Bertrudes block has finally given up!

[mr2nut123]

I generally get the idea of block sleeving, but surely when doing this, the sleeves themselves will go and you simply replace these to keep the block perfect, is that right...or are the sleeves themselves almost indestructible?


I've just found out that there are 'wet sleeves' too which have direct contact with the coolant to help temps too. Sounds awesome

[Nod]

I would imagine they must be Darton. Normal sleeves are anything but indestructible.

Lyndon.

[ashley]

I thought the issue with sleeves was the amount of material removed from the block in order to fit them?

My original block was sleeved and in fairness the sleeves held up fine, it was the rest of the block that didn't...it cracked on the deck between cylinders 2 & 3, kinda like this:
00l00

Either the material removed to fit the sleeves meant the remaining block was too weak and so twisted, or the remaining block was simply too thin to deal with the heat and so cracked into the water way between the cylinders.

[Nod]

I've seen a sleeve crack in the same place the block had cracked behind it previously.

Lyndon.

[JJ]

I understand all the possibilities / doubts with sleeves...I'm talking about the different rates of contractions etc with the sleeves against the block... I'll give them a shot though... in my eyes, the combustion area of the block can only be improved with the increased ductility of the sleeve. I'm speaking from a mechanical engineering angle and also people that have had to convince me too...

I havent fitted wet sleeves, can't really do them to these blocks, usually thickness issues applies, but often enough a slight defect / impurity in the cast iron will make it "weak" in an extreme context.

I've done studies on the block and found some of the boring is done slightly off centre too which doesn't help..... it makes for example the intake side of the blocks wall thinner than the turbo side of the block.. and vice versa.... this all done with thickness checks instruments / x rays etc. I'm suprised to see most of the areas around the cylinders are covered in some 7mm > 4mm thick cast iron, however.. the weakpoints tend to be around the 4mm points which you can expect ! I measure one failed block that was down to 3.6mm.

The liners do effectively bore out the existing bore, but not to the point where you're boring out the original block cast turning it into a wet liner .... there isn't enough space, but you need the original block material to seat the liner into position and with a top hat design, its unlikely in any case to move under any conditions.

I've been testing it since the snow went, its holding up just fine at the moment... havent really pushed the boost considerably up at present as I'm trying to get a few heat cycles behind it, but its taking a continuous 1.4/ 1.5 bar through it..... I'll push it higher... should be good for 2 bar + all day long, but again... doing it in phases and ensuring the tuning isn't behind the block crack ( ie too much ignition advance )

What sleeves have you used JJ?

Greeny... if theres any consellation, the sleeves that I'm using is powering a 800 odd bhp 2 litre at the moment reliably, whilst I dont believe them to be branded as Darton Sleeves, they are an equivalent heavy duty type.

I was all for importing some Darton Sleeves and getting the machine shop to fit them, but good recommendation came by the machine shop.

I generally get the idea of block sleeving, but surely when doing this, the sleeves themselves will go and you simply replace these to keep the block perfect, is that right...or are the sleeves themselves almost indestructible?

Luke, there can be many issues around pouring / manufacturing the cast iron block, impurities etc ( i'm talking very small % ).. thickness issues once machined... the liners are hardened / almost forged, in laymans... 2mm steel liner is a 100%+ stronger than 2mm of cast iron.

Again.. there are many other factors which contribute to block cracking.. tuning / overheating... In cylinder temps can be almost 1000 deg C's ( fuel leaning / retarded ignition / restrictive turbo ) which can gas the surrounding coolant if the coolant isn't passing through the block quick enough... which summarises why many of us running far higher boost can get away with it, and some of us just cranking it up to a BPU.. and block failing.

I thought the issue with sleeves was the amount of material removed from the block in order to fit them?

Ashman, these steel liners I've had fitted are effectively a displacement to the cast iron... ie... bore 2mm out the cast iron, replace with 2mm wall thickness steel liners.. I think like most, people think fitting liners is completely removing all cylinder walls and replacing them with a thick wet liner... you see them with honda and nissan engines.. mainly because their blocks are aluminium alloy with liners fitted.

it cracked on the deck between cylinders 2 & 3, kinda like this

I remember this.. and could probably only conclude on tuning being an issue or simple integrity of the cast.. both of which is difficult to identify the root cause of the failure.

I waffled a bit there didn't I !!

[mr2nut123]

I understand all the possibilities / doubts with sleeves...I'm talking about the different rates of contractions etc with the sleeves against the block... I'll give them a shot though... in my eyes, the combustion area of the block can only be improved with the increased ductility of the sleeve. I'm speaking from a mechanical engineering angle and also people that have had to convince me too...

I havent fitted wet sleeves, can't really do them to these blocks, usually thickness issues applies, but often enough a slight defect / impurity in the cast iron will make it "weak" in an extreme context.

I've done studies on the block and found some of the boring is done slightly off centre too which doesn't help..... it makes for example the intake side of the blocks wall thinner than the turbo side of the block.. and vice versa.... this all done with thickness checks instruments / x rays etc. I'm suprised to see most of the areas around the cylinders are covered in some 7mm > 4mm thick cast iron, however.. the weakpoints tend to be around the 4mm points which you can expect ! I measure one failed block that was down to 3.6mm.

The liners do effectively bore out the existing bore, but not to the point where you're boring out the original block cast turning it into a wet liner .... there isn't enough space, but you need the original block material to seat the liner into position and with a top hat design, its unlikely in any case to move under any conditions.

I've been testing it since the snow went, its holding up just fine at the moment... havent really pushed the boost considerably up at present as I'm trying to get a few heat cycles behind it, but its taking a continuous 1.4/ 1.5 bar through it..... I'll push it higher... should be good for 2 bar + all day long, but again... doing it in phases and ensuring the tuning isn't behind the block crack ( ie too much ignition advance )

What sleeves have you used JJ?

Greeny... if theres any consellation, the sleeves that I'm using is powering a 800 odd bhp 2 litre at the moment reliably, whilst I dont believe them to be branded as Darton Sleeves, they are an equivalent heavy duty type.

I was all for importing some Darton Sleeves and getting the machine shop to fit them, but good recommendation came by the machine shop.

I generally get the idea of block sleeving, but surely when doing this, the sleeves themselves will go and you simply replace these to keep the block perfect, is that right...or are the sleeves themselves almost indestructible?

Luke, there can be many issues around pouring / manufacturing the cast iron block, impurities etc ( i'm talking very small % ).. thickness issues once machined... the liners are hardened / almost forged, in laymans... 2mm steel liner is a 100%+ stronger than 2mm of cast iron.

Again.. there are many other factors which contribute to block cracking.. tuning / overheating... In cylinder temps can be almost 1000 deg C's ( fuel leaning / retarded ignition / restrictive turbo ) which can gas the surrounding coolant if the coolant isn't passing through the block quick enough... which summarises why many of us running far higher boost can get away with it, and some of us just cranking it up to a BPU.. and block failing.

I thought the issue with sleeves was the amount of material removed from the block in order to fit them?

Ashman, these steel liners I've had fitted are effectively a displacement to the cast iron... ie... bore 2mm out the cast iron, replace with 2mm wall thickness steel liners.. I think like most, people think fitting liners is completely removing all cylinder walls and replacing them with a thick wet liner... you see them with honda and nissan engines.. mainly because their blocks are aluminium alloy with liners fitted.

it cracked on the deck between cylinders 2 & 3, kinda like this

I remember this.. and could probably only conclude on tuning being an issue or simple integrity of the cast.. both of which is difficult to identify the root cause of the failure.

I waffled a bit there didn't I !!

Yes you did I'm baffled, but you can tell you have REALLY done your research and it will be great to keep an eye on so keep all updates coming! Mine's a rev2 block with rev3 head and it's taken a few months of 1.4 - 1.5bar action which seems to be very minimal compared to a lot of these 1.8 - 2bar motors on here these days.

[JJ]

Mine's a rev2 block with rev3 head and it's taken a few months of 1.4 - 1.5bar action which seems to be very minimal compared to a lot of these 1.8 - 2bar motors on here these days.

Luke, rule of thumb for me, limit to 1.5 bar... unless you've got some £1500 min laying about and plenty of patients and time...

I'll keep the updates coming for those interested in another thread, greeny might bash me if I keep writing to this one !!

[Chris]

Don't forget to let me know too JJ If it holds I'll try do a deal with the engineers for a group buy

[JJ]

Don't forget to let me know too JJ If it holds I'll try do a deal with the engineers for a group buy

Cant forget you can I ?!?! You're the ruddy backbone of the UK MR2's !!!

Hows the Jaaaaaaaag, mine made an all time low, averaging 9mpg !!

[mr2nut123]

Mine's a rev2 block with rev3 head and it's taken a few months of 1.4 - 1.5bar action which seems to be very minimal compared to a lot of these 1.8 - 2bar motors on here these days.

Luke, rule of thumb for me, limit to 1.5 bar... unless you've got some £1500 min laying about and plenty of patients and time...

I'll keep the updates coming for those interested in another thread, greeny might bash me if I keep writing to this one !!

Yeah I seem to get a similar impression too. I don't really even want to go over 1.4bar as i've heard this is the perfect safe amount of boost really. A GT3071r at 1.4bar of boost will make over 400bhp, I guess this is the turbo to go for!

I'm an IT guy so don't fully understand the complexity of the whole boost vs power stuff, I find it weird that somebody can make 450bhp at 1.2bar for example, and it's safer than someone at 2bar making the same power with a smaller turbo.

[greeny]

Yeah keep us informed JJ

Im surprised the liners are only 2mm, yet i see the point about them being stronger.

So if your taking only 2mm out the cast liner you dont get into the water ways?

[JJ]

So if your taking only 2mm out the cast liner you dont get into the water ways?

Thats correct... no waterway intrusion / issues !! Liners available are 90mm +.. so going on that assumption, they're 2mm+ wall thickness minimum on a stock 86.00mm bore .. I used 2mm as an example of the minimum as most liners are manufatured in the states - work in inches... so the conversion to mm is + XXmm ... Most liners are 2-5mm sidewall thickness depending on application...

If you look at darton catalogues for similar applications :

Nissans SR20 engine - GTI-R / 200SX S14/S15 86.00mm bore etc
Wall thickness : 0.148" = 3.75mm
Thats on an aluminum / alloy block ( weaker block than our 3S cast iron )

Look at the RB26's which is the cast iron lump used in skylines ( similar composite / properties / manufacturing )

Wall thickness : 0.115" = 2.92mm

As mentioned previously, the 3S block is quite compact as in cylinder to cylinder spacing.... and I have seen some with larger spacing between no.2 and 3 ( smallest spacing for sizing up liners ) so it is almost essential to appetain a consistant liner for all 4 bores where it isn't intrusive to the water channels, utilising the original block for strength in retaining the liner in situ ( no floating )

Anyway, my blocks under scrutiny and testing at the moment and I will tell it how it is, so if its a non starter for long term reliability.. I'll not be recommending it.... as the comment suggests, its a long term reliability test / solution... I'm not going to be doing anything that would be different to others....so details will take its time since I'm quite busy around this as well.... So far soo good though !