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131mirafiori home => The Garage => Topic started by: simon abarth on November 30, 2014, 11:29:05 PM



Title: cylinder diameter
Post by: simon abarth on November 30, 2014, 11:29:05 PM
 hi all,
anyone know how can we re-bore maximum LAMPREDI engine   ???
then I go to 86MM? can I keep the original head gasket?
I hope your answers

pascal

( 84mm for departure ) ;)


Title: Re: cylinder diameter
Post by: TfP-Motors on December 01, 2014, 04:40:51 AM
I have 85.5mm with orginal head gasket, but there are some tolerance in dimensions cylinder holes, so you have measure yourself gasket what you think use. Payen , Elring, Goetze are good manufacturers.

i have project motor with 86mm bore, but there i have flame rings, and not started engine yet...

also i been heard 87mm bore, but not seen it on action...


Title: Re: cylinder diameter
Post by: simon abarth on December 01, 2014, 04:17:58 PM
thank you,
I think to be the maximum 86mm, I have heard many times,
I'll watch what you say to the cylinder head gasket
I own an engine block 82mm bore x 90 mm stroke
it will be good to do, where to 84x90 Other
I thought up pistons 86mm Opel GSI 16V (MAHLE) + 16V cylinder head fiat? must check the height of the piston / block
+ Compression ratio. should not be bad  ::)

the other answers are hoped to bore

simon abarth


Title: Re: cylinder diameter
Post by: simon abarth on December 04, 2014, 12:38:59 PM
no other answers ???


Title: Re: cylinder diameter
Post by: Fiat 131 Abarth#2 on December 04, 2014, 02:48:59 PM
this is an question for an engine builder!
he will give you the right answer.


Title: Re: cylinder diameter
Post by: simon abarth on December 04, 2014, 07:06:50 PM
yes it's true enzo,
is not to many requests about it  :-\
but I expect guys like roger (toad)
I think it will have ideas of what  ;)

thank you


Title: Re: cylinder diameter
Post by: sdebez on December 05, 2014, 10:46:28 AM
Can not remember where i read it, but I am lead to believe boring a fiat
Block to 86mm is more luck than judgement because you are getting
In to the area of tolerances during cast process.
Some blocks bore ok some don't, and some look ok until they have
Pressure on them.
So if it breaks in to the water jacket during boring heres the option of
Sleeving, which is what was done as a matter of coarse if going to 86mm.
This may need checking due to my foggy mind.
Sach


Title: Re: cylinder diameter
Post by: simon abarth on December 06, 2014, 08:13:54 AM
sach thank you, it is true what you say,
I would just use these pistons I have already (86mm)
and I will have new cylinder bore ::)

if some one have information other, I listen!

pascal


Title: Re: cylinder diameter
Post by: sdebez on December 06, 2014, 11:29:01 AM
Hi
If you do go 86mm, and struggle for a head gasket there
Is the option of wills rings
Sach.


Title: Re: cylinder diameter
Post by: miro-1980 on March 22, 2015, 09:00:41 PM

Hi

I believe the max size was 84.1mm due to class limitation ( 1999cc )

From experience : such modifications typically backfire, as the block needs to be greatly weaken ( 3 mm on each side.

I would not recommend it. My advice go for standard 84.

Miro         


Title: Re: cylinder diameter
Post by: simon abarth on March 23, 2015, 10:34:51 PM
thank you for your answer Miro,
I'm still not at that level of preparation, but I'll watch it. TFP motors-have 85.5 on his, the Group A Lancia Delta turbo was 84.6 homologation ...
( with 8 valves )
pascal


Title: Re: cylinder diameter
Post by: miro-1980 on March 25, 2015, 10:15:50 PM
hi all,
anyone know how can we re-bore maximum LAMPREDI engine   ???
then I go to 86MM? can I keep the original head gasket?
I hope your answers

pascal

( 84mm for departure ) ;)

There were many different block castings and therefore there are as many answers as block casting types. Going 2 mm larger seems like risky , but the only casting type i know well is the basic 124/131/132 casting type with 80 mm bore. I am not sure about the later block especially for non FIAT ( i.e. Lancia).

By the way it is easily measured just by inspecting the the engine block.

Miro