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Drive belt for oil pump


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Are there any dry sump owners on here who could help with my search for a drive belt for the oil pump for my 1980 Essex? Have already tried Lotus and SJ but no joy so far - any suggestions greatly appreciated as these appear to be harder to come by than hens teeth! 

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Because the pulley and belt combination would define the tension. The differences in belt lengths were likely too great to adjust the tension by the small amounts required, so a combination of the two

I had this chat with Gerald at GST he didn’t change my belt as it apparently is in great condition but I am pretty sure he knows where to find them or the equivalent. Give him a call (don’t email he d

Mate if Gerald says it ok that’s good enough for me. 

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I had this chat with Gerald at GST he didn’t change my belt as it apparently is in great condition but I am pretty sure he knows where to find them or the equivalent. Give him a call (don’t email he doesn’t do email) he is a lovely chap and I am sure he will help you if he can 

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Sj’s do a drive belt for the oil pump on a dry sump but it is only 1 size so might not fight some cars, but I’ve bought one for my dry sump and it’s the same size etc as the old one that came off so maybe order one and try it and see. 

IMG_2018.JPG

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Hi Tim - already tried the SJ belt and it doesn’t fit needless to say! 

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6 hours ago, JNW3 said:

Are there any dry sump owners on here who could help with my search for a drive belt for the oil pump for my 1980 Essex? Have already tried Lotus and SJ but no joy so far - any suggestions greatly appreciated as these appear to be harder to come by than hens teeth! 

Try an agri factors - any belt any size should be simple to acquire

 

https://www.bearingboys.co.uk/Transmissions-1001-c

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Only here once

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Thanks for the suggestions gents - the only issue we have is that the belt currently on the car is not an original Esprit part and doesn’t fit properly so can’t be copied frustratingly 

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In the topic "Essex 007" i read that the previous Australian owner installed an aftermarket tensioner years ago.Is it no longer present?

My engine is currently under rebuild and i bought the drive belt from "SJ" too.We will build an eccentric tensioner for the oil pump drive belt.This might be the best option for the future....

 

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Sorry I can't help you finding a belt but I do wonder why Lotus made different lengths and differing pulleys. Anyone know why this would be?

:) 

It's getting there......

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Hi Jonathan,

I'm currently removing my engine and here's what I have on my '81 dry sump. It's a powergrip 41060 16mm. Hope that helps. Hope your cambelt is better than mine! (There are splits all the way along the belt :cry:)

Cheers, Steve.

20171106_110924.jpg

20171106_110539.jpg

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On 04/11/2017 at 20:11, TAR said:

Sorry I can't help you finding a belt but I do wonder why Lotus made different lengths and differing pulleys. Anyone know why this would be?

:) 

Because there is no tensioner, so they had to select exactly the required size for proper tension. If someone has found a way to add a tensioner that would be good but it needs to be a 100% reliable setup owing to the disaster if the belt comes off!

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1 hour ago, Andyww said:

Because there is no tensioner, so they had to select exactly the required size for proper tension. If someone has found a way to add a tensioner that would be good but it needs to be a 100% reliable setup owing to the disaster if the belt comes off!

I,ll take some pictures (and a short video) when my engine is ready and post them in the "restoration" section.We would like to use the eccentric tensioner and bearing from Lotus and fit (maybe machining)them to the A/C compressor bracket which is mounted at the bottom of the sump.So its the same bearing as for the automatic cam belt tensioner.It will most probably still take some time until the engine is ready.I hope before Christmas.

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3 hours ago, Andyww said:

Because there is no tensioner, so they had to select exactly the required size for proper tension. If someone has found a way to add a tensioner that would be good but it needs to be a 100% reliable setup owing to the disaster if the belt comes off!

That doesn't make sense. as both the oil pump pulley and the crankshaft pulley are fixed so the belt would be the same for all cars. Lotus did belts that were both plus and minus sizes and they also supplied oil pump pulleys with differing numbers of teeth (differing circumference). Why bother with all that complexity?

:) 

It's getting there......

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9 hours ago, TAR said:

That doesn't make sense. as both the oil pump pulley and the crankshaft pulley are fixed so the belt would be the same for all cars. Lotus did belts that were both plus and minus sizes and they also supplied oil pump pulleys with differing numbers of teeth (differing circumference). Why bother with all that complexity?

:) 

Tolerances. The oil pump is a bolt-on unit so its own mounting face machining tolerance, the face on the scavenge manifold, and on the main bearing housing would all affect tension as would gasket/sealant thickness. 

Its very likely that Tony Rudd didnt design it to use selected belt lengths but they likely found in production they needs to select the belts. 

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so I'm happy with the explanation for the belts but why the differing pulleys? With various belts surely you wouldn't need a selection of pulleys?

13 hours ago, Andyww said:

Tolerances.

:) 

It's getting there......

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Because the pulley and belt combination would define the tension. The differences in belt lengths were likely too great to adjust the tension by the small amounts required, so a combination of the two changes, pulley and belt had to be used.

Not at all an ideal situation for a production environment! This kind of thing would be OK for an F1 engine. Incidentally the dry-sump system is very similar to that of race engines such as the Cosworth DFV. I am not sure how many other road cars have ever used a design such as this. The Ferrari 308 early cars had so-called dry sump which were not actually dry sump at all. They still had a full sump wheras the Esprit has no sump at all.

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Hi Jonathan,

I follow this with interest as I salvaged a dry sump motor from an insurance write-off Turbo which I happened upon by chance. It is to find a new life in the bay of my S2, now in the long grind of total restoration. As to belt tension I believe the guiding principle in this is to think of a cog belt as something of a flexible gear train, or chain drive if you prefer. Slippage is not to be abided under any circumstance so it should never be run loose. I have been told that the backwards bend arising out of use of a tensioner is contrary to belt life, though designs of the sort are ubiquitous. Absent any sort of effective tensioner I would seek to set up the belt with a decidedly firm level of tension. Don't know how to quantify this but perhaps the old 45 degrees of twist by fingers at the limit of strength? Enormously powerful Harley-Davidson motorcycles often piloted by really large chaps are driven via cog belt, for those who may not have noticed.

 

Cheers

Steve

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