Does this work? 1989 b25 -> late 1987 b27

[fanofe30s]

Recently I've been having trouble with a rocker/lifter that decided it doesn't want to fully open/close. Tried to get it loose in a number of different ways, but none of the conventional methods worked.

I had a friend of my dad's who used to work in a machine shop take a look at it, and he was saying the valve was blocked off. We figured we'd get the valves resurfaced, and the seats cleaned.

Thing is, my dad went to the junkyard a couple days ago and pulled the head from a December 1987 325e..

I'm familiar with people swapping an I head and other I parts on the E engine, but I'm not really sure how it works the other way around. So my question is, could the head on the b25? Or would I need to swap over anything else like pistons from the 325e?

edit: so the head is from a SETA, and has 885 casting

[BenM]

Are you talking about the rocker arm shaft? 12/87 "e" should be a super eta, which uses the same 885 casting as the "i" heads. The only difference would be the cam and the single valve springs. Check the casting for a number stamped, it should be "885".

Also if you can get the bottom end cheaply you can have yourself a nice 2.7 stroker.

[jlevie]

You really don't want to put the head from an M20B27 engine on your M20B25. Pull the head from your M20B25 and take it to a machine shop. They will be able to find out what the problem is and fix it. I suspect a bent valve or a binding rocker.

[fanofe30s]

Ah, so after having a chance to actually read into it, I think I'm starting to get it. So basically the problem is that the SETA head, which has the same casting as an I head, wont rev past a certain point (~5500RPM?) without the dual valve springs and cams?

And the only way to actually get a 2.7l in the form of a stroker is to go the route of I head and E or ES bottom end?

I didn't have a clue about engines a week ago, but the info you guys are providing is really helping me direct my questions and what to search for, thanks!

[MR 325]

If the car is from a 12/87 325e it's most likely from a Super Eta car. Since you said the "new" head is an 885 casting this pretty much confirms it's a Super Eta head. The super Eta head has the same casting and valves as the 885 i head but different valve springs and camshaft. Just so you know, there was NO eS model in 1988 and the eS would not have come with the 885 head.

As far as the issue with your current head, I am really not understanding what went wrong with it. Why would you not just take it to a machine shop and have it checked, gone over, fixed if needed, and resurfaced?

[BenM]

MR325 is right as usual. The "es" designation doesn't mean anything more than sport an airdam, sport seats and a steering wheel, the engine is exactly the same as the "e". The difference is in the model years produced as follows:

325e produced 07/83 - 08/87 = 2.7 ETA , 200 Casting Head

325e produced 09/87 - 06/88 = 2.7 Super ETA, 885 Casting Head (same as 325i except has single valve springs and "e" cam)

325i (all years) = 2.5 "i", 885 Casting Head

[fanofe30s]

My mistake. Whenever referencing ES in my posts I was referring to Super ETA, I thought they were the same thing. Hope that didn't cause too much confusion. I'll edit my posts accordingly.

As far as the current situation, I told my dad I didn't want the Super ETA head, in there so he's probably going to return it. Unless he can find another I head that doesn't require more then 10 minutes worth of work to pull, the plan is to take the head out and probably take it to a machine shop to see what the problem is.

[jlevie]

In my experience, a head that has been in use has enough warp to require surfacing. It might seal if you install it as is, or it may not. So if I am going to install a used head it gets surfaced and rebuilt first. So, in my opinion there is only a slight cost advantage to a used head over the one you have (the cost of the bent valves).

[MR 325]

Exactly!