B11GNS

The engine in my car has recently been rebuilt but with a 1mm overbore on a 205 block, am i limited to how much power i can run due to this overbore?

Rs Gus

iTrader: (2)

yessssssssssssssssssssssssss 1mm on a 205 fook mme

B11GNS

That dont sound good, so what is the most i could run? it runs a stage 1 at the moment

Rs Gus

iTrader: (2)

PROBABLY WHAT U HAVE IS SAFE I WOULDNT SAY MUCH MORE ON 1MMoops caps

B11GNS

Not really what i wanted to hear, is the reason that its now too weak due to the thinner walls?

Rs Gus

iTrader: (2)

yes the 205 block is weak as std m8

B11GNS

So a stage 3 is out of the question then?

pugo

stage 3@ 22psi will be fine

as long as everything else is up to it

B11GNS

It had 4 new 4x4 pistons, new crank, fully rebuilt head.

Anymore opinions as i now seem to be getting different ones

ImaRacing 700

Hi....my opinion is liner it so you can use std size pistons....its what i did on a stage 3 running 2bar peak .....The liners are stronger than the block so you take all cracking risk out.....1mm is pushing it imo although i have never run it so can only guess.

markk

iTrader: (2)

m8 if the engine shop checked the block and was happy to bore it then dont worry , i have a 205 block and lets put it this way its bigger than yours , stage 3 would be fine, as for 205 blocks being weak - its bollox , they are differant in casting but detrimental i think not - the argument will go on for ever m8, just be aware the 205's are generally older then the 200 series. personally wouldnt have a 200 block due to past experiances and thats from a competition point of view not just road driving m8

CharlieSaff

Phone Stu @ MSD in the morning and he will tell you what he told me. 380 brake is about the limit with 1mm oversize (just rebuilt mine with this)

Mine is going back on stage 3 for now.

CharlieSaff

How many of the people who've replied are engine builders?

pugo

I am

not going to go into metalurgy of this but cast gets stronger with age..older the better
i would rather an old 205 over a new 200 any day of the week....an old 200 is a different matter though

markk

iTrader: (2)

Stu @ M Developments

iTrader: (12)

Its far more complex than a single figure TBH and im sure i will have mentioned 4wd Vs 2wd block flex due to grip as well unless i was very busy

As Mark says, theres plenty of ultra high torque motors running well on 205s but sometimes bolting that successfull motor into a 4wd car will crack it.. lol

markk

iTrader: (2)

a man with sence

markk

iTrader: (2)

corrosion is generally the 205 blocks downfall im afraid , top end casting is the 200 blocks downfall - those who have built them will know what im on about

B11GNS

If stu says its ok then thats good enough for me, wont want to go as much as 380 anyhoo

ImaRacing 700

Yes i build my engines...but not on 1mm over.....as i always run liners

Stu.....of course 4x4 needs the 200block due to increased grip which increases the chance of cracking...a 2wd is shit for grip if left,so in reality you could put 800bhp thru a 1mm oversize block and not crack the fucker

pugo

so if you always run liners why not fit thicker liners so at 1mm o/size you still have a wall thickness greater than std????or are these off the shelf liners and not fabricated by yourself?????

Pugo

CharlieSaff

Just what I thought

simonc

I have a 205 block that is 1mm overbore, has done 3k since rebuild,2k of that at 22 psi stage 3 T34/greens/500 i/c, L8 pectel bb etc, mapped by Paul Hills @ 365 bhp at flywheel, he said if i were to fit greys & cams i would see about 400 bhp but when i told him it was on a 1mm overbore he said keep it at stage 3.

Simon.

pugo

as i said earlier...............stage 3 will be fine

pugo

B11GNS

Stage 3 it is then

Ollie

It aint ideal but i wouldnt worry unduly , stg 3 should be fine if u had a good 205 block to start with , u are in to other issues after that any way

Anonymous

Funny how i have seen a stage 1 escort cos block cracked then...

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