Bad asparragus in South America

Eduardo et al,

I've now been to a mechanic who seems to have given me a believable reason for all the problems my engine's given me.

Nito Vargas in Rio Gallegos, Santa Cruz, Argentina said that my asparragus are not strong enough! As far as I understand him an esparragos in Spanish is one of those double ended bolts (I don't know the word in English) that holds the head on tightly(?). It seems that the asparragus that I have from the Huerfanos rebuild in Santiago don't behave well when hot, i.e. they extend. So the heads become loose making the valves badly adjusted and resulting in a loss of compression.

Has anybody else had problems with loose heads because of these screws? Nito suggested they need replacing to fix the problem, for the moment he readjusted the valves and tightened the heads up to 3 (I think the units are m kg) (he said the ones that weren't loose were already at 2.4). He also said I wouldn't find replacement asparragus in Punta Arenas, but that I would in Comodoro Rivadavia.

I'm thinking of driving down to Ushuaia, Punta Arenas, Puerto Natales, El Chalten and then to Comodoro Rivadavia, a distance of a few thousand kilometers partially on dirt road before fixing the problem. At least I know what it is now and I can deal with a loss of power as long as I can start the bus.

It seems the problem with starting the bus was partially that I was using too much choke and that the 3000 km of dirt road had clogged up the carburetor. I will see tomorrow morning whether she will start cold. I still have the liquid starter fluid just in case.

Now all that remains is to replace one of the shocks, buy three new tyres, weld the back bumper on and fix the lights!

Thanks all, especially Eduardo, for all your help,

John.

Reply to
John Reid
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the 'esparragos' are the head studs. they not normally stretch that much, but the thread in the engine case gets weak and the stud pulls out of its thread in the case when the engine gets hot...

Thats what I was trying you to tighten, but my explanation was not that good and you ended up tightening the rocker arm nuts :)

welcome to the club, heres one of mine when it pulled out.

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The proper fix is to get new studs and install 'case savers' in the head. You can get bronze ones in Chile for around US$1.50 each. They install in the case with a large drill (12mm or so) and a tap to make a larger, stonger thread. The head stud (esparrago) then threads into this case saver.

I dont think you will have much trouble. If Nito gave you a temp fix, you will most likely make it 1000kms if you dont overheat the engine...

Nice ! :)

the back bumper should be bolted on...

It has been a pleasure helping you. If you cant find the required parts in Comodoro Rivadavia (I doubt it, its not a small city) I can ship them from Chile. Shipping is cheap by bus and I can get a set of head studs (used but good) for around US$20.

Reply to
Eduardo Kaftanski

Careful. You are talking about "head studs". Head studs rarely are weak. But they can pull out of the crankcase when the engine is hot. Usually, when an engine is rebuilt, "case savers" are installed into the crankcase to prevent head studs from tearing out. It is VERY IMPORTANT not to over-tighten the head nuts because the heads were loose. This will cause the head studs to tear out even worse! Your heads should be tightened to 22 ft/lbs, I do not know the metric equivalent. If your head studs are the special ones that go skinny in the middle, they should be tightened to only 18 ft/lbs. I think. . . Other opinions, please . . . Colin

Reply to
Colin

What happens when they tear out? A loss of compression and power? The engine will fall apart?

1 pound per foot = 1.48819 kilo per meter

so I guess that

1 ft per pound = 1.0 / 1.48819 m per kg = 0.67196 m per kg

so 22 ft per lb = 14.8 m per kg

and 18 ft per lb = 12.1 m per kg

nowhere near 3. Anyone have any ideas what units 2.4 and 3 might be in?

Thanks for your help,

John.

Reply to
John Reid

THey normally pull out just enough to loosen compression but not enough to fall apart...

You are converting the units inverted...a footpound is one foot multiplied by one pound... to convert to mkg (meter kilogram) you need this:

1 feet pound = 0.3048 meter * 0.45 kilogram = 0.138 meter kilogram

Using that formula, 22 foot pound are 3.04 mkg... just what Nito torqued your head studs (which should be 10mm in a brazilian engine)

Reply to
Eduardo Kaftanski

Very nice conversion, Eduardo. Now why did they loosen? Usually it is not the stud or the nut that causes dropped torque. Usually it is pulled studs, meaning damaged threads in the case. Were they damaged before Nito got to them or after? Or, is there some collapse of soft head sealing rings like the Type 4 engines had? Colin

Reply to
Colin

The engine has to be partially dropped & dismantled to do this. I think the reason you are advised to follow the strict factory instructions on this is because if you do it right it should never be necessary to retorque them. Did you ever see or hear of a VW dealer doing this on new vehicle? No. I have never had to do it on any of my rebuilds.

Reply to
Oldbie

John's engine is a 1600 type 1 from brazil, rebuilt just before he left for a 3000 kilometer trip. 1000 kilometers were decent highway, the rest of it its mostly dirt and gravel roads. I hope its just a combination of not retorquing after the break in period and the violent shaking of the engine on those lousy roads....

To give you a picture of how bad the roads are, John lost the rear bumper, the exhaust, one shock absorber and several tires on that 2000 kilometers.

Reply to
Eduardo Kaftanski

I can give you a little history. We bought the bus with a reconditioned engine in Santiago 3 months and 5000 miles ago. After a

1000 miles there was a loss of power. We were told this was because of loose heads and badly adjusted valves. I guess the second is because of the first. Nito is the first mechanic that's retorqued the heads, several others have got us going again by readjusting the valves but leaving cylinders 1 and 3 low on compression. I 'd lay money on Nito having done a good job, I'm not an expert but I've seen plenty of South American mechanics and he knew what he was doing.

John.

Reply to
John Reid

Eduardo,

I think the quickest route here is indeed 3000 km, but we've taken a few detours and done over 8000 km since leaving Santiago. I'd guess somewhere up to 4000 km on gravel/dirt roads.

John.

Reply to
John Reid

It must have been an incredible trip... and you still have argentina and maybe brazil to go to....

Coming to Chile at the end?

Reply to
Eduardo Kaftanski

Yes almost definitely as if we don't return the car to Chile, customs will be on to us. I've heard I should be able to get a reasonable price for it in Paraguay though!

We're not 100% sure of the route yet but we'll probably be in Argentina for some time to come then Brasil briefly and lastly Bolivia and Chile down to Santiago.

I'll let you have pictures as when I can. Perhaps you can post them somewhere for RAMVA readers to see?

Regards,

John.

Reply to
John Reid

Paraguay is the Meca of car smugling down here... :)

You can send them to me. I already have a directory for your pictures up in my web server. I will send login information in case you want to upload them via 'scp' or something like that...

Reply to
Eduardo Kaftanski

If there are damaged threads in the case will it need replacing or rethreading?

I imagine they were damaged before Nito got to them.

John.

Reply to
John Reid

I expect that the newer Brazilian cases come with case-savers already installed. Perhaps not? Anyway, if the studs are pulling, you need case-savers. Colin

Reply to
Colin

The newer ones maybe... but I dont think they do.

Reply to
Eduardo Kaftanski

You can install 'case savers' or 'insertos' in spanish. Bronze or steel thread replacements. Case should be reusable.

Reply to
Eduardo Kaftanski

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