2.7 stroker

[formula driver]

I have a couple questions aout the 2.7 stroker. I have a 87 is and can get a 86 es block for dirt cheap. I have the tools and experience to do the motor work so it will only take me a week or so to do this work. Im not worried about that part. I would like to know if you can just slap an eta block under an I motor and go. If so what chip would I use? I would also like to know how many HP can be gained form doing this? You think 10 HP down to the ground is realistic? Thanks in advance guys.

[llll1l1ll]

http://www.bmwe30.net/cgi-bin/datacgi/database.cgi?file=articles&report=view&ID=00129&Section=03

Read that

[formula driver]

So what he's sayin is your not gonna get any power gains unless you use a proper piston with your stroker motor that will fill the combustion chamber's? So the answer is no? No power gains form just swappin the two? Whats the least that has to be done to the eta block to get power? Just a piston upgrade? Thanks

[formula driver]

Ive riddin in Alex's old car (2.8 stroker). Its a powerful car. I dont want to go as extreme as he did and to be honest all Im lookin to get is maybe 10 hp to the wheels. But I would deffinatly like to get a better idea of what's involved in the 2.7 liter stroker.

[Matt86es]

Do you have a chip?

[llll1l1ll]

Haha, sorry about that article. I got sidetracked midway through posting here and forgot to come back and add here.

There's some decent amount of power to be had here--but honestly, I would definitely get someone else's opinion here, too.

[Fred]

Re: 2.7 stroker

I would like to know if you can just slap an eta block under an I motor and go.

The only way you can do that is if you use an 88 325/88 528e block. Use any other year and it won't be worth the effort.

[formula driver]

Do you have a chip?

Yea.... I have a chip for my 325is.

Thanks Fred... I was hoping you would chime in. I have an 87is. But the head has just been rebuilt and its a unit form a 1989 325is. Whats the difference in the heads? I didnt see any when I had them beside eachother on my workbench. I still have all the 87is shit. Intake manifold and so on. So wil this combo work for me? Slapping the 528e block under my set up? Thanks again guys

[formula driver]

Fred.. I just spent some time browsing through your site and found a lot of valuable info. After reading I only have one question. I have an 87is but I rebuilt my head with parts from a 1989 325is. So I cant do the stroker at all because I need the 88 M20? That seems weird. I thought all is heads were the same.

[lovnbmws]

Since I recently broke the timing chain on my 87is and toasted my head I’ve been thinking about doing a 2.7 stroker. I have an 86es a euro e21 323i and now a pile of “is” parts just sitting around. If I were to do it I would use the e block in combination with the e21 head thus yielding the proper compression ratio and throw in the remaining "is" parts like the intake, exhaust, computer. Not sure if anyone around here has tried this specific combination of parts but I think it could be interesting especially since I have all the parts just lying around. But for now it’s a project that will have to wait until after my m30b35 swap. 8)

[Jon325i]

Since I recently broke the timing chain on my 87is...

Its a belt, not a chain. All M20 motors use a belt for the cam.

Jon

[formula driver]

Since I recently broke the timing chain on my 87is and toasted my head I’ve been thinking about doing a 2.7 stroker. I have an 86es a euro e21 323i and now a pile of “is” parts just sitting around. If I were to do it I would use the e block in combination with the e21 head thus yielding the proper compression ratio and throw in the remaining "is" parts like the intake, exhaust, computer. Not sure if anyone around here has tried this specific combination of parts but I think it could be interesting especially since I have all the parts just lying around. But for now it’s a project that will have to wait until after my m30b35 swap. 8)

I here ya man.. but I think the problem youl lrun into is that the piston's from the eta block wont fill the combustion chamber properly. So youll need to do something about pistoins.

[Fred]

I here ya man.. but I think the problem youl lrun into is that the piston's from the eta block wont fill the combustion chamber properly. So youll need to do something about pistoins.

No, the 323i head fits perfectly on a standard eta block. It is the 325i head that isn't a proper match. It doesn't matter what year the 325i head is, they are all pretty much the same. But like Alex McHenry's article on bmwe30.net said, if you put the 325i head (which is designed for domed pistons) on a regualr eta block (which has flat pistons), you'll have a loss in compression that doesn't make the swap worthwhile.

The reason why I mentioned the 88 325/88 528e "Super Eta" is because for that model year only, it came with special pistons that are designed to work with the 325i head.

[Madhatter]

the B23 bore is 80mm and the B27 is 84mm though so how can they fit perfectly?

[Fred]

the B23 bore is 80mm and the B27 is 84mm though so how can they fit perfectly?

Hmm, you're right. Maybe someone else can chime in on the 323i swap; I've never done one before. Let me look into that tonight.