Ford Sierra/Sapphire/RS500 Cosworth This forum is for discussion of all things pertaining to the Ford Sierra Cosworth.

Bottom end spec for 450-500hp...

Thread Tools
 
Search this Thread
 
Old Mar 1, 2014 | 09:59 PM
  #1  
turbotrev's Avatar
turbotrev
Thread Starter
Advanced PassionFord User
 
Joined: Jul 2003
Posts: 2,051
Likes: 89
From: Sutton
Default Bottom end spec for 450-500hp...

Is this bottom end engine spec good enough to reliably run 450-500+hp...

200 block with a standard bore, Cosworth Racing pistons, 7.8:1 comp ratio, 6 studded, WRC headgasket, standard grind crank, big wing sump.

Cheers Paul
Reply
Old Mar 2, 2014 | 01:06 AM
  #2  
Liam G Poole's Avatar
Liam G Poole
15000
 
Joined: Aug 2013
Posts: 32
Likes: 0
From: horsham
Default

That bottom end if fresh built and has a std std crank profile is good for 600 hp
Reply
Old Mar 2, 2014 | 07:58 AM
  #3  
Staffi's Avatar
Staffi
20K+ Super Poster.
iTrader: (1)
 
Joined: Nov 2005
Posts: 21,194
Likes: 107
From: Don't be nosey
Default

Hell yeah
Reply
Old Mar 3, 2014 | 01:29 AM
  #4  
J1mbo's Avatar
J1mbo
B1mbo
iTrader: (1)
 
Joined: Sep 2007
Posts: 14,986
Likes: 1
From: Peterborough
Default

That's good for the power you want. I would disagree with liam as I've seen the standard liners crack at 600bhp.
Reply
Old Mar 3, 2014 | 09:14 AM
  #5  
Mike Kerbey's Avatar
Mike Kerbey
Too many posts.. I need a life!!
iTrader: (1)
 
Joined: Jan 2008
Posts: 974
Likes: 0
From: Crawley, West Sussex
Default

Yep, no problem
Reply
Old Mar 3, 2014 | 02:19 PM
  #6  
turbotrev's Avatar
turbotrev
Thread Starter
Advanced PassionFord User
 
Joined: Jul 2003
Posts: 2,051
Likes: 89
From: Sutton
Default

Cool, yeah wouldn't need to be 600!
Thanks people,

Cheers Paul
Reply
Old Mar 3, 2014 | 02:22 PM
  #7  
Chip's Avatar
Chip
*** Sierra RS Custard ***
iTrader: (3)
 
Joined: Dec 2006
Posts: 47,250
Likes: 22
Default

For the power you want, standard is fine.

Just dont mistake substandard, for standard which is what a lot of people do, there are some positive wrecks of bodged up YB engines out there now.
Reply
Old Mar 3, 2014 | 02:46 PM
  #8  
Mark Shead's Avatar
Mark Shead
PassionFord Post Whore!!
 
Joined: Jun 2003
Posts: 5,472
Likes: 223
From: Marlow Bucks
Default

Originally Posted by turbotrev
Is this bottom end engine spec good enough to reliably run 450-500+hp...

200 block with a standard bore, Cosworth Racing pistons, 7.8:1 comp ratio, 6 studded, WRC headgasket, standard grind crank, big wing sump.

Cheers Paul
Why is it on standard bore is it a new block or a old engine.

Mark
Reply
Old Mar 3, 2014 | 03:32 PM
  #9  
delbee1's Avatar
delbee1
PassionFord Regular
 
Joined: Nov 2012
Posts: 409
Likes: 6
From: Twickenham
Default

Originally Posted by turbotrev
Is this bottom end engine spec good enough to reliably run 450-500+hp...

200 block with a standard bore, Cosworth Racing pistons, 7.8:1 comp ratio, 6 studded, WRC headgasket, standard grind crank, big wing sump.

Cheers Paul

I think you can use standard pistons up to 500 - 550, with valve cut outs
Reply
Old Mar 3, 2014 | 03:55 PM
  #10  
Liam G Poole's Avatar
Liam G Poole
15000
 
Joined: Aug 2013
Posts: 32
Likes: 0
From: horsham
Default

Originally Posted by J1mbo
That's good for the power you want. I would disagree with liam as I've seen the standard liners crack at 600bhp.

The liners could crack at 500 hp,all im saying is there is 600 hp cars out there with standard liners,just making the point that he is well safe around the 500 hp mark..

Mark has picked up on a good point though,why is it on a standard bore?new block or and old bore on a new piston? them questions need to be answered before you throw 500 hp at it?
Reply
Old Mar 3, 2014 | 06:11 PM
  #11  
turbotrev's Avatar
turbotrev
Thread Starter
Advanced PassionFord User
 
Joined: Jul 2003
Posts: 2,051
Likes: 89
From: Sutton
Default

Ahh ok I see what you mean, it's the bottom end spec on a car I'm tempted to look at that's for sale, but I'm after around the 450-500hp (ballpark) figure, at the moment it's only on greens, a standard head and a t34.
As far as I'm aware it's had a very recent rebuild, I guess the owner built it like that in incase of any further mods/power.

I think it's an old block just fitted with new pistons so am guessing it didn't need over boring and measured up ok....

Cheers Paul
Reply
Old Mar 3, 2014 | 06:19 PM
  #12  
delbee1's Avatar
delbee1
PassionFord Regular
 
Joined: Nov 2012
Posts: 409
Likes: 6
From: Twickenham
Default

Originally Posted by turbotrev
Ahh ok I see what you mean, it's the bottom end spec on a car I'm tempted to look at that's for sale, but I'm after around the 450-500hp (ballpark) figure, at the moment it's only on greens, a standard head and a t34.
As far as I'm aware it's had a very recent rebuild, I guess the owner built it like that in incase of any further mods/power.

I think it's an old block just fitted with new pistons so am guessing it didn't need over boring and measured up ok....

Cheers Paul

Dont sound right to me mate. The Cosworth Racing pistons would have different tolerances to the standard ones
Reply
Old Mar 3, 2014 | 06:56 PM
  #13  
turbotrev's Avatar
turbotrev
Thread Starter
Advanced PassionFord User
 
Joined: Jul 2003
Posts: 2,051
Likes: 89
From: Sutton
Default

If I do go look at it I'll find out the exact story, hopefully he'll have some receipts too...

Cheers Paul
Reply
Old Mar 3, 2014 | 08:03 PM
  #14  
Liam G Poole's Avatar
Liam G Poole
15000
 
Joined: Aug 2013
Posts: 32
Likes: 0
From: horsham
Default

Originally Posted by delbee1
Dont sound right to me mate. The Cosworth Racing pistons would have different tolerances to the standard ones

The only good thing about that is that when using a cosworth race piston its usually a little more skirt clearance needed so if it was a good old block and managed to get honed out to like 4 thou for example that would be about perfect for those pistons..

Before i put 500 hp through it id just have skirt clearance checked..,a bit of a ball ache but no real expense and piece of mind
Reply
Old Mar 4, 2014 | 08:43 AM
  #15  
Chip's Avatar
Chip
*** Sierra RS Custard ***
iTrader: (3)
 
Joined: Dec 2006
Posts: 47,250
Likes: 22
Default

Originally Posted by turbotrev
Ahh ok I see what you mean, it's the bottom end spec on a car I'm tempted to look at that's for sale, but I'm after around the 450-500hp (ballpark) figure, at the moment it's only on greens, a standard head and a t34.
As far as I'm aware it's had a very recent rebuild, I guess the owner built it like that in incase of any further mods/power.

I think it's an old block just fitted with new pistons so am guessing it didn't need over boring and measured up ok....

Cheers Paul
As ive already mentioned, condition is everything, the spec is fine for the power you want, but if its worn out then it isnt!
Standard bores certainly rings alarm bells on a 20+ year old engine thats already had at least one rebuild.
Reply
Old Mar 4, 2014 | 08:46 AM
  #16  
Chip's Avatar
Chip
*** Sierra RS Custard ***
iTrader: (3)
 
Joined: Dec 2006
Posts: 47,250
Likes: 22
Default

Originally Posted by Liam G Poole
Before i put 500 hp through it id just have skirt clearance checked..,a bit of a ball ache but no real expense and piece of mind

A leakdown test would be a very simple way to get a reasonable indication of condition.
Reply
Old Mar 4, 2014 | 11:50 AM
  #17  
Staffi's Avatar
Staffi
20K+ Super Poster.
iTrader: (1)
 
Joined: Nov 2005
Posts: 21,194
Likes: 107
From: Don't be nosey
Default

Originally Posted by Chip
As ive already mentioned, condition is everything, the spec is fine for the power you want, but if its worn out then it isn't

Have to agree totally with this.
Reply
Old Mar 4, 2014 | 01:00 PM
  #18  
Liam G Poole's Avatar
Liam G Poole
15000
 
Joined: Aug 2013
Posts: 32
Likes: 0
From: horsham
Default

Originally Posted by Chip
A leakdown test would be a very simple way to get a reasonable indication of condition.
Very true but before putting together a complete engine and then all the trouble of fitting it up etc id still like to know what my bores were like,skirt clearance how oval etc as a leakdown will just show its not knackered but if the bores measure up nice then no worries at all..

All depends how anal you want to be,im sure guys that race etc would just chuck a head on it and rag it to see if its good! lol
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Focosmitch
Ford Focus RS Parts for Sale.
5
Mar 9, 2016 01:03 PM
Focosmitch
Cars for Sale
9
Nov 5, 2015 08:12 PM
Dave_b
Ford Focus (All Models)
2
Oct 13, 2015 05:48 PM
pie-face
Technical help Q & A
0
Sep 15, 2015 10:43 AM
Tank Mike
Cars & Parts Wanted.
5
Sep 10, 2015 07:56 AM




All times are GMT. The time now is 03:38 AM.