Renault Engine Building tips

[MRN I J]

from Cast Iron or?

Cast iron I think.
Pretty fancy for the time . .  and with an eye watering price.
Here's a pic from a local racer's car back then.

Easier to buy a block of cast iron & machine from solid with a 5 axis, however the machining would need to be good, if its wrong it will scrap the block or just sieze the engine. Our shop could do it but would ££££s

[MRN I J]

looking at the photo again there are no coolant slots between the liners which suprises me

[Ultimaguy476]

It looks like mine break all the rules. 
The center two have flats on both sides and the other two only have flats on toward the middle.
Mine are.265 at the top, except where they meet where they measure .130.
They taper down from there to .100, allowing coolant to pass between the liners.
This is about half of the .180 rule, and they have worked perfectly for me. 
I wonder if metal technology has changed enough to make the .180 rule obsolete?  Or am I just lucky?

[GavinT]

Don't think of it as breaking the rules; it's really breaking new ground.
Colin would surely approve. 

[MRN I J]

It looks like mine break all the rules. 
The center two have flats on both sides and the other two only have flats on toward the middle.
Mine are.265 at the top, except where they meet where they measure .130.
They taper down from there to .100, allowing coolant to pass between the liners.
This is about half of the .180 rule, and they have worked perfectly for me. 
I wonder if metal technology has changed enough to make the .180 rule obsolete?  Or am I just lucky?

Steel liners or CI ?

[Ultimaguy476]

Both LA sleeve and Advanced sleeve use ductile iron....a form of cast iron. 
The LA sleeve site says that it uses three standard wall thicknesses....1/16, 3/32, and 1/8”.
Their most common thickness is 3/32......093.
It sounds like the advances in metal make the ,180 rule obsolete, but i am not in any position to say. 
I can say that my sleeves have been fine. 
I haven’t gone through my receipts yet but I remember contacting both companies and I think I remember getting mine from Advanced. 
When I do go through my receipts, i will post a spread sheet of my suppliers, cost, part numbers, and date of purchase.
I’m guessing that current prices as they relate to my dated prices will sometimes be more, sometimes less based on inflation, advances in manufacturing processes, and competition.
For example, i believe that custom rocker arms, especially if I (or eomeone) can get access to a CAD file, will be cheaper today than they were ten years ago.

[GavinT]

Measured an OE Alpine A110 82.5mm sleeve and a stock Renault 77mm sleeve.
The liners were clean but not scrupulously buffed to eliminate the well adhered black surface deposit common to both.
Both are measured at the flat where they abut the adjacent liner.

Alpine sleeve measured across flats: 89.15mm
Renault sleeve measured across flats: 88.84mm

Wall thickness (Alpine): 0.125" & 0.130"
Wall thickness (Renault): 0.231" & 0.243"

I took care with the measurements but only with a digital calliper. They won't be dead nuts on but should be sufficient for general discussion.
Interesting side to side discrepancy for the Renault sleeve.

Not sure what all this says.
One could argue the Alpine sleeves are well under the .180 rule so it's no wonder they suffered from barrelling and loss of compression. Though looking at the Alpine pistons, they have some serious domes going on so the compression must have been through the roof - perhaps 'special' fuel was used?

Alternatively, one could argue the Alpines decisively won the world rally championship, so the .180 rule is a little conservative!
Ha . . I dunno.

I put a file on both liners and they react like cast iron of some sort, to me.

I'm wondering if that large flange on the upper deck of the Darton sleeves might contribute some decent stiffness to the whole block/liners assembly.

[MRN I J]

from AA Bells book Four Stroke Performance Tuning  https://books.google.co.uk/books?redir_esc=y&id=OTOYHRSX_XcC&q=CYLINDER+WALL+THICKNESS#v=snippet&q=CYLINDER%20WALL%20THICKNESS&f=false  page 219, Bell is a weel respected tuner with modern British & European touring car knowledge of engines producing over 150bhp per ltr

in a cast iron block with usual dubious quality not high quality liners where the quality is strictly controlled, the top half of the cylinder is listed as
65/70hp per liner 0.095" / 0.105"
75hp per ltr 0.110"/0.130"
85hp per ltr 0.150"/.0180"
100hp per ltr 0.220"/0.250"
the latter 2 are for max rpm race engines, around 8500rpm +

This book is really the bible for a lot of engine builders

we keep our 1950s Aston 6 cylinder engines quite thick as 40 years ago we a lot of head gasket issues, eventually solved by very close liner protrusion setting & very special head studs, we are stuck on race engines at 93 bhp per ltr except for one road car engine which also had 93 bhp per ltr but a large redesign on how we do things, should make 100 hp per ltr with race cams & 45s, not triple SUs

[Ultimaguy476]

If I read his article correctly, he is referring to a cast iron block 'of dubious quality', not a lined block.  Part, if not most of his concern, is that a cast iron block is often bored as much as .040 off center, meaning that the original wall thickness is compromised.  When reboring, it can then create a weak, thin area that you wouldn't even notice until it was too late.
With liners, the wall thickness is carefully machined to a very consistent thickness, eliminating a weak spot that encourages failure.
As he says in his article, the most important part of the bore is the upper part as that is the combustion chamber that has most all of the pressures.  He states that the lower part of the bore can be as little as much as .020 thinner safely. 
The Renault liner has a thick area at the top that accomplishes two things....(1) It gives a bigger land for the head gasket....(2) It strengthens the top of the sleeve. 
Any crack in the sleeve will more than likely start at the top and work it's way down as it would take a lot of stress to start a crack in the middle of a sleeve.
I am by no means an expert engine builder, but when I had my liners made, there was no concern on the manufacturers part as to the thickness of the liners.  As I said, they usually make their liners in three thicknesses, the thickest of which is .125.

How thick are Salv's 1796 liners?  Anyone know?

[MRN I J]

Thats what I stated

I dont know how thick Salv's liners are, 30 years ago he had tried CI liners (presumably nodular CI), then he went over the steel liners, not that it bother me as i'm sticking to around 1605cc's for at least one engine because I dont have to lie to event organisers

[Ultimaguy476]

I think your first line was a misprint.  It says:
65/70hp per liner 0.095" / 0.105"
I believe it was intended to say ‘per litre’ (or liter for those of us on the other side of the pond).
That is why I thought there might be some confusion about bored blocks versus liners.

[GavinT]

Some insight here on the metallurgy differences between cast iron, ductile iron and steel sleeves.

https://www.enginebuildermag.com/2018/02/sleeves-liners-metallurgic-magic/

The 807 bore spacing is 89mm.
With a bore of 82.5mm, the wall thickness must be 3.25mm (0.128").

I believe Salv retains the stock bore spacing as does Meca for their 82.5mm sleeves.

[MRN I J]

thats the max thickness not allowing for coolant flow around the liner which only need be 0.050" / 2 = 0.025" so a realistic wall thickness of 0.100" or so at that point, the liners could have 2 flats across the wrist pin axis, the flange could be extended down to 3/4" or even 1".
I think Salv's liners are 77 or 79mm at the very top & he uses the rim as a squish band as he uses a std head gasket, the pistons are stepped.

[GavinT]

Yes, I'd have instinctively thought coolant flow might be an issue too, but looking again at the Darton stuff, perhaps not.

Did Salv recently change his liner design?
I seem to recall that both he and Meca offered clearing liners. Did I get that wrong?

Ferry did the 1860cc kit with blind liners as you describe.

[MRN I J]

Salv's pistons look to have a rim machined into them, he uses STD head gasket