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nz320i

quick advice

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GAC tells me 5000 will be a full 320 rebuild, 323 head, pistons, etc. Good for about 200 hp, and new internals.

But 5000 is a bit.. so what about quick swap to a 325 motor, once i have bought it, and taken the head off, got a grind, and maybe a cam.

I am not looking for a race motor, nor do I want something I can run a 6000 all the time, because i like the fact bmw motors last a long time!

Whats a little work to a 325 motor cost, say a new cam (valve springs?) and i dunno maybe some other stuff while im in there. I like the fact I can do most of the work then myself even if it takes some time to build the 325 motor up to scratch.

Edited by Chris C

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I personally think theres no replacement for displacement so heres what I'm going with clickity (You've probably already read it.)

Will be interesting to see what others recommend...

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bmw2002.com

3.1 ltr stroker kit + heaps of head work. You'll see 250 odd hp.

Win

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I'm looking at forced induction with low boost (6-7 psi). If you have a strong m20, then some head preventative maintenance by way of inspection of the top end, new head gasket, stronger head bolts etc, then you will get away without rebuilding the motor or upgrading all the internals. You could consider cams and uprated valve springs if you like at the same time.

Then do a junkyard supercharger setup, and keep boost low and you should get the same gains as Andrews stroker method for less money, but also less reliability as you won't have a fully rebuilt motor.

Options Options...

But these all cost as much or more (almost definately more) than your quoted rebuild. And that is doing lots of work yourself (which my guess is you aren't).

You can buy a strong m20b25 for $800-1200 depending on mileage or if its been rebuilt and installation is as close to plug and play as you can get. You'll be swapping a tired 90kw or less m20b20 for a 125kw m20b25. Good idea. That's 30% gains for a couple of grand and you still have the old motor to flick off.

Edited by bravo

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Ahhh the super charger with new head bolts, head gasket sounds really good, how much do you think this would be, it seems like a lot of work .. what parts do you need? do the head work, then just bolt a supercharger on and make an intake pipe??

or

http://store.nexternal.com/shared/StoreFro...ID=327&All=

Edited by Chris C

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Ahhh the super charger with new head bolts, head gasket sounds really good, how much do you think this would be, it seems like a lot of work .. what parts do you need?

or

http://store.nexternal.com/shared/StoreFro...ID=327&All=

Very rough idea:

All of the above (head bolts etc).

Plus piping, intercooler (optional - recommended), s/c Brackets and fabrication to install. fair bit of work to design and install with a belt to run s/c, get piping to fit and work etc. Then you probably should run an aftermarket computer to make sure you get it tuned right and thus avoid the negative effects of running too rich or too lean etc (can blow headgaskets and more). Cheapest option as far as aftermarket computers is about $1000 plus installation and tuning.

This is the roughest run-down. Missed a few details, but I'm yet to fully price up and sort out a parts list myself, so thats the best I can do. But at this stage looks definitely cheaper and easier than turbo.

Edited by bravo

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Hell ill say its looking easier than turbo, and more room under the hood, where would the belt run from though that might be tricky?

Can I buy a used super charger off t/m?

Dude we should buy parts together and get discounts if your super keen? (new parts)

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im pretty set on the 325 idea just because its god gain for money but would give it a good run over beofre it goes it, or http://www.trademe.co.nz/Trade-Me-Motors/C...5793237.htm?p=1

is it too old?

2.7 engine is only 125hp from memory,(and really soft cam so doesn't rev) where 2.5 was 170hp out of the box. 2.7 only good if you are building a stroker (lotsa $$$$ to do properly)

To me this one is a no-brainer: go for a 2.5 swap, and spend the balance of your $5K freshening it up and making it faster. I VERY much doubt you will get a 200hp M20 2.0 for $5K!

Edited by conrod

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think the 325 is the go, supercharger would be cool however im unsure what it would cost..maybe wait and see how you get on bravo :D

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I VERY much doubt you will get a 200hp M20 2.0 for $5K!

x 2 !

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