CRANKSHAFT FOR 131

[miro-1980]

Guys,

I am looking for the strongest possible stock crankshaft for a very powerful (180-200 bhp) high RPM (8000 +) 131 2 liter engine I am trying to build.

Anybody knows if Lancia Delta Integrale crankshaft would fit a standard fiat 131 2 liter engine block? I imagine that with LDI 300 odd bhp the crankshaft would be stronger than stock fiat's.

Were Abarth crankshaft any stronger than civilian stock ? I know they were lighter.   

I was told that the crankshaft from Croma fits, but I am not sure if it is any stronger than stock 131  and also that one from Lancia Thema does not fit ?

Any other ideas ?

[theredx19]

Turbo cranks have different crank pins and any of the 16 valves have the oil pump on the end of the crank so they dont fit..

[mirafioriman]

Is the standard crank not steel? Pretty strong as standard I think.

[parrish]

You need advice from here.

http://guy-croft.com/index.php?sid=bab6143c053945c0b2c759b9b307e81b

[alan.acs]

Hi MIRO i use the standard 2,litre twin cam crank in my rally car it has 211 bhp as measured on 3 separate rolling roads
and its is fine.

The crank as standard is steel ,balanced and tuffrided and has five main bearings which means it wont flex or cause any problems just make sure you use the best quality bearings you can get.

Also we are building a new engine which we are hoping to get about 225-230 bhp and still use the 131 twin cam crank.

[miro-1980]

Thanks alot !

I do feel reassured !

We will go for standard 131 crankshaft !

[alan.acs]

Also by the way try and use the block that the crank came with as it is line board.

[Testament]

the fiat 2L crank is about as strong as the come - forged EN39B or EN40B, then nitrided/tuftrided - all the "old style" cranks are more or less interchangeable 131/132/lancia beta/fiat strada abarth 130TC The FWD engines do have a slightly different recess in the flywheel end of the crank to suit a bush instead of a bearing - but a bearing can be made to fit so that they can be used in a RWD setp.

Its only after 1986 with the "reverse port" engines and then 16v versions that things changed a bit with the crank driven oil pump. the material of the crank is the same though.

All the other Fiat/Lancia twin cam cranks are forged (although i think only the 2L ones are nitrided) EXCEPT the 1585cc motors which have a cast crank. That said I have not heard of these being "weak" at all even in 200+hp delta hf turbos.

As far as 200hp/8000rpm 2 litre motor goes, the crank isnt an issue - connecting rods and valve springs will need to be changed though. There are plenty of turbo or supercharged engines out there making 300-400-500hp or even more on standard cranks.

[miro-1980]

Testament and alan.acs !

Thank you guys!

I actually have the original crank from the block we will be using .

Miro