She is finally started ....

[ZeroG]

I was finally able to start her up tonight.  I replaced the HG among other things over the last 2 months.  I took my time as it was my first time doing this, I was also extra careful with everything just to make that I did not damage anything in the process.

So anyway she finally started back up.  She was idling clean and everything.  A little loppy at first, which is normal for my car being as modified as it is.  I did notice one thing, and I just wanted to make sure that it was normal.  I was bleeding the radiator system and I notice that there was some oil in the water as it overflowed on to the floor.  I figure that this is normal since I just had the head off during which liquid may have gotten all mixed up.

Is this normal?  Do I just need to let it run a little bit and then flush the system out?

I am also running high perfomance aftermarket cams.  272 x 10.5 to be a little more exact.  Prior to the HG replacement she use to have about 10.5:11 inches of vacume at idle.  Now I know what you're thinking that this is low and that there must be a vacume leak somewhere.  But I have been told that this kind of a characteristic is normal for a car that has a cam profile like mine.  During the HG replacement I wanted to try and reduce overlap so I rolled the cam back (counter clockwise) on the ajustible sprocket as far as possible.  Now that car only has 5 or 6 inches of vacume.  Which worried me a little bit, as everyone I know sees like 20 inches at idle.

As soon as I get on the throttle it will drop to 15 and then to 20 inches, but without any throttle input I see about 5 inches.  Does this sound OK?  I do not believe that there is a vacume leak as the car was idle fine and was not hunting at all which is normal for a car with a leak.

Any input would be greatly appreciated.

[Cristian G in Oz]

When I rebuilt my M30 3.5 I used Alpina Cams. I can't remeber the specs but they were lumpy at idle. The whole car (E12) used to get a roll up at idle.

Anyway, when I set it up, the mechanic that wa guideing me said to always look for the best vacume you can at idle and then adjust it to how it runs in the real world. When I did this it ran great. If I lowered the vacume at idle it lost power higher up in the rev range. I never got anywhere near factory specs for vacume on my car but a brand new fully balanced M30 does not lack suction.

My advice is set it back where it was and then check how it drives. You may well find that the but-o-meter responds better to it than it does now. The only definative way to sort it would be a few hours of dyno time, but if your like me thats no possible for this task. Maybe try a couple of settings till you get the best one.

Let us know how it goes.

Good luck

Cristian

[ABuseO]

Yo, good job on getting it running, just got mine running yesterday, drove it about 20 miles today.
The thing is when you get water into the system like that, it will drop to the bottom of the oil pan. When i changed my oil just a few ounces of water spurted out. Also when you're starting it there might be a bit of water in your catalytic converter. I started mine up yesterday and it started smoking pretty bad after about 6 minutes, but when i started it up today there was hardly any smoke at all.
I had to replace the whole cylinder head because it was cracked, so i had a slight scare when the radiator hose came off (because it hadn't been properly fastened...) water shot out and my engine temp shot up. Fixed it, drove it around quite a bit more. I am satisfied after about a month...
Next up...windshield...

[gearheadE30]

How do you adjust intake vacuum?

BTW good job on getting it running. Do the long-duration cams make much of a difference?

[ZeroG]

So anyway I figured out the that cam duration directly effects vaccum measured at the intake mani.  I guess when I had the valve cover off I rolled the exhaust cam the wrong way.  I maxed it out as far as retard goes, I think it was about 5 degrees.  I saw about 5" of vaccum or less.

I then advanced the cam to the max + 5 degrees, and intake vacuum shot up to about 15".  I was talking to Jim at Metric Mechanics who always talks way over my head, and he said that ideally you want to see about 12 to 14 inches on vacuum at idle.  He also said that I need to get a dial indicator and make my own cam timing instead of being limited to the factory adjustments and specs.

The long duration cams make my car very peaky, so off the line is decent, but once you get in the upper RPMs 3500 to 4000, you're gone.  It will pull all the way to 9K strong if you let it.  My car is supercharged which likes to make a lot of low end tq, so I need to play with the cam timing a bit to see if I can get a more well rounded engine out of the set up that I have.

[Febi Guibo]

supercharged? pics pls!

[ZeroG]

supercharged? pics pls!

As requested, here are some pics: