Need advice rebuilding M30B35. What else to replace?

SamSpade · Post by **SamSpade** » Jan 12, 2009 5:45 AM

I just started restoring a 1985 E23 728i. It'll get an M30B35 from a 1989 E34 535i. I'm now rebuilding the M30B35 and will drive it for a year to iron out the kinks and make sure it's reliable. Then maybe put on a TCD M30 Stage 2. I won't go nuts on the boost and just limit it to 12/13psi at most, even maybe just 10 psi.

I'm rebuilding the engine so it'll run another decade or so reliably even with the turbo.

Current engine condition
Compression is poor (80-100 psi) on half of the cylinders, but the cylinder walls seem ok with the hone marks still visible and no visible scoring. I'll have the machine shop check it to be sure but I only plan to hone the cylinders and replace the pistons rings if everything checks out.

I already took off the head and disassembled it. The camshaft is fine but the rocker arms are moderately scored and pitted. Valves are dirty but still within BMW specs. I'll have a valve job of course but using the old ones.

New parts
So I'm planning to install these new parts, focusing on reliability and readiness for a moderately-boosted (12-13psi) turbo:

11-12-9-059-238: Cylinder head gasket set (M30B35) including head gasket, Elring Klinger
201-4602: ARP head studs
11-11-9-059-234: Engine block gasket set (M30B35), Elring Klinger
11-33-1-271-833: Rocker arms, 12 pcs
11-33-1-744-354: Rocker arm eccentric, 12 pcs
11-25-1-714-383: Piston rings, Goetze, 6 sets
11-24-0-618-100: Connecting rod bushings, Glyco, 6 pcs
11-24-1-284-550: Connecting rod bearing set, Glyco, 1 set
11-21-1-261-033: Crankshaft main bearing set, Glyco, 1 set
11-24-1-719-991: Connecting rod bolts, 12 pcs
11-24-0-518-321: Connecting rod nuts, 12 pcs

Questions:
- What else do I need to change, or do I really need all the parts above?
- Should the conn rod bearings and main bearings be changed even if they turn out ok?
- Should I get new valves instead of reusing the old ones?

turbodan · Post by **turbodan** » Jan 12, 2009 10:22 AM

You'll need new rocker arm shafts to go with the new rockers. I would probably reuse the valves if they aren't significantly worn. If they are worn you can have them cut as long as you have enough valve head thickness to do so.

Replace every bearing and bushing you can while you're in there. That inlcudes the small end rod bushings. Order up new ones and take the rods and wristpins to a good machine shop. I dont see an oil pump, timing chain and tensioners/guide rails, crank and cam sprockets or valve springs on the list. Might as well...

Entropy_Engineering · Post by **Entropy_Engineering** » Jan 12, 2009 4:09 PM

Make sure if the valve seats need work the machine shop does it with a cutter, not a stone. The BMW valve seats are so hard the majority of the time a stone will start to chatter a little and make the seat rough. A good machine shop should be cutting with a machine like a Serdi.

turbodan · Post by **turbodan** » Jan 12, 2009 6:35 PM

I've never had to cut valves or seats. Usually they lap in.

Rich Euro M5 · Post by **Rich Euro M5** » Jan 12, 2009 6:47 PM

No mention of valve guides. These should be replaced when you have the head work done.

Rich

turbodan · Post by **turbodan** » Jan 12, 2009 6:56 PM

If they're sloppy, IMHO. No need to punch them out just to do it.

I've also run sloppy guides with no problems, but if you never plan on being in there again you might think twice about it.

Duke · Post by **Duke** » Jan 12, 2009 7:09 PM

hackodan wrote:I've never had to cut valves or seats. Usually they lap in

.

turboHACK wrote:If they're sloppy, IMHO. No need to punch them out just to do it.

I've also run sloppy guides with no problems, but if you never plan on being in there again you might think twice about it.

You are such an unbelievable hack. Save your *ucked up advice for your salvage yard buddies. Your advice costs people more time and money than they will ever know.

Jimmie G · Post by **Jimmie G** » Jan 12, 2009 11:12 PM

You might want to go with some Deves rings they are what I put in my B35 rebuild. Swedish metalurgy made in usa.

Jimmie

George · Post by **George** » Jan 12, 2009 11:33 PM

Duke wrote:
hackodan wrote:I've never had to cut valves or seats. Usually they lap in
.

turboHACK wrote:If they're sloppy, IMHO. No need to punch them out just to do it.

I've also run sloppy guides with no problems, but if you never plan on being in there again you might think twice about it.
You are such an unbelievable hack. Save your *ucked up advice for your salvage yard buddies. Your advice costs people more time and money than they will ever know.

Who have they hurt Duke?

Post by **Jeremy** » Jan 13, 2009 12:05 AM

Considering the valve guides are usually worn out of spec by 150k miles, I'd say an overwhelming majority of people with m30s have "worn" valve guides at this point and don't even know it because it just doesn't cause any issues.

The valve guide seals, on the other hand, should definitely be replaced.

Jeremy

turbodan · Post by **turbodan** » Jan 13, 2009 12:23 AM

Duke wrote:
hackodan wrote:I've never had to cut valves or seats. Usually they lap in
.

turboHACK wrote:If they're sloppy, IMHO. No need to punch them out just to do it.

I've also run sloppy guides with no problems, but if you never plan on being in there again you might think twice about it.
You are such an unbelievable hack. Save your *ucked up advice for your salvage yard buddies. Your advice costs people more time and money than they will ever know.

Are you going to start blaming me for your fucked up engine? Are worn valve guides the reason I blew my last head gasket? You're ridiculous. I think your track record makes your opinions and advice a lot more questionable than mine.

BTW, still running great on my original bottom end, now with a Garrett GT3582R. All I've got left to do is finish some plumbing and tune it. Should be a blast.

///ARINUTS... · Post by **///ARINUTS...** » Jan 13, 2009 1:11 AM

Jimmie G wrote:You might want to go with some Deves rings they are what I put in my B35 rebuild. Swedish metalurgy made in usa.

Jimmie

I've heard that Goetze rings are the way to go.

paul burke · Post by **paul burke** » Jan 13, 2009 1:17 AM

Entropy_Engineering wrote:Make sure if the valve seats need work the machine shop does it with a cutter, not a stone. The BMW valve seats are so hard the majority of the time a stone will start to chatter a little and make the seat rough. A good machine shop should be cutting with a machine like a Serdi.

Like this?

Paul

Entropy_Engineering · Post by **Entropy_Engineering** » Jan 13, 2009 1:50 AM

I can't tell on that pic. And I'm not 100% sure it's always a problem. The ones I saw that chattered had like a wavy finish with probably 3mm between waves. That looks smooth to me. Like Dan wrote, I've basicly always been able to lap them in. I don't see too much what slightly worn guides would hurt either. Once they wear a little they just start lubricating themselves better. Excessively worn intake guides I guess could lead to loss of octane from oil injestion, but I don't see that happening. If you do ever replace guides, have bronze manganeze type installed they hold up better.

SamSpade · Post by **SamSpade** » Jan 13, 2009 1:59 AM

Thanks everyone for the tips, pls keep them coming.

One of my suppliers is offering TRW for intake valves and Bock for exhaust ones. Are they any good? How about the Intervalves brand that are sold by most vendors? Any other valve options?

Also, I just re-checked the camshaft, and some lobes are scored at the tips. Are the Febi replacements as good as OEM or are they enough for my needs? I don't plan to go aggressive on the cams.

paul burke · Post by **paul burke** » Jan 13, 2009 2:11 AM

The head was cut on a Serdi 60 using a five angle cutter. Seat is 1mm wide and it has Bronze Manganese guides installed..

NO RA COMMENTS PLEASE!! Don't want to start that stuff again.

Paul

Entropy_Engineering · Post by **Entropy_Engineering** » Jan 13, 2009 2:22 AM

Uh, holy crap sir. That is beautiful. Now ship one to me immediately.

paul burke · Post by **paul burke** » Jan 13, 2009 2:25 AM

That can be arranged as I do many. PM me if you are serious.

Paul

Entropy_Engineering · Post by **Entropy_Engineering** » Jan 13, 2009 2:27 AM

Looking at that head makes me almost pissed, and realize why I love the SOHC BMW's at the same time. I've got my old 928 I love. Ah yes bow down it's a Porsche (cheer please) it's got a v8 (chear again). Joking. The valve layout on the old Porsche's is like so many vehicles with it's inline configuration. I love the canted angles on the BMW heads. I think an m20 has the same size valves as the porsche and the bore is so much smaller on the m20. There's a lot of under appreciated engineering and potential in these motors.

Entropy_Engineering · Post by **Entropy_Engineering** » Jan 13, 2009 2:27 AM

No no I can't afford that now. U do other heads as well? I may set you up with some customers.

Entropy_Engineering · Post by **Entropy_Engineering** » Jan 13, 2009 2:33 AM

So back on topic, unless you know a machine shop that is really affordable and good, I don't suggest replacing the small end rod bushings. For what it costs with new rod bolts you can basicly get aftermarket rods. Also, anyone chime in here if I'm wrong, but I've never seen a BMW engine damaged from worn rod bushings. Actually, I haven't seen rod bushings with much wear. I also haven't ever seen a worn out oil pump, with the exception that I've seen the relief piston bore get scored and jam the piston open (no oil pressure below redline). I think that was influenced by other sources though.

SamSpade · Post by **SamSpade** » Jan 13, 2009 3:32 AM

Ok then, I won't change the small end bushings since I won't change the pistons anyway.

Any comments about the valve brands I mentioned earlier? TRW, Bock, Intervalves? And the Febi camshaft?

paul burke · Post by **paul burke** » Jan 13, 2009 3:42 AM

TRW valves are considered OE replacement by most and are of good quality. FEBI is a well known BMW aftermarket supplier and most of the time there stuff is OK. Since your talking camshaft, they are usually repackaged and come from a common source. There are several companies selling the same camshaft so I would shop for the bargain.

Paul

Duke · Post by **Duke** » Jan 13, 2009 8:33 AM

paul burke wrote:Like this?

Paul

Naaaaaaaaaaaaaa.......TurboHack says just lap them. What you do is stupid.

Paul, you know nothing....TuboHack knows much better....

Here he is hard at work -

turbodan · Post by **turbodan** » Jan 13, 2009 10:46 AM

Duke wrote:
paul burke wrote:Like this?

Paul
Naaaaaaaaaaaaaa.......TurboHack says just lap them. What you do is stupid.

Paul, you know nothing....TuboHack knows much better.

How much does a valve job like that cost?

Why does my car run without one? How can that be?

I guess what I'm trying to say is that I would love to do all kinds of elaborate head work and have custom pistons and cams made, but I just can't justify the expense. I've got two Yamaha RD's that I could sink a couple grand into. Shit, I could even buy an RZ. I could find some ways to spend some money on my KX too. When I can get by just fine without dropping shit loads of money for MAXIMUM HP, I'm probably going to go ahead and do that.

Canuck YYC · Post by **Canuck YYC** » Jan 13, 2009 12:30 PM

paul burke wrote:

NO RA COMMENTS PLEASE!! Don't want to start that stuff again.

Paul

Hey...that Ra is all wrong man.

Duke · Post by **Duke** » Jan 13, 2009 2:40 PM

Canuck YYC wrote: Hey...that Ra is all wrong man

No way dude (TIC).....that is a RA16. Pefect for MLS HG use.

MyE28.com

MyE28.com

Need advice rebuilding M30B35. What else to replace?

Need advice rebuilding M30B35. What else to replace?