ·
Hi Mark,

sounds like everyt


Hi Mark,

sounds like everything is back on track


Happy Holidays, JRV
 
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