Noob M30B35 Build

[tig]

BTW, for those following along who are as clueless as I am:

BMW has used the same rocker arm design, apparently, forever. These new rocker arms I got, part # 11 33 1 271 833, work interchangeably in all of these cars:

5' E34
530i (M30)
535i (M30)
7' E32
730i (M30)
730iL (M30)
735i (M30)
735iL (M30)
1500-2000CS
1500 (4-Zyl)
1600 (4-Zyl)
1800 (4-Zyl)
1800ti (4-Zyl)
1800tiSA (4-Zyl)
2000 (4-Zyl)
2000C (M10)
2000CS (M10)
2000ti (4-Zyl)
2000tii (4-Zyl)
2000tilux (4-Zyl)
1502-2002tii
1502 (M10)
1600 (M10)
1600GT (M10)
1600ti (M10)
1602 (M10)
1802 (M10)
2000 (M10)
2000tii (M10)
2002 (M10)
2002ti (M10)
2002tii (M10)
2002turbo (M10)
3' E21
315 (M10)
316 (M10)
318 (M10)
318i (M10)
320 (M10)
320i (M10)
5' E12
518 (M10)
518i (M10)
520 (M10)
520i (M10)
520i (M20)
525 (M30)
528 (M30)
528i (M30)
530i (M30)
535i (M30)
3' E30
316 (M10)
316i (M10)
318i (M10)
5' E28
518 (M10)
518i (M10)
525i (M30)
528i (M30)
533i (M30)
535i (M30)
M535i (M30)
2.5CS-3.0CSL
2.5CS (M30)
2800CS (M30)
3.0CS (M30)
3.0CSi (M30)
3.0CSiL (M30)
3.0CSL (M30)
6' E24
628CSi (M30)
630CS (M30)
630CSi (M30)
633CSi (M30)
635CSi (M30)
2500-3.3Li
2.8L (M30)
2500 (M30)
2800 (M30)
2800Bav (M30)
3.0L (M30)
3.0S (M30)
3.0SBav (M30)
3.0Si (M30)
3.3L (M30)
3.3Li (M30)
7' E23
728 (M30)
728i (M30)
728iS (M30)
730 (M30)
732i (M30)
733i (M30)
735i (M30)
745i (M30)
745i (S38)

I continue to be amazed at how LITTLE engineering BMW has done over the years

[Mike W.]

Rods are the same, I've mixed and matched them, pistons are interchangable given the right bore and stroke although technically 6 cylinders have more offset. Really the M30 is just a 6 cylinder M10 engine. Valves don't swap though, different length.

[Rich Euro M5]

Update on the head from the machinist:

"Cam is serviceable but if you want to do it right I suggest you get it reground or source a new one. You'll also want to do new (or rebuilt) rocker arms too. Valves look good. Springs are fine. Head's been bead blasted."

On the block: "Will get at it tomorrow, but am optimistic."

So, on the cams:

My goal with this engine is to make it smooth and bulletproof. Thus getting a more aggressive cam is not in play for me. But I want to do it right, so 'serviceable' is not good enough.

What are my options on cams then?

1) Find someone to grind these, send them off...?
2) Buy a new set?
3) Buy an already ground used set?

Same with rockers. Do I just bite the bullet and buy new rockers or should I have these ground along with the cam; assuming I do #1?

If you want a performance camshaft, contact Paul Burke for his recommendation. Otherwise, use a new OEM camshaft for your build.

[Mark 88/M5 Houston]

Update on the head from the machinist:

"Cam is serviceable but if you want to do it right I suggest you get it reground or source a new one. You'll also want to do new (or rebuilt) rocker arms too. Valves look good. Springs are fine. Head's been bead blasted."

On the block: "Will get at it tomorrow, but am optimistic."

So, on the cams:

My goal with this engine is to make it smooth and bulletproof. Thus getting a more aggressive cam is not in play for me. But I want to do it right, so 'serviceable' is not good enough.

What are my options on cams then?

1) Find someone to grind these, send them off...?
2) Buy a new set?
3) Buy an already ground used set?

Same with rockers. Do I just bite the bullet and buy new rockers or should I have these ground along with the cam; assuming I do #1?

If you want a performance camshaft, contact Paul Burke for his recommendation. Otherwise, use a new OEM camshaft for your build.

What Rich said.

[tn535i]

Um' bottom of that list of applications for the rocker arm is a 745i(s38).

What's with that?

[Mike W.]

Update on the head from the machinist:

"Cam is serviceable but if you want to do it right I suggest you get it reground or source a new one. You'll also want to do new (or rebuilt) rocker arms too. Valves look good. Springs are fine. Head's been bead blasted."

On the block: "Will get at it tomorrow, but am optimistic."

So, on the cams:

My goal with this engine is to make it smooth and bulletproof. Thus getting a more aggressive cam is not in play for me. But I want to do it right, so 'serviceable' is not good enough.

What are my options on cams then?

1) Find someone to grind these, send them off...?
2) Buy a new set?
3) Buy an already ground used set?

Same with rockers. Do I just bite the bullet and buy new rockers or should I have these ground along with the cam; assuming I do #1?

If you want a performance camshaft, contact Paul Burke for his recommendation. Otherwise, use a new OEM B35 camshaft for your build.

Fixed.

[wkohler]

Um' bottom of that list of applications for the rocker arm is a 745i(s38).

What's with that?

I just was going to say something about that. Surprised to see that listed in RealOEM since it was a South African thing. Has to be an error since, well, they wouldn't work in the M88/3.

[tig]

Yesterday afternoon I talked to the machinist about the block and cylinder bores. I was driving and had a hard time hearing him. I did not have a chance to call him back and am now trying to decode what he said.

He was talking in "thousandths" and I assumed since it's a metric engine that's what he meant, but now that I've read up, it doesn't make sense.

What is the definitive word on a stock B35 setup and the acceptable range for piston/cylinder clearance?

This doc I found says the range is 0.02mm to 0.05mm which jives from what I read in threads on this board. In inches that is 0.00079" to 0.00196", FWIW.

Standard B35 bore is 92.00 to 92.01 mm.

Here's what I heard him say:
- Before honing the cylinders were "4 thousandths".
- After honing to get the marring and rust in #6 off they are "6 thousandths". This is the upper acceptable limit.
- The pistons have marring on them too. I should either replace them with oversized pistons or have the skirts coated (graphite).

I think what he meant (or said, but I didn't understand) was

- Before honing the cylinder-to-piston clearance was 0.04mm.
- After honing the cylinder-to-piston clearance is 0.06mm, which is the maximum acceptable. This means the new bore size is 92.03mm.

I think we have two options:

1) Buy new "00" (92.050) pistons for ~$181 each. With these I"ll be at exactly the minimum clearance of 0.02mm.
2) Have the existing pistons coated with graphite or some of the piston skirt coating at about $40 each.

We have to buy new rings regardless (~$55 per piston).

It sounds like the coatings can provide up to 0.1mm of new material. The site linked above (Swian PC-9) is the first I found in a search.

What do folks suggest? Am I missing something?

[Mike W.]

First thing I'd do is go talk to the machinist in person and not guess what they said on the phone.

The coatings are interesting, I hadn't heard of it before to reduce excessive clearance due to wear. M30's are pretty tolerant of relatively large clearances, .004" is no problem at all, .006" is large, but I've run it without problems, but for your build I would target .004" or less. New or a fresh bore you would shoot for ~.0015". And I see no reason to coat the tops, so it would be more in the $20 range than $40, if needed.

BMW rings are the best if replacements are the same as OE, $55 per cylinder is expensive but less than I thought they ran. You can get Geotze for less than half that, but OE are better.

[tig]

First thing I'd do is go talk to the machinist in person and not guess what they said on the phone.

The coatings are interesting, I hadn't heard of it before to reduce excessive clearance due to wear. M30's are pretty tolerant of relatively large clearances, .004" is no problem at all, .006" is large, but I've run it without problems, but for your build I would target .004" or less. New or a fresh bore you would shoot for ~.0015". And I see no reason to coat the tops, so it would be more in the $20 range than $40, if needed.

BMW rings are the best if replacements are the same as OE, $55 per cylinder is expensive but less than I thought they ran. You can get Geotze for less than half that, but OE are better.

Mike, I appreciate the response. I totally plan on talking to the machinist today, but writing my thoughts down over the weekend helps clear things up in my mind.

Why are you using inches in your description? It's really confusing and doesn't make sense to me. .004" is 0.1016mm and 0.1mm can't be what you meant. I think you meant "0.04mm is no problem at all and 0.06mm is large".

I *do* think you mean't "shoot for ~.0015" though (0015 inches = 0.0381 millimeters).

I called Swain this morning and it will be $26 per-piston for their PC-9 coating which will add up to .004" (1mm) of material. They said that I would then have to sand the pistons down myself to get the exact diameter I wanted. I assume (but will check) my mechanic can do this.

I plan on getting BMW rings.

[tig]

Well, shit.

Talked to machinist and got clarity.

1) He's not happy with the piston ring grooves on the pistons. He says they will work, but given the importance of tight fit, and the money/time I'm spending on this engine, he is really recommending I get new pistons.

2) He meant thousandths of an inch. And my bores are currently 92.0508mm (0.002" oversized).

Via getbmwparts.com, "Nueral/alcan" 92,485MM(+0,50) pistons are $181 ($1086 for the set). It is not clear if they include rings, but everyone I've talked to seems to believe they do.

On eBay I see I can get a set of Maxsil pistons (which include rings) for $619. My machinist said he's worked with Maxsil pistons before and they'll be "ok" for a non-tuned engine like mine.

Or, I could change my rules for this build, and go with CP Forged pistons (10:1 compression) for $1,049.95. I'd then be building a tuned M30B35 which has never been my intent. If I started down this path I'd likely get sucked in and end up doing a different cam grind, etc...

Lots to think about. I love everyone's input...

[Justin_FL]

Seems like a no brainer now that the whole thing is apart, IMO. Unless you had a budget in mind

Bump the compression a bit, get a hotter cam, slightly larger fuel injectors, and then get Mark D'sylva to burn you a custom chip for the 179. He should have a pretty good idea what you'd need based on the modifications. Maybe throw in some head porting and do larger valves, too.

[tig]

Now we're cooking with fire...

I just got off the phone with the legendary Paul Burke. We have a plan. I'm going to go with his mild cam and 10:1 pistons. Once I get the cam from him, my head is ready to go with the new rocker arms I bought and the 3-sided valve grind my machinist has already done.

He says my rods are ideal but I should replace the rod bolts. He also says that the crank is ideal.

The only wrinkle in the plan is that Paul really does not think I should use this block, as it is one of the later "lightweight" B35 blocks and is prone to cracking ("1 in 5 crack in stock form"). I may argue with some of you, but I'm not going to argue with Paul Burke. I have not yet purchased motor mount adapters that I'd have to use if I continued down the previous path, so that's some lemonade here...

Paul says the 179 ECU (Motronic 1.3) will drive this engine fine, but I'll want to increase the fuel pressure.

So now I'm on the hunt for either an early B35 (stamped Nov. 1987 on the block) or a B34 block. Anyone in WA have a good one for cheap? :-)

[shwaa]

Cool !! I have been following your thread and I have to say I am excited to read this.

I just completed the following:

b34 block bored to 92.5
Paul Burke b35 10.5:1 pistons
Paul Burke N31 cam
port match and valve job
b35 head and intake manifold
bavauto headers

I also did the Miller maf and WAR chip with 24lb injectors but I am pretty sure others have run 10:1 on a 179 ecu without issue (don't quote me on that)

You will be very happy !!!

[Brian D]

I just got off the phone with the legendary Paul Burke.

So that's who was tying up the line! I wish I could help you, I have a B34 block but it's in Arizona. You should be able to find something up there pretty easily though.

I just completed the following:

b34 block bored to 92.5
Paul Burke b35 10.5:1 pistons
Paul Burke N31 cam
port match and valve job
b35 head and intake manifold
bavauto headers

Is yours running yet? How do you like that cam? I'm hoping to take delivery of my project later this month, and I can't wait!

[tig]

Cool !! I have been following your thread and I have to say I am excited to read this.

I just completed the following:

b34 block bored to 92.5
Paul Burke b35 10.5:1 pistons
Paul Burke N31 cam
port match and valve job
b35 head and intake manifold
bavauto headers

I also did the Miller maf and WAR chip with 24lb injectors but I am pretty sure others have run 10:1 on a 179 ecu without issue (don't quote me on that)

You will be very happy !!!

The new plan summary is:

• B34 block (yet to be acquired) bored to 92.5mm
• Paul Burke B35 10.5:1 "806" M30 B35 CNC Dome piston set
• Paul Burke N21 camshaft (a bit more mild than the N31 you got)
• 3-sided valve grind (done)
• B35 head, rods, springs, crank, manifold
• 19lbs mustang injectors (should I go 24?)
• 179 ECU
• Bav Auto headers and Ireland Engineering exhaust
• 17lbs flywheel

I have no desire to have lots of knobs to tweak on this engine once it's installed. I have enough of that shit in my home control system and other computer stuff I do all the time. I want this car to just work. I know I'll be giving up a little by just using the 179 and AFM, but that's OK. Of course, I reserve the right to change my mind later.

I will shortly have a whole bunch of B34 engine parts to sell as well as my perfectly good B35 block.

[shwaa]

Is yours running yet? How do you like that cam? I'm hoping to take delivery of my project later this month, and I can't wait!

Yep ... Got about 650 miles on it. I love the cam and the motor all together. Tons of torque and runs out smooth all the way up. I still have some tuning to do with the Miller stuff but overall .. all good.

[shwaa]

Oops .. Sorry cek .. I misread your earlier post and didn't realize that you talked to Paul about the 179 ecu.

How much fuel pressure ? I am using a Bosch Porche 944 fpr that looks like a stock BMW unit but 3.5 bar.

[_marshall]

I will shortly have a whole bunch of B34 engine parts to sell as well as my perfectly good B35 block.

My hoarding sense is tingling. Will be watching for that thread!

[Mike W.]

The only wrinkle in the plan is that Paul really does not think I should use this block, as it is one of the later "lightweight" B35 blocks and is prone to cracking ("1 in 5 crack in stock form"). I may argue with some of you, but I'm not going to argue with Paul Burke. I have not yet purchased motor mount adapters that I'd have to use if I continued down the previous path, so that's some lemonade here...

I don't know the numbers but B35 blocks cracking is common knowledge. Around the bolt holes.

Sounds like you're in for quite a build, I'd love to do similar but my checkbook isn't up for it. It's starting to hurt with me just talking about it.

[tig]

At about 11:30am yesterday this got dropped off at our house.



By 2pm, CJ & I had it all the way down to the block.



This engine came off the same car (an '88 white 535is) that my exhaust came off of, but via a different seller. Small world.

The inside of the valve cover is spotless. Supposedly the head had recently been redone and it has a "euro camshaft". I hope I can find a buyer for the head and other parts; lots of good stuff. I'm going to hold on to most of it until the engine is rebuilt, just in case I need any of it, but if anyone in the Seattle area needs B34 parts, let me know...



But best of all, we now have a good B34 block to build the new engine on and it was dirt cheap. From a budget perspective, ignoring the fact that buying the Paul Burke camshaft & piston kit about doubled what we were planning on spending, I get to save because we won't have to buy motor mount adapters for that B35 block. Tee-hee.

[tig]

I want to confirm some things:

The oil pump design on the B34 and B35 is quite different. I plan on using the B35 oil pump I've rebuilt and the B35 oil pan on the final build. Those parts will fit on the B34 block, right?

Are the accessory mounts (e.g. for A/C, PS, Alternator) the same between the B34 and B35 blocks?

[tig]

My plan is to use a standard AFM and stock 179 chip initially. But it seems likely I'll want more control over the tune; maybe as far as having a Miller WAR chip.

So I snapped up a used Miller MAF and Miller 179 chip. I figure if I don't end up using it I can just re-sell it.



Pistons and camshaft are due next week. Realized yesterday I need to source new rod bolts/nuts and piston wrist pins. Paul Burke says just use OEM so that's what I'm going with...

[tig]

Pistons have arrived.

So pretty.




Camshaft should now arrive next week.

[waferman]

Great thread- I always like the engine build threads. I'm an E28 guy now, but used to be an E21 guy. I rebuilt my engine in my 83 for a project, for pretty cheap. I had a local shop in PDX do the machine work, and I used Maxil pistons. After 7 years, they are still close to the same compression on all for cylinders- good job on me I only had them balance the crank to the flywheel, and it was a pretty smooth engine.

Rebushing the rockers with new rocker shafts will quiet the head down, also. People always think it's the valves that need to be adjusted, and while that's true for the most part, the valve train as a whole gets worn, and you can't turn that out by adjusting valves. I had a very un-bmw sounding engine- very quiet