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Alex's v8 re-build thread warning pic whore inside >:)


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Yes buddsy I have only done one side but if I can't get oe stuff then they will be different and no good I'm sure lotus graded there pistons so I have to find the same or I'll have to do all 8 regardless and all 32 valves instead of just 16

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Hi Alex, good to see you are getting stuck in - good luck! You said you require a new clutch, FYI; I bought one from GTO Engineering - still expensive but much cheaper than from Lotus. Not sure if you have a clutch alignment tool? I used a gearbox input shaft - also from GTO - you can borrow it if you need - no worries. 

 

Cheers

 

Julian

Esprit SE-V8

TVR Cerbera V8 4.5

Range Rover V8

Jaguar XJR

Suzuki GSXR1100

Honda CR500R Red Rocket

ZIP 250 Racing Kart

VW Golf GTi

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Well buddsy the pistons are just stamped but the problem is the turbos the engine runs hot so marks on the pistons would mean hot spots and eventually holes so no point might as well do a proper job .

Thanks for info Julian I have a clutch tool but what was the price I've seen sj do updated one for 900

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Hi Alex, that's £100 less than what I paid for so good price. Mine wasn't exchange thou... I still have the old unit.

Cheers

Esprit SE-V8

TVR Cerbera V8 4.5

Range Rover V8

Jaguar XJR

Suzuki GSXR1100

Honda CR500R Red Rocket

ZIP 250 Racing Kart

VW Golf GTi

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This is the problem buddsy do I hunt for four originals which I'm guessing will be like hens teeth or do I just do all 8 for some forged ones valves aren't so much of a problem those can be made .

Thanks for the comment wilf glad your enjoying it . I'm hoping if anything else I supply amusement for people's coffee break :)

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You forgot merry Christmas :-). Made me chuckle but perhaps you should both take a step back. Good thread Alex and Gunter you have some good suggestions but if Alex doesn't want to listen then so be it.

Trevor.

I'll get around to it at some point.

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Hi all, just had a read through this and gonna have my little say...

I happen to know Alex personally and very well and also know his car very well....i also happen to have been 5ft from the rear bumper when the belt let go but thats another story all together....lol

I also happen to be a motorcycle mechanic so used to dealing with complex engines and have built a race bike or 3 in my time.

Now with regard to some of the issues stated about the rebuild of the engine, there will be no messing about, if it needs to be done it will be, there will be NO CUTTING valve guides off(i mean really who even thought of that anyway)

The engine failed due to a component failing with no prior warning and had unfortunately mangled the r/h bank and thus caused a large head ache for Alex and a potentially very large bill for the repair.

The head will be crack tested and then have new guides fitted one once valves are obtained they will be cut and lapped in correctly, pistons will be replaced for oe quality and spec and if they are not available then Aftermarket will be fitted to all 8 cylinders

Big end shells will be checked and replaced if any signs of wear are noticed, rods will be checked for trueness and then checked for balance and any signs of heat damage or hot spots and then all this will be assembled correctly using where neseccery the correct LOTUS tooling...

As mentioned earlier there has been talk of removing and refitting the liners and if this is done it will be done once the head is fully assembled and all parts are ready to be fitted so the heads can be bolted down to ensure the liners are pressed fully home and to allow the fitting glue to distribute evenly around the base before curing...

A few other bits and bobs including several critical bearings will be changed as well so once done the engine will be pretty much a fresh rebuild, bringing it unto the same spec as the rest of the car.

Its also going to have the hydraulic lifters checked, cleaned in a sonic bath and then all rechecked for pressure holding and oil capillary blockages...

Now although this is a real PITA that it happened in the first place i personally feel that the engine rebuild will mean Alex has a Lovely Esprite that will last him a very long time of pretty much niggle free driving pleasure....

 

Anyway just thought id drop this into the thread lol, I'm actually looking forward to the rebuild and to see in it back out on the road where sit belongs.....

 

Gav

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:thumbsup: I can only echo what buddsy has said. 

 

I,ve met Alex at castle coombe and you come across as being a nice guy, whilst I haven't met Gunter in person I've spoken to several people who have and likewise they all say he is a nice guy!. Due to the language barrier it just doesn't appear that way when reading his written text at times :turned:  I too have been on the receiving end of gunters input and I just take from it the useful information I can use.

 

I think its widely recognised amongst us v8 owners that two of the most knowledgeable guys on here are Gunter & Mike Sekinger (although Mike is having a sabbatical) so lets go easy on the one remaining fountain of information.  I think (although I could be wrong) that gunter is always looking for other alternative sources of components for our cars/engines either due to cost or availability of said items, which I don't see as bodging as long as the replacements are up to the spec, after all our cars are mostly built from other manfacturers parts bins!!

 

I think as stated everyone needs to take a chill pill, if either of you guys don't like what is written in a post then just ignore it

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I like of course if someone does his homework in general on those cars we like ..and as such I would help him with the offer for some 'factory-packed' new valves left over.  

 

On the other hand there still is the cheaper option to simply fit a different arrangement with an other match (from different OEM source) - I mean a usable match out of valve-guide/valve stem dimension, as the catalogs from Mahle and other part manufacturers are full of it. http://www.motorenteile.mahle.com/product_catalog/modules/motorComponent/specs/index.xhtml?subId=10

..it just needs to find the right size that fits into the valve seat with the same valve diameter and a valve guide who fits into the bore there in the head.  Lotus themselves have enginerd the 918engine with GM parts, as we can see on the followers/ hydraulic tappets ..so the workshop book refers on a specific position for the valve guides to be inserted, just to protect the upper arrangement out of follower and spring and still offer sufficient lift on the cam lobe -so from the engineering point of view it is not said that it will not be allowed to use different & shorter valve guides (or simply cut the now broken open portion off, the one that sits in the intake / exhaust ports an is in reality just a point where it minimizes air flow ..with other words to port the heads now as those are already off in the moment -see Mike S. engine modifications as example)

 

*ps @ Gavin:  ..think you and me, we both knwo that one of the aims of a valve guide is the heat transfer into the head, and of course a long valveguide without material surrounding  can't transfer heat into "nothing"   ..that's why I mention to simply grind the remained portion off, in a way that all is smooth again  

 

..same is for the "damaged" pistons   --my engine was in most of its years in use with petrol and E85mixtures, as some of you know, and in his first life in the prior owners hands the engine suffered from one of those 'factory concept' faults on the intermediate drive bold there.

Long story short -the crowns of several pistons showed old contact marks from this older engine failure and small cracks there, as I opened the engine to rebuild it partly 2008/9 (as it failed on my timing belt problem years later). So the factory 'cast' pistons are not that bad, at least good enough to let the engine run within factory boost range, even if there is sometimes a hot combustion situation in place (as for lean mixtures on fuel experiments) .

 

This means:

..from the cost factor -in Alex situation I would think about an slight sanding on the damaged portions, and use those OEM pistons for a ceramic coating

..as those are named as the "softer" ones, those would benefit from the protective coating, right ? ..and as the pistons are still the not so critical ones on points of thermal expansion and sizing in the liners (compared with what is said about the available aftermarket forged versions) it is a good option to -compared especially with the money for forged ones with an additional coating ..?!  

..we even could see how many 'good ones' from the cast OEM I have left over from my rebuild, as in the end I used the full set out of new liners & pistons to replace my worn and allrady rebored liners (the factory offered only full sets of liner& piston those days there as replacement..) .  My engine was fitted with *B -class size pistons  ..if this is a match to your liners, Alex ?

 

 

more options - replacement with special fabrication (made out of forged 'pre-modelled' pistons)

http://www.wahl-spezialkolben.de/index.php/de/produkte

 

As far as I know -SWLC (south-west-lotus-centre *the lotus cdentre) still does have a full set of forged pistons available, not something I would cal a 'cheap option' ..but available directly in UK now

Edited by Buddsy

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to name the things if I see them, that's what I call integrity..

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on the point of *clutch problem*

 

The DIY aligment tool I mentiond (and used) ..an other broomstick thing, ou know  ..is maybe not anyones way to go.

 

-but there is at least the *Helix sport* clutch package on the market, different in some details to the Lotus AP setup ..but think this should be a cheaper option for an replacement (in relation, at least..) 

 

AP -replacement friction plates cost around 140 GBP per item  ( have got some from Steve, SJ-sportscars in 2012, he was very fast & good on delivery arrangement)

 

Helix-sport version of those plates cost nearly the same, as single plates .. http://www.motorsport-tools.com/helix-lotus-esprit-35-v8-competition-twin-plate-clutch-rigid-plate-1.html

 

 

..of course, Alex ..this time please give it a go -with my mentioned note from the workshopbook, about the machining on the flywheel and (!) mounting face for the cage

Edited by Günter

*********************************************************************

to name the things if I see them, that's what I call integrity..

*********************************************************************

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Every valve guide needs to be fitted in a specific position -seen in relation to the way of movement the cam-follower/ tapped and the valve stem does make. In simple words the valve guide needs to be fitted deep enough into the head (viewed from top of the head) -deep enough, so that in all cases of wear & tear and expansions the cam lobe can still push the valve, with all the parts in contact, can push it into the int/ex. port/combustion chamber -without contacting the top end of the valve guide.

Mention there a small pieces attached to the steps, on top end of the valve-stem.. locking the valve-spring/upper plate in place ...and also the cam follower with his inner hydraulic part does have a own dimension -this all needs space too.

 

So if you design an engine it is cost wise not good to make the valve guides as short as possible, only to let it look good.

-the guide of course not only "guides" the stem,  there is also a heat transfer going on steady .. but this transfer only works if the material of the valve guide does have the head material (the alloy) surrounding him, you understand what I mean ?

 

*if someone is up to smoothen out/port the head -[blue] it would be an option to even smoothen out the sharp broken sections of the exposed guides [read]  ..some engines run this way, and as I recall correctly Mike had choosen for one of the customer rebuilds to port those channels there on one of the 918 this way too intakeport.jpg

 

..so as engineer you would chose the next available (and cost effective) length that still matches your material specification from the blue-prints. What causes on the other hand that there are in most times remains left over, viewable on the side in the port  ..a notable portion of the valve guide is exposed in the intake/exhaust ports.  This exposed portion, in case of a sintered material mix [as it is on our 918 engines] is prone to braking off, on side loads -those side loads happen with bend valve stems .. just as you can see on Alex pictures - clear ? ;)

 

..I too have pictures of the exposed portion from a valve-guide, from one of my heads -this is a normal process within the actual design so far

Edited by Günter

*********************************************************************

to name the things if I see them, that's what I call integrity..

*********************************************************************

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Looks like I'm strolling down the vauxhall route I'm guessing c20let engine or xe turbo something of other which would be nice a set of four forged ones for 400 so times 2 would be acceptable , valves , guides and seals look quite common and easier to find

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Have you tried Ferrari piston services? They are a supplier not the car company.

Amateurs built the Ark

Professionals built the Titanic

"I haven't ridden in cars pulled by cows before" "Bullocks, Mr.Belcher" "No, I haven't, honestly"

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  • 2 weeks later...
..there is a mounting point for an automatic tensioner, with a positioning hole in the cast structure -but for some reasons the development team changed its mind -who knows why :/
 
The early V8 engines did have dynamic tensioners. Not sure at what point the change to static tensioners was made, maybe it coincided with the change from the 107 tooth timing belt.
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Does anyone have the toothed flywheel locking tool for the bell housing i need to undo the crank pullie and intermediate pullie without breaking the engine . I've tried a snap on battery gun and no movement . I'm guessing it will either need a big bar or a friends got a half inch air gun nick named Bertha ...... but i need a proper method to stop the rotation

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if your engine is on the ground.. Put your flywheel bolts partially on and put a large wrench over one bolt and lever it against the bolt next to it. This will give you the necessary leverage you will need (you should have someone holding the engine from falling over) to undo the main crank pulley bolt.

Modifying esprit's.. now that's fun..

PS... I AM NOT A CERTIFIED MECHANIC.. I Have chosen to help those in need, in the past and must not be construed as being a certified technician.

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Machine mart do a electric 1/2" rattle gun which will knock off the hub nuts  with the hubs / shafts already detached from the car. Its a Clarke cew1000 £68 or less on a vat free day.  

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@Alex:  ..the 'bar / lever' method to lock the flywheel is the best and effective one (so no risk to damage the ring-gear there on the flywheel with any improvisations that go wrong..)   If you have the gearbox off you can also use the rear mounting bolds there in the engine block as a rest, and fit a srewdriver in the clutch-cage mounting points. Same is if you manage to undo at least one of the flywheel bolts first, use this point and simply fit a bar between one of this holes and one of the rear engine/clutch housing mounting points

 

@Buddsy:  ..on the point of 'valve guides'  ..sure, the stem is supported by the guide, as the word says ..but I think it is enough that the valve guides supports it with his upper & middle portion (the one above the head cast and the one pressed into the alloy)  ..those remained around 4mm there in the intake/exhaust ports are there for the reason that the next available valve-guide size in the market was just this long. And if I'm wrong on it ..after now allready 10 years out of production -I think it would be allowed to get some development background information on it from Brian, so we could ask him ..dont you think ?

..one complication of course is the material specification, as the workshopbook/production documentation notes 'special made' valve stem material that is more heat resistant if I read it right ..so maybe that is why the stems on the 918 engine can be so small and light, think the traditional sodium filled ones are normally heavier and bigger. The valve guides are specified as we can see as a 'sintered' type, but that is mostly good from point of fabrication tolerances and the effect of mixing materials that do not form an traditional alloy in other ways of production technics ..and of course sintered mixtures have the benefit to be good carriers for lubrication, as you can store oil in the structure.  From the replacement cost factor, and as most of our cars are not driven like professional racecars, I think it would also be possible to fit an cheaper (and therefore more traditional) arrangement with simple bronce valve guides and other valves.

 

@sailorbob:   ...not sure that the fault there on the engine from Alex was the same that forced Lotus engineering to change from the smaller idlers and shorter 107tooth belt to the now 'common' arrangement in the 918 line.

 

For me it looks more like a last minute cost factor problem in the supplier line, or something with 'short call' changes in the development early on production start. As none has ever mentioned so far an serious number of faults on the 107tooth layout, or customer claims that would have caused something like this change in the V8 Esprit history.

Whereas on the other hand we all have read about liners & Loctide vs. Hylomar,  and the belt tension recall/ service note story about the change in tension setup within the later production life of the 918 engine, and also have experienced or read the reports about failed intermediate shaft bolts, or for example the factory assisted change to an different clutch system.

 

The workshopbook illustration there clearly shows it with automatic tensioners, right ..but that is maybe just an old illustration reused out of a early development document ??

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to name the things if I see them, that's what I call integrity..

*********************************************************************

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In an Esprit service notes document I have that's dated 09/05/96 it contains details of both the dynamic and static tensioners in Section ED. There is also an engine parts function list that gives the tensioner part number as B918W0297 (it doesn't give the 'supply route' letter) so the 'modification identifier' is one letter earlier than the current part number.

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