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Cambelt replacement


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Im currently replacing the belts on my 96 V8. There is more room than I thought so removal of all necessary parts has been quite straight forward by just laying on top of the engine. 👍

My only problem so far is that my Crankshaft pulley has no markings against any of the 4 vanes? One vane did have some evidence of possibly some yellow paint on it. 

Anyway I locked the crank at all vane positions and the tolerance pins only went in at one position. On the 2nd go around I might add, starting at the 'yellow' vane.

Im assuming that the pins only go in at one position 10 deg BTDC (firing) No2 Cylinder.  Does anyone know if this is correct?  Im pretty sure but want to double check before continuing.

Cheers

Andy

 

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Yes.  The camshaft drillings are all made with that one reference to 10deg BTDC #2 cylinder (firing).

The TV Damper should have a marking on the side corresondining to that.  It may have been missing on very early cars, but I can#t say that I've seen one without it.

Note: that the crank needs to be turned twice for one complete revolution of the engine (half-speed idler)

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1996 Esprit V8, 1998 Esprit V8 GT, 1999 Esprit S350 #002 (Esprit GT1 replica project), 1996 Esprit V8 GT1 (chassis 114-001), 1992 Lotus Omega (927E), 1999 Esprit V8SE, 1999 Esprit S350 #032, 1995 Esprit S4s, 1999 Esprit V8 GT (ex-5th Gear project), 1999 Esprit V8SE ('02 rear)

1999 S350 #002 Esprit GT1 replica

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Definitely no mark?

The other engine I have  is marked as in your picture.

I read that some early engines have two drillings of the camshafts one at 10deg BTDC #2 cylinder and the other at 10deg BTDC #1 cylinder!

I did two rotations and the pins only went in once out of the 8 options!!

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Then you have your answer 🙂

Now you know the reference point, make your crank position pointer and you are on your way.

1996 Esprit V8, 1998 Esprit V8 GT, 1999 Esprit S350 #002 (Esprit GT1 replica project), 1996 Esprit V8 GT1 (chassis 114-001), 1992 Lotus Omega (927E), 1999 Esprit V8SE, 1999 Esprit S350 #032, 1995 Esprit S4s, 1999 Esprit V8 GT (ex-5th Gear project), 1999 Esprit V8SE ('02 rear)

1999 S350 #002 Esprit GT1 replica

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Thanks Mike. 
I found some time this morning to replace the belts. I did another check of the timing position, the pins only go in one time out of eight possible positions. My unmarked pulley/ damper is now marked!

Belts are replaced now and timing still good after 2 rotations of the crank. I just have to check and adjust the tension now. A bit fed up of turning the crank over so I’ll do it another day. Belt tensioner and  idler pulley bearings are good. Auxiliary belt tensioner pulley is a bit wobbly so will order a new one. (30,000 miles).

For anyone doing this job the hardest thing is probably turning the crank over. Maybe combine it with a spark plug change😂

Also, buy the timing pins and crank locking tool. I wouldn’t mess around with drill bits. With the proper pins you know when they’ve gone in properly. Well worth the money £130 from PNM. I made a tensioning tool. 
 

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Good stuff.  It's definately not a job to rush.

I dug out the images showing the comparison between the Clavis and the software app.   I remember that I did source a decent low frequency microphone for this.

DSCF0016.thumb.JPG.47639bfbc8d4df9d25a6e64cc665c9ef.JPG

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DSCF0022.thumb.JPG.e8e9fa5502ec116af3359f333985fc2d.JPG

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1996 Esprit V8, 1998 Esprit V8 GT, 1999 Esprit S350 #002 (Esprit GT1 replica project), 1996 Esprit V8 GT1 (chassis 114-001), 1992 Lotus Omega (927E), 1999 Esprit V8SE, 1999 Esprit S350 #032, 1995 Esprit S4s, 1999 Esprit V8 GT (ex-5th Gear project), 1999 Esprit V8SE ('02 rear)

1999 S350 #002 Esprit GT1 replica

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Thanks Mike. I wonder why the clavis gauges are so expensive I have £20 guitar tuner which is obviously bang on. I guess the proper automotive gauges are lot more robust and no so much in demand.

Anyway, I got round to tensioning the belts today. It took 3 or 4 goes, just a case of getting to know what is needed adjustment wise. Again turning the crank twice every time is a pain with the engine in the car. I found his easier from underneath. 

I have one question, after adjusting the tension and then rotating the crank twice to get it back to the correct checking position I get 130Hz. If I then give the belt a twist/pull it reads a lower amount, say 100Hz. If the crank is then rotated a further 2 times were back to 130HZ. I'm assuming that the belt tension is checked while in tension from the said rotations, not in a "relaxed" state. In the same position. ?

 

 

 

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Yes, agreed turning the engine from underneath is easier.  Popping up and down is a bit tedious. I've experienced dependable readings with changes but manually playing with the belt will affect the frequency reading.

The tensioning positions and values for new belts were re-specified in a Service Bulletin in mid-1999.

Bulletin-Tension.jpg.553100709168fb244270edf04018c9f5.jpg

1996 Esprit V8, 1998 Esprit V8 GT, 1999 Esprit S350 #002 (Esprit GT1 replica project), 1996 Esprit V8 GT1 (chassis 114-001), 1992 Lotus Omega (927E), 1999 Esprit V8SE, 1999 Esprit S350 #032, 1995 Esprit S4s, 1999 Esprit V8 GT (ex-5th Gear project), 1999 Esprit V8SE ('02 rear)

1999 S350 #002 Esprit GT1 replica

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So I tripled checked the tension. I got 122 Hz on the left bank and decided to try to match it to the 130Hz I have on the right bank. Suppose to be 120-135Hz on new belts. Anyway I spent ages adjusting it and settled back on 122 in the end! It’s tricky adjusting the tension and tightening the bolt. I’ve gained plenty of experience of what’s required to increase or decrease tension. 
I don’t know why I didn’t do it myself before. 


The car starts and runs at idle. I haven’t road tested it because I’m waiting for a new auxiliary belt and pulley. 

For anyone planning to do this job the adjustment of the tensioner is tricky and turning the crank is a bit hard work. Not difficult just tricky because of access. It would be very straightforward with the engine out of the car.  
 

I did notice that center section of the plastic belt covers has split where the metal tubes are inserted , these are where the retaining bolts go through. The metal tubes have corroded and split the plastic. Which is a shame. I have another one and that is similar, not quite as bad. I’ll probably replace it next time. Unless I find a way to repair it in the next 4 years 😂

 

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