3-Series (E21, E30)Chat relating to the BMW 3-Series from 1975-1983 and 1984-1991 line. Specific models: BMW 315, BMW 316, BMW 318, BMW 318i, BMW 320/4, BMW 320i, BMW 320/6, BMW 323i, BMW 320i. E30 Family models include: BMW 325e, BMW 325i, BMW 325is, BMW 325ix.
I have an 89' 325i m20 with #1 piston gone. (not sure yet as to damage). I will be purchasing a 1984-87 BMW 325E 2.7 complete motor.
I will be using the bottom end of the E and the upper of the I.
1) Is there a direct fit piston that would be better than the E without any shaving etc? Or would it be better to just stay with the simple swap?
2) With the parts from both motors and being that i may have to purchase new pistons anyway (being i am not sure of the status of the I #1 at this time), what configuration could i get away with between the two motors for hp/trq. Keeping in mind i do not want to go down a road of adding a lot of mods to this project. trying to keep it simple with what i have.
For those that i have IM, thanks, i still would appreciate your replies.
I know parts of this have been addressed in other posts but i can't seem to get to my exact situation.
I don't believe you can do that, there are too many differences..for instance the head gasket is different for an E than the I...problem right there. different ignition wires, the valve springs are different, O2 sensor different, exhaust connections different, air flow meter different...just for starters..no. I don't believe you can put an I head on an E block..I think it would be easier to simply relace the I engine with the engine (and that would not be simple) than to do what you suggest as I don't think that would work anyway...if you decide to go that route and it works call me a two toed horney toad and tell how the heck you pulled that off...I would just fix the I myself and be done with it....good luck
as a conclusion let me say this. these are not legoland cars, the parts are not interchangeable from model to model. why would they do that? they are in business to make money. there are some things you can interchange and are common across makes, but not very many. For instance you cannot use the same windshield wiper motor from a 733 in a 633...they look almost the same but they are not...more different parts...more money...don't think for a minute BMW is in this to not make money on replacement parts...they are.
They are not alone, they all do it... and Bosch is right up in there with them...I don't blame any of them..it's just business....
I appreciate your comment, you will see in posts here that this interchange can be done; i have researched this for over a week now and over 100 posts have I read. You should search (stroke) in the m20 forum on this site and others. There is a plethora of reading. I just haven't been able to filter it all out to my circumstance.
OK, anyone can tell you anything, but I will say this not possible not to even speak of reasonable. I'm not going argue...I'm just saying it won't happen. The Internet is not very reliable for this kind of thing, never believe it is. Anything you want to hear you can find on this stupid web..as good as is it also is as worthless...I am telling you this will not work for many reasons. Let me know if it does work..hell, call me for detail...Cliff
it may have something to do with piston crowns. I believe it goes further than that in foolishness...what the hell are you talking about? This concept is extemely flawed, it just won't work....are you kidding me? Cliff
hey sled... again i appreciate your responses, but i think your tone is a little overboard. there are plenty of people that have done similar swaps and numerous more that have "swapped" parts in these engines.
If you don't "think" this can be done, because it doesn't seem you yourself have even attempted it; but are readily willing to discard the notion. 1.3 Motronic Up-Grade & 2.7i How To - R3VLimited Forums read this post. Nor was it my intention in this post to do so. I can't make a believer out of someone who doesn't want to believe. In addition, i never asked for your negative opinion on why not to do it, please keep that to yourself. As i have posted this to get answers. Thanks for your 2 cents.
Oh and by the way sbc 350 and 305, sbf 302 and 351, ford 2.0 and 2.3, volks 1.8 and 2.0 all have parts that interchange from one another. In addition, i also own a 98 Infinti I30 that i use Nissan parts in place of.
I will try to post updates of work done, parts swapped and etc, when done. i had a family illness that will required a trip out of town once a month for the next 6 months or so and that take s away from the budget.
But, will post as it happens.
Ok, well all the answers you need are in an article in the Sept 2008 Edition of Total BMW Magazine. If you send me your e-mail i'll scan it and send it to you :0
The options are as follows:
Use the ETA bottom end with a 320i or 323i head
Use the ETA bottom end with a 325i head
Use the ETA block with 325i pistons and head.
ETA and 325i head gaskets are the same......
You will need your complete 325i Eng Management |Unit, ECU inlet manifold and injectors . You need to remap the ECU as the ETA unit has a faster piston speed so it gets to the top of the bore quicker......
The compression ratio problem isn't a biggie if you use the eta bottom end with the 325i head. 325i chamber volume is 42.5 cc.... as opposed to 38cc but that still gives you a comp ratio of around 9.5..... plenty. Obviously if you skim the head that will be improved.
If you fit the 325i pistons, you need to fit the 130mm ETA 2 litre con rods and shave 1.5 to 2 mm off the block.
As the cam and crank will now be closer together, the timing will be out so you need a vernier adjustable cam pulley.
You need longer bolts to fit the E30 sump onto the ETA block
Finally early 325i pistons need 12mm shaving off the skirt but your 89's should be ok.
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