It's always something

[yellowss7]

Took the Caterham to the track on Friday for a couple days on the track. After 14 years, about 60++ trackdays and 8 years of autoxing, I finally put new pads and front rotors on. :svengo: Funny thing is the pads still had plenty of life left in them. Gotta love light cars.

 

I knew that the pads needed to be bedded in, so I did a few 30 to zero stops in the paddock and went out in the first heat figuring I'd have a chance to do the 70 to 30 stops under the first lap yellow. Got in at the back of the pac and on the first straight got up to 70ish and hit the brakes. WHOA NELLY. Locked them up and had to hold on as the car made some wild gyrations. Did it again on the next two straights and had similar reactions. Pitted and joined the group at the back end again and did three more similar braking applications and it seemed to respond better.

 

Did the next session and all was good. Third session, the car wouldn't start. Seems that Alternator went tits up and drained the battery. Done for the day. :nopity: Charged it overnight and it started up and ran great for the session. Put it back on the charger and Nope it wouldn't start. Charged it again, and got another run in and called it a day. Felt good to get back on the track, and the car felt good and I got a good workout getting in and out with the new rollcage. Guess you got to take the good with the bad.

Tom

Edited April 19, 2014 by yellowss7

[xcarguy]

Tom,

 

I can relate. :iagree: And my latest “It’s Always Something’ had me stumped for a bit.

 

As you know, my March track day went well but revealed a slight on-track oil starvation issue that was in need of immediate resolve. This resulted in the immediate install of an Accusump system which, sans a leaky liquid-filled air pressure gauge that I opted to use in lieu of the Canton-supplied el-cheapo gauge, also went well. I ditched the liquid-filled unit and reinstalled the el-cheapo gauge . . . works great for reading the air-charge side of the accumulator. :iamwithstupid: The Accusump test hop resulted in the system working as advertised, but resulted in an intermittent, and finally, nonfunctioning oil pressure gauge about ten minutes into the drive. When the oil pressure gauge finally dropped to zero, I checked the Accusump air-charge pressure gauge and it showed 50 psi (engine oil pressure). The 20 psi low oil pressure warning light was also not illuminated. I pulled to the side of the road, de-energized the Accusump electric valve and turned off the car. I then powered up the car (not running) and energized the Accusump system. The accumulator pre-oiled the engine (accumulator air-charge gauge dropping to 10 psi), but still zero oil pressure. Once the accumulator emptied, I started the car and the accumulator immediately filled back to 50 psi. This was a definite indication that the engine had adequate (normal) oil pressure. I headed home and the gauge started working again, functioning flawlessly for the rest of the drive. Once home, I shut the car and off and then did a restart; no oil pressure on the gauge.

 

Now, at this point, I’m thinking either bad gauge or bad ground, but I was a bit puzzled by all because I made no mods to the gauge during the Accusump install. However, I was of the mindset that this was too coincidental to not be related because both the gauge and the light functioned normally prior to the install. I started trouble shooting connections with a test light which revealed that I was getting power to both the oil pressure gauge and the low oil pressure warning light. But testing with the ‘test’ light also revealed that I now had NO GROUND at the oil pressure sending unit or the oil pressure warning light sending unit. This made no sense; I had not changed ANY existing wiring for either of these.

 

Before, I finish my story, I need to provide a little car history and gauge insight. First, the Autometer gauges (all electric) currently installed in my car are the original gauges I purchased prior to selling the car in 2007. While I mocked up the dash layout for the gauges, I sold the car to Mike Sharkey before connecting any of them to the engine. When I bought the car back from Mike, the gauges were functioning as they should and all connections looked good. Second, the Autometer oil pressure gauge has a huge-a$$ sending unit that will not screw into the stock LS oil sending unit location on the side of the oil pan because of its (sending unit) size. Mike, during the LS install, replaced the stock LS oil pressure sending unit mount and bolted on an after-market Lingenfelter oil pressure adaptor. From this adaptor, Mike ran a -4AN SS braided line to a brass fitting into which both the low oil pressure warning light sensor and said huge-a$$ oil pressure sending unit are fitted. Back to the story.

 

Test light, power in, and NO GROUND; time for Autometer instructions and an ohm meter. Digging out the Autometer oil pressure gauge instructions (yep, I keep everything) revealed that, just as expected, the sending unit ‘ground’ through the threads on the unit itself; normal stuff. Touching one end of a piece of 18 gauge wire to the brass fitting mentioned earlier and the other end to the driver’s side aluminum foot well resulted in the gauge and the oil pressure light working normally; GROUND!!!! Removing the wire resulted in both ceasing to function. This still didn’t make any sense because the sending unit is housed in a metal clamp that is bolted directly to foot well and connecting one ohm meter probe to the threads on the sending unit and the other to the sending unit case revealed no resistance, thus sending unit case-connected-to-clamp-connected-to-aluminum foot well should produce a ground. I then removed the sending unit from the clamp and when I did I found a thin strip of self-fusing tape that Mike had used as a shim because the clamp was slightly oversized for the sending unit. I replaced the tape with a thin aluminum shim. This action resulted in an excellent grounds for both sending units. :party:

 

So, what happened? Prior to removing the after-market Lingenfelter oil pressure adaptor on the side of the LS pan, the sending units (light and gauge) were getting their grounds through the brass fitting-connected-to-the SS braided line-connected-to-the-oil pressure adaptor-connected-to-the-engine block-grounded-to-the-frame. The Accusump install I did required my removing the Lingfelter oil pressure adaptor and replacing it with an Improved Racing oil pressure adaptor. Connecting the -4 AN SS braided line to the new adaptor required my using a 1/8th NPT male to -4 AN male fitting. This was an existing fitting that had been used in the old adaptor, but I made sure the NPT end received a liberal amount of Teflon tape which, when installed in the new adaptor, broke the ground that was previously provided for the sending units. During the drive, the vibration of the oil pressure sending unit inside the loose fitting clamp was enough to cause an intermittent ground/no ground condition.

 

Tom, as you and I have both proven, any mod (be it roll cage, brake pads, Accusump, etc.) causes electrons to become confused and disoriented to the point of complete shutdown. I believe your alternator failure is directly related to your roll cage install and brake pad change. :smilielol5:

Edited April 20, 2014 by xcarguy

[yellowss7]

Sounds about right. Can't wait to see what changing over the front hubs and stub axles for the upgraded one will cause to fail. :svengo::toetap05:

[Kitcat]

Tom: Sounds like your trusty Rover engine made it thru w/o incident. That has to be a huge relief as you were concerned abt engine replacement at end of last year.

[yellowss7]

Hey Mike, I replaced the head gasket and followed all the steps recommended by Dave Andrews, the UK Kseries guru. Checked liner heights, Peened the fire rings, did a light skim, used new head bolts and the recommended gasket. Oh, and replaced the plastic locating dowels with the upgraded steel ones. Dave said those steps should ensure future reliability. Couldn't find any sign of a breach in the gasket, but Dave said that it's not always easy to spot. I was surprised that it still had the old style plastic dowels, but knock on wood, everything is good now.

 

The car ran great and coolant levels and temp were perfect.

 

I did buy a new Duratec on Ebay in the fall. Just trying to figure out what power level to take it to. I talked with Jon Nelson last week and he thought the 263hp R500 level was a good compromise. It's either around 225 with no bottom end work or whole hog is around 290-300hp. I picked up the Duratec because it was a great deal. Unfortunately, to switch to the duratec, it requires all new mounts, bellhousing, exhaust, clutch, TB's ECU, loom and ancilliaries, before I even think about internal work to get the big power. Just have to determine how much pain I want to endure trying to convince the wife I need to spend the bucks needed to do it right.

 

Luckily the current engine is running great, it's just not quite able to keep up with Blubarisax and Croc or the other Big Dogs on the track. Yesterdays frustration was the inability to hold off a GT2 Porsche on the track. Had him on the turns but he ran me down and over on the straights. Another 100hp would probably have help me. :jester: Happy Easter. Tom

[Kitcat]

Tom:

 

Just buy the R500 for sale in Ohio and be done with it:)!

[yellowss7]

Yeah, that's probably the smart move, but I've had the car for 14 years now. I built it and as you know it's been VERY reliable for all the years on track and autoxing. I have a special attachment to it. Plus I like Clams. :jester: So yeah, financially it's probably smarter, but not many have accused me of being smart. :svengo:

 

Tom

[HOTTTCAR]

Yesterdays frustration was the inability to hold off a GT2 Porsche on the track. Had him on the turns but he ran me down and over on the straights. Another 100hp would probably have help me. Happy Easter. Tom

 

Tom

Be careful....thoughts like that got me into a V8 Storker...... Not that I don' t love it.

Gale