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A good arguement for using Mobil 1

PostPosted: Sun Mar 27, 2005 5:17 pm
by MVZ944T
Early in the second run session at Fontana, I picked off a succesion of cones coming out of the last turn onto the straight. Not thinking it had done any damage, I continued around the course, pretty well tapped out in 5th. When I braked to turn into turn 3 I was getting some smoke in the cockpit. I thought I had picked up a traffic cone, so I kept running all the way around the back side of the track between turns 3 and 4. At that point, I found out I had a small oil fire and shut down. :(

After being towed back to the pit area, I checked out the damage and found that the cones had pushed in the splitter and pushed the lower radiator hose off, dumping all the water probably instantly. As I had turned the boost up, I had been watching the boost gauge for a reading, and not looking at the water or oil temp. :?

Consequently I cracked the head, so I was done for the weekend for sure. Also, I could not find the source of the oil, so that was a major worry.

I wound up taking the car back to the previous owner as he had built the engine originally and I was confident that he could do a good job on a rebuild. We went down to Huntington Beach yesterday to pick up the car, minus engine. Steve had the engine out and torn down. What we found was: main bearings and crank, perfect condition. Pistons, rods, bearings, virtually perfect. I had recently had a compression test done and at that time all cylinders were 125lbs. One sleeve had a very minor scratch up the side. The # 2 sleeve which is the trouble spot on 944's, was perfect. The interior of the engine was in amazingly good shape. So the extent of the repairs minus some upgrades will be a new head with porting and machining costs.

Now keep in mind, Steve had last had the bottom end apart when he first purchased the car in 1992. He figures that he had at least 15k race miles on the engine, prior to my purchase. Most of his race miles he ran with 20lbs of boost, which equates to 365hp at the rear wheels on this car on a 2.5ltr 4 banger. The original engine had 50K on it. I guess that I have probably 4-5K miles on the car since I purchased it, lately runnig 15lbs boost. Included in that have been a number of over rev's on missed and too early down shift's ( I am getting better).

So, is the cost of replacing the oil after every run weekend with Mobil 1 worth it. I would have to say yes. Also, is the 944 2.5 lter engine a solid engineering achievement. I would also have to say yes! :lol:

PostPosted: Fri Apr 01, 2005 12:16 pm
by TheStig
IMO I think almost all of Porsche's bottoms are sound. Usually issues with motors have been with headstuds, guides, chain tensioners, and timing belts.

I've only heard of few occurrences where some people have spun bearings severely on 944s and 928s. Usually it was due to a history of beating that motor to a pulp :shock:

PostPosted: Fri Apr 01, 2005 7:12 pm
by MVZ944T
Stig,

Do you have a new yellow Lotus? License plate says "thestig"? The engine on my car may not have been beat, but 20k race miles, driven hard, most at 20lbs of boost, I would say is pretty hard use.

Mike VZ

PostPosted: Fri Apr 01, 2005 8:07 pm
by pdy
I can echo the benefits of synthetic. My 924 Turbo track car went
through several meltdowns, rebuilds, warped heads, disintegrated
pistons, etc. I never had to replace the snail. I attribute this
success to using Mobil-1, changing it fairly often, and idling the car
for a few minutes to cool the turbocharger's bearings.

My '86 930 had 103k miles on it when I sold it. It still had the
original turbocharger. These cars are notorious for eating snails,
sometimes needing them every 15-30k. Same maintenence,
same oil, same result. Synthetic just holds up better under heat.

My 2 ยข

Paul.

PostPosted: Fri Apr 01, 2005 10:32 pm
by harnishclan
I was thinking about this post while paying $34.00 to buy enough Mobil1 to change the oil in my truck yesterday.

PostPosted: Fri Apr 01, 2005 11:50 pm
by TheStig
MVZ944T wrote:Stig,

Do you have a new yellow Lotus? License plate says "thestig"? The engine on my car may not have been beat, but 20k race miles, driven hard, most at 20lbs of boost, I would say is pretty hard use.

Mike VZ


not that I know of, just 2 Porsches :P I don't think I'd buy a Lotus, but I love 'em!

PostPosted: Sat Apr 02, 2005 9:18 am
by Tim Comeau
Synthetics are the way to go, aren't they? :wink:
I've had great performance in terms of oil temp and pressure with Liqui-Moly oil for the last 2 race seasons. Last year, that included four 3-hour enduros. The Molybdenum Disulphide molecules help even more to keep the viscosity stable under high racing temps.
Great stuff.