1 (edited by m610 2017-07-29 06:32 PM)

Topic: The Tinyvette's Glitter Bomb.

(Also post on FB and Opel GT forum)

So much stuff was about the break. I'm glad that even under pressure we all took our time. The bases of the lifters were cracked. How the hell does that happen? The alternator bracket, the beefy one Alan reinforced, bent, cracked, and was about to fail completely.

With help from the whole team we took care of all this and on Friday got the engine in the car. It fired right up, cam run-in (new lifters) went well, follow-up valve adjustment, too. All going really great. Packing and final details took a while and we got to the track at 1 AM today (Saturday). Kurt drove the car the hour or so to the track while I followed with a trailer and tools. It was a perfect opportunity to see what we had before we started the race, plus Kurt has rarely had a chance to drive the Tinyvette.

By 7 AM were up up and at it again. Zep took the car through late-comer's tech himself and returned so we could take care of the few things left on our to-do list, such as wash the windshield. Really minor stuff. We had arrived ready to race.

Eric noticed a few drips of oil on the pavement so when Zep got back we investigated. For this race we had installed a new oil cooler and lines, and one fitting was loose. Dealing with that meant minor disassembly and reassembly so the hoses pointed in the right direction. The minor amount of oil spilled in the process went into a clean pan. When Kurt was done and I pulled the pan out from under the car I saw our fate. Glitter, just like in the previous engine. Damn.

Decision time. Do we race? Yes, we at least start the race. Zep has a good head for the condition of the car and what needs to be done so he'd take the first stint. While dressing we changed the oil and filter. While circulating, prior to the green, he noted the brakes were bad, pulled hard to one side, and was worse than the previous race. Convinced he had no brakes on the right front he brought it in. Our best guess was a crimped flexible hose, so I replaced it. Zep rejoined the race, already in progress, and the brakes were no different, and soon oil temps were over 240, then 250, with water temps around 210, higher than normal for us.

In the pits, Eric, Kurt and I discussed the situation, and now the question was, what were our goals for the weekend? We certainly would not be racing in any meaningful way. Zep said temps were manageable if he didn't rev past 5000 rpm. We told him to have fun, stay safe, and when he came in we'd put the car on the trailer. A couple of hours later we were packed and heading for home, having sold our unused 30 gallons of fuel to friends at Restart Racing.

This really, really, sucks. This is our third DNF in a row and for one reason or another for the past year+ we have been averaging almost an engine per race. The two recent DNFs were for broken stuff, a diff and a rod bolt. But the fate of the engine on the diff-weekend was the same as today. Postmortem indicated debris damage of the bearings and our best guess for the source was debris in the oil cooler. This time, with a new oil cooler and hoses, and me being really anal about cleanliness, we had the same result. (Assessment based on symptoms. Postmortem scheduled for tomorrow.)

So all that work and the weekends of four friends, down the tubes. Yes, I guess it is true what they say, that racing is the most heart-breaking sport around.

The other thing, what do I do now? That was my best effort and everything looked like it would be golden. Do I refresh this and build a third glitter bomb and get a fourth DNF in a row, 750 miles from home? I'm thinking of taking all my parts to the shop of a guy who has done our machining work and sit and watch him inspect the parts and put the engine together. I am obviously doing something wrong.

This really, really, sucks.


Re: The Tinyvette's Glitter Bomb.

Where is the oil bypass?

On a British A-series, there are 2: one in the block after the pump and before the filter (which dumps over-pressured oil back into the sump) and then there's a spring loaded ball check valve in the filter head that if there's enough of a pressure differential between the pre- and post- filter oil, it will open and allow unfiltered oil into oil galleries because the theory was that unfiltered oil is better than no oil.

Many modern filters have a filter bypass built into them, so that could mean a 3rd oil bypass in the system.

On the A-series, I have learned (the hard way) that the ballcheck valve in the filter head is crap. I now block them off with either removal and installing a grub screw or just JB-welding over it.

If you are allowing the machine shops to install your oil gallery plugs, DONT. Shops don't clean very well, I've found. Get the block back naked and install them yourself.

Also, check your crank oil galleries after a regrind..

And trust nobody. Plastigauge every journal on reassembly, at a minimum. Some people don't like using it and prefer using micrometers, but I'm happy with the ballpark I get from Plastigauge.

Consider having your cam and lifters sourced from the same place. Then, have one of the lifters tested for hardness. The new ones for the A-series have a very very bad reputation both for not being ground with the proper radius and for not having the proper hardness. I know Schneider Cams here in San Diego will refinish lifters and it actually costs more than buying new ones, but they are supposedly done properly.

Re: The Tinyvette's Glitter Bomb.

Thanks, Spank.

The timing chain cover includes the oil pump and oil filter connection, two bypasses that regulate the pressure and one that bypasses the filter. I've jammed one of the pressure-regulating bypasses closed and use only the one right at the oil pump. The one at the filter is normal.

I've had the plugs removed and tapped for pipe fittings. That way I can really clean all those passages, and I was really anal about cleaning them.

The cleaning procedure for the block starts with some Simple Green sprayed liberally on everything. I then go over all flat surfaces, especially those which have gasket sealer on them, with green scratch pads. When I have the big stuff off I use a garden hose to not only rinse the block in general but also the galleys, every orifice, being as thorough and aggressive as possible. I end up pretty wet myself at this point. I also shove bottle brushes in them to loosen up any stuck stuff. As soon as I am done with the water I hit it with air to dry everything as quickly as possible, including all tapped bolt holes, then I follow that immediately with a light spray of CRC 3-36 (like WD-40) to prevent further rust formation, being careful to not get any in the water passages. Finally I use paper towels moistened with CRC 3-36 to wipe the flat surfaces and cylinder walls and I use Q-tips to inspect/further clean the passages feeding the mains. When done everything goes into a clean garbage bag to protect it from dust and dirt while I work on other parts.

The procedure for the head is the same, although I do not remove the plugs in the lifter galley. I do go after it pretty hard with water and CRC 3-36 though.

The mains bearing caps get a similar treatment.

For the crank it gets soaked with CRC 3-36 then wiped clean. The oil passages get the bottle brush treatment followed by Q-tip cleaning/inspection.

This is a recent problem. I've built motors before that did not die this way. This is our eighth year of racing.


Re: The Tinyvette's Glitter Bomb.

So what has changed then, recently?

RE: Threaded oil passages: On the A-series, it is possible to thread them in too far and to block off or partially block off a galley.

5 (edited by Greg S 2017-07-30 07:23 PM)

Re: The Tinyvette's Glitter Bomb.

Some thoughts and questions:

I don't know your motor, my core experience is with building Alfa motors but.....

The bearings, do the mains and rods show an equal amount of damage? Also does the damage show up in a progressive way from the bearings closest to the oil pump?

Do you or can you spin the oil pump to prime the motor before you first fire it up. I do mine while its still on the engine stand. I use a short hose to complete the missing oil cooler.

Did you just add the oil cooler or did you always have one? Is it plumbed through a sandwich plate? I'd check that plumbing very thoroughly. You could detach the hose and spin the motor with the plugs out to check delivery volume.

I've seen Accusumps that have check valves in their plumbing that can cause an issue. (Spun a bearing due to swapped hoses)

Also there is a lot of misinformation about relief valves, people shim them to "raise" the oil pressure. It does nothing. Oil pressure is determined by bearing clearances, oil delivery volume and viscosity. The relief simply determines maximum oil pressure, usually only when the oil is cold so that at race temperatures the relief valve does nothing.

When I am building a motor I measure and record every dimension and record them. I also test and record the drag in inch pounds it takes to rotate a fresh motor lower end to have something to compare to and to make sure I don't have excessive drag

Also can you monitor oil pressure from more than 1 location? Choose a few that will show the pressure drop as the oil gets to its discharge points.

That's a good tip WRT to threading and using pipe plugs, its easy to block a oil passage inadvertently.

Meticulously examine how the oil circulates in your motor. Make sure that the bearing inserts have grooves and or holes in the correct location to let the oil pass on to the next distribution point. (say mains to rods) I've seen aftermarket bearings missing oil holes.

Get in the habit of cutting the oil filter and pulling apart the media looking at how much metal there is there. Race motors seem to always have some but you'll get a feeling for a baseline. You can use a magnet to see if your dealing with bearing metal or ferrous metal.

Lastly, it sucks to spend the time we spend building cars and engines etc. then have them fail and have to go home after all that expense an time. I've been there. Take some time and regroup and work through it  you'll get it.


1987 Alfa Milano (Bellissima since 2008), Lemons racing since 2008 Stafford Springs,  2nd overall 2011 NJMP, 4th at NHMS 2011, 2nd at Summit point 2011, Into the wall hard at Stafford Springs 2011, 2nd at Monticello 2013, 3rd at NHMS 2013, 2nd at NHMS 2016.

22,000 racing miles over 29 races in 10 years. Yes its the same motor. Tell me again how Alfas suck? Update: Big moneyshift = new motor

Re: The Tinyvette's Glitter Bomb.

The only thing that has changed is I finally thought I was doing this right. Earlier my problems had been due to being too cheap, using mismatched parts, and not getting a machinist involved. This time the big ends of the rods were correct, the crank, damaged in a previous race, reground, and the block got checked out. These old parts have a lot of history and I am learning the hard way to not assume the best case of any of them.

The last two motors can together really nicely. Everything was in spec, the crank turned nicely by hand, everything. They also ran strong and didn't leak anywhere, which is uncharacteristic of Opels. Alas, an hour later, we had glitter.

I have good oil pressure, and I do prime the system, pre-filling the oil cooler and filter, then cranking until I see oil coming up around the lifters.

My procedure is here: www.kstreetstudio.com/OMC/articles/Blitz-2017-02-Commissioning.pdf

One tip I got recently was that with the journal (bearing cap?) that holds the end-play bearing in snug but not torqued, I am supposed to wack the crank at both ends with a hammer to set the position of that journal. Not doing so will leave the bearing halves offset and the edges will get ground off, and with crap in the system the engine is doomed.


Re: The Tinyvette's Glitter Bomb.

What oil type and viscosity do you use?

What was the post mortem?

Re: The Tinyvette's Glitter Bomb.

I haven't taken the motor out yet. That will happen tomorrow.

Oil is Valvoline VR-1, 20-50 weight. We've used that oil since the beginning.