Esprit Turbo project car - part3 - the further continuation

[Lotusfab]

Looks good. J B weld repairs?

[Andyww]

Those water spigots are a bit pitted but I think they are OK.

[Lotusfab]

Once the J b weld is smoothed that will be perfect.

[williamtherebel]

On 18/01/2020 at 18:27, drdoom said:

I would not get overly wound up with concern for wear of the oil pump in the conventional sense as that is not something I have ever heard or read of in my many years in the hobby. I regularly socialize with senior mechanics who share various accounts of noteworthy engine and vehicle troubles, the only one pertaining to oil pump was as victim in the KIA/Hyundai engine failure fiasco unfolding in recent years. Do go ahead with checking the pump nonetheless as it's a simple thing, remember my earlier points regarding clearances within, if you will. The markings on parts revealed in the posted pics are not those of simple, conventional wear, rather they are witness to hard particles having circulated in the oil system.

To William's account of the Alfa cam cover piece I say good luck to any who think laying on a sealant to the underside of said cover will endure. Not on any engine I'd be responsible for.

Cheers

Perhaps I should have given a more detailed description regarding the "sealant". The guy who did it laid the cam cover on  a sticky sheet of  high temperature resistant plastic sheeting. The edges were then cut off and the bolt holes blanked off. The cam cover was then blasted,(cant remember what type), then powder coated, then baked in the oven. When it came out the plastic was then removed. So there was no sealant on the underside of the cover. Ive tried to find the episode on youtube and although there are bits on regarding the car I cannot find the pertinent bit on the cam cover.

[drdoom]

Good to know the operational details, Fabian. Oil pressure figures look entirely fine. No less a figure than A.C. Rudd, guest speaking for the benefit of our local Club in '86, offered the design criteria at 10psi per 1000RPM to a happy minimum of 45psi hot. No issues with somewhat higher pressures up to 65 psi, but no more than that to be beneficial. 

4 months of operation with notable presence of particles or beads in the oil would account for the scoring, can't imagine what else could be the cause of that. Visible scoring is localized and association with anything further is speculative, whereas absolute wear must be confirmed by measurement  Perhaps the fracture in that tappet was coincident with a score line, this is a known mode of failure in a brittle component. That the tappet broke is certain and indicative of brittleness. Well aged cast iron in question by various accounts. For there to have been sufficient wear in the tappet - bore area beggars belief and would have raised quite an audible ruckus, one would think. Get those measurements in hand and then consider the likelihood. There is always the option of presenting the tappet remnants to a materials analysis professional for expert evaluation, likely at quite reasonable cost.

In summary - scoring is due to oil contaminant(s); PRV stuck due to same; tappet failure yet TBD pending measurements / expert evaluation but brittleness seems unavoidably linked. I do not expect proper steel would have failed in this situation, scored or not. Ultimately the stuck PRV and tappet may or may not be linked by way of the contaminant(s), scoring conclusively points to contaminant(s) and late arriving oil pressure is absolved of blame. The tappet failure has yet to be shown as other than coincidental.

[Andyww]

All of the above seems very logical. What other plausible cause could there have been for the sticking PRV other than particles in the oil? The spring was intact, nothing failed.

[Fridge]

8 hours ago, Lotusfab said:

To be fair to the chap who  blasted it after doing so warned me. He said that I must clean it really well and advised me to change the oil and filter when it got hot, which I did. Dave is probably correct in that a tailored cleaning regime might make the risk of contamination extremely low and bring it down to an acceptable leve.  I dont know what his  regime is, but even with  a very large ultrasonic tank I personally would not use this process again. Painting is the way ahead when it comes to engines.

Finding some of the earlier parts of this recent episode difficult to follow. However I cannot see the reason for painting the inside of the engine casing if that is what is being suggested. I'm not even sure what you could use that would withstand that environment?! 

Are we entering a new era in car restorations? I better dig out my old school recorder pipe cleaner for my tail pipes .... 

[Lotusfab]

E

6 hours ago, Fridge said:

Finding some of the earlier parts of this recent episode difficult to follow. However I cannot see the reason for painting the inside of the engine casing if that is what is being suggested. I'm not even sure what you could use that would withstand that environment?! 

Are we entering a new era in car restorations? I better dig out my old school recorder pipe cleaner for my tail pipes .... 

Definately NO paint in the engine! I was refering to vapiour blasting the ouside tonmake the engine look good. Avoid this clean the  outside and paint it! 

[Lotusfab]

Oil analysis

Reports not out yet maybe later today. I spoke to the lab techniician. Surprising reults. He said the silicon content was within normal parameters but the test only identifies small particles. He is going to check for glass bead in the oil with a microscope! 

Really interestingly he said there may be an issue with fuel in the oil that has thinned the viscocity!! . I noted a misfire on number two when hot, that wasn't there before when at idle. This only happened recently. This is the cylinder that had the cam follower failure on the inlet valve.  He also said the oil smelt of fuel! Could it be somehow fuel has diluted the oil to such an extent to cause wear? If so how did this happen? Was it a symptom ofbthe inlet cam follower breaking up? Maybe as it started to go it affected the inlet valve  clearance.  

There  was a strong smell of fuel which wasnt there when the car was first run. I thought it was loose filler caps, which I fixed. 

Pleased I seem to be getting somewhere now.

Thanks to Dave his carb set up kit has arrived, thanks mate! So I  should be able to calibrate the pump jets correctly. Will post the report when it comes out. 

[CHANGES]

On 18/01/2020 at 19:21, Lotusfab said:

Heres the secondary small outlet hole on the pump. The oil from here is direct from the pump, bypassing the filter. I believe it feeds the head. I cant be sure until I get the auxillery housing off and check which gallery the hole aligns to. If this were blocked I believe you would have a pressure issue.

Interesting little observation here..  The secondary small outlet you refer to was, as some one mentioned , created as part of the drilling procedure for the aux shaft lubrication.   However on the early engines they did have priming issues on start up , so this hole was used as a small direct feed into the the upper gallery to help with priming..  If you look at the actual gasket you will see a small cut away section to allow small feed to vent  the pump into said gallery..  This was to help prime the engine oil.   When the engine would be at pressure the flow though the small gap would be neutralized by equilibrium of pressures with minimum unfiltered oil getting though..    see pic       Hope that is of help..     

 

[CHANGES]

On 20/01/2020 at 10:18, Lotusfab said:

Your correct though Dave, if I rebuilt these engine everyday the failure risk would be lower, but I am sure even you have had issues with some builds?

 ( My reply does not cover the development work I have done, which exposed weaknesses in certain components when pushed to the limits of  design criteria. )  

I had to think hard on that , to be perfectly fair the answer is no not really.. Its a process , when you follow a set procedure you really should not have issues..  As many others have done also ....  This why we are all so interested in how you have managed to have such a catastrophic failure in such short miles.    Finding the exact reason will prevent others doing the same ,   Its sad to see, but in this case your dilemma may educate others                                                                                                                                    

[Lotusfab]

I have started to do a 180 in thinking. I have just found petrol traces around the no2 piston area. Could this have been as simple as the cam follower breaking up? The change in inlet clearance allowing unburnt fuel to leak into the oil. Oil thins, lots of wear on rest of the engine. Residue from cam follwer causes scoring? 

[Lotusfab]

Also Im not happy with the combustion. Its not clean enough. I suspect oil getting in on valve guides. Time to get the head completely redone. New valves and guides. Thre doesnt appear to be any valve guide oil sealing on this head? 

[andydclements]

The engine is designed to loose a little down the valve guides, the emphasis being  little, so if the guides are excessively warn then you will get build up of oil combustion deposits.

[Andyww]

But I thought you found the PRV was stuck before the break up of the cam follower? Or are you suggesting two issues, the cracked cam follower and the PRV issue. BTW what was actually visible in the PRV, was there some scoring or particles in the plunger hole?

Edit: On the subject or the PRV I have not looked at this one but on another engine (Ferrari V8) the PRV spring is really hard, it would take a major obstruction to jam the plunger and I dont think contamination particles would be enough. Is that the case here?

[Lotusfab]

Prv was stuck open when I first tried to start after the rebuild. I realised this was why there was no oil pressure. I took it off cleaned it and put it back then gotboil presure.  When I first took the engine apart I found the pick up strainer araldite had broke up.

The new thing here is fuel in the oil, how did it get there? Was this responsible for the failure? Its certainly not normal. Hopefully the report will enlighten me.

[Chillidoggy]

The oil report found no blast media present, and there would have to have a significant quantity of fuel in the oil for it to cease working as most oils will cope with a degree of fuel in them. With what I’ve seen so far, and with micro-welding pick-up displayed in the cam bearing bores, oil starvation would be my conclusion, nothing else.

I wish you better luck next time around.

[Lotusfab]

36 minutes ago, andydclements said:

The engine is designed to loose a little down the valve guides, the emphasis being  little, so if the guides are excessively warn then you will get build up of oil combustion deposits.

All of the valves clearances were measured and checked. They were in spec. Maybe the range means you can have some oily deposits and its acceptable? Anyway Its not upmto my standards so im replacing everything. I will look into the Gary Kemp valves with sealing washers. Not sure if they are suitable, will have to research it. 

[910Esprit]

Looking at your earlier photo, the car was clearly running very rich, I suspect that may be the source of the unburnt fuel?

[Lotusfab]

Possible. Was just told by the lab the dilution was only 0.3 per cent. So the drop in oil viscocity was not due to fuel. They said the drop in viscocity might be due to overheating.. This is difficult now as I measured the water temp as 90 degrees max at the sensor. The report comes out tomorrow the microscope showd only a tiny piece of bearing ( not good news) no glass bead. He suggested oil starvation which brings us back to the PrV not wotking correctly. I need to test the pump.

[Choppa]

3 hours ago, Lotusfab said:

Was just told by the lab the dilution was only 0.3 per cent. 

IMO that or a slight drop in oil viscosity won't have caused your problems, my bet is  that all the wear you can see now was caused  when you first fired up the engine and it ran for however long with zero oil pressure, and you've been "lucky" that it's run for a few months and a few hundred miles before the follower gave up. 

As an illustration on how resilient an engine can be to fuel contamination, many moons ago I drove a Lancia Beta Coupe. It had a  mechanical fuel pump probably driven off the camshaft but I can't really remember how it worked now. Anyway the diaphragm in the pump failed  while the car was on my drive and just  ticking over. The pump failed in such a way that the sump filled up with fuel and spray coated the engine compartment with an oil/fuel mixture. When I lifted the bonnet to see what was going on (the engine had stopped!)  the mixture was coming out of the dip stick pipe just like a small fountain in a garden pond.  On checking, there was absolutely no damage to crank or cam shaft, I just cleaned it all down replaced the fuel pump and drove it around for a couple more years before the rot killed it. 

Also agree with Steve that the head did look very sooty for something that had only done a few hundred miles

Edited January 21, 2020 by Choppa

[Barrykearley]

On 12/01/2020 at 09:15, Barrykearley said:

The oil pumps are awful and do not self prime if dry.

it could have caught me out on the S4s - but with the cash injected into mine and the new turbo it was worth the time and effort to check what some might ignore. The turbo supply line is the last pipe on the galleries until oil is returned to the sump. Priming that pump was a complete and utter pig and needed a decent pump to pump oil round the system backwards.

its one of the key issues to make sure you get correct on any engine - had I not checked - a few seconds of running would have added 10s of thousands of miles of wear to my engine

This ^ @Choppa

[andydclements]

2 hours ago, Choppa said:

IMO that or a slight drop in oil viscosity won't have caused your problems, my bet is  that all the wear you can see now was caused  when you first fired up the engine and it ran for however long with zero oil pressure, and you've been "lucky" that it's run for a few months and a few hundred miles before the follower gave up. 

As an illustration on how resilient an engine can be to fuel contamination, many moons ago I drove a Lancia Beta Coupe. It had a  mechanical fuel pump probably driven off the camshaft but I can't really remember how it worked now. Anyway the diaphragm in the pump failed  while the car was on my drive and just  ticking over. The pump failed in such a way that the sump filled up with fuel and spray coated the engine compartment with an oil/fuel mixture. When I lifted the bonnet to see what was going on (the engine had stopped!)  the mixture was coming out of the dip stick pipe just like a small fountain in a garden pond.  On checking, there was absolutely no damage to crank or cam shaft, I just cleaned it all down replaced the fuel pump and drove it around for a couple more years before the rot killed it. 

Also agree with Steve that the head did look very sooty for something that had only done a few hundred miles

I managed to add 2+ litres of water to my sump of an Excel by means of water into the airbox (drove through flood), and drove it for a few days before getting round to stripping and replacing head gasket, only then did I realise the water was present and had emulsified with the oil. No real damage to bearings etc, and I hadn't been treating it gently as I was keen to understand whether I'd lost power. That water thinned the oil a lot.

[Lotusfab]

My question now is could this scoring be cause be caused just by lack of oil? Im not sure but it seems like contamination. The oil test is not conclusive as it only  detects very small particles, much smaller thatn the glass bead. The sample came from the sump which was checked with the microscope. I should have saved some of the cam oil and tested that as well or got a microscope! 

The good news is with no sump contamination Imdontbhave to throw away the new oil cooler pipes and the rebuild will be easier.

 

[Barrykearley]

There’s plenty of images and pics about just like that. It’s either oil starvation or contamination. There’s really not a lot else it can be other than excessive play. This weblink shows some images and gives some explanation 

https://www.pioneer-engineering.com/resources/main-bearing-failure-modes