REBUILDING & UPGRADING AN 912 ENGINE

[johnpwalsh]

Hi Giorgio, just a comment on using that old belt, simply DONT, rubber products have a shelf life of approximately 5 years before they start to break down, bin it and fit a new one. Good the rebuild. 

 

John.

[giorgio67]

Hi gents,

with a titanic delay...I post some pics of the engine rebuild and in the next I will post more detailed pics of the assembly.

The first pics just to show a great trick to remove the crankshaft pilot bearing...it's just a question of bread and pressure....a big shot with an hammer and voilà!

 

Then, finally solved the bearings problem and everything have been assembled easy and with no issue.

You can see the 3° main with no groove, it's just a plane with hole bearing, to get more surface area, my original Vandervell bearings were different as they have the 3° main with groove and hole.

Very happy about my new piston installer and my new dynamo wrench!

Next jobs will be oil pump, water pump, tensioner, pulley etc...I'm seeing the light at the end of the tunnel

Comments welcome.

Ciao

Giorgio

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[molemot]

Always enjoy building engines...possibly the most satisfactory part of all car fiddling. I love your Bread Bearing Extractor...I've always used grease, myself, but bread would be less messy!!! In both cases, as you say, a determined strike is needed, no pansy tapping.

 

Roll on the First Start......(!)

[brian.harper@netassoc.net]

Most end up with cylinder leak problems when fitting the pistons without the use of cylinder clamps. Perhaps the Loctite is strong enough to not use those?

Brian

[giorgio67]

I think so...my liners are impossible to move after a month, loctite is really a good stuff!!!!

[molemot]

"Most end up with cylinder leak problems"....wot? Never happened to me. Even when I first had the engine apart, from new, in 1991 or thereabouts. Getting the liners out of the block is quite a task...need a good strong puller tool to shift them. Absolutely no way are they going to move by accident! The Servicing Notes has a picture of the works tool for liner removal...and they're not joking...

[Mike6]

I found the liners came out fairly easily on my car by rotating the crankshaft once the head was off.

[molemot]

I'm amazed...maybe the later ones aren't stuck so well? The 1982 glue did NOT want to let go at all...(!) No harm in using clamps...I'd made some and used them too, until I tried to get the liners out and realised I'd been wasting my time!

[giorgio67]

Just some more pics of my engine as it is now.

four pistons installed

 

aux housing and oil pump fully rebuilt and ready to go

 

 

Loctite 518 on both side of the new gasket

 

 

gasket in place

 

 

oil pump sprocket, water pump and freshly rebuilt tensioner assembly installed

 

 

checking the play of the crankshaft sprocket and the HTD belt as my engine was a trapezoidal unit,

no probs here as the front crank cover is the later type and it don't need any modification.

 

 

More pics soon, I've ordered a new alternator and some other bits to finish my engine as soon as possible, I really want to see it mounted in my fully rebuilt chassis.

 

Giorgio

[giorgio67]

Guys,

 

I think I will put the end word on my chassis engine rebuild......yes the saga is finished.

I'm very happy guys, as you know my father died in January so It has been hard to find enthusiasm about my restoration, I have all my father's tool in the workshop and I think he gave me a big help to finish the job.

Here some pics of my little jewel, I will put as soon as possible a video of the start up procedure of the engine on chassis..

 

Thanks to you all for the big help!

Now I will finish the bodywork to have the car painted in a couple of months.....I hope!!

 

Ciao

Giorgio

[molemot]

Funny how the departed generations still seem to be looking over one's shoulder....it's the same with me. I have my father's tools, and his father's too...plus Grandfather's certificate from Rolls Royce hanging on the wall....so there's always an unseen but noticeable presence in my workshop.

The restoration seems to be everything we've all come to expect from your sagas....roll on the First Start (!)...and the Final Assembly.

[giorgio67]

Thanks John, always happy to read your post.

Maybe it's a little thing compared to  a father's death  but it has been a great help this forum and his marvellous bunch of guys.

Hope to meet you soon on the road, but be aware that now I have something like 200 HP on my engine so be careful....

Ciao

 

Giorgio

[Bibs]

That's looking terrific Giorgio, very nice mate

[vintaylor]

top work Giorgio

 

Did you replace the alternator fan ?  Mine seem's different.. I was going to try and find a replacement online

[giorgio67]

The alternator is new Vin, I will compare the fan with my old one, bought on Ebay and it's a new not remanufactured part.

 

Giorgio

[vintaylor]

Thanks Giorgio

[giorgio67]

HI Guys,

does anyne know how many Lb are the 90-95 units or the 104 hz references for the cambelt tension (HTD)?

Maybe I recall that they translate to 50-52 Lb on the Krikit gauge or I'm wrong?

Thanks

 

Giorgio

[Mesprit87]

Nice work Giorgio,I used the krikit when I changed my timing belt. I know I wrote down the value...I looked but didn't find it. I'm sure someone will confirm your values quick enough. Otherwise I'm sure it's in a thread somewhere.

Luc

[molemot]

Hi Giorgio....progress is being made, then!! As for cambelt tension, I made a calibrator for my tension gauge. You take an old cambelt, cut it and make loops in the two ends by drilling through and pop rivetting with washers to spread the load. Then hang the device up and hang weights on the bottom loop....use the bathroom scales to get 90 lbs. At this point you have a belt with 90lbs tension..and you can apply whatever tension measuring device you like and be sure that the reading you get will be the reading you want for the new cambelt. You could plot a calibration curve by repeating this and varying the weight used. 

[mjcarter73]

Hi, great job! Doing a similar job myself. Just wondering how you fitted the cylinder liners? Did you adjust nip and if so how? Also do they slide in easily or need persuasion?

Thank
Mike

[molemot]

Liner fitting...easier if you put them in the freezer first...slide in easily, then! There is no easy way to adjust nip. You have to ensure that the flange in the block casting where they rest is absolutely squeaky clean, as any remaining sealant will stop them seating correctly. When I did mine, I tried all the liners in one position and measured the nip for each one. Then used one liner in each of the four pots and measured the nip for each pot. That meant I could put the best fit liner in each pot...even up the nip across all four. In reality, it worked out well. Be careful to check the piston fit in each liner and the ring gaps, too... it seem the pistons are made to the high end of the acceptable tolerance and the liners to the bottom end!! I had one piston that wouldn't fit into any of the four liners I bought.....so it is essential to check the fits.

It takes a pretty impressive pull to get the liners out...you need either the factory tool or something similar you can extemporise. Has to pull the liners up squarely... Once you have all the sealant off, the new ones go in fairly easily..but need to be exactly square on or they will jam. The zero thickness sealant S&J sell works well, it's an anaerobic stuff so only goes hard in the absence of air...thus any that gets squeezed out from between the liner flange and the block won't go hard...until the engine is back in and the block has been filled with coolant. The main seal is between the liner spigot and the holes in the block...a goodly amount of sealant around the spigot and rotating it slightly back and forth when fitting spreads the film nicely.

Have fun....(!) 

[PrecisionMike]

Hi, I'm in the process of the same project. A point of clarification please. I had understood that the 912 valves had smaller dimples but the inlets in your photo appear to have large dimples suggesting they are from a 907. Was that intentional perhaps to tune compression ratio or am I incorrect?

Edited November 24, 2020 by PrecisionMike
Spelling correction

[giorgio67]

I have fitted 300S valves, the biggest one you can put without changing the seats, just machining job with the correct angle, I have bought the In&Ex valves from Garry Kemp.

G.

[rgh0]

Hi Giorgio

Great post on your 912 engine rebuild.

I have a 912 engine ( plus a spare 907) waiting in my workshop and one day i intended to build a "Big" engine for my S1 Esprit.   Unfortunately it looks like a retirement job in a couple of years as my  Historic racing Elan keeps me busy currently as just finishing a full race engine and gearbox rebuild and my Plus 2 130/5 is still waiting for attention as it is part way through a full rebuild plus my spare Elan race engine and gear box both need rebuilds .... as of today my Esprit is my only running Lotus 😳

 

cheers

Rohan

[PrecisionMike]

On 17/08/2013 at 22:30, giorgio67 said:

Just some more pics of my engine as it is now.

four pistons installed

http://i303.photobucket.com/albums/nn145/ghe67/My%20Esprit%20restoration/032.jpg

 

aux housing and oil pump fully rebuilt and ready to go

 

http://i303.photobucket.com/albums/nn145/ghe67/My%20Esprit%20restoration/024-1.jpg

 

Loctite 518 on both side of the new gasket

 

http://i303.photobucket.com/albums/nn145/ghe67/My%20Esprit%20restoration/025-1.jpg

 

gasket in place

 

http://i303.photobucket.com/albums/nn145/ghe67/My%20Esprit%20restoration/026-1.jpg

 

oil pump sprocket, water pump and freshly rebuilt tensioner assembly installed

 

http://i303.photobucket.com/albums/nn145/ghe67/My%20Esprit%20restoration/029.jpg

 

checking the play of the crankshaft sprocket and the HTD belt as my engine was a trapezoidal unit,

no probs here as the front crank cover is the later type and it don't need any modification.

 

http://i303.photobucket.com/albums/nn145/ghe67/My%20Esprit%20restoration/038.jpg

 

More pics soon, I've ordered a new alternator and some other bits to finish my engine as soon as possible, I really want to see it mounted in my fully rebuilt chassis.

 

Giorgio

Hi Giorgio, you mentioned  a front crank cover modification.......what was the mod?