Alpina 2.7 cylinder head

[Richardacton]

Can anyone advise me on the specific specifications of an Alpina c2 2.7 cylinder head over the standard 2.5?


Long and short of it I’m after a replacement head if anyone happens to have one kicking about!


Thanks
Richard

[flybynite]

As it is based on the 885 head which is prone to failure you wont find many kicking around. They were an 885 head, hemispherically ground and (AFAIK) some had enlarged valves.

At a pinch I understand a standard head can be used as long as you have the standard Alpina cam

If you are having one made then an AMC head is as good a starting point as any, it is new and doesn't tend to crack.

Or you could save yourself a headache and do what I am doing and get pistons made to match a standard 885 head profile.

Depends on what you need/want as far as originality

[Richardacton]

Yeah I think you are right about the bigger valves.

I think I will go down the amc route as hopefully it will hold up better than the older ones. Just need to find a decent shop to replicate the original head.

Surely that will change the power and running of the engine if you just used a standard head?

Thanks
Richard

[flybynite]

Yeah I think you are right about the bigger valves.

I think I will go down the amc route as hopefully it will hold up better than the older ones. Just need to find a decent shop to replicate the original head.

Surely that will change the power and running of the engine if you just used a standard head?

Thanks
Richard

Hopefully Reggid will chime in here when things wake up down under but I remember him saying there was not much to be gained by the hemispherical grinding of the head, if anything. You are probably just as well off keeping the squish band as BMW designed it.

All comes down to originality and how much you want

[HJ1981]

I had a suspicion, that the Alpina head had larger valves, is it both intake and exhaust?

Rich, i have an AMC head installed on my 325i, the PO went down that route and i was about to go for the 885 head just to be OE. There is one very reputable shop near Köln/Frankfurt that do nothing but race E21s and E30s in every EU event they get their hands on. They strongly recommend, with every single engine rebuild, head gasket replacement or anything related to removing the cylinder head, to get the AMC head and never pick up 885 heads.

They claim that they experienced nothing but cracked heads, even when they rigorously tested the head for cracks and found none, after the install it cracks (it has something to do with rust building up in one of the coolant passages, exactly where the 885 material is at its thinnest).

From a performance perspective i know JPS E30 325i has a stock balanced engine (stock 885 head) and they installed a bigger cam and "polished the rockers" and managed to push 245hp or so (most likely due to running crazy jungle juice race fuel + advanced timing) without issues.

I will be watching this thread, incase any new information pops up regarding the head grinding and anything else about that Alpina head we missed.

[Richardacton]

I’ll order up an amc head over the winter and go from there. I’m fairly sure the valves (both) are bigger however.

I’d like to keep it close to original as possible. It is interesting that you say grinding a hemispherical chamber won’t make much of a difference.

I have contacted Alpina to see if they can shed some light on the exact specifications of their cylinder head for the 2.7, so I’ll post on here if I get a suitable response.

[flybynite]

I’ll order up an amc head over the winter and go from there. I’m fairly sure the valves (both) are bigger however.

I’d like to keep it close to original as possible. It is interesting that you say grinding a hemispherical chamber won’t make much of a difference.

I have contacted Alpina to see if they can shed some light on the exact specifications of their cylinder head for the 2.7, so I’ll post on here if I get a suitable response.

Where about are you? Give Barry at BMR performance (BSS325i on here) a call he will be able to get it done. If it is a genuine C27 I would not be taking any part of it anywhere else. This is one they have done

78950153_2501309490104715_614141724456910848_o1.jpg

If you have a moment or 10 have a read through this thread, goes into a lot of the workings of a 2.7.

viewtopic.php?f=112&t=70115&hilit=simon13

This is Barry' s own car if you want to know the standard of the work

viewtopic.php?f=112&t=266832

[reggid]

Typed reply but it wouldnt post.

Alpina head is stock 42/36 valve size, tbh unless you have an alpina chassis it’s not that great. The Hemi style chamber is a step backwards from a combustion standpoint . A decent local porter can probably do a better job as far as flow goes but will need to do a bit of research to find someone who has a clue as most head guys are just machinists not experts on engine air flow dynamics

Stock amc head is a turd, but it’s an ok start point for a porting job but it needs shitloads of work. Id look for a good oem core 885

[flybynite]

Alpina head is stock 42/36 valve size,

Wasn't sure about the valves, I know they put bigger valves in some but I think it may have been the ones based on the 731 head

[Richardacton]

Thanks for the information, it’s a massive help. I’ll have a good look through that thread as well and see.

I did actually speak to him before I purchased the car (it is a genuine c2/2), long story short - I went to view and found a bit of gunk in the coolant and the murky looking oil on the dipstick. It’s fairly minor I’ve seen way worse. It had just had the head repaired along with a new genuine cam from Alpina and Valves rockers etc less than 300 miles ago - it had been sitting for a few years since.
I’ve attached a few photos of what I found.

8E986D21-71EF-48C6-B977-78719FFF95BC.jpeg

F1A703EA-7BBC-4AE5-94B2-50C8A731AE6A.jpeg

C389BE9D-E22C-4B16-829D-A9F19CE76D24.jpeg

It runs great and shows no signs other than those.

I’m not sure if the best option is the flush everything and see if it returns. Or do I bite the bullet get it repaired or a new replacement. I suppose it may be residue left. It seems odd that it would have gone again I’m so little miles since the work

Richard

[Brianmoooore]

If there's been oil and coolant mixing, which has been repaired, it takes months for all the mayo to make its way into the coolant bottle. Set the level in the bottle about 20mm low, and see if the level changes over time.

[Richardacton]

I pray that is the case but I honestly have a feeling it isn’t unfortunately. I’ll run it for a few days next week and see, I will report back! The oil isn’t a great colour on the end of the dipstick either, it was a bit milky too in a few corners when I took the rocker cover off.

[Richardacton]

Ok so to revive an old thread with an update;

I have been running for a while no issues not overheating and only a very small change in coolant level but nothing major at all, but more Mayo in the expansion tank - nothing in the oil so I could see...

I’ve got some time off isolating because of this virus so I thought no better time for a service, I decided to drain the coolant and thoroughly flush out and clean expansion tank etc. There was a fair bit hidden away but it was only when partway through the oil change I decided to take off the rocker cover and I see a few small pools of blue coolant.
No Mayo at all in the cylinder head The oil was a rad murky but not too bad at all really.

Where would you see this type of mix? I feeling it’s a cold crack it’s not being put under your typical high pressure which causes the Mayo in the head??

I’m about 3/4 of the way through the strip down so when I get it off I’ll have a closer look but I don’t think it’s from the usual places as it’s been pressure tested a while back and was fine.

Just interested if anyone has any thoughts

[Brianmoooore]

I'd buy an ebay coolant pressure testing kit, pressurise it up and watch for beads of coolant appearing in the head, especially from the rear two cam bearings and the deck between them. Check it hot and cold.

[Richardacton]

I did consider that, but having monitored it for a few months there is definitely an issue.
The breather hose to the to the rocker cover is absolutely full of gunk so it’s definitely gone as it is worse. Hopefully it’s only a minor crack but I’ll have to see

As this would be the third time it’s been repaired I have a feeling I’ll be looking around for a decent 885 head to be modified...

[Brianmoooore]

It seems to be a very minor leak if the coolant level hasn't gone down much. Have you considered adding a proprietary leak stopping additive to the coolant?
Wouldn't normally advise this, but in this case......