Ranger's Dec09 motor rebuild thread (lol)

#81

cwbaader wrote:

I tried that and it turned out to be a struggle. As I recall I couldn’t get the little cap off of the “port”, or whatever you call that little access door to the oil pump’s drive shaft. So then I put a drill on the front t-belt gear. To my surprise no oil seemed to come up to the head so I doggedly kept at it. It was about a minute of drill work later that I noticed the big pool of oil spreading around my shoes. I hadn’t put anything in the OEM oil pressure port so the oil I pumped about a quart of oil out on to the floor.

Getting smarter is a long process. And the first couple of years are particularly full of misadventures.

The front garage’s floor is 50yrs old and looks it. It’s roughness and porosity made far a long cleaning effort. I spent about 30min on my hands and knees scrubbing with dish soap.

Here’s another hapless tale. As everyone knows it’s been raining a lot lately. That has made it a pita to work on the car’s motor because it’s in the driveway. I can’t do it in one of our little garages because there’d be no room to maneuver the hoist.

So on Saturday I was working to remove the oil pan. The purpose of this was to inspect the rod bearings. This was before I figured out that the head a stuck valve.

The oil was long since drained and I’d removed all the oil pan bolts that I could get to. I undid the engine and tranny mounts and then wrapped the hoist’s chains around the motor mount legs. With some patience and jiggling things around I was able to lift the motor a couple inches.

The room under the car was extremely limited because not only did I have my “big” jackstands under the frame rails, but the hoist’s legs were also under there. And of course it was raining. So me and the mechanics roller wriggle under the car in the tight confines.

I’ve learned that you have to be very careful of your jackstands when you are under a car. Sometimes there is no weight on the jackstand. I know that shouldn’t be the case, but sometimes it just seems to spontaneously happen. And if it does happen, you can easily knock the jackstand over. And that’s when the car will try to settle on the missing jackstand and crush you like a bug. So now I’m excrutiatingly careful not to touch the jackstands when I’m under the car.

So I was under the car and not able to move forward, right or left. Only backwards out the rear of the car if I chose. And I was removing the last of the oil pan bolts, now that I could get to the problem children.

Which is when oil started coming out of the bolt holes in a thin pour at about my belt-line. I was pretty much trapped. If I inched out towards the rear, the oil would get all over my chest, face and hair while I inched out. That sounded lousy. So I just kinda sucked it up and took 3-4 tablespoons of oil between crotch and belly button.

#82

I made a tool to prime the motor…Jim has it. You must remove the upper bearing/gear for the op drive, remove the drive, and insert the tool (actually two drive shafts welded together) and spin with any drill…I used an electric. Remove tool, reinsert drive shaft and bearing/gear, and start motor…win/win. CB

#83

BMW made a tool to prime the oil pump…the starter motor with the coil wire removed.

RP

#84

Yes, if you don’t mind grinding on the starter for a couple of minutes. Takes a drill about 15 seconds to get full pressure. CB

#85

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#86

I mostly agree…(you knew this was coming) But I have a few comments. My motor makes more hp at 160degrees than at 180…proven on dyno.

Due to the thermostat design (blocks one hose and opens another) you must run a thermostat or somehow block off the heater arrangement.

Agree with poorly bled systems, that is why there is a hole in my thermostat…don’t have to bleed anymore.

I’ll stick with BMW’s design of the cooling system. It was designed to run at or near full throttle for hours. What we do racing, IMHO, is far less stressful. CB

#87

I think that I’ve figure out the issue of what encourages decent water flow in the rear…

It’s the HG that controls flow.

Background:
Flow volume is proportional to pressure difference and pipe size. So if pressure difference is low, you can increase pipe size and get the flow volume back up.

So here’s the deal:
Consider the pressure difference between the water jacket and the top of the head (not front…top) at each piston. The pressure difference in front is a lot because the water inlet (front of block) and outlet (tstat housing) is right there. The pressure difference that pushes coolant from block to head is a little less at cylinder 2, less at 3, even less at 4, etc. So if the cooling ports from block to head were the same size at all cylinders, water flow volume would be good in front and suck at the rear. Remember…if the pipe size is the same and delta P goes down, then flow volume goes down.

And the ports are the same size. But the holes in the HG are not the same size, at least not on the exhaust side. If you look at a HG’s exhaust side you’ll see that it’s coolant holes are the same size for cylinders 1-3, but cylinder 4 has 1 large oblong hole. Cylinders 5-6 have 2 large oblong holes. So the HG compensates for the lower delta P by allowing a bigger pipe. And that creates roughly equal flow volume in the rear as the front.

I’m neglecting the issue of cooling the intake side of the head because it’s just not a big deal.

The coolant water would be warmer by the time it gets to the rear so less cooling would occur at the rear. So maybe the larger holes overcompensate a little and water flow is actually faster in the rear.

So what does this mean. Well, it probably means that blocking off your heater port on the back of your head is fine. But connecting it to the right side of your thermostat, which seems to be legal, might work even better. I don’t know that it’s worth bothering with tho. And it’s always risky to screw with mother nature or products of lots of engineering sweat.

If there is clear evidence that M20’s have a cooling issue under race conditions, I’ve not come across it.

#88

cwbaader wrote:

[quote]I mostly agree…(you knew this was coming) But I have a few comments. My motor makes more hp at 160degrees than at 180…proven on dyno.
[/quote]There’s no argument from me on this fact, dyno’s tell the truth and Hyperbole is just that, conjecture and hearsay, but it’s worth considering fundamental engineering when making brrmbrrm noises at your desk at work all day.

#89

Bernoulli would have been proud of you. :wink:

#90

Re. colder engines make more power.

Last summer I made several visits to a dyno to attempt to understand why my monster motor, wasn’t. That was my first ever experience at a dyno. One of the lessons learned was that when you make a change you always have a good dyno run. Because during the change the engine cooled down. So after you make a change you have to do 2 dyno runs and discard the first.

That synchs with what Chuck was saying about cooler = stronger.

I’m sure that there is some ideal temp range for our motor. Who was it again that we tasked with getting himself an old BMW engineer father-in-law?

#91

I think the difference is that a “colder” thermostat is just working the radiator harder allowing the water jacket to cool off at a lower temperature. In all likelihood the Germans are ahead of us and the combustion chamber tamps are held at optimal despite out best effort to screw up the systems they designed. Crafty lot those Lederhosen wearing Bavarians. If the Thermostat is indeed still in it’s proper location.

#92

kgobey wrote:

[quote]cwbaader wrote:

[quote]I mostly agree…(you knew this was coming) But I have a few comments. My motor makes more hp at 160degrees than at 180…proven on dyno.
[/quote]There’s no argument from me on this fact, dyno’s tell the truth and Hyperbole is just that, conjecture and hearsay, but it’s worth considering fundamental engineering when making brrmbrrm noises at your desk at work all day.[/quote]
It is a fair statement to say that engine efficiency increases with temperature, which in the general case means power increases with an increase in engine temperature. And in the days of carbs and simple fuel injection that held true. It may not necessarily be the case with a smart fuel injection system since one map input is engine temperature. A colder engine results in a richer mixture and that could, in the absence of custom tuning, result in a performance gain.

#93

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#94

kgobey wrote:

That’s so, like, last year.
http://www.gress.org/Home/Cars/TrackTales/DIY/OilingSystem%20Improvements/Oil%20Debate/The%20Great%20Oil%20Debate.htm

I was poking around the idea today of a 10W40 Winter oil for CMP. But the only decent ones I could find are the pricey ones, Redline and AMSOIL. The chemistry of all the others just sucked.

I ended up getting some Redline ZDDP engine break-in additive. That will allow me to use a number of 10W40’s that would be ok if they just had more ZDDP to protect our cams and rockers.

Synthetics are fine, but if you change your oil pretty often, Dino oil is ok too. And besides, most oils labeled Synthetics, are actually blends.

The best stuff are the race oils that are not intended for passenger cars. They don’t have much detergent in them so they can’t take long oil change intervals (OIC). Therefore you get more oil and less soap in a quart bottle.

www.BobIsTheOilGuy.com is the center of all oil knowledge.

#95

pass the Glock.

#96

kgobey wrote:

I’m trying to decide if you did that on purpose or if you truly don’t realize what you’ve just done.

  • Maybe you’re actually Scott/Ranger and have figured out a way to converse with yourself without looking TOO crazy.
#97

shifter11 wrote:

[quote]kgobey wrote:

I’m trying to decide if you did that on purpose or if you truly don’t realize what you’ve just done.
[/quote]

I figure it was an honest mistake. Was funny tho.

#98

So, Why is a valve sticking out of your head? Where’s the debate on that??

#99

bdigel wrote:

Is that an unusual result for a coolant loss situation? Since it’s the first valve I’ve ever had stuck in my head, I don’t know much about it. Both wife and Gasman have mentioned wanting to stick things in my head before, so I wasn’t all that surprised.

What are valve guides made of anyhow…brass or something?

#100

Gasman wrote:

It took a little while, but Gasman and I are in complete agreement. :laugh:

Oil discussion? I think kgobey might just be an alias that Ranger is using to stir sh!t up. :S