Hi, as subject suggests, does anyone have these?

Cheers!

Well, its just a thought, engine is comming out.

It isn't modifying I guess. I want to keep it standard, so it just as well be built the best it can be with blueprinting and ballancing. It all depends on what BMW's machining was like in 1990!

It may give the power BMW quotes if this was done???

No experience to back this up, but I would have thought that the S14's were very much a pick and choose affair when they were put together, and pretty closely matched components.  I might be wrong here. but I think the internals are close to where they should be.  It seems to me that the biggest step forward that anyone can make iis in breathing and management - like Alpha N.

I think you could spend a lot of time and money needlessly matching and machining.  It's not like the S14 doesn't like to rev.

Speak to Richard Baxter, as he had his 2.5l out and in peices himself.  I'm sure he would know.  Either that or chat to Bexleys, as they know what they're doing on these things.

I have just built an S14 2.5, very close to Group A spec (320bhp) and I used all new parts, from BMW, on the bottom end. The crank was brand new and already balanced from the factory but when I had it checked it was a mile out.

I gave the crank, flywheel and clutch to my engineering shop to have the crank knife edged and all the components balanced as a complete unit. They took 2kg off the crank and the middle journal is now about half the size of the others in order to get it balanced. When I questioned it, he said most of the BMW cranks he balances are way off even though they do have the drill holes in the journels where the factory has supposedly balanced them.

So don't take it for granted you can just bolt everything together and it will be spot on !!! 

I think you have to consider who you are talking to and at what level he is judging things. If he is crap he might speak for his own wallet, if he is really good, he might effectively be talking about 1-3% which in his perspective is quite a lot.

Like Uwe says, if you see how many M3's will easily do 200.000 kilometres and rev to 7.000 rpm it can't be that bad. If you take it above 7.000 for sure you need to do something extra and I am also positiv that a M3 engine can be blueprinted for racing.

John

Thanks for all your advice, I understand that these engines are superb, last miles, and can handle abuse even with well over 150,000 miles.

For the cost of ballancing (not alot) I would have thought it would be worth having it checked, and ballanced up with all other components connected. eg flywheel, clutch cover, pulley, etc. I wouldn't have thought BMW would have done this to every single crank,pulley,flywheel, etc all fitted together. If it was a ford CVH engine back in 1990, to blue print the block you could take upto 40thou off it to get it to the exact blueprint. The combustion chambers too were wildly out. The ballancing wasn't too briliant either. An XR2 from Ford in 1986 produced 96BHP. When ballanced and bluprinted 115BHP was common, even more with some miles on it. A fully ballance and blueprinted CVH engine is actually a cracking little screamer, but don't over rev them! 

I know the S14 wasn't built by Ford, but I wondered if anyone has taken time to take a close look at one of these engines and decided that it would benefit with some blueprinting and ballancing.

As I'm stripping my engine, I thought I would take a close look at it while its apart. I am keeping the car so I feel it would be worth a look. I just want the car as best it can be.

So..if anyone can supply me with some blueprints, please PM me.

Is the block supposed to be black?

Who knows, it may be that I got a one off crank that had not been balanced as it should have been at the factory, but I am glad I had it checked.

It depends on what you are planning to do with your engine. If you are building it for "fast road use" a crank direct from the factory will probably be fine. So yes, you will be able to just bolt it all together and away you go for 200,000kms reving to a standard 7,850rpm but my engine will safely rev to 9,400rpm, that is the difference. So for the majority of people my mods will be overkill, so it boils down to what you want to use your engine for.

My engineering shop is building specifically race engines for customers, so as John states, my guy saying the balancing is a mile out might not necessarily be so to an engineer building street engines. Uwe, when your crank went away for balancing, it came back without a scratch on it, which I fully believe, but they will have not spun it up to 9,500 - 10,000rpm knowing it will never see those sort of speeds.

Maybe I misunderstood what SHEPSM3 wanted to achieve from his engine, it's horses for courses.  

9400 rpm?!?

er, best get it balanced then.

RESPECT.

I have known people take cranks, etc for ballancing and had them returned "untouched". I have no idea if thats because they were ok, or whether they just charged for it and not done it (Ah! he wont notice, its only a road engine!)???? Unfortunately, there are people like that out there.

If I get it ballanced, it would be nice to get it done upto the 9500-10000 RPM, even though it won't go that far up the range, if its being done, it may as well be done to that RPM. Saying that, if its fully ballanced at 9500 RPM, would it be ballanced at say 7800RPM? I just had in mind a wheel which has lost its ballance weight. Its ok at 40MPH, but at 70 the wheel shakes, but at 80 the wheels have no shaking. Would the same apply to engine ballancing? I can now feel you all thinking about that one.

Ultimately, I want to keep the engine standard, or to a blueprint/ballanced spec. I have thought about cams, slight porting/gas flowing, upping the compression ratio, lightening the flywheel, etc, etc, but this takes it away from being standard.

The aim is to build a cracking engine which will produce what it should and how BMW intended. I could just chuck a 2.5 crank in and be done with it. But that 'aint me. We'll see

Or talk to him

http://www.bmwcarclubforum.co.uk/forum_posts.asp?TID=22157&PN=1 - http://www.bmwcarclubforum.co.uk/forum_posts.asp?TID=22157&a mp;PN=1  

he'll help you out with serious performance (and money).

John

Thank you Uwe!  

Is there a tolerance in this?

Thanks

I thought ballancing was spinning the crank with flywheel, crank pulley, clutch cover and bolts all bolted together and machining to improve, The pistons all weighed and matched to eachother (all weigh the same) and the same with the rods?

The reason for knowing the combustion chamber cc is that mine has had a valve replaced previously and although it maybe overkill for a road engine, while its apart I didn't think it any harm to get all the chambers equal. I just want to get the engine as near to perfect as possible. As I have no plans to sell, I think it worthwhile.

How do you work out compression ratios? I've been looking for the calculations, but unable to find it. I am just curious on what mine is with the 2.3 crank fitted? Again, just out of curiosity, how high a compression ratio can you go for an effective power increase on the S14?

Hey guys,

the DTM cranks are BALANCED at 1100 RPMs.

if you balance each component to very tight tolerances on their own, then in sum they should be quite ok. gr. A engine specs are for each component (rod, pistons, crank..)   you CAN then dynamic balance the full assembly, but if you ever change the type of clutch/flywheel, it is no better than not balancing the entire assembly -- and it could be detrimental if not all of the components were well balanced each for themselves.  in fact, if I knew my assembly required a further correction as a whole, then when swapping in a new component like a flywheel (which will be balanced on its own), id still check the entire balance again.  do you realize what this entails?  lets say you decide to go from a sachs sport clutch to a tilton or AP twin disc carbon clutch with magnesium flywheel. That would represent a large change in inertia that is seen at the end of the crank.

the second issue to consider here is that I dont trust just anyone on a crank or a balancing machine. BMW has the best machines available, I dont know if your local garage buddy down the street has the same.  When someone starts taking metal off a crank, Im also leary.  Not every Joe knows what the stress inside the crank is. Even engineers dont know it. Thats why they model it, then they run numerous tests. This is something that can effect longevity. Although even the factories have take the inner 2 counter weights OFF ENTIRELY on a 4 cylinder crank. They got it balanced. But it is meant for racing where longevity is not the same issue as on street. As long as we are clear on that, no problem.  With this technique you can get a S14 crank down to sub 14 kg easily enough.  On my own (street) engine, I decided not to go down this route. I still currently have no CF clutch installed (yet), I figure the latter make a huge change in revability (think motorbike), coupled with a magnesium clutch this should be more than necessary to make my engine rev happy -- although it is ALREADY rev happy.  I voluntarily limit it to 8500 rpm. It is built to handle 9600 rpm. I would have to misshift and hit > 10000 rpm before I get piston-valve collisions.

I have a few pictures I got from the internet on the S14 head. whoever it was that wants it email me. They are technical drawings.

I also have some gr. A specs -- motorsport always gives tolerances for their measurments.  I believe (from memory) the head chamber is 43 + 0.5 cc.  I hope you know how to CC more accurate than .5 CC :) If you are getting into this, you are going to need every single spec, every tolerance, and you will have to measure every chamber, every piston, every rod, every fuel injector, the volume of ever intake and exhaust port, piston to valve clearance on every cylinder, valve heights on every valve, valve spring rates and shim stack on every valve, weights of pistons, weights of your shim under buckets, your valve weights, measuremetns of each cam journal etc. etc.  (OK relax: atleast for a few parts, like the cams, if they are motorsport cams you get documented measurements for the cams -- every single journal to very high tolerances)

This is what I believe they mean in the USA when you read "blue printing".  If you do it all -- you will fill about 25-30 pages of engine build charts and spend a lot of time. Some people just measure a SINGLE cylinder and ASSUME the others are the same, as when they dial in cams and just check clearance to the piston on 1 cylinder  -- they also say they have blue printed engines. Thats not really correct (but does not mean their engines not well built anyway, they are just not "blue printed" to the full extent).

So, I hope you know what you are getting into here :)  I can help you with the gr. A stuff, I just need to find it laying around somewhere here.

But BEFORE you get all excited about this -- remember this is also a typical MARKETING/SALES point to pull more money out of your pocket.  The pros really to build top engines like this, but they are also very expensive build ups. They also x-ray engine blocks. Ask your local tuner if he has this capability...  You need to have a very honest builder to work with and have full trust that the work you are asking for is actually being done, and done right with all the proper machines at their disposal. Machines cost money which will reflect itself in the price of the work you are charged. If the shop has no machines, well, they cant do the work, they out source it.  You should be able to drop into the shop without notice to find someone working on your parts and seeing top notch work being performed. There are VERY FEW people at the "grass roots level" I trust with this sort of stuff; the people I do trust know me very well and we have a long working relationship and when I have parts machined, I can stand right there and watch while its done (which I do). Famous companies can probably do the work (like Randlinger/Quintec in Germany, or some of your famous shops in England) -- but they also have nice prices.  There are Randlinger hillclimb S14 engines that cost 100000 DM back in the day (49000 euro).  Unfortunately, with engine work you outsource to various shops, its very hard to say later who did what wrong when something goes wrong. This is part of the reason why a builder should be able (==knowledgeable) to understand all the processes and steps involved -- and check them.  Some builders do this, some just CLAIM to do this.  This is time intensive work, so it also costs a bit of money for all this "blue printing" and checking and double checking. We often read about various engine build prices, but really you can just read a build-spec sheet and know exactly what kind of work went into it unless you did it yourself.

BTW, on my engine things like rods and pistons were balanced down to 0 on the scale which had a 0.001 g accuracy. But gr. A does not demand this, and there is also a spec for the rods with the pistons which must be met (I dont remember at moment but can look it up). Getting piston mass perfect is also a bit of a TRADEOFF with compression ratio if you measure any chamber volume differences, or your crank has a slightly longer stroke on one cylinder than another. you can take mass of the underside of the pistons, or on the top at the dome, but the dome is adjusted to get the desired compression ratio. You can go for perfect comression ration on all pistons, or perfect mass on all pistons. doesnt really make sense does it? thats why we have tolerances.  as a result of this, we are also going to see varying intake flow into each cylinder, and injectors are normally rated to 3% unless you have some specially matched ones (gr. A balanced injectors that are matched run 200 euro a piece). Motorsport cam lifts have up to 0.05 (maximum) toleranc on lift though they are usually significantly below this number.

The end result is: you can play the "tight tolerances" game to get as much power as possible, but it does cost time and money. and I will reiterate that I truly believe a lot of shops are not HONEST and tell you a bunch of crap because it sounds good and it pulls the money out of your pocket. So be careful. When you find the right people who know how to do this kind of work, you will know.

John

I run 12.3:1  compression ratio. Some people run 12.6-12.7:1 CR. (as CC'd in the engine! not via "nominal" CR rating of the piston)

This also depends on cams.

Your spark plugs and engine mapping should also suit.

John

Hi John, Some good reading!

I'm not after a fully blown racing engine, but a nice, strong, powerfull standard engine. I want to keep this car standard, but to an extremely good standard. I heard the Evo3 in standard trim struggles to make all the 238BHP BMW say it does, so I want to have a go at getting the full 238, or more???? just with ballancing, blueprinting and carefull assembly.

I don't know much about the measurements or capacities, tolerances of the S14 2.5 or the 2.3 either, and have struggled to find any solid technical information and dimensions of all the components.

Any help in this area would be much appreciated.

Are you John with the red Evo3 at the ring? Thats a superb car you have if it is you, and I would love a passenger ride - er...if its on offer ofcourse?

Paul.

Paul,

Don't take a ride with John in his red M3. You'll be hooked!!! For sure after that your SE won't be build to standard SE spec.  It's gone cost you.

John

Uwe, he wont find much in the TIS. But can find in the gr. A shop manual. e.g. the roughness of the hone is specified in that and much more.

gr. A engine are blueprinted.  but, BMW motorsport "selects" parts. e.g. if you buy bearings they are closer than if you get them from BMW. If you buy their injectors they are a balanced set. If you buy gr A valves they all weigh the same within tight tolerance (I know because I measured them). If you buy valve spring the spring rates are matched.

anyway, back in the day BMW motorsport got 220 hp out of its gr. N engines  when the stock one for the street was only making 200 hp. not all the parts were from normal BMW parts supply, but some special motorsport race parts (like the block which was honed differently)

John

John-M3, be carefull, you may have an evo3 engine shipped to you for a nice rebuild soon!

When I raced my old 1.6 XR2, standard power output for these were 96bhp, but after blueprinting and ballencing it made 104bhp straight away, then after playing with ignition timing and fueling made 110bhp. After a season of racing and testing I dyno'd it again as the engine was feeling particularly free and strong and it made 123bhp. This engine was stripped, measured for machining and ballancing, and rebuilt by a chap who used to work for the SVE department of Ford. It kinda helped that he was heavily involved with the delevopment of that CVH engine beck in the late 1970's, so he knew exactly what the measurements should be. It made a shocking difference. One thing, he or I never cheated. Fords machines were that bad! 40thou off the block for starters!

As Jon90 suggests, it may not be worth going out and out blueprinting of all components for the road, especially if you may only get another 5bhp. If 15-20+ bhp can be regularly seen from going that route, it maybe worth it. I was basically looking at the sort of work Jon90 is suggesting, as that is kind of blueprinting and would make the engine run very smooth and nice.

Anyone know what my compression ratio would be with a 2.3 crank fitted to my 2.5 engine? I have been trying to work it out, but its doing my head in!

Uwe, I dont know. I thought we were just talking aber a theoretical 84 mm crank in the evo3 block with standard 95.0 mm pistons. rod length 144 mm the same in either case. In such case, we should see around 9.8:1.

I do not see a reason to install an 84 mm crank in the evo3 block.  evo3 cranks are cheaper than 2.3l cranks (or atleast when I checked some time ago).

Roops, I have no experience with Kempower. They may be good. I have to say, since I am in Munich I have access to pretty good machinists, e.g. people that worked for BMW Motorsport for 30 years and can still get a head done like they were done for DTM, because he is one of the SAME guys that worked on them. If I want my block bores+honed, then I have the guy in Bad Tolz that did DTM blocks, if I need an exhaust system, I have 2 people in Bad Tolz that make exhausts. etc.

John

UweM3 wrote: SHEPSM3 wrote: Anyone know what my compression ratio would be with a 2.3 crank fitted to my 2.5 engine? I have been trying to work it out, but its doing my head in! with which pistons?????

Uwe, 2.5ltr pistons. My engine is definately an evo3 engine, except when the engine was rebuilt by a previous owner, they fitted the 2.3 crank. All other parts, ie piston rings, inlet and exhaust valve were all for the 2.5ltr. There is an invoice in the file I have a couple of days after the crank was supplied which is for the nut to hold the front pulley on. IDIOTS! calm!

1.5mm down the bore at TDC must mean alot of compression pressure lost I would have thought. I have still yet to dyno the car to see what power it is putting out with that crank. But it feels alot more powerfull than the 160 it had when I got it!

Hey Uwe, I just plugged the numbers into a little calculation program I have.  So I may have made a mistake.  But, I assumed all things are the same, just the crank changes.  Not comparing to a 2.3l setup with 2.3l pistons. so for the comparo: the rods are 144.0 mm in both cases.  the piston is the same 95.0 e3 piston in both cases.  so if we have case a) 84 mm crank and case b) 87 mm crank, the piston in case a) should be 1.5 further down the bore compared to case b), right?

thanks for posting the schematic.  where did you get the block deck measurements from?  218 and 218.25 mm?

just an observation: in the e3 piston with compression height 30.75 mm and dish depth 0.75 mm, my piston if machined flat (e.g. no dome) would have 30.66 compression height and no dish.

John

rule of thumb on CR  for every full point gain, you get about 3%.

assumes its not pinging and your mapping takes advantage of it.

John

UweM3 wrote: You kidding me! I am sorry but actually the piston is 2.25mm down, not 1.5 I still don't believe this has happened. OMG!

It has happened! I can't believe its happened either. I only wished I knew about the nut/bolt thing before I bought the car. The engine numbers are certainly correct though and don't look as though they have been messed with. Part number of crank fitted is 11 21 1 310 618 which I am sure its a 2.3 crank. It couldn't be a 2.0 crank surely?  I am sure though that the owner who rebuilt the engine had no intention of fitting the wrong crank, and I suspect it was the supplying dealer who got it wrong and the owner was none the wiser? Trust me, I want the correct parts in my engine!

2.25mm down the bore? Is this because the 2.5 piston is 0.75mm shorter from the centre of the gudgeon pin to the crown of the piston than the 2.3 piston? Also I thought bore sizes between the two were different too??

You would have to drive the car (and your welcome to) to believe how well it does actually go considering how far down thebore the pistons are from where they should be. Its only on light to 3/4 throttle where it feels as though its holding back. I was going to get the chip ignition timing advanced up 4-5 degrees throughout in an attempt to make the engine livelier. Pointless now I am changine the crank for the right one anyway. 

John-M3 wrote: rule of thumb on CR  for every full point gain, you get about 3%. assumes its not pinging and your mapping takes advantage of it. John

Do you mean a full one compression ratio, ie a 11:1 will give 3% more than 10:1? Obviously with some mapping to stop detonation.

SHEPSM3 wrote: 2.25mm down the bore? Is this because the 2.5 piston is 0.75mm shorter from the centre of the gudgeon pin to the crown of the piston than the 2.3 piston? Also I thought bore sizes between the two were different too??

that assumes a 2.3 piston was installed which I dont believe it is as you have a 95.0 mm bore? so I think you have a 95.0 mm piston in there. 

yes to your CR question.  it is a rule of thumb.  It is probably not accurate if you deviate by a large amount from the intended CR. e.g. if you used 8:1 instead of 10.5:1, or 14:1 insteado of 10.5:1

for a given engine, there is an optimal location of the main "peak pressure pulse" which occurs after initial combustion. This is located some degrees after TDC  ideally near where there is maximum mechanical advantage.   The air-fuel mixture burns at an exponential rate in time.  This depends on the type of gas/octane, cylinder pressure and temperature  AND rpm.  so your ignition advance is just the amount needed to start the fuel mixture burning early enough so that the main pressure pulse reaches the piston somewhere near maximum mechanical advantage.  If cylinder pressure and temperature are disregarded for the moment, the burn-rate of the fuel is mostly contant, so as RPM goes up we have less and less time to burn the fuel, therefore we have to increase ignition advance. Now when we open the throttles & the cams are online, we will increase the amount of air-fuel mixture that is then compressed resulting in higher cylinder pressure. To accomodate this, we have to reduce the ignition advance, as the mixture under higher pressure will burn faster. This way you again have the peak pressure pulse somewhere near maximum mechanical advantage on the piston.  Intake temperature and cylinder head temperature also have an effect. Generally, we'd like to keep things cooler. e.g. have your water temperature near 80C for max power, have cold spark plugs to pull as much heat out of the cylinder head as possible, etc. Compression ratios lead to change in efficiency and local temperature (as well as a shift in the by products-->emmissions).

Point of all this is that there is more to it than simply increasing compression ratio... many factors that ultimately may or may not lead to a power increase

John

Thanks Uwe and John!

I know the crank has to come out, and it will as soon as my new one arrives. As 215dmx said before - just right for turbocharging!

If it wasn't a sport evo, then maybe that is what I would have done. But it 'aint, so like you say Uwe, that crank has to come out, and wrapped around the head of the owner who rebuilt it or L&C who supplied it in the first place. It may have better effect if it were tossed through thier showroom window!  JOKE!

I'll do a compression test and dyno the car next week, and post the results on here. I can only give kw/bhp power at road wheel figures though.

Uwe, not that its too important, but we are talking about changing the crank only; nothing else. so if the crank has 3 mm less stroke, it means the piston is 1.5 mm lower down ALL ELSE EQUAL. I dont understand why you are adding up other parts dimensions, unless you are assuming he has other parts? It sounds like that is what you are assuming.

John

I was out today and did a short little acceleration video:

john.gmstech.de/video/airbox4.wmv

it was against the sun so a bit dark.

John

Thats great John  I hope that wasn't my passenger ride?

That engine note is fabulous!

thanks. those were 8500 rpm shifts, but I backed off near the top of 4th gear/begin of 5th as it was a bit faster than the speed limit there :). for some reason is doesnt sound in real life like it does on the video. its louder and more intense.  everything always looks slow on video too, even if you are doing 200 kmh, it looks slow.  Im going to experiment with a remote cam soon, perhaps it will look faster if the cam is closer to the pavement :))

for a passenger ride you are welcome if you are ever at the Ring.

John

John-M3 wrote: thanks. those were 8500 rpm shifts, but I backed off near the top of 4th gear/begin of 5th as it was a bit faster than the speed limit there :). for some reason is doesnt sound in real life like it does on the video. its louder and more intense.  everything always looks slow on video too, even if you are doing 200 kmh, it looks slow.  Im going to experiment with a remote cam soon, perhaps it will look faster if the cam is closer to the pavement :)) for a passenger ride you are welcome if you are ever at the Ring. John

Cheers John, I'm hopefully going early next year, so will keep an eye out for you!

A good place for the camera would, I would think, be behind the kidney grill, you should be able to get a good sense of speed, hear the engine as it screems past 8000 rpm, and then hear the windnoise build as you fly past 200kph!