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M30 B35 rebuild/freshening up
Posted: Mon Apr 18, 2011 8:14 pm
by Lmarkey
I have a B35 that I am about to tackle. It is my first engine rebuild. I inspected the the larger bits and all looks well enough in terms of the honing of the cylinders, the pistons look pretty good but will get cleaned up and the head is level to the deck. I am going to replace the old 735i cam with a much more lively 533i cam. I have new rings, I have the old b30 oil pan and pump. I am going to stick with the b35 intake manifold (I do have a set of 320 intakes and all the later 528i management just in case I change my mind, but I figure going with the later style will be a lot easier to connect the Motron 1.3. brain and I can chip it.
Question-gaskets, I assume I need all b35 gaskets except for the oil pan. But what do I need to glue them down, and do I glue all of them down?
Should I get new head bolts?
Where can I find a chart of all the torque amounts I need to know for rods, head and what ever else I'm not thinking of?
Where can I find those brass nuts I sometimes see guys use?
Where can I send the injectors to get serviced?
That"s it for now, I'm sure i will have more questions as I go, thanks guys.
LCM
Posted: Mon Apr 18, 2011 11:47 pm
by anthony
I am keeping the b35 cam in my conversion to the b35. I am under the impression that the whole motronic system works together.
I would like to hear from others on this. But I'm not changing cams.
The head bolts don't stretch so they can be reused.
Posted: Tue Apr 19, 2011 12:25 am
by Lmarkey
Concerning the cam, I've been told by a couple of guys I trust here in the San Diego area that the cam that (at least the one in the 735i like mine) for the American b35 were purposed for low rev to get the heavy luxury mobile a little pep out of the drive way. Conversely, at the higher end of the band. the cam limits the performance. The 533i (especially the early one) were faster than the latter 535is (with our engine). Since it only had a 3.2 engine the cam made a big difference. Also consider (I could be wrong here) but the head I have from a an 1985 635csi I think is same generation that was on the 533i. That particular head has a smaller combustion chamber than the b35 head. I don't know what the pistons 533 had but its clear the cam it had made a big contribution to the power the b32 put in it. Hence why I going with one.
Posted: Tue Apr 19, 2011 5:39 am
by Peter Florance
Lmarkey wrote:Concerning the cam, I've been told by a couple of guys I trust here in the San Diego area that the cam that (at least the one in the 735i like mine) for the American b35 were purposed for low rev to get the heavy luxury mobile a little pep out of the drive way. Conversely, at the higher end of the band. the cam limits the performance. The 533i (especially the early one) were faster than the latter 535is (with our engine). Since it only had a 3.2 engine the cam made a big difference. Also consider (I could be wrong here) but the head I have from a an 1985 635csi I think is same generation that was on the 533i. That particular head has a smaller combustion chamber than the b35 head. I don't know what the pistons 533 had but its clear the cam it had made a big contribution to the power the b32 put in it. Hence why I going with one.
I thought the B35 was a all markets engine unlike older M30's
Posted: Tue Apr 19, 2011 11:21 am
by Lmarkey
I was under the same impression until I started discusing that with a friend at Autobahn Distmantlers in SD. I know they started using that engine becuse the over all weight of the cars of that generation were; well as we saw, heavy enough for a v8. But what was pointed to me (and I don't if this is consistant thoughout the 635, 535 and 735) that although the rest of the engine was the same, bmw didn't use a high performace cam because (especially with the prodomantly auto trans 735i) they didn't want the customer to have to rev the engine to get initial power. So the compromise was the cam it has, giving the heavy car the low end torque it needed but then flaten out the long end of the power curve for the higher speeds.
Posted: Tue Apr 19, 2011 11:29 am
by Peter Florance
Lmarkey wrote:I was under the same impression until I started discusing that with a friend at Autobahn Distmantlers in SD. I know they started using that engine becuse the over all weight of the cars of that generation were; well as we saw, heavy enough for a v8. But what was pointed to me (and I don't if this is consistant thoughout the 635, 535 and 735) that although the rest of the engine was the same, bmw didn't use a high performace cam because (especially with the prodomantly auto trans 735i) they didn't want the customer to have to rev the engine to get initial power. So the compromise was the cam it has, giving the heavy car the low end torque it needed but then flaten out the long end of the power curve for the higher speeds.
The B34 has a shorter duration cam than the b35. I wonder if he's thinking about that.
Posted: Tue Apr 19, 2011 11:53 am
by Lmarkey
the 533i had a b32, not a b34.
Posted: Tue Apr 19, 2011 12:01 pm
by Peter Florance
Lmarkey wrote:the 533i had a b32, not a b34.
Sorry I lost track of which engine we are talking about
I think the B32 and B35 cams are similar in duration and the B34 is shorter duration.
Posted: Tue Apr 19, 2011 12:17 pm
by Peter Florance
I think the confusion is there were 2 "3.5" l engines
B34 and B35
Posted: Tue Apr 19, 2011 12:42 pm
by Lmarkey
Right, thats what I thought as well. But what these guys were telling me was the cam for the 533i b32 was (out of the three b32,b34,b35) was noticably better in terms of both longer duration and/or lift than b34 and b35.
Posted: Tue Apr 19, 2011 1:20 pm
by Peter Florance
Posted: Tue Apr 19, 2011 1:30 pm
by Blaise
Great graph.
I have a mystery cam in my replacement engine and am interested in figuring out what it is. Is it possible to put a dial indicator on a lobe and measure? I suppose that with a degree wheel, one could at least figure out the basic characteristics.
Posted: Tue Apr 19, 2011 3:12 pm
by Lmarkey
Great link. I guess I need to re-think / re investigate what I was told. Or just go with a Shreck Cam. Thanks for that. I still need guidance with the gasket glue? Any help there?
Posted: Tue Apr 19, 2011 11:13 pm
by Mike W.
Here it is with better resolution,
It was done by a friend of mine named Devinder from the E28 world. The B32 cam does have more duration than the B34, but somewhat less and less lift than the B35 cam. Blow it up double and it will really become apparent.