jorj7

OK, here is the "Race" video from the 2013 NORC. Of course, it doesn't have any footage of the race, so you'll just have to imagine that part.


Don't know why it's showing up twice....


George
90 S4 Grand Prix White (Murf #5)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com

jorj7

I was playing with the GPS logs and tracking it on Google. Here's an interesting image of the Radar Straight with the gps log overlaid. 200 mph average for 8.4 miles and 2 1/2 minutes.



George
90 S4 Grand Prix White (Murf #5)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com

IcemanG17

what happened to the "go fast" part of the video?

hacker-pschorr

Wide open throttle for 2 1/2 minutes under boost with a well bult stock 5 liter 928 engine at over 200mph.

No rod bearing issues (with stock bearings) no oil consumption issues (without any scrapers or extra oil pumps).

I don't think enough people fully appreciate how significant this is.

On top of that averaging 170mph for a full 100 miles.

Well done!!!!

jorj7

As I mentioned early on, there was some difficulty at the starting line. The Supersports were being called up to the starting line when the race was Red Flagged. A local in a 4x4 had ignored the course workers and driven onto the road while the 100 mph class was running. Of course, this stopped the race, they sent out the Sheriff to catch the guy, while the spotter plane flew overhead. The guy eventually got the idea it wasn't cool to be on the course and drove off into the desert. After 45 minutes the cars on the road were restarted (from check point 3 or 6). Then they decided the Supersports could go. We were still struggling to get suited up when they called us up to the starting line. I asked on of the yellow vested starting line guys to turn on the video cameras, since we were strapped in and couldn't reach the cameras. He started yelling for the camera guy to come and help (I guess he could hit the record button by himself). In the mean time Frank, the race director, yells "Send the next car if they aren't ready". So we didn't get any video of the run...

George
90 S4 Grand Prix White (Murf #5)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com

jorj7

Thanks for being the team cheerleader Erik. It's nice to be appreciated.

By the truth is, the race is only 90 miles, and the engine has a few "trick" parts like a Taylor drilled crank (thanks to Adam B. for donating the crank) and Jim's modified main bearings. The rods and pistons are stock '88, as are the cams. The heads, valves, springs are R2 from my original 90 S4. I do have the 928 Int'l oil filler baffle plate, as well as 4 cam cover breather ports and 2 breather ports that I added to the oil fill spout. I did loose 1 1/4 quarts of oil on this run, and I found most of it in the Oil Separator/catch cans off the oil fill spout.





So, you could say it's stock parts, just a mix of years and a couple of modifications. Jim did a great job assembling this mongrel, and I'm glad it's done so well.

George
90 S4 Grand Prix White (Murf #5)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com

Rob Edwards

I am suddenly wondering what Porsche was thinking with the 3-way 'Y' hose that comes off the driver's side top of the stock S4+ filler neck (and also drains fuel vapor)- Yes, it's a small orifice from the driver's side of the filler neck, and it's at the highest point in the filler neck, but jeez, if you can move more than a quart of oil out the filler neck in 30 (40?) minutes of admittedly very high rpm operation, any long 30-40 second freeway blast in a stock motor without a fancy filler neck baffle has got to be sending some oil directly into the lower plenum via the Y hose, in addition to that pushed into the MAF elbow....

Admittedly, George has two big-bore IV's in the jugulars of the filler neck, so it's a low-resistance circuit to bleed off oil, but the stock 'Y' hose must contribute something to oil consumption. Why's it necessary?

jorj7

Rob,

It would be nice if I could drain the oil back into the oil pan after going through the oil separator.
Or just stop that much oil from reaching the ports at the top of the oil filler spout. That way I
don't have to worry about running low of oil at the end of the run.


George
90 S4 Grand Prix White (Murf #5)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com

James Bailey

[QUOTE=jorj7;10500065]Rob,

It would be nice if I could drain the oil back into the oil pan after going through the oil separator.
Or just stop that much oil from reaching the ports at the top of the oil filler spout. That way I
don't have to worry about running low of oil at the end of the run.


The problem being positive crankcase pressure might just reverse the flow in the "drain" adding more oil to the separator. Also have to wonder how much oil is trapped in your heads and how low the oil level really is in the crankcase as you near the end of the high speed portion.... Great run, very impressive speed, well done . !!

Bill Ball

Despite a lot of hard driving on streets and highways my car never lost any oil between yearly changes UNTIL I went open road racing. Cruising at 160+ for miles and averaging 145 MPH over all caused me to spit out about 1.5 qts of oil in 90 miles. When I routed the breather lines away from intake to catch cans, I found all the oil came from the filler neck. Same thing happened when I installed the supercharger and went a bit faster. George's findings are consistent with the same source.

The filler neck sits right over the front crank throw and the oil pressure relief valve return port in the block (which splashes down on the crank). George is losing oil despite Mark Anderson's filler neck baffle. The baffle just can't stop the huge volume of oil-laden blowby. We need to deal with the blowby and/or somehow channel the oil pressure valve return away from the front end of the crank. [Ignore greyed out text.]

Speedtoys

[quote=James Bailey;10500220]I wondered the same..solution..the drain tube sits below the oil level in the sump...then case pressure cant blow up it.

Bill Ball

Since George doesn't take his foot off the pedal for 90 miles, no drain back into the pan is feasible until the end of the race. A one-way valve would prevent the reverse flow and I think drain backs have incorporated that.

ptuomov

Do you have a photo of the hole from which the oil pump pressure relief valve sprays the oil onto the crank? I coudn't quite figure out where that was whne I had a bare block in my hands. Looking at the one bare block ('89), all my tracing efforts just made it look like the oil was bypassed to the suction side without going back to the sump. Obviously, I just didn't figure it out. But if you or anyone has a picture of the exact hole from which the bypassed oil sprays, I'd love to see it.

ptuomov

I wouldn't discount the importance of the special piston ring pack and proper etching of the bore before installing them. Since blowby is by far the biggest cause of oil ejection, the fact that you don't have it before 6000 rpm is a huge deal.

Jim Morton

I am not sure that George or Bill would recall the ring pack used as no one else was around when I was installing the rings on the pistons and pistons/rings to the bores.

Also, fitting the used crank / rods took a lot of bearing sorting. I used three different boxes of rod bearings and a couple of different main / thrust pairs to get clearances where I wanted them. Many feel you can simply "slap" these pieces together... I've never subscribed to that. Heck, getting the bores ready to seat new rings is quite a few hours of work... that is if you want to best assure that the rings will break in and not pass bunches of blow by.... :^)

Seeing this engine make several ORR passes without any bottom end / valve work is pretty darn cool !