M30b30 tuning

E28 technical advice asked and given! Troubleshooting, modifications and more.
Nothintoseeere
Posts: 57
Joined: Apr 23, 2021 5:27 PM
Location: U.k

M30b30 tuning

Post by Nothintoseeere »

Its not quite e28 (i have had three) but its for an e34. In any case the car has a m30b30 which i like. However it could have more poke and i think it can. One problem is the low CR. Even over here in the U.k they are have a CR of 9:1 which will blunt any tuning done.

First step is, as the exhaust is blowing is, to have Frits Bits stainless exhaust manifold and system fitted. Since its RHD car this is the only one that can be bought. Given the exhaust studs broke when removing the old manifold the engine is out now for there removal. Removing the cylinder head could be a can of worms and once its off, its why not time.

Second step is rolling road to see what it produces. I think its in rude health but I think and it is could be different things. When it was new it has 188hp.

Step three fit omex engine management. Wave good bye to the Afm at this point and say hello to a MAP and temp sensor. Motronic won't be ditched. It will still think its doing something so the energy control will still work but it really doing just that.

Step 4 well this is where thoughts are sought. I could have the engine out and dismantled. I could have it bored out for custom pistons and if that done you might as well fit 93.4mm pistons or 94mm pistons, the b35 head ( with some minor work) a dblias cam or similar and enjoy. However thats obvious. I like the engine size. I see know reason to bore it out, its almost boring. Pun intended.

The m30b30 piston have as far as know a 10.4cc raised profile and the combustion chamber is 65cc like on the b35 head which means the raised profile would need to be 17.6cc or thereabouts to give a 10.5:1 CR. My gut tells me that might be too much. Also if new pistons are being fitted why not bore the block.

So the m30b25/b28/b34 head has a 58cc combustion chamber. Fitting this would raise the CR to 10.5:1 especially once a used head is skimmed. This head has valves that are the same size as i the m30b30 head but its the older style ports. However over that head got 218hp out of the m30b34 motor so it can flow some air.

Also for a cylinder volume of 497cc 46mm inlet valves are about right so there may not be any gain with larger valves and ports of the b35 head. The b30 head has smaller valves and inlet ports to increase gas flow speed and help low end torque. I assume thats the reason. With that in mind there maybe little that needs doing to the suggested head apart from port matching. I won't be doing that. Radco sport not far from me will be. They mostly build race engines for smaller classic british cars. Then which cam. Dblias has one with reasonable lift. Is it too much for this engine. It will be as it bow a car for driving on the road. All i want is a bit more poke without changing the engine.

Then what to do with the intake. Dblias do an ITB setup which look the part. No idea if it works well as there are almost few report of this sort of setup working well. Of course i could leave it as is. To be honest i just like the look of it.

Thats the plan as it is. Not sure if anyone has done anything similar with a 3.0l.
Ju@n
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Location: Uruguay

Re: M30b30 tuning

Post by Ju@n »

I'm not sure about most of the things you propose since they are not common combinations buuuut I can tell you b34 head won't go on top of a b35 since pistons will end up falling in love with the valves.
Nothintoseeere
Posts: 57
Joined: Apr 23, 2021 5:27 PM
Location: U.k

Re: M30b30 tuning

Post by Nothintoseeere »

Well thats helpful. I am all for love just not this kind. So is the only way to increase the CR then new pistons. Thats a bummer. Would not suitable machining of valve reliefs not fix this.
The b30 pistons have a raised area of 2.91mm thick apparently surely there is enough material there to cut a relief. Or would the reliefs themselves cause other problems.

In fact the CR would increase with a bigger bore if there is enough raised area. I would need a raised volume of 12 to 13cc just to get a CR 10:1

Is there no way to use what i thought is a simpler solution or it is bore the block, new pistons e.t.c
kojo96
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Location: Pleasanton CA

Re: M30b30 tuning

Post by kojo96 »

Ju@n wrote: Apr 23, 2021 6:49 PM I'm not sure about most of the things you propose since they are not common combinations buuuut I can tell you b34 head won't go on top of a b35 since pistons will end up falling in love with the valves.
Pretty sure it will, and it's been documented here before. Makes for a higher compression ratio than the b35 did originally due to the smaller combustion chamber, the pistons will not fall in love with the valves. A search will give you more information.
Mike W.
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Location: California Whine Country

Re: M30b30 tuning

Post by Mike W. »

Welcome to the group!

Now I might be surprised, but you probably won't find much help here. Not for lack of trying, but we're mostly US based and we never got that engine here so we don't have much experience with it.
The b30 head has smaller valves and inlet ports to increase gas flow speed and help low end torque. I assume thats the reason.
I'm skeptical on that. More so in later years, but BMW has definitely throttled down engine output at times for marketing reasons, especially in E39s, but I suspect on the 3.0 you have also. I suspect they wanted a significant difference in power between the two engines as I'm sure they had nearly identical production costs, but a difference at retail.

I'm sure with higher compression pistons and a cam you could get more power, but I suspect it would be more time and money than just getting a M35 engine and installing that.
Nothintoseeere
Posts: 57
Joined: Apr 23, 2021 5:27 PM
Location: U.k

Re: M30b30 tuning

Post by Nothintoseeere »

Not many b35 engines about here and they are all old and come from ropey looking breakers. I have had mine for nearly 10 years so i know it history. A good 535i is £8000 to £10000 and its probably an auto. I have a rather rare manual gearbox. I tend to stick to what i have. Also if i change the engine insurance costs rocket and i have to I form DVLA of a change in engine number.

So the only way to know is to mount the b34 cylinder head and find out if there is a problem. I have been searching for days and while i have reference to the compression ratio change i have not found conformation that it works with no modifications to the pistons.
Nothintoseeere
Posts: 57
Joined: Apr 23, 2021 5:27 PM
Location: U.k

Re: M30b30 tuning

Post by Nothintoseeere »

The b30 and b35 head castings are similar but not the same. The combustion chamber appear to to be the same volume but the ports are different and valves the same as the valves used on older m30 engines going back to 1968 (46/38mm) where as the b35 head get 47mm inlet valves. The inlet manifold is also a separate part. So BMW did make a separate casting for the b30 and possibly tuned it for lower end torque and it does pull well even in 4th gear from 1000 rpm.

In any case i have found these. £1152 for a set of 6 JE pistons with heavy duty pins and coatings with any CR i like. Import taxes to pay on top but i am used to that (i import alot of goods for my business).

https://store.vacmotorsports.com/mobile ... p3560.aspx

I could just get these as that would mean keeping the existing cylinder head. In fact if i used 99 octane fuel which is everywhere here how much compression could i run and which of the available camshafts would make most sense, Scrick, dblias.... E9 272 7.6mm lift any others? The e9 camshaft gave the 3.0l 197hp on old mechanical fuel injection.

Schrick data
Lift data [mm] Cam lift intake 8,7, Cam lift exhaust [mm] 8,6, Valve lift intake [mm] 10.9, Valve lift exhaust [mm] 10.8
Opening Durations [°CrA] Opening duration [CrA°] 284, Peak timing intake [CrA°] 280, intake opens 110,
Peak timing exhaust [CrA°] 110
Valve timing [°CrA] intake closes 32, exhaust opens 72, exhaust closes 70, Lift in TDC intake [mm] 30
Lift in TDC [mm] Valve clearance exhaust [mm] 1,9, Opening duration exhaust [CrA°] 1,7
Valve clearance [mm] Lift in TDC exhaust [mm] 0,25, Valve clearance intake [mm] 0,25

Dblais cam data
Duration 276 degree
Peak timing 112
Lift 11.2mm
Valave timing 26/70-70/26
Valve clearance 25/25

Not sure which to pick. Essentially i need to decide if i am buying new pistons which camshaft to pick for a given CR. Its a road car so lower rpm torque is important (i know i won't get more with a uprated camshaft). More mid range torque is important too (2500 to 5000 rpm). A bit more at the top end is good as well as it the engine stops pulling as well past 5500 rpm. I accelerate the car between 2000 and 5000 rpm and change gear accordingly.

One thing that puzzles me is how you can use the same cylinder head on different bore sizes. Bmw did it with the b25/b28/b34 engines. I would have thought the bore size and combustion chamber diameter would match. Obviously they don't have to. Why?
Nothintoseeere
Posts: 57
Joined: Apr 23, 2021 5:27 PM
Location: U.k

Re: M30b30 tuning

Post by Nothintoseeere »

Other questions with a higher lift longer duration camshaft will i need uprated springs, rockers e.t.c or are those pointless as i think they might be for a engine that will never be revved more than 6500rpm.

Either i get higher CR ,(10.5:1) pistons 89mm bore for my 80mm stroke crank and buy a camshaft and rebuild the engine and call it done and enjoy (minor head work may be done) or i bore it out to 94mm and get a b34/35 crankshaft and create a 3580cc monster. In which case how much internally would i need to alter. Would i need to replace the conrods, valve springs, rockers or will the stock items do. Then will the stock crank and conrod bearings suffice, new one can be bought or are the uprated ones that vac motorsport sell any good.

On fact is vac motorsport reputable. I can afford to go as far as i need but how far does one need to go for an engine in a family car. All i need is it to be reliable and rev well to 6500rpm. Any more and its not a family car being driven in a way my family would like.
Mike W.
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Location: California Whine Country

Re: M30b30 tuning

Post by Mike W. »

I wasn't aware of all the complications on an engine change, here smog is a big issue, but if it looked the same they wouldn't check the engine serial number, nor would it be an insurance issue.

I doubt you could bore an 89MM engine out to 94. I went from 89 to 92 on an earlier block, '80 to be exact, and the machinist didn't want to do it at first it was so large an overbore and said it was pretty thin, although I put 175K on it before I sold it. Also be careful and make sure the pistons are for the right head, as I said earlier we never got the late 3.0 here so it wouldn't be something they would be expecting.

Again, I can only speak to earlier engines as we never got the late 3.0 here, but as long as they had the bulges on the side of the block to accommodate the longer 86MM throw, you could use the 3.3/3.5 crank in a 3.0 block. The side of the block even was cast 3.0/3.3. Otherwise spend some time on Realoem but I think most of it interchanges. One sleeper you might not catch is the harmonic balancer on the front is different with longer throw crank.
Nothintoseeere
Posts: 57
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Location: U.k

Re: M30b30 tuning

Post by Nothintoseeere »

I would prefer keeping the same crank and cylinder if possible.its alot simpler.

So i think i will stick with pistons for current crank and cylinder head. Raising the CR should boost power and torque a bit and help offset the loss in low rpm torque caused by a higher lift longer duration cam. Its a 530i after all. Just writing this out helps me form up my ideas. That the point of the post. Looking forward to getting started. Well it already has. Exhaust and tubular manifold are being fitted at the moment.

The m90 block which is an m30 variant and had 93.4mm bore. Bmw used to sell 93.74mm over pistons for it. Hence 94mm bore or something close is should possible. Even with a 80mm stroke crank and a 93mm bore it becomes 3261cc and rev well which is what i like about the current engine.

One serious question. Looking on realoem the 272 cam used on the early 3.0l engine that produced 197hp is still available new. Is this a straight swap onto my m30. I know there is a drive gear for old ignition system and something for the old mechanical injection but since these are not needed. Its a less extreme camshaft and that will help with low rpm torque.

We dont have the same emissions laws over here as you do in the usa. The rules are even laxer for cars built without catalytic converters as mine is. There is a is a good reason why i bought a 1988 e34 and not a 1995 e34. All my car has to met for its MOT is 3.5% CO max at idle and 0.12% HC at idle. There is no requirement at higher engine speeds. Cars made after a certain date in 1995 have stricter laws on emissions. We also do jot have the same smog issues.
Mike W.
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Location: California Whine Country

Re: M30b30 tuning

Post by Mike W. »

Nothintoseeere wrote: Apr 24, 2021 4:21 PM I would prefer keeping the same crank and cylinder if possible.its alot simpler.

So i think i will stick with pistons for current crank and cylinder head. Raising the CR should boost power and torque a bit and help offset the loss in low rpm torque caused by a higher lift longer duration cam. Its a 530i after all. Just writing this out helps me form up my ideas. That the point of the post. Looking forward to getting started. Well it already has. Exhaust and tubular manifold are being fitted at the moment.

The m90 block which is an m30 variant and had 93.4mm bore. Bmw used to sell 93.74mm over pistons for it. Hence 94mm bore or something close is should possible. Even with a 80mm stroke crank and a 93mm bore it becomes 3261cc and rev well which is what i like about the current engine.
All M30 blocks are not the same internally, even though the outside is the same. 86MM bore blocks do not have siamised cylinder walls like the larger bore ones do, and 89MM blocks aren't the same as 92 blocks and I doubt 92s are even the same as 93.4 blocks. I'm not even sure 92 is doable on a late B30 block. There are people with tools to measure wall thickness and that might be a good idea before you bored more than 2MM. If you really want a significant bump in torque you really should go to a 86MM crank.

One serious question. Looking on realoem the 272 cam used on the early 3.0l engine that produced 197hp is still available new. Is this a straight swap onto my m30. I know there is a drive gear for old ignition system and something for the old mechanical injection but since these are not needed. Its a less extreme camshaft and that will help with low rpm torque.
I'm not sure that is actually the same cam that came in those cars, BMW often will substitute a different part that works in place of a slightly different original. However, that is a carb/L jet cam and will not work with a motronic ignition which I believe your 530 is. But it appears your cam would be the same one used in US spec B35s which has a good reputation. Personally I would just use that cam.
We dont have the same emissions laws over here as you do in the usa. The rules are even laxer for cars built without catalytic converters as mine is. There is a is a good reason why i bought a 1988 e34 and not a 1995 e34. All my car has to met for its MOT is 3.5% CO max at idle and 0.12% HC at idle. There is no requirement at higher engine speeds. Cars made after a certain date in 1995 have stricter laws on emissions. We also do jot have the same smog issues.
HC and CO aren't the problem in passing smog here, it's Nox that's the killer.
Nothintoseeere
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Re: M30b30 tuning

Post by Nothintoseeere »

I will be using standalone (omex) engine management so the question is will the early 272 degree cam fit my cylinder head. I don't care if it works with motronic or not. Motronic is going. I can't get motronic tuned. No one does it it here any more.
Mike W.
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Re: M30b30 tuning

Post by Mike W. »

Nothintoseeere wrote: Apr 25, 2021 1:51 AM I will be using standalone (omex) engine management so the question is will the early 272 degree cam fit my cylinder head. I don't care if it works with motronic or not. Motronic is going. I can't get motronic tuned. No one does it it here any more.
The early cam would fit a later head but have no provision to drive the distributor rotor.
Nothintoseeere
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Re: M30b30 tuning

Post by Nothintoseeere »

Motronic 1.3 does not use a camshaft driven distributor though unless i am.mistaken. as far as i know its older bosch systems that had the camshaft drive the distributor.

In any case omex will have fully mapable distributorless ignition. This is essential particularly if CR and camshaft is altered. The camshaft will affect the dynamic compression ratio which in turn affects ignition timing. Hence i am getting rid of the distributor.
Mike W.
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Re: M30b30 tuning

Post by Mike W. »

Nothintoseeere wrote: Apr 25, 2021 9:57 AM Motronic 1.3 does not use a camshaft driven distributor though unless i am.mistaken. as far as i know its older bosch systems that had the camshaft drive the distributor.
Correct. But it does have a cam mounted distributor rotor with a cap mounted on the upper timing cover. The signal is generated by the ECU but literally distributed by the cap and rotor.
In any case omex will have fully mapable distributorless ignition. This is essential particularly if CR and camshaft is altered. The camshaft will affect the dynamic compression ratio which in turn affects ignition timing. Hence i am getting rid of the distributor.
e12euro
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Re: M30b30 tuning

Post by e12euro »

Nothintoseeere wrote: Apr 23, 2021 6:06 PM Its not quite e28 (i have had three) but its for an e34. In any case the car has a m30b30 which i like. However it could have more poke and i think it can. One problem is the low CR. Even over here in the U.k they are have a CR of 9:1 which will blunt any tuning done.

First step is, as the exhaust is blowing is, to have Frits Bits stainless exhaust manifold and system fitted. Since its RHD car this is the only one that can be bought. Given the exhaust studs broke when removing the old manifold the engine is out now for there removal. Removing the cylinder head could be a can of worms and once its off, its why not time.

Second step is rolling road to see what it produces. I think its in rude health but I think and it is could be different things. When it was new it has 188hp.

Step three fit omex engine management. Wave good bye to the Afm at this point and say hello to a MAP and temp sensor. Motronic won't be ditched. It will still think its doing something so the energy control will still work but it really doing just that.

Step 4 well this is where thoughts are sought. I could have the engine out and dismantled. I could have it bored out for custom pistons and if that done you might as well fit 93.4mm pistons or 94mm pistons, the b35 head ( with some minor work) a dblias cam or similar and enjoy. However thats obvious. I like the engine size. I see know reason to bore it out, its almost boring. Pun intended.

The m30b30 piston have as far as know a 10.4cc raised profile and the combustion chamber is 65cc like on the b35 head which means the raised profile would need to be 17.6cc or thereabouts to give a 10.5:1 CR. My gut tells me that might be too much. Also if new pistons are being fitted why not bore the block.

So the m30b25/b28/b34 head has a 58cc combustion chamber. Fitting this would raise the CR to 10.5:1 especially once a used head is skimmed. This head has valves that are the same size as i the m30b30 head but its the older style ports. However over that head got 218hp out of the m30b34 motor so it can flow some air.

Also for a cylinder volume of 497cc 46mm inlet valves are about right so there may not be any gain with larger valves and ports of the b35 head. The b30 head has smaller valves and inlet ports to increase gas flow speed and help low end torque. I assume thats the reason. With that in mind there maybe little that needs doing to the suggested head apart from port matching. I won't be doing that. Radco sport not far from me will be. They mostly build race engines for smaller classic british cars. Then which cam. Dblias has one with reasonable lift. Is it too much for this engine. It will be as it bow a car for driving on the road. All i want is a bit more poke without changing the engine.

Then what to do with the intake. Dblias do an ITB setup which look the part. No idea if it works well as there are almost few report of this sort of setup working well. Of course i could leave it as is. To be honest i just like the look of it.

Thats the plan as it is. Not sure if anyone has done anything similar with a 3.0l.
You don't have a M30 engine. The European e34 530i used a 2 valve per cylinder 3 liter M20 engine. It's a bigger version of the e30 325i motor, that is it's the baby six. I am looking at pictures of it now.

The only M30 engined e34 was the six cylinder 535i with the M30B35. America never got the six cylinder e34 530i. The last time the 3 liter M30 was used in Europe was the early e24 630CS and e23 730 of 1976-79, they were carb cars with the Solex 4AI 4 barrel. It was replaced by the 9.3:1 184 bhp L-jet 2.8L in the 528i/628CSi/728i for 1980 in Europe.
Nothintoseeere
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Re: M30b30 tuning

Post by Nothintoseeere »

I do have a m30 engine. There is no 3.0l m20, of there was everyone would be fitting that into there e30's. I know the m20 engines and trust me on this it not a m20. I do know what i have. I also think bmw know what they put on the car and they say its an m30. This engine was also used in the e32 730i.

In any case a couple of exhaust manifold studs are rounded so its engine out time.
Mike W.
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Re: M30b30 tuning

Post by Mike W. »

Nothintoseeere wrote: May 07, 2021 5:06 PM I do have a m30 engine. There is no 3.0l m20, of there was everyone would be fitting that into there e30's. I know the m20 engines and trust me on this it not a m20. I do know what i have. I also think bmw know what they put on the car and they say its an m30. This engine was also used in the e32 730i.

In any case a couple of exhaust manifold studs are rounded so its engine out time.
You are absolutely correct. Now the late 3.0 and 3.5 were slightly different than 69-88 model year M30s, kind of a M30.1, but definitely M30s. M20s first saw 3.0 displacement in the E36 M3 as a S50, which was not a M20 but a descendant thereof.
e12euro
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Re: M30b30 tuning

Post by e12euro »

Mike W. wrote: May 07, 2021 6:20 PM
Nothintoseeere wrote: May 07, 2021 5:06 PM I do have a m30 engine. There is no 3.0l m20, of there was everyone would be fitting that into there e30's. I know the m20 engines and trust me on this it not a m20. I do know what i have. I also think bmw know what they put on the car and they say its an m30. This engine was also used in the e32 730i.

In any case a couple of exhaust manifold studs are rounded so its engine out time.
You are absolutely correct. Now the late 3.0 and 3.5 were slightly different than 69-88 model year M30s, kind of a M30.1, but definitely M30s. M20s first saw 3.0 displacement in the E36 M3 as a S50, which was not a M20 but a descendant thereof.
Please show us the picture of your engine. I disagree on this, the intake manifold is a clear sign it is not the M30.

North America never got the e32 and e34 730i and 530i six cylinder cars. They didn't use the M30, the only remaining M30 cars by this stage were the 535i and 735i, both with the M30B35.

Look at the following two links, the first shows the e34 530i 188 hp engine. The second page shows the e34 525i and 535i engine. You can now see the 530i had a derivation of the M20.

e34 530i six cylinder, look at the intake manifold

M30 on the left, M20 on the right

I was around over there when these cars came out and both the 530i and 730i were very slow sellers. Not many engines to put in e30s, and right after came the 4 valve 192 hp M50, and everyone went with those in Europe. Everyone forgot about those 2 valve 188 hp 530i/730is, but I remember. :cool:
Mike W.
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Re: M30b30 tuning

Post by Mike W. »

I agree the intake looks like an M20, however go to the specs and look at the bore and stroke. 89X80 is a M30 dimension. M20s/M50s were small bore/long stroke engines. Even as they grew to 3.0 in M54 they stayed at 84MM bore. The block just doesn't support an 89MM bore. Or look at Realoem, they show an M30 3.0 and the parts the show supports that. Or Schmiedmann, they show an M30 E34 and they're in the business of selling parts.
e12euro
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Re: M30b30 tuning

Post by e12euro »

Mike W. wrote: May 09, 2021 1:52 PM I agree the intake looks like an M20, however go to the specs and look at the bore and stroke. 89X80 is a M30 dimension. M20s/M50s were small bore/long stroke engines. Even as they grew to 3.0 in M54 they stayed at 84MM bore. The block just doesn't support an 89MM bore. Or look at Realoem, they show an M30 3.0 and the parts the show supports that. Or Schmiedmann, they show an M30 E34 and they're in the business of selling parts.
The magazines could make a mistake on specs. Yeah, the baby sixes went long stroke, that's what led to the 2.7 earlier. Look at the intake side in both pictures, the M30B35 is on the traditional M30 side, the mystery 3.0 is on the M20 side. Why on earth wouldn't they use the post 1981 M30 intake on that 3.0? And the oil filler is on the other side. By 1975 all M30 oil fillers moved to the firewall side. The pictures in both links were from 1988, you would think BMW would be consistent with their M30s.

There must be hardly any six cylinder e32 or e34 530i cars still left on the road. Most markets in the world never got them. Don't believe listings online just because they are there, and I have found mistakes on Realoem, stuff that just couldn't be.

Back on e34 launch in Europe you had the 129 hp 520i, 170 hp 525i and 188 hp 530i. All were 2 valve and I say the 530i is a long stroke M20. I want to know if that motor has a cam belt or a chain?
Mike W.
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Re: M30b30 tuning

Post by Mike W. »

Granted Realoem is not perfect. Pretty good, but not perfect. But look at Schmiedmann too. They show it as a M30 with M30 parts including a timing chain. I suspect the picture is something BMW supplied to the press and is in fact an M20 in a 525i. It was a short run before it was replaced with the 3.0 V8, but everything I see, have heard of and seen says it's a M30. As you know they weren't available here so I haven't seen one in the flesh, but all the parts say M30.
Tiit
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Re: M30b30 tuning

Post by Tiit »

e12euro wrote: May 09, 2021 1:18 PM North America never got the e32 and e34 730i and 530i six cylinder cars. They didn't use the M30, the only remaining M30 cars by this stage were the 535i and 735i, both with the M30B35.

e34 530i six cylinder, look at the intake manifold

M30 on the left, M20 on the right

I was around over there when these cars came out and both the 530i and 730i were very slow sellers. Not many engines to put in e30s, and right after came the 4 valve 192 hp M50, and everyone went with those in Europe. Everyone forgot about those 2 valve 188 hp 530i/730is, but I remember. :cool:
There is a whole wide world outside USA. Author is from UK. M30b30 in e32 and e34 is a real thing.
Nothintoseeere
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Re: M30b30 tuning

Post by Nothintoseeere »

I have not posted any pics of my engine. So how would you know what the intake manifold looks like. I also have owned m20 powered e28's and an m30 powered e28. I can tell the difference between the engines. Been around these cars for about 18 years now. I know its an m30b30 engine. They were sold in the u.k. it made 188hp and 192 ft.lb of torque when new according to the book.


Now moving on. I have never bought custom.pistons before. The best place to get them from without have to specify everything seems to be vac motorsport or ireland engineering simply because they have the pistons designs already. Never dealt with either company before given i am the wrong side of the pond. So of the pistons that both company sell is there one that a better bet than the other. Price is not the issue, ireland engineering is cheaper. I don't know if one company has a better dome shape than the other. I remind you all the engine in my car has the later 65cc m30 combustion chamber. Vac motorsport seem to offer pistons for the later engine and the 80mm stroke crank which is handy because that what mine has got. Ireland enginerring seem to do both.
e12euro
Posts: 220
Joined: Jan 11, 2007 4:28 AM
Location: EA

Re: M30b30 tuning

Post by e12euro »

Nothintoseeere wrote: May 11, 2021 4:01 PM I have not posted any pics of my engine. So how would you know what the intake manifold looks like. I also have owned m20 powered e28's and an m30 powered e28. I can tell the difference between the engines. Been around these cars for about 18 years now. I know its an m30b30 engine. They were sold in the u.k. it made 188hp and 192 ft.lb of torque when new according to the book.


Now moving on. I have never bought custom.pistons before. The best place to get them from without have to specify everything seems to be vac motorsport or ireland engineering simply because they have the pistons designs already. Never dealt with either company before given i am the wrong side of the pond. So of the pistons that both company sell is there one that a better bet than the other. Price is not the issue, ireland engineering is cheaper. I don't know if one company has a better dome shape than the other. I remind you all the engine in my car has the later 65cc m30 combustion chamber. Vac motorsport seem to offer pistons for the later engine and the 80mm stroke crank which is handy because that what mine has got. Ireland enginerring seem to do both.
I put a page from UK magazine Autocar comparing the 1988 e34 530i with 188 hp and an Alfa Romeo 164. No M30 engine ever had an intake manifold looking like that, and if someone knows different please tell me, all M30 engines after 1974 had the oil filler moved towards the firewall, not near the radiator like on a M20, which is where the oil filler seems to be on the six cylinder e34 530i pictured above.
Last edited by e12euro on May 12, 2021 4:31 PM, edited 1 time in total.
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