What is the difference between the 885 cylinder heads that has the dual valve springs vs this one that has the single valve spring. Thanks in advance Ted Sent from my iPhone using Tapatalk
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M20 885 Cylinder Head w single valve spring
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Originally posted by e30austin View Postthe cylinder head with single valve springs, is off a 325, Super ETA. the camshaft is also different, than the one found off the 325i.
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Originally posted by Motorsport1207 View PostOk, Still learning here. So my next question is what is a super ETA head and where is this used. Can this be used in a standard M20 325 engine? Thanks Sent from my iPhone using Tapatalk'72 2002 pickup | '88 M5 | '89 330is | '89 M3 | '01 Z3M | '11 328xi-t
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isnt there a difference in the drillings for the cam lubrication?89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...
new build thread http://www.r3vlimited.com/board/showthread.php?t=317505
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The m20b25 885 head and the seta 885 head have different cam profiles. I believe the seta cam has less lift, meaning it can't be reground to use as a high performance b25 cam.
I've also heard that there are differences in how many cam bearings have oil journals.
I have both 885 heads sitting in a box, so I guess I could go measure stuff...
more info:
Ask Matt for more info: MR 325sigpic
1987 - 325i Convertible Delphin Auto [SOLD], 325i Convertible Delphin Manual [SOLD]
1989 - 325i Convertible Bronzit m30b35 swapped [SCRAPPED], 325i Sedan Alpine Auto[DD]
1991 - 325i Coupe Laguna Manual [Project], 535i Sedan Alpine [SCRAPPED]
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I can help with this, might have done an m20 head, or two, hehe.
885 heads came with single springs in 1988 only. As mentioned, just add inner springs, change the cam to the "k" cam and be done with it. The castings themselves are identical.
I have never heard of, or seen a 4 bearing 885 head. A member on e30tech years ago posted about one, but AFAIK they are all 7 bearings and have a unique 88-only eta 7 bearing cam.
I have converted 200 head to use b25 cams, simple process, just have to angle drill the passages. Never measured a seta cam, but to the eye, it appears closer to the eta than b25 cam with it's pointy lobes (shorter duration). The seta had 8.5:1 compression, b25 8.8:1 and eta 9:1 - so, cams would be different in OEM applications.
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there is definitely no 4 "bearing" 885, maybe they put a 4 journal cam into the 7 "bearing" head with a different machining applied to the casting. The bare head part numbers are the .different between the 325i and SETA which could be a machining difference applied to the same 885 casting p/n.
The easiest ways is to post pics of the top of the head to show the oil drillings or compare to a m20b25 head.
the SETA barely made more ponys than the regular ETA so the cam must be as weak as the proverbial even though it was hamstrung with a lower CR.....89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...
new build thread http://www.r3vlimited.com/board/showthread.php?t=317505
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Originally posted by McGyver View PostThe m20b25 885 head and the seta 885 head have different cam profiles. I believe the seta cam has less lift, meaning it can't be reground to use as a high performance b25 cam. I've also heard that there are differences in how many cam bearings have oil journals. I have both 885 heads sitting in a box, so I guess I could go measure stuff... more info: https://www.r3vlimited.com/board/for...-answer-please Ask Matt for more info: MR 325
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Originally posted by ForcedFirebird View PostI can help with this, might have done an m20 head, or two, hehe. 885 heads came with single springs in 1988 only. As mentioned, just add inner springs, change the cam to the "k" cam and be done with it. The castings themselves are identical. I have never heard of, or seen a 4 bearing 885 head. A member on e30tech years ago posted about one, but AFAIK they are all 7 bearings and have a unique 88-only eta 7 bearing cam. I have converted 200 head to use b25 cams, simple process, just have to angle drill the passages. Never measured a seta cam, but to the eye, it appears closer to the eta than b25 cam with it's pointy lobes (shorter duration). The seta had 8.5:1 compression, b25 8.8:1 and eta 9:1 - so, cams would be different in OEM applications.
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Originally posted by Motorsport1207 View PostMaybe I don’t understand, but if the SETA cam has less lift - how can it be re grounded to be a performance camshaft. I thought the performance camshaft would have a higher lift and duration to allow more air into the chamber. Thanks Sent from my iPhone using Tapatalk
Also, from your original post; Your 885 seta head clearly has 7 cam bearings. It also clearly has all 7 drilled for oil passages to the bearings. To convert that to a b25 head, you'll need dual valve springs and the "k" cam mentioned by ForcedFirebird. If you're putting in a new (or reground) cam, you should either resurface your rockers or replace them so that the hardened pads are square to the new cam.sigpic
1987 - 325i Convertible Delphin Auto [SOLD], 325i Convertible Delphin Manual [SOLD]
1989 - 325i Convertible Bronzit m30b35 swapped [SCRAPPED], 325i Sedan Alpine Auto[DD]
1991 - 325i Coupe Laguna Manual [Project], 535i Sedan Alpine [SCRAPPED]
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Originally posted by McGyver View PostRe-read my post. I said the seta cam has less lift, so it cannot be reground. Also, from your original post; Your 885 seta head clearly has 7 cam bearings. It also clearly has all 7 drilled for oil passages to the bearings. To convert that to a b25 head, you'll need dual valve springs and the "k" cam mentioned by ForcedFirebird. If you're putting in a new (or reground) cam, you should either resurface your rockers or replace them so that the hardened pads are square to the new cam.
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