325i 885 head modification to increase compression

[bataangpinoy]

get i pistons to use on your eta rods, and shave the pistons a little bit to avoid PtV and PtH contact.

[Fidhle007]

spec, have you ever built a motor? Im talking about filling in areas on the combustion chamber to decrease the chamber, right. I Cant change the dang title, know how to do that? Thanks for catching that tho.

A machinist would know what Im talking about and trying to do I guess.

It doesn't really matter if he has or not because we can tell YOU sure as hell haven't... Any machinist worth their salt will laugh at you so hard they may pass out.

[bataangpinoy]

fidhle,
i think hes talking about adding material and then shaping it again to create a new chamber. i read something about this a year ago on e30tech,

[Fidhle007]

I know exactly what he's talking about and it won't work. There are these pesky little things called VALVES in the way...

[der affe]

i have been doing cyl head work for a long time (porting, combustion chamber work, ETC) and i would not attempt to "redesign" the chambers unless you had a lot of time on your hands for trial and error and an extra engine to pull the different heads off and on to test your designs with.
you would also need some sort of monitoring and data logging to see the effects of your changes.

BMW spent LOTS of $ to design their head and chambers. granted they did make compromises to get the widest torque and horse power across the widest bands for every day driving. you can change things, but you will loose pwer in some areas to gain in other. that is just the way it is.

you can make some improvements by cleaning up the ports where there is factory casting that overlap the ports or flashing/rough casting in the chambers is one thing. major redesigning is better left to engineers or those with the time and resources to do it through trial and error.

[payney8]

dont even play with it you obviously have no idea about engines or the design processes which happen before they become mass produced.

[dougs87325is]

Like I said guys, Super ghetto cmon lol. If welded right anyone wjho weld might know its possible. I think I can just make the combustion chamber on the 325i head like that of the ETA head, thats all. After its weled and milled it would look pretty clean if done right. And the volume of each chamber would be somewhat close.At the same time trying to make each cylinder as close as possible in size,shape.

I would end up checking the cc in the end and try to get them as close as possible for each cylinder.

[dougs87325is]

I've been a mechanic,machinist,custom fabricator for over 20 years. I own a repair business, Im suprised many of you with experience are laughing at this idea. No sense of adventure I guess, I wanted to try something different, out of the box. The negativity makes me laugh cause noone really knows what this could do. I have these heads sitting side by side, it can be done. They arent very different

[Mossman]

Why don't you use the ETA head with the I valves, and slap the I cam in. I don't know what you're really trying to accomplish anyways, cuz E bottom ends with stock I top ends work great, ESPECIALLY if you're planning on adding boost later which you said you were. But if you insist on frankensteining it further keep the E head if you think it's so great.

[evandael]

Well, if you wanna do it, do it. Its just an old hunk of metal.


I guess thats whats cool about being into old E30's.. for the most part, the parts cost next to nothing. I just don't see why you wouldn't want to spend the effort making a nice turbo exhaust manifold and scrapping together parts for a nice kit, instead of delving into a failing project.

[dougs87325is]

Fidhle007 thinks Im trying to weld the whole chamber closed, whoa there there bro.

[dougs87325is]

evan your right, old hunk of metal. Im trying to upload the pic with the heads side to side, keep getting 500 errors

[nando]

dumbest post since wyatt18yahoo's build thread

way to go for the gusto! Please continue if you want to create an inefficient, slow and knock-limited engine.

[quickervicar]

I know what you're trying to accomplish. I just think having custom HC pistons machined is the easier/cheaper/proven approach. Then you'll just have to pull them again to run boost.

Have someone put the i head/mgmt on the e block & call it a day. You'll be pleased with the results.

[Nic01101011]

carry on