&8 SC fule problem at the track (longish)

[GaryR]

Just got home from a dissapointing two days at the NNJR Summit Point DE. My 78 SC with stock fuel system and stock 3.0 was running perfectly, then a couple oddball things happened. On my 2nd run group my oil breather popped off and spewed a little oil into the reaf of the engine compartment and onto the right header, causing smoke and a black flag. Apparently the hose clamp wasn't put back on (it was loosely laying down on the other end of the breather hose) when the engine was removed to replace the tranny (I'm assuming it was removed anyway, as my mechanic said it was his fault)... Annnnyyyway, put that back on, brake-cleaned her all up, and the next run no more smoke.Ran perfect for about 4 laps (8+ miles) and then a large loss of power, wouldn't rev much past 4000. Came in, checked all connections, fuel level, oil, (new) gas cap for vacuum when removed, etc. Tried it again, exact same thing, crappy running after about 4 laps. Kept messing with it all day (blew out the fuel filter along the way) and always the same problem. Brought it to a local shop last night and he put a new fuel filter in, drained the tank, cleaned the screen, flushed the tank a couple times, and reassembled. He had no fuel pump but didn't think that was it anyway. Today first run, exact same results.. It's going into the shop tomorrow but just wanted to hear if anyone has seen this problem before?

Thanks!

[Eagledriver]

Just something to look into. The early SCs had a problem on the track of not properly scavenging oil from the crankcase. Symptoms were loss of power and overheating. The crankcase would fill with oil only on the track and then would scavenge when driven normally or idling.

Don't know if this is your problem. The solution is a later style sump screen and updated pressure relief spring.

-Andy

[Jim Smolka]

A couple of things come to mind (scary)

There should be a screen at the bottom of gas tank.

Coil going bad. Works fine cold, but then heats up...

[GaryR]

Thanks guys.

Andy - My guy here in CT made mention of the scavenging problem and will most likely address that but the car has been a "track-only" ride for about 20 DE days, this is the 1st problem i've had. The temp got up to about 2/3 on the guage and never higher, but that may be due to the fact I only dove about 8-10 miles each run...

Jim - The screen in the fuel tank sump was removed and while there was a little bit of dissolved gunk fuel still flowed quite freely from the line to the fuel pump. The tank was flushed a couple times until the fuel had no residue but I had the same result the next day.

I think that the car is used to running Limerock and Summit had too many left turnns for her!!

[sfoster13]

Do you have a Perma Tune box by any chance?

[GaryR]

No, all stock parts..

[304065]

Gary,

I have to confess that I don't have ANY CIS kung fu whatsoever. However, checking the fuel pump is easy enough. In the little white spec book (or somewhere in the Pelican archives) you can find the fuel delivery rate which is measured in cc's per 30 seconds or some such. Convert that to Imperial Gallons per decade or empty milk cartons per commercial break or whatever convenient measurement works for you and test it by pulling off the fuel line and having a helper turn on the key. Of course, you should wear one of those silver asbestos suits and have a couple hundred gallons of AFFF foam handy anytime you work with the fuel system, lest you be a modern interpretation of the Blue Oyster Cult video. Anyway, that will tell you whether the fuel pump comes up to spec.

Stepping back from the physical for a moment let's think about what the car is really trying to tell you. The car is really trying to say, "Listen Jocko, while it is a well known fact that my fuel tank has been shown in factory crash tests to be compressible to half its volume before the seam splits, what I would really like is an ATL 17 gallon fuel cell with an integral "black box" with an inexpensive Walbro fuel pump and the most expensive fuel pressure regulator you can buy. I realize that this and the associated aeroquip plumbing are a couple thousand bucks, but it's justifiable insofar as it's really SAFETY equipment that makes you go fast too."

Good luck! Isn't it fun to have THREE left turns instead of only ONE?

[GaryR]

Hehehe... don't worry John, a new fuel cell and delivery system is coming soon. And yes, I was starting to enjoy the rythem of that track and my car was handling perfectly even with the wet conditions (aren't Hoosier Wets great!). It's amazing what a looming mechanical problem can do to your concentration though, always waiting for the car to sputter out every turn killed the whole DE.. what REALLY sucked was that I left after 1 (4 lap) run the 2nd (DRY) day.

[GaryR]

Well.... the fix is when an oil breather line pops off be SURE you put it back on where it belongs!!! There is a plastic fitting on the bottom of the air cleaner box sticking out, VERY invitingly, and THAT is where the breather line lined up with and fit on like a glove. BIG DUH. Problem was the breather line goes to a fitting behind the oil tank fill neck!! I effectively BLOCKED the breather and after 5 minutes or so was pressurizing my crankcase.. not a good thing to do. Amazingly I didn't do any damage, blow any seals, or anything else. I had my original stock 915 rebuilt and a new LSD put in and they even checked my RMS for any seepage, all A-OK.. To think I had a shop look at it at Summit, SHOWED them the line I replaced and they didn't catch it. At least I have a clean tank and new fuel filter!!

On to WGI 6/7-6/8!!