Pamola

Anyone need a new project?

http://germancarsforsaleblog.com/massive-bmw-collection-in-connecticut/

Kevin, No problem. I'm just glad you did not have any problems on Chicago's highways.

Kevin,

If you need some help or want a break from the Indiana Autobaun (I-65). I am in Lafayette and will be around.

-Jayme

Well done.

Same thing happened to my 93 Volvo 240 two months ago in a Walmart parking lot.

Step 1. Call police and file report.

Step 2. Never go to Walmart again.

Step 3. Used the incident to give a boady shop I am thinking of useing for the 02 a trial run.

Step 4. Never go to Walmart again (seriously this was my third car damaged in thier parking lot) 

Oh jeez.

I has a similar thing when I moved and my wifed cat decided to show it's displeasure with the change in the status quo by micterating all over a Flowfit. You just can't get cat pee out of foam.....

Complete bunk,

First:Multipoint ignition from some cuts in the combustion chamber? Nonsense. The flame grows from the spark plug. J-gap spark plugs create a single flame kernel. A multi-torch (snowmobile style) spark plug develops multiple flame fronts (until they form one large front late in the burn) due to jets of flame exiting the spark chamber. The only way to create multiple ignition sources with shapes in the combustion chamber is if you create hot spots that cause runaway pre-ignition.

Second: There are several ways of changing in-cylinder charge motion (turbulent kinetic energy): 1. By shaping the flow pre-intake valve (turbulent vanes, curves to create a spin etc). 2. By shaping the head right by the intake valve (masking, scallops). 3. By shaping piston crown geometry. That's it. Shapes near the spark plug will have negligible or localized effect around the spark plug and will not impact bulk charge motion.

Third: Increase in laminar flame speed will often increase knocking tendencies, requiring spark timing to be reduced to keep the engine out of knock. This often mitigates the benefits of the faster burn. The paper does not even mention this and how it was overcome. You can get a phd on this sub-point so I'll stop here.

I don't want to call BS on MM but I would not spend my money on the technology without a lot more convincing.

Could be a head gasket if oil getting in the combustion chamber. What does the #4 spark plug look like?

Bill is there a specific questions with AFR to CO? As jimk said fuel chemestry is important so if you fill up the tank with E0 vs E20 you are going to see some changes. I don't know what you have out in MD but if it is available I would only put in E0. Just my 02 cents but with an old car with valuable engine parts (that is not a track rat) fat and happy is good as long as there was no smoke, drivability is good, and the plugs are clean.

By clamping force you mean modulus of elasticity. A modern stud can be extremely strong and can have less elongation than an OEM bolt. However, unless you are going to significantly increase your peak cylinder pressures to the point where the head bolts stretch enough to let combustion gasses leak there is zero need to upgrade. I would suggest this. Look at the 2002 turbo head bolt PN. You know that will be good to at least 177 lb-ft (since it is not a torque to yield bolt it will hold more than 177 ft-lb safely). If you plan to go higher consider upgrading if you don't stick with what works.

...also take some pictures of cam lobes / journals (head and cam) and main bearings.... Good luck.

(nt)

Tom,

AFR setting in my humble opinion is the hardest part of your project. It's hard because you will not be able to find LBT (lean best torque) that needs to be done on an engine dyno. Perhaps there are some 02 speed freaks on this board that have a lot of hard worn experience that provide some guidance. If it was my car I would set the cruise and idle area at stoic. That will provide the best responsiveness to load changes, appropriate hardware temperatures, and lower Nox emissions. Your engine modifications do not list anything that is going to raise head, and in cylinder temperatures so there is no need to go super rich to protect parts and countermeasure volumetric efficiency reductions due to high temperatures lowering the density of the incoming charge. I would pick 12.6 for WOT areas at low to mid range rpms and 11.9 for the peak RPM areas. If you get black smoke dial it back, if your thermocouple is reads more than 850c (this temp is my particular old valve pucker factor) after everything is dialed in add some more fuel. Oh and about the thermocouple. I’m not sure what you have but I would suggest a 1/8” sheathed, grounded unit. That will provide a good mix of fast response and durability. You do not want a thermocouple breaking off near and exhaust valve. The negative pressure pulse from the backside of the exhaust event can suck that little fella right into the engine.

I strongly recommend the dyno tuning. It will allow a much more controlled and safer environment for everything except your wallet. If you are going the dyno route installing a K-type thermocouple in one exhaust runner (lab grade or something scrounged up) will help immensely with choosing the correct ignition timing.

Step 1. Choose AFR. If you move AFR effects laminar flame speed in the cylinder and consequently ideal ignition timing. Choose AFR based on your parts durability pucker factor. Lean is mean but it is hell on parts.... Personalty with my own $ on the line I prefer fat dumb and happy but that is just me.

Step 2. Repeat at 1k 2k 3k 4k 5k.... at WOT, -200 kPa, - 400kPa intake manifold vac..... At each point sweep timing and record EGT. Stop if the temp starts to go back up while advancing timing or when you here knocking. Look at your temp data at each running point and choose the timing that produced the lowest EGT before knock. That will be your most efficient and powerful timing. Do not pay attention to the torque numbers from the dyno those are a like cutting with a chainsaw when the thermocouple is more like a paring knife.

Here is the hard part. High intake air temps and dryer air will increase flame speed and thereby reduce the timing in which the engine will knock. You could run a hot temp & cold temp maps if needed. Or you could run maps with margin in them. Keep track of the air temp (and humidity) when you are dyno testing and that should help.

Have fun if this is done right the 02 will be optimized for power responsiveness and economy and you will win a nerd award....

unless someone dyno'd their car before and after, and documented what the old system was, there will be no evidence of any performance change.

And chassis dynos are terrible for measuring small changes. There are way to many variables that can not be controlled. Once in band camp I measured the flow of a new K&N air filter and found the oem paper filter was better.... Perhaps it was the sticker that made the difference.

I'll take on an keep it away from the toodler!

Oh boy.

This would be a real long shot (but easy fix). Is there any way you did a really bad job adjusting the valves?

Try the double nut method first. Buy tools next. You probably already have the hardware laying around.

One more item to the check list….

Check the valve guide ID and guide centerline location (if possible) they are critical for proper valve seating. If the valve is not seating properly the wear on the valve and seat will be increased. Then you combine bad seating with high temperatures (eg lower yield strength) and high RPM there will be all kinds of mechanical badness going on.

Nissan SR20DET

The Good.

1.Tough as nails

2. Lots of aftermarket support (the drift and JDM crowd loves them)

3. Hits your output target in stock form while running pump gas

4. Nissan made oodels of them

5. Early 90s 'lectronics

6. Was put in AWD FWD and RWD platforms

The Bad.

1. Not imported to the US

My home shop and parts are open if he needs it in Lafayette, Indiana ( between Indy and Chicago). Heck I'll even toss in a tour of the Cat engine plant where he can see engines being built and dyno tested that are so big you need a ladder to change the spark plugs.

Great googly boogly. You could have Jesse James build one for less.

17:1 air fuel ratio is lean. At idle there is very little flow in your exhaust system compared to wide open throttle at high rpms. I don't see how a exhaust system change would do much to a four stroke engine at idle. But I am not a tii guy so perhaps you will teach me something.

IMHO

1.Air leakage into the exhaust stream is the most likely culprit. You smell exhaust and air can leak into the exhaust. Wave dynamics in exhaust systems can do funny things. Because of this I would suspect a leak or leaks is located upstream of the collector. Excess air in the exhaust would also explain the high AFR. Make sure you check around the O2 sensor for leaks especially if you did not replace the crush washer when swapping the sensor to the new exhaust and or did not torque it to spec.

2. Is your sensor heated? Is it still working properly?

Thank you. Order submitted.

I felt like a misfit in the CCA 20 years ago. The owners of new BMW's did not seem to want to be around people who had petrified grease under their fingernails and exhaust systems that where 10% Budweiser cans.