Esprit Turbo project car - part3 - the further continuation

[Lotusfab]

So just for interest this is what I found out. The crank shaft had grooves up to 7.5 thou. It was standard before so easy to grind to 10 thou. Piston were OK, the reason my measurements were out of spec was the temperature I measured them at. Its normal to have slight scoring on one side of the thrust face. The rings I was using, although new, were really poor. The oil control ring design was floored scraping too much oil off the liner. They were 4 mm rings and difficult to get. Bespoke ones could be made. Best solution switch to Mahle pistons with new rings. I managed to get a good used set of these pistons. They are forged and much stronger and durable. They can sustain a slight overboost without melting, should the wastegate foul. The con rods were already superior HC with a cut out to splash more oil into the barrels. All of the bearings need replacing. The flywheel bolts were stretched and are all being replaced. The liners had scoring and were out of spec.i wont be installing the new ones  - this will be done professionally. Im getting rid of the adjustable tensioner and putting a fixed one on - thats about it for the bottom end bar the astronomical bill! Hard to believe its costing so much even though I have done all the work. It so far has  consumed five years of hard work and the cost is approaching that of an Essex. You see many of these cars that look just as good as this for less than half the price. The difference is this car will be just as good underneath. With effectiveky a brand new head and bottom end Im hoping to cover at least 60k miles without issue - but then agian it is a Lotus! 😄😄😄😄😄😄 So will I be driving it by the end of march? 

[andydclements]

As you are going with the fixed tensioner, I'd recommend the later shape belt and pulleys, as they are not as prone to wear & slip. Lotus moved (back) to fixed tensioner at the same time as moving to HTD belt profile, I don't know whether one predicated the other but given all of the work you are putting in, I'd suggest it's worth that extra piece of mind of a more reliable belt drive for the cams etc.

[Sparky]

Fabian, you change your mind more often than my missus when she's shopping for a new outfit.

[CHANGES]

3 hours ago, Lotusfab said:

So just for interest this is what I found out. The crank shaft had grooves up to 7.5 thou. It was standard before so easy to grind to 10 thou. Piston were OK, the reason my measurements were out of spec was the temperature I measured them at. Its normal to have slight scoring on one side of the thrust face. The rings I was using, although new, were really poor. The oil control ring design was floored scraping too much oil off the liner. They were 4 mm rings and difficult to get. Bespoke ones could be made. Best solution switch to Mahle pistons with new rings. I managed to get a good used set of these pistons. They are forged and much stronger and durable. They can sustain a slight overboost without melting, should the wastegate foul. The con rods were already superior HC with a cut out to splash more oil into the barrels. All of the bearings need replacing. The flywheel bolts were stretched and are all being replaced. The liners had scoring and were out of spec.i wont be installing the new ones  - this will be done professionally. Im getting rid of the adjustable tensioner and putting a fixed one on - thats about it for the bottom end bar the astronomical bill! Hard to believe its costing so much even though I have done all the work. It so far has  consumed five years of hard work and the cost is approaching that of an Essex. You see many of these cars that look just as good as this for less than half the price. The difference is this car will be just as good underneath. With effectiveky a brand new head and bottom end Im hoping to cover at least 60k miles without issue - but then agian it is a Lotus! 😄😄😄😄😄😄 So will I be driving it by the end of march? 

Fabian, 

I still think you are out of focus on all of this,  A lot of what you are proposing makes some sense, but without consideration of the finer details..   I have tried to point you in a direction and privately offered advise..   But you still seem to shoot off in all directions from one day to the next....  I would like to see you get this sorted, but guess work is going to put you dealing with another set of issues..  

What I am noticing and will point out , just so your readership understand is..

1.  Piston measurement out due to temp ...      Plausible but what temp where you at .  we measure at 18-20 ' and make allowances for temp difference , but 10' is tenths of a thou on a piston , so you may just need to look more at your own measuring procedure first..   Also did you zero you 75-100mm Micrometer with measuring block first. ? 

2. Rings and pistons..  Fitting sub standard rings can happen, which is a supply thing,  but they rarely over scrape in such short mileage unless gapped wrong..  Changing the Mahle pistons is an upgrade , but be aware ..  The crown design is different as is the deck height, This may be due to variation in compression height.. This all needs considering.. The Mahle pistons came with rings suitable for Nikasil liners , these will not be suitable for iron liners.  These pistons are designed for the 8.0 :1 compression ration set up, not the 7.5;1 you have now .. You will need to change your combustion format or your tuning set up to suit.. Also best to fine tune on dyno when finished..   This can all be easily achieved but you need to be aware of the finer details and calculate all the changes involved ..  A professional would know all this  ..  Just fitting it all may work in a fashion , but that's what you did last time and none of us want to see you have a repeat of that.

3. Bearings..    This is a supply thing , make sure they are 3 ply quality not the cheaper 2 ply crap that is available out there ..  again a professional would be aware of this 

4. Stretched fly wheel bolts.....  Check your torque wrench calibration . Only over torquing would cause this ..

5. Liners scored ..   How bad,   could they have been bored and honed .010 or .020.  Then custom pistons from Omega to match the size with correct crown design or at least deck height/compression height altered to suit require c/r.   At the same time you could reduce the size of the wrist pin along with piston weight to reduce reciprocating mass weight loading.. better all round for performance and engine life.. research and  talking to a professional would have made you aware of all this...      But if fitting new liners , getting a pro to set them in place with correct nip height is a good move.  

6 Fixed tensioner ..   Good move .  I did a conversion recently for customer , Its as @andydclements said , be best done with belt and pulley upgrade at same time ..  My customer went for Vernier cam pulley's at the same time to insure cam timing was absolutely spot on..  ..    might be worth considering.. 

7  Astronomical bill for bottom end ...   Uhmm should not be in the scheme of things ,... Its all relative , good kit and good work cost a bit more , but last a long time .  cheap parts and guess work cost a lot less , but somehow you always end up spending more ....   

We all would like to see you get some focus and solid direction on this .  Getting professionals to do things for you will not take away any of your personal involvement and achievements.  Share the experience with them and learn at the same time ... anything else is just guess work..        

[Andyww]

There seems to be some disagreement about using the fixed tensioner with the early style belt. Mike at Lotusbits has said it is OK but then again the whole reason Lotus designed the spring tensioner was because on the first Jensen engines the belt would lose tension when very cold and jump teeth.

Using the HTD belt/pulleys no issue of course with the fixed tensioner. 

The swap requires drilling and tapping a hole in the block.

[andydclements]

My main reason for suggesting HTD belt is that the tooth design is a more constant delivery of the turning force on the sprockets, which if going with the other upgrades that could lead to higher engine speed the improved control over the cams would be nice (may be essential if you go to the extreme such as @CHANGES has- darn I so want to be back driving my Esprit even though I'm probably 100+ BHP down on Dave's engine). 

[RichardJGC]

Here you go. 
A very worthwhile upgrade and means you can set the static timing perfectly.

Whilst you’re at it bung an a/c compressor on and enjoy some cooling air in summer (Bond had a/c)

[Andyww]

Bloody hell, dont get Fabian started on A/C !

Thats such a massive undertaking, been there done that and would not do again!

[RichardJGC]

2 minutes ago, Andyww said:

Bloody hell, dont get Fabian started on A/C !

Thats such a massive undertaking, been there done that and would not do again!

Admittedly a bit harder in an assembled car...but quite straightforward when in its component form.

[Andyww]

6 minutes ago, RichardJGC said:

Admittedly a bit harder in an assembled car...but quite straightforward when in its component form.

Different aux housing, alternator, crank pulley, most of the water plumbing, triangular bracket, idler, 2 mounting brackets, hoses/fittings, compressor, evaporator which means removing heater assy, condenser, receiver/drier, control panel, electronic controller and a lot more I have forgotten

[Lotusfab]

2 hours ago, CHANGES said:

Fabian, 

I still think you are out of focus on all of this,  A lot of what you are proposing makes some sense, but without consideration of the finer details..   I have tried to point you in a direction and privately offered advise..   But you still seem to shoot off in all directions from one day to the next....  I would like to see you get this sorted, but guess work is going to put you dealing with another set of issues..  

What I am noticing and will point out , just so your readership understand is..

1.  Piston measurement out due to temp ...      Plausible but what temp where you at .  we measure at 18-20 ' and make allowances for temp difference , but 10' is tenths of a thou on a piston , so you may just need to look more at your own measuring procedure first..   Also did you zero you 75-100mm Micrometer with measuring block first. ? 

2. Rings and pistons..  Fitting sub standard rings can happen, which is a supply thing,  but they rarely over scrape in such short mileage unless gapped wrong..  Changing the Mahle pistons is an upgrade , but be aware ..  The crown design is different as is the deck height, This may be due to variation in compression height.. This all needs considering.. The Mahle pistons came with rings suitable for Nikasil liners , these will not be suitable for iron liners.  These pistons are designed for the 8.0 :1 compression ration set up, not the 7.5;1 you have now .. You will need to change your combustion format or your tuning set up to suit.. Also best to fine tune on dyno when finished..   This can all be easily achieved but you need to be aware of the finer details and calculate all the changes involved ..  A professional would know all this  ..  Just fitting it all may work in a fashion , but that's what you did last time and none of us want to see you have a repeat of that.

3. Bearings..    This is a supply thing , make sure they are 3 ply quality not the cheaper 2 ply crap that is available out there ..  again a professional would be aware of this 

4. Stretched fly wheel bolts.....  Check your torque wrench calibration . Only over torquing would cause this ..

5. Liners scored ..   How bad,   could they have been bored and honed .010 or .020.  Then custom pistons from Omega to match the size with correct crown design or at least deck height/compression height altered to suit require c/r.   At the same time you could reduce the size of the wrist pin along with piston weight to reduce reciprocating mass weight loading.. better all round for performance and engine life.. research and  talking to a professional would have made you aware of all this...      But if fitting new liners , getting a pro to set them in place with correct nip height is a good move.  

6 Fixed tensioner ..   Good move .  I did a conversion recently for customer , Its as @andydclements said , be best done with belt and pulley upgrade at same time ..  My customer went for Vernier cam pulley's at the same time to insure cam timing was absolutely spot on..  ..    might be worth considering.. 

7  Astronomical bill for bottom end ...   Uhmm should not be in the scheme of things ,... Its all relative , good kit and good work cost a bit more , but last a long time .  cheap parts and guess work cost a lot less , but somehow you always end up spending more ....   

We all would like to see you get some focus and solid direction on this .  Getting professionals to do things for you will not take away any of your personal involvement and achievements.  Share the experience with them and learn at the same time ... anything else is just guess work..        

Dave, I have to say I wouldn't bother doing  engine or gearbox work again on a Lotus Engine, unless it was just repairing. It takes too long and there are too many variables and unknowns and conflicting information. I would just farm it out. I have spent far too much time and money already! I did everything right the first time around and it still failed. I have been advised by a specialist to go down this route as the best option.

I measured the pistons at 12 degrees, too cold. The company I am using have seen many engines built by both amatures and professionals that have failed for a variety of reasons. One of them was due to the ring type I was using. They dont make them anymore and were after market. The big problem is there are many parts out there that are not fit for purpose. The rings were gapped by the previous builder not me.

Theres no way to know the part quality unless you have seen a failure because of it. If you start with a working engine in the first place it would be much easier. I have learned the hard way how temporamental this engine design is. Back in 1988 the engine on this car blew up and it had a new short engine. Its sort of done that again! Not sure I can face it again! 

The Mahle pistons I have got have new rings for use with the iron liners which are being installed professionally. 

I understand the compression will be increase  but wasnt aware of any other modifications this would require. I'll look into it and ask the company, thanks.

I must admit Im finding this project a real roller coaster of ups and downs. One things for sure I know a great deal more about the engine and gearbox than when I started out. 

 

 

[Lotusfab]

Well looking on the bright side theres no more measuring required, its all new!

[CHANGES]

11 minutes ago, Lotusfab said:

I did everything right the first time around and it still failed.

You Think !!!

13 minutes ago, Lotusfab said:

I have been advised by a specialist to go down this route as the best option.

Am I not correct in thinking you had advise from a specialist  before and they measured everything and said it was spot on.. 

16 minutes ago, Lotusfab said:

The company I am using have seen many engines built by amatures and professionals that have failed for a variety of reasons. One of them was due to the rings I was using. The big problem is there are many parts out there that are not fit for purpose.

So again did you not go to a specialist and have all these parts checked...  Did you not fit and gap new rings on your build..   Yes there are parts out there that are sub standard , but you don't have to buy them..  Novices especially should research twice and buy once, pro's do all the time.  

21 minutes ago, Lotusfab said:

Theres no way to know unless you have seen a failure because of the part. If you start with a working engine in the first place it would be much easier.

I just do not see that as a plausible excuse ...   On this particular forum you have a plethora of information on do's and don'ts. Possible the easiest forum to post a question on a section you are doing and get a qualified answer on best way forward.  However if you don't verify and heed advise given then best guess is your only option.  And we have seen where that leads. 

29 minutes ago, Lotusfab said:

I have learned the hard way how temporamental this engine design is

No more than any other engine ....  it about experience , ability and understanding limitations..  When you are not fully familiar with anything you should first research and ask , then only proceed when fully competent.    The alternative is poor end product or failure.

33 minutes ago, Lotusfab said:

Back in 1988 the engine on this car blew up and it had a new short engine. Its sort of done that again! Not sure I can face it again! 

Well the clue there was in 1988..  they can blow up if faulty...  What has happened this time has nothing to do with the last time ....  You fully checked and reassembled this engine , the failure was due to something you did wrong regardless.. Maybe if you have lost confidence , it is best you put the work out..  There are lots of people out there very capable of assembling these engines , some better than others..  But all should give you a guarantee for piece of mind..     However, always remember , there is a huge difference in stripping cleaning and reassembling and engine and having one re-built by and engineer... The clue is in the price..  An engineer will like to supply and fit parts he knows are correct for the job , anything you supply he will disclaim along with any resulting damage in his guarantee..    

44 minutes ago, Lotusfab said:

The Mahle pistons I have got have new rings for use with the iron liners which are being installed professionally. 

And you are sure of this how?  If these are second hand pistons as you say you need to be sure ... If wrong and they fail because of being wrong , your engine assembler will just say ..... ''i fitted the parts you gave me''  so not my problem pal !! 

52 minutes ago, Lotusfab said:

I understand the compression will be increase  but wasnt aware of any other modifications this would require. Ill have to ask the company.

Maybe this is a question you should of asked first. 

4 minutes ago, Lotusfab said:

Well looking on the bright side theres no more measuring required, its all new!

And why would you think that ..   

[Lotusfab]

23 minutes ago, CHANGES said:

You Think !!!

Am I not correct in thinking you had advise from a specialist  before and they measured everything and said it was spot on.. 

So again did you not go to a specialist and have all these parts checked...  Did you not fit and gap new rings on your build..   Yes there are parts out there that are sub standard , but you don't have to buy them..  Novices especially should research twice and buy once, pro's do all the time.  

I just do not see that as a plausible excuse ...   On this particular forum you have a plethora of information on do's and don'ts. Possible the easiest forum to post a question on a section you are doing and get a qualified answer on best way forward.  However if you don't verify and heed advise given then best guess is your only option.  And we have seen where that leads. 

No more than any other engine ....  it about experience , ability and understanding limitations..  When you are not fully familiar with anything you should first research and ask , then only proceed when fully competent.    The alternative is poor end product or failure.

Well the clue there was in 1988..  they can blow up if faulty...  What has happened this time has nothing to do with the last time ....  You fully checked and reassembled this engine , the failure was due to something you did wrong regardless.. Maybe if you have lost confidence , it is best you put the work out..  There are lots of people out there very capable of assembling these engines , some better than others..  But all should give you a guarantee for piece of mind..     However, always remember , there is a huge difference in stripping cleaning and reassembling and engine and having one re-built by and engineer... The clue is in the price..  An engineer will like to supply and fit parts he knows are correct for the job , anything you supply he will disclaim along with any resulting damage in his guarantee..    

And you are sure of this how?  If these are second hand pistons as you say you need to be sure ... If wrong and they fail because of being wrong , your engine assembler will just say ..... ''i fitted the parts you gave me''  so not my problem pal !! 

Maybe this is a question you should of asked first. 

And why would you think that ..   

Dave, lets not give the impression here professionals dont have failures, they do. You know just how many of these engine have failed both professionally rebuilt and amature for a variety of reasons. It just isn't publicised for obvious reasons. At least I'm up front about it! 

 The rings I used were responible for the failure of a professionally built engine on a very well know show. The engine needed a total rebuild afterwards. Of course this isnt shown on the program. You probably know the engine Im refering to!  Another builder suffered the failure of four newly built engines because of blast media on the underside of the cam covers. I know of other  professional builds that all failed and ended up at a specialist. 

Ive been pretty unlucky really. I got all parts checked  last time and this time. The PRV was missed for whatever reason. A professional who knows the car would have found the problem when there was no oil pressure build up prior tomrunning the car. That was my big mistake! I know that now, so does everyone reading this, I didnt gao the rings or buy them. The previous owner had that done by a chap who builds historic F1 cars. You can bet though this time I will gap them myself. 

It may well have saved time and money to let a professional to  build the engine in this case. Unless of course they missed the PRV and did exactly what I did. In fact theres an example of exactly that on the forum!

This time around im not really doing anything apart from bolting and sealing. The head has been totally rebuilt with everything by Ht Howard. The bottom grinding, balancing bearing sizing all by a specialist. The oil pump and housing all new as are the camshafts and housings. I could carefully edit what I write and make it all perfect, but thats not what happens in the real world. 

Lets see what happens this time around. The only reason I have considered farming it out is time due to work commitments. But now I think I have really got to carry on forvthe sake of the people reading who havnt git an option but to do it themselves.

 

 

 

 

[Lotusfab]

For those of you reading this sometimes things that are written come across not as intended. I have called Dave Changes today and had a long chat. He has a vast amount of experience with these engines and I for one am glad he posts on here and imparts some of his knowledge, as most experts dont  bother. We have come to an understanding If he thinks Im doing a cock up he will tell me. I dont need any more engine failures! Thanks Dave.

[Lotusfab]

Lets keep an eye on the prize!

[Lotusfab]

Cylinder head update

Nothing is easy! The head has been stripped with all the guides removed. There are some grooves on two of the guide holes on the inlet side. These have to be honed out. Fortunately you can buy oversized guides which can be used to repair the problem. Oil can leak outside of the guides or down the stem, so its essential to get this correct. There will be no issues with the valves themselves as they are all new. Good used valves are available from the usual suppliers if you wish to take that option.

The gutting thing is have to throw away all of the oil cooler hoses which are brand new Mocal and the oil cooler. I was hoping I could find a racing car company that have a facility for flushing the hoses.

[Lotusfab]

Et Volla! The reason for failure. I pressed out the PRV, very easy to do. The piston is heavily scored which was causing it to bind. If only I had know, firstly it was in there andsecondly how easy it is to press out! Oh well you all learned it here, at least it didnt cost £5 k,which is my new estimated parts cost!

You can see the heavy scoring on the piston. Its binding in the sleeve. Probably why the valve was stuck open in the first place. 

Would have taken minutes to polish out the scores! 

[CHANGES]

Yep that's well naffed..   part of the new collaboration , telecom discussion and instruction on how to... and result..    easy peasy...  but that to be fair is not short mileage marks ,  that has been sticking for a while ....  may have been cause of original failure and never addressed on rebuild..   this is why the small details that are not in the book are so important ...      Well done good find . 👍

[Lotusfab]

Well I need to draw a line under this now. If I had known about the pressure relief and the fact it could be removed and replaced the cam folloers Im pretty sure my engine would be running perectly. Don't let what happened to me put you off doing your own builds. The information on this blog is probably enough to avoid all of my mistakes. Its a pretty simple engine. If you ensure the specs are spot, check the oil pump and PRV and dont assume anything anyone else has done is ok you shouldn't have any issues. When Inhave more time Im well placed to do another one. 

I have added up the cost of replacing all of the parts and come to the conclusion its almost the same price as if I had got got a company to rebuild it. Coupled with a work change, at the moment, I no longer have the time to do all this  and the ski racks. . I need to finish the racks, skis and just put the engine back in.

So I have decided to let the professionals finish the engine. 

[Barrykearley]

I hope you chose wisely on the professionals front. There’s absolutely no shortage of horror stories.

[Lotusfab]

Dont scare me Barry! I need this to be done and dusted. If the deal isnt right I may have to make time!

Funny enough this engine had a new oil pump in 1988 when it has a brand new HC short engine. Strange how the pumo failed again. Its hardly done any miles since the rebuild. 

[Barrykearley]

1 hour ago, Lotusfab said:

Dont scare me Barry! I need this to be done and dusted. If the deal isnt right I may have to make time!

Funny enough this engine had a new oil pump in 1988 when it has a brand new HC short engine. Strange how the pumo failed again. Its hardly done any miles since the rebuild. 

Sadly chap there’s folks all over whom believe they are engine specialists, V8 specialists, gearbox specialists, sports car specialists...... I’ve seen it first hand on numerous occasions. Some of the “specialists” very often referred to on here have chequered stories if you hunt on here 

[pete]

PNM seems to be the one most use

[910Esprit]

3 hours ago, Lotusfab said:

I didnt think this was a numbers matching car

I'm confused now.   I thought the original engine had previously been replaced by a new HC short block?   or is that the S1?

NB I currently have a set of brand new HC Mahle pistons and matching Nikasil liners on Ebay

Edited February 16, 2020 by 910Esprit