COSCAST MOTOR?

From
http://www.rv8r.co.uk/index.html


The flange at the top is quite apparent. What is less noticeable is the cunning little seal at the bottom which effectively gives the liner all the attributes of a wet liner, allowing no route for sump pressure to go up, nor water to find its way down. This works in tandem with the flange.

The flanged liner has a number of benefits when compared to the original. It can be appreciated that it is much more positively located. The flange is a press fit into the rebate machined into the head by Turner Engineering and provides a much better seal. Pressurised cooling fluid is effectively stopped from finding its way into the combustion chamber as the edge of the flange is covered by the headgasket so stopping any leakage.

When the head is bolted down it acts upon the flange, forcing it into its seat and, of course, creating the seal. And, because of the way it is located there is no chance of the liner slipping.

The new liner can be made of ductile cast iron which is much stronger than the normal spun cast iron, so making it more suitable for high performance engines.

So far so good and if that was all there was to it, it would be satisfactory. However, there is more.

Near the bottom of the liner, and on the outside, is a seal. This effectively changes the RV8 into a wet liner engine so that even if there is a coolant leak through a crack or hole in the bore behind the liner it cannot go anywhere else. Further, there is no possibility of the gasses from the combustion finding their way into the cooling system.

And also...

Heavy duty Ductile iron flanged liner (top hat flanged liner) - Ductile iron is an extremely heavy duty material which is used in high performance race engines including top fuel dragsters. This extremely robust material offers significantly higher strength in the critical flange area of the liner. Turner's design is unique in that it also incorporates a seal at the bottom of the liner. This type of liner is manufactured by Darton Sleeves exclusively for Turner Engineering and is not available elsewhere.

Ductile iron is twice as hard and strong as the grey iron and is appropriate for applications that are far less predictable, such as in very thin-wall iron block motors or most aftermarket aluminum blocks. “In aluminum blocks, where wall thickness is a major consideration, an engine builder will want to use ductile iron because the ductile material will actually reinforce the lightweight alloy blocks,” Metchkoff says. “The ductile can be warped under a heavy load, but it will return back to its beginning origin because it has tremendous memory. The material has the ability to adapt to the movement of the piston or aluminum block and bring it back to round.”

Material differences aside, there are two basic types of cylinder sleeves: the dry-type and the wet-type. Simply put, a dry-type sleeve does not contact the coolant, while the wet-type sleeve IS in direct contact with the coolant.
“A wet sleeve, when installed, completes the cooling system,” says Jay Wagner of MAHLE Clevite. “Without the liners in place there is no cooling jacket. The top is sealed by an interference fit somewhere in the counterbore area and this seal area can include sealing shims or seals. The bottom is normally sealed with O-rings in grooves, which can be either on the sleeve or in the block.”
The dry-type sleeve is pressed into a full cylinder that completely covers the water jacket. Because the sleeve has the block to support it, it can be very thin.

Funny thing.
I was up at All $x4 spares and they told me they had just got a shipment of 4.6 from UK and would sell to me for $3750 .
I said "well they must be the new Coscast Motors."

They looked at me as if I was a Martian and had NO IDEA whether they were Coscast or not.

I would think they would have to be if the Coscasts are the only ones now made, but they could be some NOS getting around I guess.
one would think that teh Coscast would be a BIG DEAL but there you go.

Regards Philip A

Thanks traco, been a great help except you lost me abit lol... but you sound like you know what your talking about, so i definately will be going with the turner block... do u think a remanufactered or seasoned block would be best???

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Originally Posted by DANMAL

so i definately will be going with the turner block... do u think a remanufactered or seasoned block would be best???

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Yes it will because it will have 'settled' and should provide a more stable basis for the upgrade. Have a look at V8Developments website I think they may have put up some reasons why they prefer to top hat well used blocks over new ones.

Of course it may be argued that the best outcome would be a Coscast block that has had top hats inserted into it, but the earlier LR blocks are claimed by all and sundry to be bullet proof once flanged liners have been fitted. V8Devs have never had one fail and they have done hundreds including their 96mm bore/long stroke 5.2 race engines which are effectively wet liner.

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Originally Posted by Traco

Yes it will because it will have 'settled' and should provide a more stable basis for the upgrade. Have a look at V8Developments website I think they may have put up some reasons why they prefer to top hat well used blocks over new ones.

Of course it may be argued that the best outcome would be a Coscast block that has had top hats inserted into it, but the earlier LR blocks are claimed by all and sundry to be bullet proof once flanged liners have been fitted. V8Devs have never had one fail and they have done hundreds including their 96mm bore/long stroke 5.2 race engines which are effectively wet liner.

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Sorry to be a pain but what would you do, do you think a seasoned bottom end from turner(already comes tophat) if it were u??

I would rather an ls2 or better yet ls7 lol yeah in my dreams, oh n I'd have to say goodbye to driveline haha

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Originally Posted by DANMAL

Sorry to be a pain but what would you do, do you think a seasoned bottom end from turner(already comes tophat) if it were u??

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Have you considered a local supplier?

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Originally Posted by p38arover

Have you considered a local supplier?

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I would if I new one... Do u know any???