Rebuilding an 821 is EMOTIONAL

[skippopotamus]

Pretty much everything from the old (original) head was screwed up so I used everything from the new head.
I need about 6 mm of length either in the adjusters or the push rods.  It turns out that adjusters are expensive to have custom made so that's off the table.  I'm looking into custom push rods. 

[jbcollier]

I would be interesting to compare the valve length of the valves for the old and new heads.

PS:  I always fit new exhaust valves.  They get the hottest, take the most stress and are the most likely to drop their heads.

[GavinT]

I need about 6 mm of length [...]

I reckon 6 mm is a lot.
Even using longer adjustment screws, the valve train geometry will be significantly altered.

I realise you're trying to save a head gasket but I think the best thing to do is to take the head off and measure stuff.
As John says - check valve lengths.
One thing you could do prior to disassembly is to measure the rocker pedestal heights in the wild hope that the Lotus ones are lower.

[jbcollier]

I have both made custom pushrods and shaved rocker pedestals in the past.  Hard to recommend a course of action as we don't know what the issue is.

I would recommend reading up on rocker arm geometry and checking that first.  Then you will have a better idea of which course of action to take.

[skippopotamus]

6 mm seemed like a lot to me too.  I talked to some push rod makers and to them it didn't sound like a big deal to go 6 mm longer.  I didn't know that it is common practice to make custom length push rods.  I am doing research and asking around about how changing my push rod length my valve train geometry.  I'll report back.
Also, thank you John and Gavin for responding.

[jbcollier]

Duh, of course in this case you would be shimming the rocker pedestals.

Really, I ought not be let on the internet unsupervised...

[skippopotamus]

If anyone needs custom pushrods for their Renault they are less than $100 a set from Smith Brothers Pushrods in Oregon.  They are familiar with the Renaults and have what they call a Dave Bean radius.

[gideon]

 Can they do a pushrod upgrade, i.e. lighter and/or stiffer than original?

[skippopotamus]

I'm sure they can do pretty much anything given enough money,  Gideon.

[skippopotamus]

We had a few sunny days in row here in rainy California so I buttoned up a few things while the access is so good.  Rebuilding the Renault was humbling and it took me a number of tries to get a leak free cam box. 
Once that was done a few friends helped me put the body back on.  It's not completely down in the picture.  I have to rebuild the firewall and I think it'll be easier if I have a little extra room.  Plus it's easier to get in and out of the car if it's up high.  I'll be in and out of it a lot doing the interior and the wiring.

[dakazman]

Congrats Skippy, 
    Thanks for posting more vendor options for us to bring these engines back to life.
Dakazman
   

[TonyWa28]

Folks,
I'm relatively new to the Europa board but I am a longtime Elan and Europa guy (since the late 70s).  I have lots of twink experience, but I am working on my first Renault powered Europa (S2/1565cc 821-30).  I need some info on valve guides.  The car I started with had what appear to be bronze silicone guides which were well worn.  The bronze ones also had a shoulder on them. I chased down some R16 guides that appear to be cast iron, but are longer than the bronze ones I removed and have no shoulder.  Can someone give me the material, dimensions and description of the correct stock valve guides?

The ones I obtained are:


13.14 x 7.95 x 49mm  The O.D. and I.D match the ones that came with the car, but the length is different 45mm for bronze ones.

pardon my crude diagram.  Thanks!  TonyWa

[jbcollier]

There are lots of debates about whether bronze or cast iron make the best guides.  As long as the guides are good, I don't worry too much about it.  Originally crossflow engines came without valve seals.  Fitting them is a good idea.  Your machinist will have to machine the "left" side of the new guide to suit.  All pretty straight forward work.

[TonyWa28]

JB,
Thanks for the reply and I apologize for hijacking the thread.  The important remaining question was the length of the old guide vs. new.

TonyWa
69 Elan
69 Europa
60 Bugeye
72 Suzuki Titan 500
.... and a cast of thousands.....

[jbcollier]

It will probably have to be shortened to allow space for the valve seal.