Esprit Turbo project car - part3 - the further continuation

[drdoom]

Fabian,

Your points regarding specialists are well founded, I am very selective in choosing any and generally turn over work that is beyond my scope. It is clear that my obsessive attention to detail will keep me clear of grief that would certainly emerge out of work done by the best of specialists. Case in point, as noted over on Stevens interior thread concerning non-functioning dash vents: in handling my adapted '95 S4S HVAC casing on the bench one of the vacuum control valves moved minutely but enough to fail its function by the actuating cam. It would have quite possibly been overlooked had I farmed out the work and simply plunked the thing in place upon return.

Work done by oneself saves buckets of money at the expense of precious time, but at least there's the great sense of accomplishment and often better confidence in a solid outcome. There are many employed as specialists, not so many who are truly up to the task. Lovely work on the interiors! As to engines I generally do the assembly, and check all measurements within my scope after work contracted out, so quite in line with your own preferences. 

[Lotusfab]

On 31/01/2020 at 18:31, Paul Coleman said:

I had exactly the same problem when I tried this and gave up and just set them like every other one I've seen, so I'm keen to learn if you fix this!

Ok Paul heres some pics for you.This bit is under the brass screw. It has a ball bearing at the bottom and a spring. It is in the feed to the pump jet. If its stuck or anything is blocked and the pump lever arm isnt moving when you open the throttle then no pump jet fuel!

 You can see the pump jets on the left and right sides. The bottom of each jet stick out in the barrel and delivers a squirt of extra fuel when the throttle is opened. Very simple to sort. Just looks complicated.

[Andyww]

Note, from experience if you activate the throttle with carbs on the bench the jets squirt halfway across the garage and sprays the car with fuel which all needs to be washed off  

[Lotusfab]

Yep you need the Dave test rig with manifold bolted on. Less fuel everywhere!

[drdoom]

5 hours ago, Andyww said:

Note, from experience if you activate the throttle with carbs on the bench the jets squirt halfway across the garage and sprays the car with fuel which all needs to be washed off  

Wee story from one happy, sunny club track day - one of the chaps thinking he might have had carb trouble with the DCOE's on his Seven, was  persuaded to remove them for a good look. Chap #2 ( not myself! ) takes one carb in both hands, holds forth as one would binoculars, though at arms' length, and proceeds to activate throttle thus dosing his eyes with petrol from the pump jets. No lasting harm . . . .😃

[Lotusfab]

Filling with coolant and bleedin the air out??.

Well, why we are getting to the bottom of some of the issues on this car has anyone come up with a full proof method of filling the coolant up. I will have to do it again and last time it took ages tomget all the air out. Yes I jacked it on it nose squished the front pipes etc. I can believe Lotus went through this with every car they made. Do we know anyone who worked in the factory to ask them what the secret is?

[Barrykearley]

Don’t the earlier cars have rad bleed points on the top of the rad??

ive a really handy thumb turn one on mine - makes bleeding a doddle

[Lotusfab]

Yep. Trouble is air is trapped in the pipes and doesn't reach the rad.

[Lotusfab]

Engine

Well the cylinder head is now with Ht Howard Slough. He is of the same opnion as me that the exahust guides should be replaced and the N4 inlet guide. They will check everything and hand it back for me to reassemble. They are going to grind the crank amd I can fit the new bearings. They are also going to balance it all for me. The pistons and liners still look good to me, but I will get them to measure them as well and cross check my figures. Should all be done in about two weeks . I have replacement cam towers and camshafts.

Should not take too long to rebuild it when the parts come back. This time most of it  will be new! Especially the oil pump! Now need to get the oil hoses off! It would be boring if I didnt have to rebuild it. 

Harrys video has got me thinking, Cortina here I come!😄😄😄😄😄

I estimate my cock up will cost about £2.5 k. The good thing is the engine will be much better adn should see me out! 

[mdw]

21 hours ago, Lotusfab said:

Filling with coolant and bleedin the air out??.

Well, why we are getting to the bottom of some of the issues on this car has anyone come up with a full proof method of filling the coolant up. I will have to do it again and last time it took ages tomget all the air out. Yes I jacked it on it nose squished the front pipes etc. I can believe Lotus went through this with every car they made. Do we know anyone who worked in the factory to ask them what the secret is?

Mine was an 88 Stevens  but I do seem to remember having to blead air out at the heater matrix pipes as well. 

[Lotusfab]

Well, engine wows continue! I have decided because of the oily burn which is not acceptable to me  and even thought the book clearances are  ok, Im replacing all of the inlet valves, inlet guides and exhaust guides. Ill replace any exhaust valves if thats recommended This will all be done by HT Howard.  Since the main and big end bearings come in 10/20/30 sizes restoring the crank with grinding and polishing isnt a problem. Then theres the con rod bolts, they really have got to go! Im also replacing some of the valve collets, I dont like the look of them! No more fatigue failures on this engine! We have already discussed the cam followers. All the cast iron ones are heading for the bin. Its new steel ones all around. I also don't like used shims. So as I have to reshim Im replacing all of them. Ive come to the conclusion rather that measuring everything and paying for labour just replace. The measuring of some parts is tricky and subjective. I dont want to do this again, so,I am building it to last. I plan to clock up miles quickly then test it long range and then head to Cortina, maybe with Andy on here. Harrys video makes me want to set off into the mountains! 

[snowrx]

You're not alone, here's a broken tappet in Exhaust # 5 on a newer car.

https://www.ebay.com/itm/1990-Lotus-Esprit-Camshaft-Carriers-housing-and-camshaft/303469725446?hash=item46a8348706:g:2MoAAOSwBO1eNef6

 

[Lotusfab]

6 hours ago, snowrx said:

You're not alone, here's a broken tappet in Exhaust # 5 on a newer car.

https://www.ebay.com/itm/1990-Lotus-Esprit-Camshaft-Carriers-housing-and-camshaft/303469725446?hash=item46a8348706:g:2MoAAOSwBO1eNef6

 

Having spoken to many different expert rebuilders this is quite common. The lesson is whenever you take the cam towers off, maybe change the timing belt, swap out the cam followers if they are cast iron. In 1990 they were probably steel but if the car has had a thrashing they might be fatigued. The problem is you dont know. My engine is 40 years old thats a long tine on the same conrod bolts and head studs. Theres no way Im risking them on a second torque up. I have been told by the  engineering shop there is a variance of 1.5 thou on the exhast valve stems. If you go into this in detail you could replace everything. Maybe thats the way I'm heading. Im now balancing the rods and pistons as its a small cost relative to the other balancing. Im thinking of putting in new liners and pistons. If I do the only part that isnt brand new is the con rods and they were replaced by the previous owner. Im now worried about the camfollowers in my S1.  Although that engine is running a lot less power. When aim on my way to Cortina it will all be worth it. Not sure what might happen to my skis on the autbahn though! 

[Lotusfab]

Oil pump hole

So heres a question that needs answering. Remember this hole which feeds directly into the rotor. Well we established its blocked off by the block casting. But why? I have heard its function is to aid the priming of the pump and release trapped air. It would be very simple to drill out the engine block, so this hole is open to the gallery. Thus aiding oil pressure build up. Any thoughts?

[JerryS]

On the dry sump cars this hole is sleeved and the adjacent oilway in the block is elongated to connect to it. This provides an oil feel to that end of the aux shaft as the usual oil channels in the aux housing are all blocked off.

[JerryS]

I understand this to be the bleed hole you're thinking of:

 

[Lotusfab]

Ahhh, thanks Jerry.

Juts spent 4 hrs cleaning the block and sump. I did it using degreaser, very powerful jet wash, brake cleaner and lots of cleaning brushes of all different sizes. I cleaned systematically bearing feed by feed. I also removed the central plug, Dave Changes was correct, its a lot easier to get into the channel. Its really clean now just as it was before. I have decided to replace all of the exhaust valves. They dont make Sodium valves any more. They are solid. I expectvthe engine to run hotter but Im not racing so dont think its an issue.

[Lotusfab]

The head on this car will be as new. So now I have to decide what to do with the pistons and liners???

[Lotusfab]

[Lotusfab]

Learned something new. Apparently its easy to punch out the PRV in the oil pump housing! It has an O ring on it.I will do this with the old housing just to see if  there are issues with it.

The replacement cam towers and 107 cams have arrived. They are the later style with the cover locating studs. A bit of engineering required as I want to keep the original cover look. I was very luckyntomfind some at a reasonable price. About another week and the engineering work should be done. Then its all going back together again. Any more falures and I will be seeking therapy before the next rebuild! This time I plan to,log the miles and do extensive driving before I set off to Cortina!  

[jonwat]

1 hour ago, Lotusfab said:

Any more falures and I will be seeking therapy before the next rebuild! This time I plan to,log the miles and do extensive driving before I set off to Cortina!  

Got to hand it to you Fabian, most guys would have given  up when the engine they'd spent months rebuilding blew. Full marks for perseverance. 

[Lotusfab]

Thanks John, ill beat it one way or another!

[Lotusfab]

If anyone needs new 107 camshafts S and J can get them. 

[Lotusfab]

Well my tales of woe continue! Just measured all the pistons and liners. The method of measuring is 15 mm up fromt the skirt on the thrust face. Below is the piston two measurement. All are out of spec and so are the liners. They are grade B pistons(stamped on the top)The head now has all new guides and valves. Looks like the bottom end is going to be brand new as well.  Ill get one of the experts to confirm my measurements before I replace the lot! The specs and measuring methods are all in the manual.           Piston 2     95.12 mm! 

Only liner 4 is in spec!

Ker ching!

The good news is the later cam towers will easily adapt to the old cam covers and they are better as they have locating pegs to hold the cover in position.

[Lotusfab]

I decided to go for it. This time my engine bottom end will have Mahle pistons, new liners, HC rods, new bearings all round and a new oil pump. Evrything is getting balanced! 7000 rpm here I come - Cortina or bust!