LS3 block

[p13rka]

Doh!
For those that were at thunder road, it will come as no surprise to hear that I'm looking for a new LS3 block.
Unfortunately it seems that my genuine part corvette exhaust valve (friction welded) let go. = valve head dropped - smashed piston then went every where.
Oh well --it happens.
For sale 6 standard pistons + crank and upgrade cam .... I'll be going 4.125"crank and stroker kit from here on.
alas i need to catch colin in his M3= ls3 = 174mph.

[Bonnie and Clyde]

I was there, which car do you have?? Its not on your profile?? Did you break it at TR??

[S800VXR]

They are quite reasonably priced new - speak to Mark at Rapid.

Any ideas what Harrys engine problem was..? Tapet or more likely a broken piston...?

[after_shock]

Bonnie and Clyde said:

I was there, which car do you have?? Its not on your profile?? Did you break it at TR??

Was the Z3 wasnt it?

[gsd2000]

I thought the z3 had clutch issues but then again it was being towed by the m3

[Boosted LS1]

OP, unusual for a valve head to let go. Have you got a radical cam installed or are your springs stock, ie lots of valve bounce? I've got loads of solid stem stock valves if you need some to fix up the heads.

I've heard quite a lot that there can be issues with hollow valves in extreme installations but there are better grade materials available at a price, expensive to!

[stevieturbo]

And 4.125" is a hell of a stroke. I wouldnt want to be revving that too hard.

[Bonnie and Clyde]

after_shock said:

Bonnie and Clyde said:

I was there, which car do you have?? Its not on your profile?? Did you break it at TR??

Was the Z3 wasnt it?

I don't know and now he's buggered off we'll never know

[Boosted LS1]

stevieturbo said:

And 4.125" is a hell of a stroke. I wouldnt want to be revving that too hard.

That's what he wants next Stevie (not what he had) so maybe he won't rev it as high.

[Dr Prod]

Boosted LS1 said:

OP, unusual for a valve head to let go. Have you got a radical cam installed or are your springs stock, ie lots of valve bounce? I've got loads of solid stem stock valves if you need some to fix up the heads.

I've heard quite a lot that there can be issues with hollow valves in extreme installations but there are better grade materials available at a price, expensive to!

Sorry to hi-jack, can you check this thread boosted

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

[Boosted LS1]

I saw it DP but he's just 'thinking' about it. I try to avoid the them nowadays. Thanks for the nod though.

He's not thought about his gaskets either but has had some good advice from other posters.

[ringram]

yeah 4.125 is a large stroke for the stock sleeves. but a long stroke creates a good pressure delta to work good heads. Pistons need to be good with compression height and ring lands etc.

i take it you trashed your block then mate? You could pm trailermasher. He 'may' have an ls2 block spare soon. Or skip the ls3 and get one of the newly released updated lsx blocks and do it properly with 454 cubes!

[Boosted LS1]

Be very careful with that stroke and ls3 sleeves as something nasty may happen at bdc. You can feel the pistons rock and it's not a nice feeling. It goes away once the rings are fitted but I wouldn't do it.

Darton/RED have been heavily involved with developing wet MID sleeves for this block. There's a new book out, "How to Build and Modify GM LS-Series Engines" by Joseph Potak. It is available through Amazon. Most of chapter 2 is about MID sleeves and Darton stuff although I've not read it myself. I know the sleeves are longer (for piston support), stronger and of a wet configuration. The conversion is quite popular in the US.

[eliot]

p13rka said:

Doh!
For those that were at thunder road, it will come as no surprise to hear that I'm looking for a new LS3 block.
Unfortunately it seems that my genuine part corvette exhaust valve (friction welded) let go. = valve head dropped - smashed piston then went every where.
Oh well --it happens.
For sale 6 standard pistons + crank and upgrade cam .... I'll be going 4.125"crank and stroker kit from here on.
alas i need to catch colin in his M3= ls3 = 174mph.

Are the heads scrap?

[Boosted LS1]

^ Are they ls3 heads or earlier?

[p13rka]

Mine was the z3, It has damaged 1 of the heads so I'll replace that, I definately want a replacement LS3 block so I just need to scrape the funds together then get on with it.

[p13rka]

Sorry forgot
The cam is not radical atall it just seems I was unlucky,and yes it was thunder rd
I will relace with 1 piece mahle valves.. like i said i have a while to spec and build it so no rush.
Need crank rods pistons head gaskets cam chain etc it will be all new again.
thanks for the comments.

[p13rka]

Also forgot
It had standard LS3 heads but changed valve springs.

[bennno]

Was thinking about putting an LS7 in my VXR8 - what is a 2400 mile old LS3 worth?

Bennno

[Magic919]

£3K on a good day.