Coscast blocks we're cast by cosworth as a replacement when normal lr blocks stopped production. As we know on most engines a block is for life not so on rv8s. They are reckoned to be better cast but are still not top hat linered. I would be tempted to contact someone and have it top hatted. Unless your certain it's ok
can you take a look at the pic of the bore please mate, ive now found the coscast stamp on the block, could you tell me from that pic from the bore if its sleeved or do they come from production like that (i really dont know nothing about these blocks)
thanks ian
coscast_zpsv3qvapiv.jpg
[/URL][/IMG]
coscast1_zpsp1ousfeb.jpg
[/URL][/IMG]
 
Piccy not working, but the liner is visible in the first pic you uploaded on page 1.
Did you find engine number and compression ratio on outside of block?
 
coscast2_zpsyvajoiuj.jpg
[/URL][/IMG] i cant work out what im doing wrong with the pics.
on front off engine top left side , just under wher head sits... T460091 AND THE OTHER 1 ....coscast lcf000250.
thanks again ian
 
That is a non top hat liner block. The big chamfer aids Piston insertion and also gasflow as it unshrouds the valves. Is this good or bad for you? Are you gonna rebuild without top hats? Save you a grand but introduces some risk. I'm not sure what my approach would be. I know these blocks still have potential problems. But the rebuild cost might be tripled with top hats. The value of a top hat coscast will always be high though.
 
4.0 and 4.6 share the same bore size.........putting a 4.0 crank , rods and pistons into a 4.6 block will give you a 4.0..........4.0 pistons into a 4.6 engine will raise the compression ratio .........hope that helps
 
Rpi also provided bigger capacities on request upto 5l maybe 5.2l. how this was acheived I'm not totally sure. ( Obviously either/ or stroking or boring!) You may find it's got a bigger bang than you thought.
 
Be extra careful with your rebuild as journals and rings and rods may be any size in this block. Land Rover blocks are fairly standard. This may have offset ground big ends different rods etc etc.
 
cheers for all your answers.
i will check crank number, and measure the bores later just to see,
little bit gutted , i was hoping this to be a little gem, coscast with top hats done, would of been a keeper with fully worked tuned top end.
ian
 
You've ascertained that it's an RPI built Coscast block, non Top Hat motor. Have you measured the bore and stroke to work out the swept volume (cc) per cylinder? That'll then tell you what size it is.
Have you actually asked RPI if the can give you any more info from their serial number?
 
Yep, LCF on the block indicates a later standard LR block casting (i still have my old one in the garage). I had one in my '02 4.6 P38 & it dropped it's liners. I had an earlier WYF block put in with top hats & 4.0l pistons / 4.6 crank but that block cracked within 30k.
 
cheers for all your answers.
i will check crank number, and measure the bores later just to see,
little bit gutted , i was hoping this to be a little gem, coscast with top hats done, would of been a keeper with fully worked tuned top end.
ian
I would be made up if I were you.
You have a (assuming it's fit) coscast block 4.6 rv8. It doesn't need top hat liners.
You say you haven't took a v8 apart before. Have you experience in rebuilding engines? If not, give it to someone who has. Imagine doing all the work, fitting it and having to pull it apart again because of an oversight, or worse.
Do all that is necessary and nowt else.
 
cheers for all your answers.
i will check crank number, and measure the bores later just to see,
little bit gutted , i was hoping this to be a little gem, coscast with top hats done, would of been a keeper with fully worked tuned top end.
ian
If its a 4.6 ......and you want to sell it ........I;de be interested in it
 
I would be made up if I were you.
You have a (assuming it's fit) coscast block 4.6 rv8. It doesn't need top hat liners.
You say you haven't took a v8 apart before. Have you experience in rebuilding engines? If not, give it to someone who has. Imagine doing all the work, fitting it and having to pull it apart again because of an oversight, or worse.
Do all that is necessary and nowt else.
i should of said . never pulled a range rover v8 lump out..built a few lumps over the years, and where my lock up is i got 2 car work shops either side of me, and i let them park there customers cars...any tools info or even help, they come straight round.
engine must be 1 of the last good ones, no probs at all with it.not even a oil leak.
even the heads look like they just came straight from the factory, eve
b2.jpg
engine1.jpg
engine2.jpg
n the valley of the block was spotless
 

Similar threads