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F20c or M20?!

F20C or M20  

33 members have voted

  1. 1. F20C or M20

    • F20C
      17
    • M20
      16


13 posts / 6765 viewsLast Reply

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Hello all, this is my first, so please be gentle.

I'm looking to perform an engine swap on my 1975 BMW 2002 Automatic.

But, I'm torn between using either an F20C, which is a Honda engine out of an S2000, or the well known M20.

The end result I'm after is a fast, reliable, simple car, that can be daily driven.

Where I live, I must get everything checked by an engineer, and signed off, before I can register and legally drive the car on the road, so if there is anyone out there from Australia that has any tips that I should be informed of, feel free to let me know! I'm only young and still rather ignorant!

I figure I will post the pro's and con's to each that I've come up with thus far:

F20C-

Pros:

- It's a much newer engine

- More power

- More efficient

- Is a similar weight to the original M10

Cons:

- Very expensive when compared to an M20 here in Australia

- Little information available in comparison to the M20 in regards to a 2002 swap

- It isn't BMW

- Not entirely sure if the CA Tuned mounts will work with a RHD automatic car (emailed them but had no response)

- I assume in order to utilise the 240HP I will need a stronger diff, which I believe requires the install of an E30 rear subframe

--------------------------------------------------------

M20:

Pros:

- It is a much more common swap, and there is a lot of information here (6 into 2 does go)

- Very affordable in comparison to the F20C, allowing money to be spent on new engine parts and maintenance

- From the brief read of the 6 into 2 does go guide, it seems I can use stock engine mounts from an E30 and my own car? (correct me if I'm wrong) which would mean I wouldn't need to purchase custom mounts from California

Cons:

- Older

- Less efficient

- Less power

----------------------------------------------------------------------------------

SO!

If I'm incorrect or missing anything, please by all means tell me!

The thing shying me away from the F20C so much is knowing I would have to mount an E30 rear subframe to help deal with the power, which leaves me to ask, if I was to use the M20 (probably the 2.5i or 3.0i), would the stock diff be able to cope? if not is there another option when it comes to differentials that can be used in conjunction with the stock rear subframe that would suffice?

Also, I believe that an M20 swap is easier than the F20C swap, which is appealing.

I'm by no means an expert or a mechanic, but I'm willing to learn, and will appreciate any knowledge or advice.

Thanks in advance!

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Based on your criteria (feasability, mech. ability, etc.) you'll be happier with the M20 engine. It will take less overall modification in general.

As for the differential, run the center section from an E36 318ti

see here...

http://www.bmw2002faq.com/component/option,com_forum/Itemid,50/page,viewtopic/t,379621/

If I may be so bold, go through your suspension first, this will be a great starter to better understanding what goes where.

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M10 Injected with a 5 speed , a few engine mods to bring it up to 150-160 HP

problem solved , easy to work on , fits, surprisingly fast (3.9 lsd) good acell .

If you want to use a s2000 engine and your not mechanical or electrical savvy its going to cost you big money getting someone else to do it .M20 swap is easier but its still not easy still requires mod work and being RHD here exhaust is a bit of a problem (steering issues).

Get a drive in a well sorted M10 2002 ....there are lots of people here who have given younger and more powerful cars a big surprise.

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Wouldn't it be ideal to get what you have sorted, if its running ok, upgrade or bring back to full reliability what needs to be, realize what more you need to learn (then learn it), realize how inadequate your toolbox is and then realize how much you need to spend on tools.

Then go for it.

I bought a basket case 54 Ford f100 as a teenager. Dad said it's a lot of work and I thought I could fix it. I had plans of grandeur. Sexy pearl color shifting paint job (it was that long ago), big block, mustang 2 front suspension, 9" rear, tuck and roll interior (so long ago), tilt front end, fuel cell tucked under the bed boards, dual carb tunnel ram, predator carbs (so so long ago) etc etc.

I rebuilt the kingpin suspension, threw in a junkyard nine inch one legger, vinyl interior, rebuilt the 289 5 bolt bell that was already there (already had a transplant from the y-block 292), learned how to weld new cab corners in, sand, prime, paint, scored a rebuilt c4 at the junkyard and upgraded to power brakes.

Point is I learned more just wrenching on what I have like, OMG, non power drum brakes completely suck on an automatic and my leg throbs at long stop lights. I sorted what I had and was pretty proud of it. Athough my high school friends loved to do th sanford and sons tune when I drove in. That was an f1 not an f100 by the way. spent lots of money on tools, realized what a budget was and learned how to measure a project based on number of expletives required to complete.

But there is the go with what makes you feel saucy, just sort what you have now and decide if you still want to take on a swap challenge seing as you stated you aren't a total mechanical genius but who is.

Then there is the I'm a hypocrit because if I lay eyes on a mk one Tina I will be going for a lotus motor, then see if there is a bda somewhere since that will fall through, then maybe think 2.3 turbo is what I am left with before I purchase and install the bda's bastard cousin for giggles (4age)

My reply is most likely useless...but there you have it.

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I appreciate all the responses thus far, and am really taking into consideration what everyone has said.

There is some temptation to modify the M10, but the more I think about doing so, and the work involved in that (having to find a manual transmission, machining the tail shaft etc etc), it makes me even more inclined to jump straight in and do it right the first time, so to speak.

I'm taking this year off from education to really get stuck in and learn more about the automotive world, because just like every other young kid, I'm obsessed, and I figure a project like this will help me in my future university design course which I'll start next year.

I figure the M20 is the simpler and cheaper option, and thus am swaying that way.

If anyone has any experience with an M20 RHD swap, please let me know!

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F20.

Whatever (non stock) thing you do is going to take the same

steps, and the M20's really not a very impressive engine.

I know, I race one.

M50, M54, even S14, THOSE are impressive engines.

The F20 is even more so, as it STOCK goes over 8k.

However, an EFI M10 with a 320 5 speed, 3.91 diff and Volvo front brakes

is a very nice car that you can still call a vintage 2002.

That's my take.

t

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Cutting the tunnel to fit the f20c is going to make engineering it very hard. In Australia cutting the firewall is not really an option.

BMW motors will fit with out cutting in most cases.

I went sr20det. It will also get engineered and driven on the road.

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The F20 is more expensive and in my opinion a much bigger project compared to the m20. Unless you get a crashed s2k be ready to spend some $$$, the little stuff adds up. Fuel pump, wiring stuff, engine management, custom exhaust, sliced driveshaft, mounts, etc etc etc. Ask me how I know haha.

M10, M20, and F20 all have the positives and negatives. It just comes down to what is the most important aspects to yourself.

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I think he can also find a used engine in reasonable price and for this purpose craigslist is best which provide the all type of engines fro sale in reasonable prices. You can search through this search engine. http://www.searchallcl.com

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Cutting the tunnel to fit the f20c is going to make engineering it very hard. In Australia cutting the firewall is not really an option.

BMW motors will fit with out cutting in most cases.

I went sr20det. It will also get engineered and driven on the road.

I'd do what nlewis did. SR20's are good engines, parts are easily available here and its more of a 'drop in' in some respects. Also, ability to tune to almost any level you desire.

Curious though, what-the-F does the hot rod community do to overcome all these un-thoughtout new laws that seem to be coming into affect everywhere? (and don't get me started on road safety policy in this country - talk about putting your head in the sand gubberment!)

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I cast my vote but would like to know if you considered a Mazda rotary such as a 13b? Light weight, reliable, plenty of power, high revs, plentiful, affordable, and proven.

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Guys Im sorry but whats a BMW without a BMW engine? Premier builder of some of the finest blocks on the planet, when I see a o2 without a Bavarian plant I laugh, and then I cry, good enough to power a Messerschmidt should be good enough to power your grocery getter

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