325i sport head

Post Wed Feb 27, 2013 9:47 pm

I think I might want a new head for my 325i sport. There's nothing wrong with the one I've got but it's just a bit worn and tired and a bit rattly so I was thinking if a new (secondhand) head was cheap enough, I could go through it all and recon everything so I can just swap it over when I'm ready ?
I fancy doing it this way cos the car is my daily driver so I don't want to rush things etc

Post Wed Feb 27, 2013 9:55 pm

A sport head is no different to a normal head.

Put a wanted add up, should be able to pick one up for £150-250. I would suggest trying to buy a tested one as they have a tendency to crack.

Post Wed Feb 27, 2013 10:05 pm

try adjusting the tappets if its rattly, makes such a difference!

otherwise, I have a good cam and rockers available if your cam is worn.

Post Thu Feb 28, 2013 8:46 am

Adjust the valve clearances, check the injectors, and check the manifold studs if you can hear tapping. As for paying £150-250 for a head, you're not far off getting a new engine with £250

Post Thu Feb 28, 2013 9:16 am

Chris_B86 wrote: As for paying £150-250 for a head, you're not far off getting a new engine with £250

That's about right. M20B25 bottom ends rarely fail, and it's not at all unusual to find a 200k+ mile one where everything is still within factory spec., so consequently they have little value.
I would guess that approximately one third of the B25 heads ever produced have cracked by now, so a good head is a valuable object and in demand.

Post Thu Feb 28, 2013 9:18 am

Brianmoooore wrote:
Chris_B86 wrote: As for paying £150-250 for a head, you're not far off getting a new engine with £250
That's about right. M20B25 bottom ends rarely fail, and it's not at all unusual to find a 200k+ mile one where everything is still within factory spec., so consequently they have little value.
I would guess that approximately one third of the B25 heads ever produced have cracked by now, so a good head is a valuable object and in demand.

That's fair, my thought was why buy just a head when you can get a full engine, then maybe it could be a bit of a project, maybe build a 2.7 or 2.8 stroker

Post Thu Feb 28, 2013 2:03 pm

Pretty much any head is going to be in worn condition if you buy it used. But if you can pick up a second one cheaply enough and rebuild it, then you can swap them over next time the cam belt needs doing.

Rebuild guide here:

http://www.e30zone.net/e30zonewiki/inde ... inder_Head

Don't think about any sort of porting or polishing though. There's a thread somewhere (engine swaps) with detailed explanations as to how advanced the 325i head was for its time, and how little you can improve it.

You may find though, as others have said, that you just need the tappets adjusting:

http://www.e30zone.net/e30zonewiki/inde ... M20_engine

Post Thu Feb 28, 2013 2:25 pm

Cheers everyone - some good advice there !

I got a PM from Maggspower last night who explained what he did and how much he could supply (outright or exchange) a recon'd head for. Has anyone had anything from or dealings with this bloke ?

Post Thu Feb 28, 2013 2:36 pm

Check the feedback section:

http://www.e30zone.net/modules.php?name ... ic&t=73547

http://www.e30zone.net/modules.php?name ... c&t=226109

Post Thu Feb 28, 2013 2:42 pm

That's me told then !

Will give you a call later this afternoon to discuss

Cheers

Post Thu Feb 28, 2013 2:51 pm

And another:

http://www.e30zone.net/modules.php?name ... maggspower

I've been on here almost 8 years now, and managed to keep my nose reasonably clean, and intend to keep it that way.

If you can't get through leave a message or text and I'll bell you back, my signal here is intermitent at best.