M20 324 Crank

[mobster]

Currently i am running a ETA block with an ETA crank and a complete 885 Head. I have a forged 324 crank in storage waiting to be used. If i decide to use it, is it a straight awap between the ETA crank and the 324 crank. Also, will i benefit from any power gain.

Secondly why cam do you guys reccommend for my engine. I dont really want ti too lumpy on low revs.

Thanks in advance for all help.

[eta]

Yes you can use. Why do you think there is a power gain? The crank has the dimension and can rev to like an eta crank. so no power gain.

As for cam what are you after. top end power or low end grunt.

[mobster]

Well i run a dogleg box so my top end is restricted anyway by the 1:1 ratio on 5th gear. I dont think changing the cam will give me any benefit at the top end becuase of the box, therefore, is lower end i guess.

[Mikey_Boy]

Remember that eta isn't talking about vehicle speed here but engine speed when referring to 'Top End'.. If you have more revs available to you then your shorter dogleg gearbox becomes more flexible as you have more useable engine speed, with engine 'running out of puff' a little later than with the standard cam.

Depends on use I would suspect - track or road?? If it's both, I would suggest a 270ish cam to give you a good torque spread and decent top end performance...



Cheers,
Mike

[mobster]

Car is road use. I definately want to go for a Schrick cam. I might stick the forged crank in there as it is only sat round collecting dust.

[eta]

There is no gain in replacing your eta crank with the 324 crank unless your eta crank is worn out or you want the extra work.

For road use there is little wrong with the stock cam if coupled with the correct diff ratio. With the engine you have the static CR is 9.35:1. Fitting a cam with longer inlet duration/valve overlap is not going to do the dyamanic CR any good and will make it lower. What I am trying to say a cam upgrade will have an effect but not as much on a higher CR 2.7 build. There is only so far you can take a 2.7 eta with 885 head. Also you will to change the timing belt which adds cost and propably remove the head so that means a new headgasket. So all that cash for 10 ish hp. Does not sound like a good deal to me. This is why I have bought a turbo.

[Andyboy]

The standard cam is a bit weak. Likewise, don't go mad with wild overlaps and stuff - something around 270 degrees will be fine. Lumpy idles mean big hydrocarbons and an MOT fail.