Lotus Elan

Crankshaft pulley

PostPost by: stuartgb100 » Wed Apr 04, 2007 5:02 pm

Whilst adjusting the timing, I found that the bolt securing the pulley to the front of the crankshaft is loose.

Before launching into this (and bearing in mind that the engine is in the car) has anyone a method for torquing the bolt up ?

Regards,
Stuart.
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PostPost by: carrierdave » Wed Apr 04, 2007 6:59 pm

Hi Stuart,
Two options - First try putting the car in first gear and then torque the bolt up. If this doesn't work then take out the starter motor and try holding the flywheel ring gear with a screw driver to stop it turning.

Personally if you have good compression then the first one should work fine.

good luck

Dave
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PostPost by: john.p.clegg » Wed Apr 04, 2007 8:08 pm

Maybe a little better than putting it in first is putting it in reverse and applying the brakes (handbrake if yours works)....

John :wink:
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PostPost by: denicholls2 » Fri Apr 06, 2007 7:15 pm

I'm not intimately familiar with the Twink's pulley and chain drive setup (don't have one yet), but a loose crank bolt can cause other hidden problems that may be costly if you don't address them before they bite.

My Fiat 124 came to me this way. The pulley tightened against the cam drive sprocket and kept it from wiggling on the crank. When loose the pulley fretted against the Woodruff key, which fretted out the key slot. If I'd just tightened the bolt, I figure within a thousand miles or so I'd have been looking at a lot of bent valves with a very long face. :cry: The parts were VERY worn. Car had a total of 40,000 miles at the time.

If the Twink is similar, you need to check the condition of the key and keyway before reassembling.
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PostPost by: 1964 S1 » Sat Apr 07, 2007 1:54 am

Fiat? Lotus.
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PostPost by: garyeanderson » Sat Apr 07, 2007 10:22 am

A week ago Wednesday I was at my friend?s shop when some one brought in the engine from an Albatross (that?s a boat). The engine that was used was a 1216 cc Coventry Climax that was also used in the Lotus Elite. Anyhow we were looking at the parts and in a visual inspection of the crankshaft., He noticed that had been turned on the rods .040inch. He also noticed that the crank snout where the pulley goes for an automotive use (crankshaft was from a Lotus Elite) had been run many hours with a loose pulley bolt with the characteristic fretting. The words that came out of my friend were "time for a new crank".
Getting back to the twin cam, does the engine have the correct washer under the head of the bolt? It is a thick washer that is nearly 1/4 inch that prevents the head of the bolt from bending the washer thus appearing loose.


Gary
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PostPost by: stuartgb100 » Sat Apr 07, 2007 4:00 pm

Hi Gary,

Yes, the correct washer is in place.
A couple of weekends ago, I was checking valve clearances and then changing the shims. I reckon that rotating the crank sprocket with a spanner, caused the bolt to loosen. I therefore think it to be a recent problem.

Nevertheless will check for fretting.

Thanks all.

Regards,
Stuart.
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PostPost by: schroeder » Sun Apr 08, 2007 11:50 am

I was discussing replacing the bottom pulley with the engine in place with a very experienced engine builder earlier this week. He was keen to point out how important it was the the bolt was very tight. I suggested in gear parking brake (for what it is worth) on but he remained concerned.

His recommendation was a pneumatic wrench (like the tyre guys use). This will need the radiator etc off for access.

Stu
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PostPost by: john.p.clegg » Sun Apr 08, 2007 6:15 pm

Stu

Hate to raise my head above the parapet,but,the figure is 24-26 ft/lbs,and is you let any grease monkey with an air-wrench anywhere near it you'll be sorry....

John :wink:
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PostPost by: schroeder » Sun Apr 08, 2007 9:51 pm

John

Thanks for preventing a costly mistake.

Stu
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