Coscast blocks

[TRip]

Hello everyone.  I'm completely new here and this is my first post.  


Does anyone know anything about Coscast blocks?  

Are they exclusively an aftermarket item from http://www.mahle-powertrain.com/ or, can they be found in later model 4.6 Rover V8's?

Are they readily available and how do you ID them?

I have tonnes of questions about the project that I'd like to carry out on my TR7 to TR7V8.

So I'd be thankful for any and all insight that you may share.

Thanks in advance.

Trip

[TRip]

 -- moved topic --

[NixVegaGT]

I haven't heard of them. Anybody else?

[castlesid]

Trip,

I haven't actyally heard whether any of the coscast blocks made it into any production vehicles or were used to replace cracked 4.0 /4.6 blocks under warranty.

I was told by a LandRover engineer that they were cast to a far higher standard than the originals and having seen pictures of the castings I was under the impression that was the case.

However within the last week I have heard  that amongst 19 blocks V8 Developments had in for repair with top hat liners, that two were Coscast blocks, but I did not hear this direct from V8 Devopments so cannot swear to the accuracy of the information.

You don't show your location but if in the US it may be cheaper to find a used 4.6 engine and have it top Hat linered.

Kevin.

[TRip]

Hi Kevin,

Thanks for the insight.  

You're right, if Coscast blocks are coming back with the same issue, then it wouldn't be worth the expense of new.

Top hat linered 4.6 may just be the way to go.

If you get any confirmation or further info about the "V8 Devopments" report could you please post or PM me?

I'll also check into it and post when I find any info.

Thanks,

Trip

[roverman]

Trip, Please read ,"new Rover blocks" ,several entries, including one from ,"Nic", remember Nic? I've been talking to Mahle drivetrain to attempt/convince them to sell bare/flanged, linered blocks in aftermarket. Since there was no real intrest from this forum, it has'nt went anywhere.   Good Luck, roverman.

[TRip]

Okay, I'll read the ,"new Rover blocks" post.

BTW.  I've been researching Coscast and have come across a co. http://www.v8developments.co.uk/ that states that they use Coscast blocks in their builds.  I've emailed them to enquire if they sell bare blocks.  I'll post when I have an answer.

Trip

[MGBV8]

I'd love to have one, but $1700 for just the block. I can't do that.

http://forum.britishv8.org/read.php?6,8208

[roverman]

Carl, Mahle drivetrain quoted you that amount? That sounds like a "V8 Developments" price,(retail), but when I contacted them, they had no interest in selling bare blocks. Obviously the better way is to buy them here/direct. If/when the TA or "other" hiperf. heads are fully exploited, they'll need a sturdy block. I'm thinking if enough people inquired of Mahle drivetrain,who knows we might even get a sonic report for cylinder wall/alum. thickness? I've already asked them to consider flanged liners and taller lifter bores,(use std. chev. roller lifters). roverman.

[TRip]

roverman, you and I both wanted the Coscast block to eliminate the issue of porsity.  However, a friend contacted V8 dev and got the following response:

We can no longer supply Costcast blocks or short motors.

Coscast blocks  do not  address the problems associated with  Rover blocks ie slipping liners and porosity.

We use top hated blocks as these address all the problems. The liners cannot move as they are clamped between the head face and the block

And the fitting procedure eliminates the porosity problems. We have used top hated blocks for over 30yrs  and to date have had

No failures .  The blocks are top hated, New cam bearings fitted, line bore checked, cam alignment checked, new core plugs fitted and the

Oil gallery plugs removed then the is block  acid dipped and chemically cleaned.  The cost of a top hated block on exchange is £895 + VAT. An

Outright purchase is available for £995 + VAT.

 

Thanks for your enquiry

Ray Webb

[v8fangio]

RPI Engineering U.K. have them on their website

[hoffbug]

Nic and I both have used blocks bought domestically  that we are having fitted with top hat liners from Westwood in the UK..

http://westwoodcylinderliners.co.uk/index.php/products/marques/liners/rover_v8/

Nic's are done .. mine are still in the box awaiting capital... LOL

[roverman]

Ok, so if we're to believe, anything in that, How to build a Rover V8,unless I "missed" something, the "issue" was core-shift  in the bores not porosity. Big difference. If were building a 'pink"  or otherwise, block and using "flanged liners", a wise choice would be a thoughrough visual after orig. sleeves removed,dye penetrant, pressure  and sonic test, all sound insurance to purchase prior to proceeding further. If you don't like the wall thicnesses on say , major thrust side,(sonic report), you can still offset compensate. I still believe if enough people requested blocks without liners or with flanged liners, including a sonic report from Mahle, it could happen. roverman.

[hoffbug]

Nothing a 4 axis boring machine couldnt compensate for..

[NixVegaGT]

Well I just sleeved a block I'm CERTAIN has cracks in it. The way it was heat cycled by the time I got it two liners had already dropped. We'll see what happens.

SO that's a couple things I'm testing.

1. Hyper eutectic pistons with moderate compression but no chance of detonation.
2. Block porosity behind the cylinders.

I'm eager to see what happens. I didn't have the balls to just pin the liners. LOL. Otherwise I'd be testing that too.

[TRip]

Hey Nicholas,

If the sleeves drop again, get a set of top hat liners next time around and have the block checked and welded.  If the motor hasn't been put together yet, it may be best just to top hat it now before assembly rather than having to break it all down again in the future.

"Hyper eutectic pistons" ie: cast pistons are good for stock applications but if you plan on adding a lot of HP and or compression, forged pistons are the way to go.

Not sure that pinning the liners is the ideal way to go.  Top hats are.  Top hats also reduce the possibility of coolant getting by the heads/block into the cylinders and also pressurizing the coolant system... More problems

Trip

[hoffbug]

Anthony .. Nic and I have top hat liners.

[TRip]

Nice... you guys definitely made the right choice.  No dropped liners next time.

Trip

[roverman]

Yeah and .002" "proud" above the deck for o-ring effect? AnAn  maybe a "little" relieving on top of bores to enhance air flow? roverman.

[Roverboy]

good point roverman,

I was just wondering if decking was not part of the overall process.  However with decking and head planing we need to difert some attention to head gasket thickness and or valve/piston clearance issues and this more so  dependant on the cam profile lift/duration etc etc.

we must be respectful that one change will affect other components on any engine rebuild.

I do however like the tophat sleeving solution, but care must be taken in choice of sleeve, wall thickness etc etc.

[Robrover]

One of the best solutions seems to be provided by Turner Engineering who use the incredibly strong ductile iron flanged sleeves.  They insert these into seasoned 4.0/4.6 blocks, and sometimes new ones (presumably NOS Land Rover blocks, not Coscast ones). They even guarantee them for 3 years. I've never heard of one failing.

RPI claim that one of the dangers of top hats is that the flange at the top can, in certain circumstances, crack or break off - though I've never seen or read any reports of that happening other than the RPI site advertising the advantages of Coscasts.

But with V8Developments reporting cracks starting to appear behind the (non top hat) liners of Coscast blocks it seems the safest bet is to go for a strong flanged block - and Turners appear to have demonstrated best practice here.

[pcmenten]

Did I hear 'long sleeves'. Nic and I were bench racing a stroked engine using a Buick 340/350 crank. Nic concluded that the long stroke would pull the piston out of the bottom of the cylinder. Perhaps this long sleeve is a potential solution.

[NixVegaGT]

That would be nice...

[castlesid]

Guys,

From what i've read even a 3.4" stroker crank needs some relieving of the block, anything larger is going to need careful consideration.

To use longer liners you would have to remove the registers at the bottom of the bore and then there would be nothing to seal against, you may also run into problems with cam and rod interference.

Kevin

[NixVegaGT]

I think you can get away with it if the liners are flanged. Are those longer ones not flanged..? I wasn't paying close enough attention.