¶ Sleeving Technology for Boosted Engines
As power and boost levels spiral out of control . This can be too much for some factory alloy blocks and this results in a range of problems right up to the point where the sleeves can actually split . We're here with John from Dart and Sleeves to talk a little bit about sleeving technology .
Welcome to High Performance Academies' tuned in field report podcast series . In these special midweek episodes , we look back through our archives to find the best conversations we've had through years worth of attending the best automotive events across the globe .
We've pulled the audio from these tech filled interviews with some of the industry's most well known figures and presented it in podcast format for you to enjoy as a quick hit of insider knowledge . Now for a start with a high level view what is a sleeve and how does it fix that particular problem that I've just described ?
Sleeving actually adds more rigidity and more strength and more structure to the blocks themselves . A lot of times with the aluminum blocks and stuff they are better materials now than they were before , but they're still weak in the cylinder areas and stuff to where that's the sleeve involved .
It makes the block a lot stronger , especially more than with the stock application intended it to be when they were first originally made them .
So the other element here is a lot of these alloy blocks .
The way that they are cast is that they are what we refer to as open deck , which in a nutshell means that the existing sleeves essentially aren't linked or connected to the outside of the block , and this can result in problems like the sleeves tending to flex and move around and cause head gasket failures at high boost levels .
So what is the solution in the aftermarket with a sleeve to fix that particular ?
element . The first thing we do is we actually make where we call our MID sleeve . It's actually a lot thicker and creates an actual removable option and a closed deck option for the sleeve . So what we're doing is we're eliminating the stock freestanding wall and the casting and replacing it with a ductile iron sleeve .
So what that does is actually same thing and makes the block more rigid and then actually closes and gives the block complete support up at the top . So you don't have that problem .
When there are high boost applications where you got a lot of sidewall load , where we have what we call sleeve walk with the open deck configuration , that fixes that and stuff and closes everything off and gives added support to the top . So you don't have that problem stuff with any movement . So you don't have that head gasket issue in the long run .
Now , one of the common problems we hear with slaving in the aftermarket and this is not just for the Darden brand , it's every sleeve out there is that it seems to be a bit of a lottery as to whether or not you're going to suffer from a sleeve dropping once the engine is assembled and it's run for the first time and it's heat or heat cycled , I should say
Now , before we get into what causes that , can you expand on what I'm actually meaning , what that term a sleeve dropping actually refers to Generally , what that is , is when the sleeves actually are installed .
Once they're ran , the sleeves either settle and they'll actually sink below the deck surface , which essentially that causes you to lose head gasket seal . So you'll have generally a response to have a flush deck . Once the sleeve sinks it moves down below that deck , so then essentially losing all the embossment that's around the compression area loses complete seal .
So then you actually get leaking into the cylinder itself because you just there's no seal for head gasket anymore due to the sleeve sinking below the deck surface .
We're only talking potentially a few thousandths of an inch here . That's not a lot of movement that's required to cause this problem , correct .
Correct . You're looking like maybe 3000 , or make a few any type of seal , because once that embossment moves away from that surface , then you're going to get water goes where it's going to go , especially so it's going to seep 1000 , 2000 . It's going to create some type of leakage or even compression out and stuff into the cooling system , depends .
You know what kind of power levels
¶ Sleeve Installation Issues in Aftermarket Machining
you're looking at .
Okay , so this is a problem that we hear a lot about . What is causing it ? What is the problem that's actually resulting in these sleeves dropping ? If you look at the sleeve .
It's a solid piece of metal . There's no moving parts to it . So generally it's a process problem . When we actually machine blocks you look at the sleeve . You measure the register where the sleeve is actually supposed to sit . When you go to machine the block you generally recommend doing that , say , 5000 shy .
So what happens is once you put the sleeve in , you measure the sleeve , measure the block , see where your register depth source to be . Say you do it 5000 shy .
Once you put that sleeve in , once it's seating up from that 5000 , if you're using locked air or epoxy or wherever trying to seal the block , once that's in you see that the sleeves in that difference .
Then you're able to know the block is complete , the sleeve seated , and you can flush , deck that block and stuff without having any problems , because it's primarily not having the sleeve seated in the first place .
And that sounds , on face value , to be relatively straightforward , doesn't seem like rocket science . Why are there so many problems in the aftermarket with the machine shops installing these sleeves ? Is there a lack of skill , a lack of reading the instructions , or is it the equipment they have access to ?
Sometimes it's equipment . I mean you look at CNC's now they've come a very long way .
I mean there's still guys out there a lot of workshops still running boring bars and stuff and you're not able to hold the tolerances and stuff that you should be doing with like a CNC I mean they're able to do , especially when you're doing sleeving there's we're running on like half a thousand tolerances on a lot of this stuff You're doing this with like a
boring bar . It's even hard to maintain bore centers without having , say , digital and stuff . To be able to maintain all that and stuff With having everything within half to one thousand tolerances a lot of machinery you're not able to do that unless you're using a precise CNC machine .
So would you say on that basis then , really CNC equipment is a requirement or is old-fashioned equipment with a really skilled operator able to do the job ?
No , cnc I mean , it's the future and there's a lot of things you can do . Some of our sleazer they're really in-depth cutting and stuff machining . You can't do an interpolated cut with a boring bar and stuff . A lot of things you have to , especially the way cup blocks are casted . There's no just machining straight holes . Some of them you got to avoid stuff .
Some of them water jackets , you have to avoid cutting certain depths . You got to be able to call it multi-diameters and stuff . And those things are difficult to do unless you have a CNC machine .
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Okay , another question I've got is that cutting or removing the material from the alloy block , obviously it generates heat and when we look at some of these MYD sleeve installations there's a huge amount of material . Basically you're machining the entire center out of these blocks which is going to generate heat . Does this need to be accounted for ?
Because obviously the aluminum material of the block is going to expand as it gets hot with that the friction . So do we need to factor this in when the final cuts are being done , or is it not an issue ?
Well , we do because , like I said , we're holding tighter tolerances when it comes to doing our sleeves . So a lot of the machines out there there's two types of machines . You have the regular open machines and then you have flood coolant machines .
Usually when you have a flood coolant machine you're able to actually hold the tolerances better because you're able to control temperature so you can get , as say , aggressive when you're not doing flood coolant , you're sitting there . You can't just hog out a block and one from a machine pass and be able to take out enough material to put it in sleeve .
But unless you're running flood coolant , you got to take smaller cuts so you don't overheat that block and not cause distortion . So having a flood cooling machine actually helps because you're keeping that range of temperature at a more controlled level and you're about actually take out more material at once .
Makes sense In terms of getting a customer aligned with a machine shop that Darden are comfortable with , know that they can do the job and deliver that customer really good results . Do you have a resource to help customers link up with those machine shops all around the country or all around the world ? Oh yeah , we do .
On our website . We have , like our distribution list and it does give an idea of like the best shops that we deal with . And then we also have recommendations to because there are a lot of good shops that can do the machining and we give people that option . You don't have to just go to us .
There are a lot of good machine shops that we will refer people to and stuff , especially depending on what area they're living in .
All right , perfect
¶ Benefits of Using Right Machine Shop
. It's good to sort of get a little bit more understanding around the sleeve dropping and hopefully our listeners can now understand that it's not a guaranteed that you're going to have these problems . Using the right machine shop can can avoid that pain , and people want to find out more about your specific products and sleeves how they best to do so , john .
Oh , you can go to our website wwwdartonsleevescom , or find us on Facebook , instagram and Twitter . Thanks for your time , no problem thank you .
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