#460002 - Restoration

[BDA]

Those are really fancy shocks, Serge! I like the idea of mounting them upside down. Be sure to let us know how they work.

[jbcollier]

How are you going to hook up your front roll bar?

[Serge]

I have a video coming on the ARB, it will be mounted between the wishbones with a droplink to the lower shock bolt. Very similar like a Lotus formule ford or formule junior.

Serge

[Serge]

I have finally found some time to upload a new video. I have refurbished the lifters and pushrods of the 821 engine to be used again.

https://www.youtube.com/watch?v=pL9gut29N08&feature=youtu.be

Last few months have seen very little Europa progress. Those who follow me on social media may have seen I have moved house and opened my new dental office. I have been working on this for the past three years, so everything happened all at once in the end. I will hopefully get a bit more garage-time in 2020.

Black friday got me an ECU and all the sensors for the EFI system. But the car still needs a little bit of fiberglass work and then paint. In the next few months I will hopefully get all the engine parts machined so I can rebuild the engine.

There is a new Europa book and my dad got me one as a christmas present. In the book is this photograph of an S1 with a 'Europe' badge. So there might have been some S1s with a Europa badge on them?

Happy new year everyone!

Serge

[BDA]

Happy New Year, Serge, and congratulations on your new house and opening your new dental office! It's great to see you posting a new video after your absence.

I was surprised to learn that the lifters are actually flat! That's the only engine I've heard of that actually has flat lifters.

You may have given D'man some ideas. I suspect we'll hear about how he polished the inside of his engine! 

[jbcollier]

There is really no need to polish the pushrod shafts.  I just clean them with a wire wheel on a bench grinder and you're good to go.  Polishing looks pretty though.  Polishing wear-surfaces also increases the wear.  Apply polishing sparingly.

As an engine runs, surfaces wear together, smoothing off slight imperfections and form a perfect "union".  Always keep "mated" machined surfaces paired together as it eliminates break-in wear after an overhaul.

I'm very glad you had the lifters checked after your work.  You took a lot of metal off and you didn't use a jig to maintain true.  This is usually ok for small amounts but it is easy to lose true if you take off too much by hand.  The act of pushing across an abrasive surface tends to "tilt" the object resulting in the edges being machined more than the middle.  Light action and constant turning can help but proper machining is better.  In this case the very wide lifter platform also helps keep things true.

Lifters are case-hardened.  The depth of the case hardening has been reduced.  Perhaps such that service life has been reduced.  Myself, I would have had them professionally reground and parkerized.  The cost is in the $20 a lifter range.  Cheap insurance.

I thought the lifters had a very slight arc to the surface to promote rotation.  This matches a slight taper ground to the cam nose (for the same purpose).  Where did you find that they are completely flat?

The grey sections in the middle of the lifter's "shaft" are actually less worn than the polished ends.  The side loading on the lifter weights the two ends most.

Honing with a ball hone can be problematic because the two ends are "machined" less than the middle as the hone spends more time in the middle than the ends.  This results in a barrel shape.  The end machined from also is slightly larger than that other end as it gets a bit more "machining" as the hone is inserted and removed.  Also machining creates microscopic swarf.  You need to thoroughly clean the machined bore before you can evaluate fit.  Better would be to use a proper hone sized to give the correct clearance, or, use a special line hone that maintains a square cut as it is used.

Maintaining the specified clearance is critical.  The lifter bore may be differentially heated due to its proximity to the combustion chambers.  The tightness when the lifters are pushed all the way home concerns me but it may be outside the actual range of travel in service.

[jbcollier]

One last thing, steel rulers are not true!  You need a proper surface-ground, straight edge to evaluate a surface for trueness.  No big deal over the short surface you were checking but critical for longer surfaces.

[jbcollier]

Lastly, my apologies for being such picky, pain-in-the-posterior.

[dakazman]

   I had the lifters recut at $8 each and hardness tested. Much cheaper than the 400. Euro for new ones. I’m glad I took JB’s advice, there is supposed to be 1 degree negative as I saw evidence of in Serge’s video.
 Sanding with 320 is very aggressive for that surface and probably now deeply scratched. That’s just my opinion and a visual comparison of the other set of lifters that were recut for my crossflow.

BDA, Okay you got me.
Dakazman

[BDA]

I figured since Serge was aware that tappets were usually convex, that he was correct that they were supposed to be flat. Also, they were worn concave and that would seem to bolster his assertion that they are actually supposed to be flat.

Given the high pressures on the cam/tappet face - and the resulting very high hydraulic pressures in any imperfections, I would feel a lot more comfortable having the cam shop re-face the lifters. As JB says, case hardening is very thin and just checking the hardness may not tell the whole story.

I do feel a bit better that he sent the lifters to the same shop that reground the cam so presumably Serge and the cam shop had a good conversation so the cam shop would know what is required.

[lotusfanatic]

Hello Serge,

which new Europa book do you have?

Mark

[Serge]

I'll try to answer everyone below:


The new book is called 'Lotus Europa: Colin Chapman's mid-engined masterpiece' by Matthew Vale.

The Renault engines are made to have parallel cam lobes (not slanted) and flat followers. The lifters are offset to the cam lobes and this will let them rotate. This was confirmed by an engine builder on a renault forum that found NOS lifters. This particular engine builders builds crossflows for long distance road rallies. The followers are case hardened, and were tested by my cam shop, they turned out fine. I was thinking of having them reground by them, but it still was quite expensive (but maybe good insurance) and I like doing things myself. Once the engine has been built, it should be run in quite hard (20min at 4000rpm) and the cam and lifters should work harden.

I'm not a professional in all this, just me doing car things in my free time. If anything goes wrong, at least it's only my fault!

The polishing of the pushrods was to be able to remove the rust. I just went a bit too far with the polishing!

Next few months should see me going to the engine machinist to get the block bored out for the bigger liners. I think the head should be fine to go, but will let them inspect everything. Valerio had it flycut before he sent it to me, but I made some small marks on the surface when I ported the combustion chambers, not sure if this would make a difference in the head gasket sealing.

Serge

[BDA]

I appreciate your drive to do things yourself! It shows your adventurousness! We all make mistakes building our cars - I certainly have! - but I think we all are interested in your not making mistakes with something buried so deep as the internals of the engine. I'm happy that you seem to have done your homework.

I look forward to seeing future installments of your build and eventually see a video of you driving off in your baby the first time! Good luck, Serge!

[jbcollier]

Sorry for the rough ride!

Very interesting to hear that the lifters are flat.

Use camshaft/lifter assembly lube on the cam lobes and lifter faces when assembling the engine.  Here's a few examples:

https://www.penriteoil.com.au/applications/car-4wd/greases/cam-assembly-lube

https://www.crower.com/camshaft-assembly-lubricant.html

https://www.summitracing.com/parts/cca-153/overview/

[Serge]

I have stocked Joe Gibbs ‘Driven’ assembly grease (high zinc content) and run-in oil. Should give enough protection on startup.