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Fifty50Plus · Posted: Wed Jul 26, 2023 6:44 am Post subject: Interesting Failure

I ran the race weekend at Summit Point this past weekend and discovered an interesting failure after qualifying and racing on Saturday. At impound, they asked that all engine lids be opened so that they could inspect for (???). I noticed that my engine was coated with oil and it was dripping on the ground under the car.
Back in my paddock space I discovered that the oil dipstick and the tube that it goes in were missing. Queries with officials and workers didn't produce the errant pieces. Now what to do?
During the race, every time I turned right, oil would come out of the block but not smoke since the header was on the other side of the engine. The back of the car had a fine coating of oil on it as well as the bottom of the car. Now my concern was how long the pieces were missing and how much oil had I lost? Worse, how do I determine how much to put back into the sump? I opted for two quarts.
I wasn't too worried about the engine bearings since I have an AccuSump and a total of 7 1/2 quarts of oil with no flucuation on my gauge during the race. I was able to stick a barbed brass piece of fuel line connector into the hole in the block with a couple feet of fuel line feeding as an overflow to a Miller LIte beer can (the go to fix for almost anything on a race car).
I ran the race on Sunday with no engine drama but discovered afterwards that the beer can was full of oil and a bit had started spilling out onto the engine. So maybe one quart would have been enough.
Now I have to cannibalize another block before the next race on Labor Day to get a workable dipstick. Like Rosanna Rosannadanna says..."You know, it's always something".
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1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car

peterld · Posted: Wed Jul 26, 2023 12:07 pm Post subject:

Had similar problems back in the day, though not the tube itself popping out, just the dipstick. After properly gluing the tube into the block, the dipstick is now fastened with a heavy spring back to the inlet manifold.
You must have some serious compression, or blowby to be ousting that little devil.

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80/81 932/8 ROW

Fifty50Plus · Posted: Thu Jul 27, 2023 4:18 am Post subject:

Compression is 11:1 on the new engine. I'm thinking vibration more than blowby to kick out the tube in the block. Otherwise the dipstick would have just risen up or been pooted out.
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1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car

daniel · Joined: 18 Jun 2009 Posts: 677 Location: Sydney, Australia

I put an O-ring on the top section of the dip stick that goes into the block - no problems. I am at 11.3:1
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Over the top of skyline, total brake failure.... hit the wall at over 200 kp/h at the dipper, so anyone who has to brake for the esses is a pussy.
1977.5 Race Car, CAMS Group S Spec
1989 944 Cabriolet

924RACR · Posted: Thu Jul 27, 2023 10:10 pm Post subject:

On our old IT engine builds, we'd had the dipstick popping up a bit and dribbling a little oil thanks to blowby. But that was with the style with the dipstick directly into the oil pan, not the later extension tube.

Haven't had any issues with the tube style, which is in the current Prod motor build, but we haven't raced it a huge amount. Headed to Waterford again today for testing, and racing this weekend, so we'll keep an eye on it!!
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Fifty50Plus · Posted: Fri Jul 28, 2023 6:47 am Post subject:

Thanks for the ideas...since I MacGuivered the car at the track and that part held, I might just go with a larger catch tank. I'll leave the AccuSump closed, drain the oil from the engine and put back in 3 1/2 quarts.
Otherwise, I "should" pull the pan and find a way to tap or screw in a new dipstick tube. And measure some other engines to ensure that I have the height correct for a new dipstick....
Hmmm...MacGuiver technology vs. tried and true engineering. What to do. What to do. If it was a customer engine I know the answer. BUT, do I feel lucky?
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1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car

MikeJinCO · Posted: Sun Jul 30, 2023 6:00 am Post subject:

I continually had oil leakage problems due to not having an extension also So my solution to not having the extension was make my own. When the block was clean I reinforced the area around the dipstick hole with some Kevlar composite fabric had and JB Weld(one of the few epoxies still happy at 250F), then tapped the hole for 1/8" pipe and put in a 2 or 3" extension. The 1/8" pipe is a perfect size for the dipstick. Then I just moved the dip stick cap the same amount. That block is still on an engine stand in the shop and destined for the scrap yard.
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Mike

'67 MG Midget Dp
'71 Ocelot Dsr Kawasaki 1000(under rebuild)

Fifty50Plus · Posted: Sun Jul 30, 2023 10:14 am Post subject:

Mike, Wow, another weird one. In 46 years of racing I've had some strange things happen but never had the dipstick pipe (and dipstick) disappear, usually a corner worker will retrieve the errant parts and they will make it back to my paddock at the end of the day. Not so lucky this time,
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1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car