1. Lotsokids

    Lotsokids Loyal Comrade

    My Trabi started making some squealing noises after driving about 3 miles home. In my driveway (thankfully), it stalled and would not turn over. I pulled the heads and cylinders off (what a simple engine). I discovered that the right connecting rod was seized onto the crankshaft. Note the photo, red circle is where the rod is seized.

    This was my daily driver. Now I'm riding the motorcycle until I get a solution. I'm looking at two options:
    1. Bring the car in and have a mechanic repair it
    2. Look for a Trabi 1.1 engine + drivetrain to swap into it.
    [​IMG]
  2. Keri

    Keri Leader

    Far better to find either a rebuilt crankshaft or complete motor.
    A 1.1 conversion would be extremely involved.
  3. mbeamish

    mbeamish Loyal Comrade

    All the usual suppliers sell recon crank assemblies this will be easiest . Shipping won't be cheap though. Rebuilding the engine is very very easy compared to a 'normal' engine. Remove pistons, unbolt flywheel, split case, remove old crank assembly, put in new crank and thats it. Except keep everything clean as possible and a trace of hylomar or similar on crankcase halves when reassembling.
    Last edited: Jan 26, 2014
  4. Lotsokids

    Lotsokids Loyal Comrade

    Really? I thought just unbolt my entire front end and bolt up a 1.1 assembly (engine, transmission, axles, wheels... everything). Fuel tank may be a problem, but unsure where a 1.1 carburetor is located.
  5. mbeamish

    mbeamish Loyal Comrade

    The 1.1 uses completely different front suspension i reckon inner wings firewall etc are different it is probably possible but won't be easy or cheap.Gear shift is on floor as well it really won't be easy
    Fitting a new crank is very quick and easy .Most of your time will be cleaning off oil and muck the actual building will be quick
    Last edited: Jan 26, 2014
  6. Wartburg353W

    Wartburg353W Loyal Comrade

    Swap motors with another 2-stroke that'd be easiest. Don't you have a parts car? You can rebuild that one at your leisure and keep a spare.
  7. Lotsokids

    Lotsokids Loyal Comrade

    No, they hauled it away. Besides, that would be MUCH more difficult with the bureaucratic registration procedures here in Hungary. It was required that the engine stay in the car when I disposed of it. Otherwise MUCH more paperwork, office visits, etc. Very painful. Plus it was a Fiat engine mated to a Trabant transmission. There was a lot of alteration.

    The most important thing to know is how it could seize like that? I properly mix the fuel and oil. Somehow it lost lubrication and I don't want this to happen again if I install new parts. Is the fuel/oil mix the only lubrication?
  8. Keri

    Keri Leader

    The fuel/oil mix is the only lubrication. It looks like it didn't do so good!
    The #1 rod is nearest the flywheel, so I would guess the crank seal on that side may have let in air and/or dirt.

    Which fuel and which oil were involved here?
  9. turbofiat124

    turbofiat124 Loyal Comrade

    That's ashame you had to let the Fiat motor conversion go with the car. Being a 20+ year Fiat enthusiast I would have loved to have had the adapter plate and whatever other custom made bits used to do the conversion. I've got enough Fiat/Yugo parts and 1.1 liter engines laying about to do a conversion myself.

    But most likely the Artic Cat 570 conversion I've mentioned would be my prefered swap if push comes to shove.
  10. Lotsokids

    Lotsokids Loyal Comrade

    Not sure what this question is. I have been mixing .5 liters of 2-stroke oil to about 22 liters of fuel. I was told today by an older Hungarian man that's not enough oil. He said I need to stay close to 1:30 ratio.
  11. Keri

    Keri Leader

    Sorry to hear of your motor trouble.

    I meant brand names and types.
    The ratio is important. 30:1 is a lot of oil unless you like plenty of smoke and more frequent disassembly and de-carboning.
    The old Trabi motors with bushings at the piston pin needed 33:1 fuel/oil mix. This was with the oil available at the time which was not as good as modern 2-cycle oils.
    For a motor with full needle bearings, 50:1 is adequate IF an appropriate oil formulated for use in air-cooled 2-cycle motors is used.
    40:1 is a good compromise for those that want extra oil without a lot more smoke and carbon.

    50:1 is .5 liter to 25 liters fuel. this corresponds to 2% oil / 98% fuel.

    .5 liter to 22 liters is 44:1 fuel/oil ratio, which should be plenty of oil…. if a suitable oil is being used!

    I have well over 40,000km of high-speed, full power driving on 50:1 ….
    on a secondhand, somewhat loose crankshaft, using modern semi-synthetic oil which seems very thin when poured.

    For your crank to have seized up like this, one of the following is likely:

    1- pre-existing wear, damage or modification to the crank or rod, like a substandard overhaul using Chinese drill bits for needle bearings

    2- unsuitable oil and/or fuel, like using non-detergent straight SAE 40 oil, gear oil, hydraulic oil or alcohol-blended fuel that has absorbed a lot of moisture

    3- ingress of dirt through the carburetor

    4- ingress of air and/or dirt from a damaged crankshaft seal


    Good luck with whatever you choose to do….
  12. Lotsokids

    Lotsokids Loyal Comrade

    Well I finally got all the parts I need for the rebuild. I removed and disassembled the engine and got a new crankshaft, connecting rods, piston rings, all seals and gaskets, timing plates, and clutch disk. It's going to be a challenge to put back together. I thought about paying a Hungarian to do it for me. Labor is cheap here, but I try to be fair. I'll probably give it a try first.
  13. Justin

    Justin Owner Administrator

    It's really pretty simple.....So simple you will think you're doing it wrong.

    Let us know what we can do to help.
    Lotsokids likes this.
  14. Bill Overbaugh

    Bill Overbaugh King Trabi Forum Donor

    Well, now I'm in the club. My engine seized today. I've put less than 40 km on it since I bought it. Bummer.
    Very strange, too... I poured 13 oz of 2-stroke air-cooled oil into the bottom of a 5 gallon gas can, put the can in my pickup, drove 30 miles, poured it in my car. I think my ratio was an accurate 50:1, and I think it mixed well.
    So all I can think is maybe I should have been 40:1. I see Keri's post that 40:1 is a bit more conservative, but it seems 50:1 should have been OK.
    Sometimes with 2 strokes, letting them cool down will free them up, so I'm going to try to crank it over tonight and see how it goes. I'll keep you up to date!
  15. Keri

    Keri Leader

    Odd.
    13 oz to 5 gallons should have been adequate. I perform no special mixing technique, just dump in the oil, and slosh the gas with the nozzle to mix. Usually, I run until I need 6 gallons, then pour in 16oz. oil to 6 gallons gas. I do not drive especially slowly or gently, either.

    On all motors, it is important to not "lug" the motor, that is to demand high power from it at low RPM. This is especially important on a 2-cycle motor with no oil pressure. I have had good success with keeping the RPM high enough for the load, generally I keep it well over 3,000 rpm for full throttle operation.

    I'm interested in hearing what brand oil and gas you used.

    Brands I've used in the last 41,000km:
    Gasoline: BP ultimate, BP regular, Mobil regular and most often, Citgo regular. In my area, all of these contain alcohol, except possible the BP Ultimate

    Oil: after overhaul 41,000km ago:
    Break-in (first 5,000km or so?) Pennzoil air-cooled 2-cycle oil (non-synthetic)
    ever since: Lucas Semi-Synthetic air cooled 2-cycle oil

    Oil: pre-overhaul, (over 41,000km ago)
    Red Line synthetic
    AMZOIL synthetic
    Pennzoil non-synthetic
    Pennzoil non-synthetic air-cooled
  16. Bill Overbaugh

    Bill Overbaugh King Trabi Forum Donor

    I ran Sunoco mid-grade (I think that was 93 Octane) with Lucas Semi-Synthetic air cooled 2-cycle oil.
    I think the problem wasn't the oil, it was me.
    I've been trying to figure out where to set the choke, and while I was driving, it coughed on me a couple times, so I played with the choke. It seized while I was doing that. I wonder if I choked it too much, and starved it for gas, and thus oil. It'd be the same effect as lugging it... high RPMs, no lubrication.
  17. Keri

    Keri Leader

    "Lugging" a motor can not be done at high RPM.
    This describes high-power low RPM operation, which can cause the oil layer between the connecting rod and crank to be squeezed out, causing metal-to-metal contact.
    Keeping the RPM high enough reduces this possibility. Of course, going too high with RPM can cause other problems.

    Applying choke should add more fuel/oil mix, not less.

    Way too much fuel could give you a hydraulic lock, but it's hard to imagine a choke doing that unless something is wrong with the carburetor.

    added: A classic example of "Lugging" a motor would be not downshifting for climbing a hill.
    Like, oh, say, doing 60km/h on a steep grade at full throttle in 4th gear. This condition is very hard on connecting rod bearings.
    Last edited: Mar 23, 2014
  18. Bill Overbaugh

    Bill Overbaugh King Trabi Forum Donor

    Huh... you're right. Now I'm really confused as to why/how it could have seized.
    I wish I could tear into the engine, but my mechanic dragged it back to his place, not mine, and I am babysitting my daughter today.
  19. Bill Overbaugh

    Bill Overbaugh King Trabi Forum Donor

    I tried cranking after letting the car sit overnight in the cold, but no go.
    So then I tore the engine apart. These are amazing little engines, you know? I had the cylinder heads off in 45 minutes. And that was because I was taking a ton of reference pictures the whole time. (Which was a waste of time, since my SD card was back home in my laptop. Doh!)
    I did not pull the cylinders off. I'll do that tomorrow.
    Weird thing is, everything looked totally fine to me, except an oil leak on each cylinder head, but those were not severe.
    I tried turning the engine over with the cylinder heads off to see if there was any movement at all. But I didn't have an assistant to watch while I did it, and it was hard to tell when I got back if it moved a couple millimeters or not.
    There was some carbon in the exhaust, and on the tops of the pistons and bottoms of the heads. But the carbon isn't too bad.
    The driver side cylinder (as I understand it this is #1) had some oil leaking to the rear of the cylinder. But it looked like an older leak
    The passenger side cylinder (#2 I think) had a slight leak on the front, leak the front driver's side bolt wasn't quite tight enough. But it too looked older, and it wasn't a big leak.
    These are insignificant, but the cooling tins were rubbing on the fan housing. I'll try to align it better when I put it together. And the cooling tins have three different bolts on them, washers were missing from one of the exhaust manifold bolts, there's a hole in the cooling tin, which had what looks like 3" or 4" of a caulk tube to direct the air. Also noticed a cracked cooling fin. Probably also not major, but it would reduce cooling. Hmmm.. and it was in the same place as the leak in #2 cylinder.
    #2 cylinder had some metal shavings in it, but I think this was just from some scraping when I pulled the heads off. I don't think this is serious.

    Questions - I assume like a VW, these cylinders and pistons are a mated pair. Are the heads also mated? Is there a left and a right? When I bolt everything back together, what do I torque them to? Erik Honnecker tight, or is there a specific spec? Is there a torque order, or just like the wheels, alternate and gradually even them out?

    More info tomorrow when I get the cylinders off.

    Attached Files:

    Last edited: Mar 23, 2014
  20. Keri

    Keri Leader

    Nice pictures

    Metal shavings = bad.

    Minor leaks, individual cracked fins, no big deal.

    The heads are interchangeable, the cylinders are not.

    There is a left and a right cylinder. The pistons are fitted to the cylinder, but so are the ones on most other cars.
    Best to keep the piston with it's cylinder, but eh, nothing a decent machinist can't figure out.

    The connecting rod bearings at the piston end should be kept with the rod it came off of. The fit of this bearing is pretty precise.

    The cylinders remove like a Beetle. You will probably find the lower rod bearing seized on the side that had metal shavings, though it might be something else.

    When re-assembling, there is a specific torque and sequence for best results. In particular, the exhaust manifold should be mounted before the cylinder base nuts are tightened.
    Details are in this forum somewhere.

Share This Page