Friday, August 13, 2010

Purrs like a kitten

Since the head gasket looked like it was about to blow through again, I took the engine completely apart. I then took the block in to have it decked flat. It wasn't far off, but I was going to make sure that block wasn't going to be an issue. Since the head had been rubbed on extensively by Verne Colvin of BRE history, the compression was already high. I had the machine shop check it and we couldn't see light between it and a stright edge.

Then it was down to reassembly, which I thought was pretty straight forward. And yes, I put everything back where it came from (rods, valves, pistons, bearings, etc.). Although I did fix the maxed out dizzy advance by putting it in one gear back as it should have been before. This would give me more adjustability.

Refilled fluids and cranked the engine for 20 seconds to build oil pressure. Plugged the coil in and hit the starter. It started right up and purred like never before. A slight tweak of the timing and carbs settings and it was running smooth and had quick throttle response.

There's a race this weekend so I packed her up and dropper her at the track so as to have a good pit and pit layout. AND, it's supposed to be 100degrees Saturday. O joy!!!

I will update with details of how she runs. Wish us luck.

Engine Tear-down

After the lousy engine performance at ORP, I felt there was nothing to lose by tearing apart the engine to get to the root of the problem. Taking the head off revealed the effects of the unstable timing, carbs challenges, and eminent head gasket failure.

It didn't take long to locate the root cause of the poor performance. Removing the timing cover this time revealed heavy gouge marks. Not only was the cam gear grinding on the cover, but the timing chain was getting into the act too and over an 1/8" of the reinforcing rib on the inside was ground away. "Why?", I asked.

I took hold of the cam gear and the whole cam shaft would move in and out of the block some .130". I'm no pro engine builder with countless builds under my belt, but even I could see that that wasn't right. Since there's a helical gear on the shaft that drives the distributor, it was easy to understand why the timing wouldn't remain stable.

Some more disassembly revealed that the woodruff key was forced out the back of the slot when the cam gear was jammed on. This kept the cam gear from bearing against the block as it should. Thus, the shaft would slide in and out at random, and take the distributor setting with it. Flat on the ground without load, the engine would time and run well. Race it up or down a hill, and it would crap out.

And now, the train wreck picture show......

Woodruff key jammed half way out of the slot

Should the side of the cam bearing be ground into like this? I doubt it.

Another angle. And pistons 3/4.

Pistons 1 and 2

Another head gasket for the trash. And the buildup on the valve area.

Sunday, August 8, 2010

Oregon Raceway Park June 18-20

The engine wasn't right, obviously. It had a knock in the front of the engine since the day the engine builder did the initial run-in of the new build. $1500 and a whole race season lost netted me a rebuilt engine with no power and an ominous knock. Gee, thanks man! I was determined to race this year and wasn't in any hurry to give up. I ran the engine once out of shear frustration with having missed the year before. The knock didn't improve or worsen. I figured a rebuild was the worst I would have to face and was rolling the dice.

I spent time after that last race to go over the car and look for what might be causing the lack of power and the odd knocking that had been present at the front of the engine since I got it back from the engine builder.

I ran a compression check and one cylinder was higher than the rest by 30psi. Loss of compression is one thing, but increased compression? What the hell? I had the carbs running both even and balanced. Timing seemed stable. Valves were adjusted and checked at the track last time. Just the knock, compression imbalance and lack of power. I took off the bottom end and checked everything I could see. I took off the timing cover and checked the chain and tensioner. All looked fine. I decided to forego the PIR race and get ready for the very fun ORP races.

I started a new job on 6/1, but was sure to arrange being off Friday the 18th for the HDPE at ORP to test the car before the race. All I needed was the car to be right.

I asked a new friend from the track to come by and look over the car and help me see the problem that the car had... I couldn't see the problem having stared and prodded over it for so long. The extra set of eyes, and more importantly experience, would be a great help.

After messing with the timing it didn't seem to improve anything. He called his friend and we came to the conclusion it had to be the valves. We rechecked them, and sure enough, one was very loose. We readjusted it, checked the compression, and all 4 were spot on. Yeah!

I'm going to ORP.

Grass Valley- Still No Power

The excitement of the first race in Grass valley's new Oregon Raceway Park was the most anticipated race of the schedule for me. I headed out for the 3 hour drive to SouthEast of the Dalles. Got there at Friday after the drivers training had completed. Unfortunately, the other drivers had anticipated the race as well and parking was at a premium by the time I arrived. I dropped the trailer and car off in my assigned paddock space and found myself a camping spot 1/8-1/4 mile away down a gravel road.

I learned that in Eastern Oregon it gets pretty cold at night. Being in the high plains with the 30mph winds got things quite chilly. It carried into the morning. Sweatshirts under jackets with a head cover was necessary all day. The car wasn't quite running right, but I sensed it was all a function of the carbs needing adjusted.

The first run was frustrating in that I had almost no power up the hills. But, the car did run and the track was a blast.

The organizers see to it that the Novices get screwed on run times. We're the last before lunch (practice), a mandatory lunch meeting and the first run ("quals") after lunch. Since the car ran like crap, I had no time to work on it between runs. I skipped the quals to save what I did have in a car for the race. After all, it is my 4ht year trying to get through the novice program.

The race saw me run dead last with the car having almost no power to pull up the many hills of the course. But, I did get another race logged. YEAH!!!

Friday, April 30, 2010

Rose City Opener 4/24-25

First race of the year and I'm back in the pits trying for another year to complete a Novice License attempt. What is it now, 3-4 years??!?! Aaargh.

But first...Drama!

On Wednesday the 21st, I find myself still chasing an electrical demon that won't allow the car to run well. If the Field is plugged into the alternator, the car runs awful (ammeter pegs at 30). I ran the HPDE without it, so I knew I had a back-up for the weekend.

But, me and my infinite wisdom, I choose to totally, yes totally, rewire the car. New fuse block, master switch, fuel switch, wires, connections. I'm going to root out this problem and fix some other troubling items in the process. Also, I'll have a wiring diagram to work with as a result.

In 6 hours, everything was rewired and the master/kill/alternator combo was per the kill switch wiring guide (Longacre). But, it failed. Connecting the Field wire on the alternator quickly bogs the motor down. More on that later. Because I had a race to go to.

Car is "ready" with 100LL in the tank to avoid pinging, engine recently rebuilt and Accusump accumulator primed with 2qts of 40psi Mobile 1 synthetic oil. Car is purring like a kitten, warmed up and ready. I'm now strapped in, Hans, arm restraints, and the other usual accouterments. Mirrors adjusted, time to head to grid. "10 minutes early guys!" the Novice director says. So I'm there, midway down the grid, Miatas everywhere like locust. A few Pro3 BMWs and a couple REALLY fast stock cars and GTIs.

5 minute warning. The sun disappears behind a dark, very dark cloud.

1 Minute warning, car starts right up and the drops begin to fall. We head out. By lap 3, the rain is pouring. The only sollace is that everything from my neck down seems to be in the dry (speed good!). But there's no grip on my older, hard near-treadless Advans. The high speed turns are treacherous. 50 MPH sideways is thrilling, but not when the front straight wall is coming at you.

Three more laps and the water is getting deeper on the track. I pull into the hot pits because I don't want to crash me or hold up the others. "I'm waiting to see if it lets up!", I tell the pit steward. "Only 2 minutes left in session!", he yells over the remaining cars going by. So I return to my spot in the pits (under my nice new canopy I got for last year's attempt).

Hour later and the sun has returned, track is dry. "Qualifying" run goes well, but the engine won't rev past 6k and full throttle seems to bog down the engine as the session goes on. But, no oil leaks, pinging, blown head gaskets. Even the brakes are much better. I'll race today!

Race was at 4:30ish. The car ran the whole 30 minute session without major issue. Yes, I finished dead last, but I have not overdriven the car and saved hurting it in the process. I pull into the pits, shut the car down, and a wave of emotion comes over me. I sit there for 5 minutes, just realizing that the car and I finally made it through a complete Practice, qualifying and race set.

FINALLY! And I'm spent. Mentally spent. I check in with the race director 20 minutes later, and there's no issues with me from the Senior drivers reviewing the Novice Race. Job well done.

Time to pack up and go home.


Tuesday, April 20, 2010

She's ALIVE !

New year with new expectations of finally keeping things together to complete the Novice Racing Program with Cascade Sports Car Club. We (car and me) ran all 4 sessions of the first High Performance Drivers Education (HPDE) on March 20th. Weather was perfect ! Yeah! And in Oregon even!

More on the run day in a bit, because there has to be drama with this car first, right!?!?!?!

During the engine initial start-up, after it's total rebuild, the thing wouldn't really run well. The builder tried everything he could think of. After an hour of futzing and frustration, I noticed the Ammeter was pegged to one side. The builder unplugged the alternator and instantly things were running better.

There was/is also a strange knocking noise that seems to emanate from around the water pump. It does not sound healthy (or death eminent). It didn't get worse or better and the engine guy said he didn't know what it was and that it was at my risk to run it. Un-belting the water-pump as a test didn't fix the knock.

Being fed up with missing the entire race season last year waiting for my engine to be rebuilt, waiting a month and a half to start the car up (bye-bye dyno time), I wasn't about to jump on his suggestion to pull the engine and pulling it apart (we'll see if that turns out to be a bad decision). I had planned on start-up since early February when it was reassembled, but the builder was booked. Now it was the Tuesday before the run and I was seeing red mist!

Screw it! I'm running on battery only and damn the knock!

Saturday morning arrived and it was chilly, but sunny. Wife, kid and good friend Steve came by to over-see the melee around lunch time. Wife took pics, kid had lunch in the hammock in the trailer and Steve thoughtfully ensured I got my harness belts on properly (among other little but crucial details).

The 2 morning runs were great. I took it easy and felt the car out, slowly increasing engine speeds and turn loading. Things were all right!

Car ran well, albeit it ran battery only (aka a "total loss")...meaning w/o an alternator. But, I had a nagging problem with the car not wanting to rev past 5300RPM. Oh well, I was getting seat time and I could fix that later. Smooth first, speed later. Brakes too were finally working well ! Yeah!

The after lunch session was good with the family taking smug pictures. Last session of the day I had some 1-year old 100LL fuel to use up. I put it in, cranked the carb needles to be more rich, and headed out. By the third turn though, knocking was creeping in and I know how quick that will blow things on this motor. I up-shifted to 4th to lower the revs and puttered in. Too bad it pings only when the engine is loaded up. A dyno tuning session would have helped mitigate that kind of adjustment need.
I figured I had had a good day, and it was time to thank the car by letting her off easy. That, and I know not to push my luck too much.

So, in the following weeks, I have time to address some issues before the Rose City Opener on April 24th!

Meanwhile, some pics from the day.

Monday, February 8, 2010

Since I changed over to a 5-speed, I needed a 5-speed cross-member to mount the transmission onto.

The 5-speed XM is shorter (1-5/8" vs. 2-13/16" tall) and moves the transmission bolt mounting holes aft (about 11/16").

The tranny mount is in front of the X in the vehicle frame, thus the shorter of the trapezoid sides is aft. Note that the transmission mount is also different for a 4-speed to a 5-speed.