2.7 questions

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Mayze
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Post Sat Mar 07, 2009 1:43 pm

I am in the process of building a2.7 engine and just have a question that I cant find by searching.

With the adjustments that need to be made to the ignition timing and fueling can this be done by just swapping the chip for a copy of one out of a Alpina 2.7 or similar or am I looking at getting a stand alone system.

I have also heard that the eta crank is very weak and the 2.4 diesel one should be used instead.

All answers welcome
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ed325i
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Post Sat Mar 07, 2009 6:28 pm

Some one like Ant a A tech would be able to do you a chip.
The eta crank is fine.
daimlerman
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Post Sat Mar 07, 2009 6:59 pm

Eta crank was cast to suit a low reving engine.Depends on what you want from your engine as to it's suitability,2.7's develop plenty of torque at reasonably low engine speeds so you are able to use a higher diff ratio.If you are planning an engine using a lumpy cam that will push the power band above 4000rpm you may well be better off finding a 324d crank.If you are using something nearer to a stock cam the eta crank will be plenty strong enough.I regard 6000rpm as a max for my 2.7.
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Mayze
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Post Sat Mar 07, 2009 8:23 pm

Sweet thanks for the replies Im not planning on building a screamer just going to be using the crank and con rods from the eta in a m20 b25 block so ill stick with the eat crank.
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daimlerman
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Post Sun Mar 08, 2009 9:55 am

Mayze wrote:Sweet thanks for the replies Im not planning on building a screamer just going to be using the crank and con rods from the eta in a m20 b25 block so ill stick with the eat crank.
Which pistons are you using?
Mayze
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Post Sun Mar 08, 2009 12:29 pm

I was planning on using a set from an early m20 2.5
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daimlerman
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Post Sun Mar 08, 2009 12:55 pm

I would suggest that you 'dummy build' one cylinder so that you can carefully measure how much you will need to 'deck' your cylinder block top surface by..you are aware that you will require a vernier type cam pulley so that you can get the valve timing spot on?
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Mayze
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Post Sun Mar 08, 2009 1:29 pm

Yes I was planning to take it to build the whole lot up and then take it to be machined down and let them do the measuring but thinking about it it will prob be best to just do one cylinder as it will be easier to clean the block out before the full build.

As for the vernier pulley I know I need to get one and why I need it but is there anything I should look out for when getting one or are they all pretty much the same.
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daimlerman
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Post Sun Mar 08, 2009 3:16 pm

Uncharted territory to me I am afraid,I used the standard eta pistons for my build.
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ed325i
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Post Sun Mar 08, 2009 4:32 pm

What cam are you going to use ?
Mayze
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Post Sun Mar 08, 2009 5:31 pm

I was planning on using the standard one from a 325.
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reggid
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Post Mon Mar 09, 2009 1:31 am

get a nuke adjustable cam gear from PPF...........
E30 325is with M20B31
daimlerman
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Post Fri Mar 13, 2009 8:16 pm

Mayze wrote:I was planning on using the standard one from a 325.
Bit of a waste when you are going to the effort of decking the block and vernier pulley,at least an 'Alpina' spec cam is called for,be rude not to.... winkeye
Mayze
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Post Fri Mar 13, 2009 9:18 pm

daimlerman wrote:
Mayze wrote:I was planning on using the standard one from a 325.
Bit of a waste when you are going to the effort of decking the block and vernier pulley,at least an 'Alpina' spec cam is called for,be rude not to.... winkeye
Could be tempted :twisted:

It would be a lot easier to do it now when I'm building it up out of the car than putting one in a a latter date.
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eta
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Post Sun Mar 15, 2009 5:07 pm

Eta cranks are good up 7000 rpm. A-tech say so as well.
daimlerman
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Post Mon Mar 16, 2009 12:55 pm

eta wrote:Eta cranks are good up 7000 rpm. A-tech say so as well.
Agreed.But only for short bursts,maintain that kind of speed on an unbalanced crank and you is asking for trouble!In the real world that I live and drive in,my 2.7 rarely goes above 3000rpm,I find the huge amount of torque available at low speeds of more benifit than the extra few horses above 5000rpm.With a 3.64 diff.,3000rpm is 75mph,well into points territory!
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eta
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Post Mon Mar 16, 2009 8:34 pm

I agree with you Daimelerman. I found today that for the most part I barely got to 4000 rpm and excellent acceleration. I am very happy. I also have used eta pistons on 885 head. I agree with more torque at low rpms is of benifit as well in the real world. Stick to the stock 885 head cam its fine. Better to spend the money saved on getting it mapped properly, although A-techs chip seem to be doing a very good job. Wonlt know how good till get it on a rolling road.