Lots of room for error in cc'ing the cyl at BDC because of the number of times req'd to fill the burette, twelve in his case. Need to get the meniscus in exactly the same spot at the top and the bottom each time.

CR is just (swept volume) + (deck vol.) + (head vol) - (dome vol) / (deck vol) + (head vol) - dome vol.

swept vol = bore area x stroke
deck vol = bore area x deck height

Dome vol is easily determined by dropping piston below the top of the cyl and measuring the distance down and then cc the cyl. Dome vol = (bore area x distance down) - cc'd volume. It would be interesting to see what the specs show vs. actual.

Hello Spencer,SmileWavy

Memories of my calculation of CR, 7.64.
To have the volume PMH of the piston more that of the breech I had tilted my engine block to have the well of spark Plug exactly upright, then I had to fill the volume by the well, simple and effective! ;)

http://forums.pelicanparts.com/uploa...1508860416.jpg

Hi boosted, yes you're right, with 12 fills, no matter how carefully you fill and drain to the same level (and I was very VERY particular in doing both, removing the burette away from the engine, using another dead-vertical stand to hold it and then drain off any excess) there is the opportunity to introduce errors.

After you posted the other day, I checked, re-checked and re-hacked the formulae; tried numerous online static calculators, tried the formula you described and eventually did build the head onto the cylinder to liquid-measure the TDC+Head volume (in a very similar fashion to Pat's post above)....not once have I got a consistent, definitive answer!

I also spent a decent amount of time cleaning the combustion chambers - would you believe, after 3x fills, the delta between spotless clean chambers, and as-they-were when after the last engine debacle, there was 1.4cc greater capacity; 87.7cc previously, 89.1cc now. Again, the calculations were changed to reflect this.

(for completeness and transparency, when re-checking my homebrew formulae, I had errored on the deck height allowances, so thanks for pointing that out!)

It should be the simplest thing, to calculate all of this, but when your head's fried and to then get different results but using the same parameters, it drives you crazy....and it needs to be correct, in order to then calculate the dynamic CR's; S-CR is a parameter for the D-CR formula.

Anyway, I ran out of time before leaving for a short vacation with my daughter, so will come back to it over the weekend

I also ordered a bar of copper stock (should arrive at home today), so that I could look at spark plug indexing. I noticed on the old pistons when stripping down the engine, that there was evidence of some electrode "kissing" on the piston tops. The marks were on the exhaust port side, i.e., the additional set of plugs that were added when the heads were being modified, 4-5yrs ago.

Looking at the protruding plug depths now that the heads are off, they are fractionally low into the combustion chambers, so....whether this was a true depth setting issue, or whether the excessive piston rock (that smashed the rings) was the cause for this, who knows, but now's the time to address that and space them up a little, and at the same time do this in a way that positions the back of the ground strap towards the inlet valve.

I'll make up set of different thickness washers out of ally, just so that I can get the correct index per hole. I'll also number each plug, so that things don't inadvertently get swapped. Once I know the quantity of each, I'll make the washers out of the 20mm copper stock. Should be an easy job.

** Reveal of significant changes to project **
 

Ok, so I've eluded a couple of times in previous posts, that there's a pretty significant project change in progress.

There'll soon be a thread title change to reflect that I made the decision some time ago, to change who I'm working with for the management and mapping work. Up until now, per the thread title, I've been running with MBE management with my mate Steve doing the mapping. Of course, the last couple of years have been spent rebuilding the damage that was done to the cylinders and piston rings, but in that time I think it's become clear that we have "artistic differences" (as all the best bands say) when it comes to what this engine needs to be, in order to be a well behaved and driveable *road* car. I don't think it would be fair to elaborate any further on a public forum - we've certainly not fallen-out or had arguments - and I'd like to thank Steve for the work he's done. I think I'm right in saying that being friends for almost 25 years and working on a project that he knows has cost me a huge amount of money (and blood, sweat and tears), also brings with it a pressure that perhaps isn't there with the average punter.

So.....1) why the change of engine management system? 2) Was there anything wrong with the MBE management?

2)...An emphatic "no"...there's nothing wrong with MBE system. Still very popular in the UK and the bang per buck for that system is (still) very good.

1)....As has often been said in answer to questions on many fora, the best ECU is the one that your chosen calibration partner is familiar with.

If I was living in the US, then without a doubt I'd go AEM with Chris (TK) and Tony working their magic. But I don't live in the US, and therefore I need to work with somebody local to me who can easily work on the car to further refine that calibration, "bum in seat". The guys working with me now on the management side are Torque Developments in Essex, and a chap called Sam Borgman.

When I first met Sam, not only does he come across as extremely clever with his intimate knowledge of what the Syvecs/Life systems can do, but also a complete propellarhead outside of work, trying all this stuff out on his personal car (Subaru Impreza). He also demonstrated a very healthy level of enthusiasm about the prospect of calibrating the engine, which was nice. Being a techie (IT presales) myself, I'd like to think I have a great BS-radar, and unless I've got it completely wrong, I think I'm in very capable hands with Sam at the laptop.

Now, Sam *is* capable of mapping on MBE - he's done it before - but the guidance he's given is that to program the maps in MBE takes approx 3x as long as doing the same in Life Racing / Syvecs, which is his sweet-spot. Therefore it's a false economy. For the same estimated spend on MBE calibration labour, I can buy a new, latest model Syvecs, fully loaded and enabled with functionality, more powerful in CPU terms and (from what I'm told) a more logical mapping suite for a novice (me) to learn and navigate....I did always struggle to retain my familiarity with the Easymap (MBE) suite. Another option *could* be that Sam could pick-up the existing maps already in my MBE ECU, however I know if it were me, I wouldn't want to continue with anyone elses work, for fear of there being something in the calibration that has a fatal flaw (or even just something minor in there that takes ages to find and change). Overall, I guess there's a liability angle, and so starting again would be the only option (at 3x slower pace than with Syvecs)

So, I invested in a new Syvecs S6 Plus ECU some months ago; To explain further, Syvecs are a different company to Life Racing, but they have an OEM arrangement where certain Life Racing ECU models are rebadged as Syvecs but then sold with a more road-going focus. For example, the Life Racing model may have 4x pitlane speed limiter modes; completely unnecessary on a road car. Conversely, the Syvecs models are typically licensed with all features enabled, whereas Life Racing is more akin to a-la-carte licenses.

Life Racing are the electronics arm of AER, who some may be familiar with in relation to Le Mans powertrains; AER provide a lot of the LMP2 class engines (amongst many other engine types, I'm sure). I guess it's similar to the setup with McLaren having their own electronics division (who supply the F1 grid with their engine management).

Some other interesting functions of this change are:

• Torque Developments International (TDI) are about 80 miles and just over an hours drive from where I live - very local indeed
• TDI have a fantastic hub dyno setup, inhouse; I believe its a rig that is ex-Mercedes AMG. So, once the engine is rebuilt, it'll be going into the car and not into an engine dyno cell like we did the first time around. Check out the video below, hosted by Sam, with a walk-around of the dyno cell.
• TDI allow folk like me to hire the facility at the weekend, either with or without a calibration engineer, so that quantifiable changes can be made to the engines mapping
• TDI also offer mapping courses, again for numpties like me who want to get a little more experienced (or even to go as far as learning to a professional level)
• In the very recent past, Sam has now actually departed TDI but has gone to Life Racing themselves. Sam is still very keen to map my engine, and so the plan will be to get him down to my house for the initial base map build, get the car fired up, make sure there arent any daft problems. Once satisfied, we'll then commit to booking time in the dyno cell for the remaining calibration work.

<iframe width="560" height="315" src="https://www.youtube.com/embed/W27QzJpRVD0?rel=0" frameborder="0" allowfullscreen></iframe>

<iframe width="560" height="315" src="https://www.youtube.com/embed/ig5YfIm7GoA?rel=0" frameborder="0" allowfullscreen></iframe>

<iframe width="560" height="315" src="https://www.youtube.com/embed/jERDWEOOTp4?rel=0" frameborder="0" allowfullscreen></iframe>

<iframe width="560" height="315" src="https://www.youtube.com/embed/9XkshcddM8g?rel=0" frameborder="0" allowfullscreen></iframe>

Of course, to accommodate this change, the loom has needed some reworking. Fundamentally, the changes aren't huge to switch the connection blocks from an MBE type to the plugs which Syvecs use....but...in usual Spencer fashion, why do something easily when you can make complication into an artform?

The loom is back with Simon at Sileck, and I have to say, it's pretty much a complete rebuild of both halves of the loom. Some of the changes we're making:

• Addition of 2x knock sensors
• Adding a second Lambda sensor, relocating original sensor and will run them on the secondaries for each bank (bosses already in place, currently for exhaust backpressure sensing)
• Integrating of EGT thermocouple harness into main harness (they are currently externally run, directly to an AEM thermocouple interface unit.
• Adding a half-bridge controller for fuel pump speed control (engine bay pump, not lift pump)
• USB power feed, to power a micro TP-Link wi-fi router situated under the seat adjacent to the ECU (rather than plugging in the laptop via USB each time)
• Adding input to run Bosch yaw sensor (I already have it, never got around to hooking it up with the MBE)
• Additional boost control valve control - I'm now going to run phase and anti-phase boost control, so the lightest boost spring can be installed, and we can then run zero boost if required

The Syvecs unit can also accommodate the K-Type thermocouples being input directly into the ECU, no need to now run my AEM 4-channel ADC.

There you go, the full skinny on what the future plans are. It actually feels quite Cathartic to get it all typed up on the thread. Hoping the loom will be ready in the next week or so. I can then get on and sell the MBE (still the flagship model in their range) as well as the AEM thermocouple interface.

After receiving the tech data from Chris for the Carrillo pistons I'm using, all the CR calculations now tally; my manual maths, vs 2x online static CR calculators all now give me the same ratio. Fantastic!

So, from this we can derive exactly the base gaskets setup to run, then then plug those results into the dynamic CR calculators, and get a real-world set of numbers.

Next job, to re-lap the heads into the re-faced cylinder mating surfaces >>

http://forums.pelicanparts.com/uploa...1509495491.JPG

Nice clean combustion chambers >>

http://forums.pelicanparts.com/uploa...1509495479.jpg

...and then stripping down of the valve gear for a thorough clean, not least of which to the backs of the valves. While I'm at it, I'm going to replace the valve stem oil seals; they're green, so likely Victor Reinz (but were supplied with the rest of the head hardware, so I can't be sure). I have a new set of black Wrightwood seals in my gasket kit, so makes sense to fit those - only a 5min job. Going to make up a mandrel to seat them safely onto the valve guides. >>

http://forums.pelicanparts.com/uploa...1509495491.JPG

I received some stock rod material the other day for the spark plug spacer washers...only trouble is, they sent me brass instead of copper. Hopefully the copper will be here tomorrow so I can start knocking out various thickness spacers.

What deck height and CR did you end up with?

Hi Boosted; apologies, as much as this is a very (too) transparent build thread, and I try to write-up everything that I can remember, Chris has very generously spent a lot of time on the phone and email, spitballing the permutations and what he feels we need to shoot for in the setup. All of this pertains to his design of piston and the experience he has measured so far, what works and what doesn't. Therefore, as a courtesy to Chris, I'd like to refrain from posting the specifics on here ("boo, hiss", I hear you say). Let's just say that with the combination of components being used, the dynamic CR's are somewhat surprising....well, they were to me!

Hello Spencer !

It's understandable that Chris does not want to give this information although I am also curious to know your CR! :D

Ahhh...Pat...you know the saying... "Curiosity killed the cat" :D

:RÉ
Since your engine turns as a clock, it is all that I ask for for you, and too bad for the CR! :D

Good night Spencer ! ;)

Thank you my friend, fingers crossed it'll be like a Swiss watch...or rather a German watch, like a Sinn or something from the Glashütte region :D

It is maybe because of my translator, when I formulate a message that writes anything... In brief, I understood what you wrote! :D

Weekend update....

Well, the weekend got off to an inauspicious start. I received my new valve stem oil seal removal pliers on Friday, and being a little too eager, I went to try them out, assuming that the new Wrightwood ones I have in my gasket kit were going to be the ones replacing the unknown items. After trying (unsuccessfully) to remove the first one, I then remembered to check the fit of the new ones. And they didn't - stock valves have (nominal) 9mm stems, my Schrick valves are a nominal 8mm. And I've now buggered the one I tried to remove. After much swearing, it's actually proven to be one of those fortuitous situations....it's made me examine a little close the original seals that were "installed" by the idiots that did my headwork many years ago....there are a number of seals that are damaged, the metal sleeve being squashed on one side where the install tool (probably a socket, knowing them) has been hit off-centre. I've also noticed that some of the seal tops are also oval, only slightly, but oval nonetheless.

A call into Porsche Tonbridge on Saturday morning, and I've got a complete set of 12x 993 seals on their way (which are 8mm) - hopefully they'll be here in a couple or 3 days time.

So, other than ordering parts, I didnt get much done yesterday - a very long week for our financial quarter-end meant a couple of days working through the night on Thursday and Friday. Light duties, just decided to have a start with indexing the spark plugs and making the copper spacers.

http://forums.pelicanparts.com/uploa...1509925589.JPG

http://forums.pelicanparts.com/uploa...1509925589.JPG

Time to get the protractor out and see how much indexing is required to place the spark plug ground strap in the direction of the intake valve. There's a good level of consistency with these Denso plugs, generally needing either a 0.6mm or 1.1mm spacer (depending on whether its the top or bottom plug)

Todays jobs, however, were many and successful.

First job for the day was to clean the valves. I left them soaking overnight in Swarfega Jizer (which I have to say, is pretty good for parts washer use. About as good as I've used apart from the proper solvents that you can only get on a commercial contract basis). To be honest, I dont think the soak did anything to soften the baked on muck. Before and after, below....the inlets being far worse than the exhaust. 3M Scotchbrite didn't touch it. In the end I carefully used a razorblade scraper, which brought it off great, it almost chipped off.

http://forums.pelicanparts.com/uploa...1509926204.JPG

Next job was one I've been meaning to do for AGES...clean the damn RH timing box housing that I've been moving around the workshop for months! Completely unremarkable (you're thinking) BUT...in doing so - ***top tip*** Swarfega Jizer is brilliant at softening Curil-T. Brake cleaner and paraffin that I've tried so far, just don't touch it. There you go, don't say I don't give you anything.

And then I needed to take a few brave-pills for. Time to un-shroud the secondary spark plugs in the combustion chambers. I confess it's not something that even occurred to me on the first build, but remember seeing that Chris mentioned to Costa on his excellent build thread, that its a good thing to do.

So, time to get to it, can't delay it any longer....

As they were before...

http://forums.pelicanparts.com/uploa...1509926918.JPG

Some marking out - 15mm sockets can be so useful sometimes....all marked the same with a 22mm measurement from the back of the spark plug hole to the front of the blue line...

http://forums.pelicanparts.com/uploa...1509926918.JPG

Then after some die grinder action, then grit paper and finally some Scotchbrite to finish...


http://forums.pelicanparts.com/uploa...1509926918.JPG

...and all finished. I have to say, I'm very pleased and extremely relieved - no mishaps, just took my time, used an airflow limited on the pneumatic line to slow the bit down, and carefully removed the material. I reckon a could've been a dentist!

http://img.photobucket.com/albums/v2...d/IMG_1337.jpg

Last job of the day was to re-lap the valves to the valve seats, Probably unnecessary, but seeing as a lot of cleaning has been done to remove a lot of carbon deposit, I thought it well worthwhile for the sake of another couple of hours.

Next job tomorrow will be to re-do the capacity measurements of the heads, because of course the volume will increase, changing the CR calculations. After that, time to give everything a final wash before re-assembly, once the new valve seals arrive midweek.

Very good job Spencer ! ;-)

I am maybe "a little bit obsessive", but it seems to me to perceive a difference of manufacturing got out of it from candle between both last ones veered astern of your photo, the exit left-hand side.
It is very well made all the same, but I hope that this difference of manufacturing will not change your CR on a breech with regard to(compared with) the others.

Pat

Hi Pat, are you referring to the factory machined recessed for the original spark plugs? If so, I *think* it may be the angle of the photograph - but good point, I'll check them tomorrow. Until now, nothing has looked obviously different, I think it may be an optical illusion. ;)

Good evening Spencer,
Yes, it is very possible whether it is the viewing angle(viewpoint) which gives the impression that the exit(release) of the hole of candle is not identical.
If you made them all exactly in the same way, with the same angle and in the same depth, any concerns(marigolds)! :)

Hey Pat,

I've been out in the workshop this evening doing more lapping in of the cylinders to the heads (wasn't entirely satisfied that they were as good as they could be last week). You were right, and something I've never noticed - the factory spark plug castings *are* different on one of the heads!

The shape on 5 of the heads....
http://forums.pelicanparts.com/uploa...1510096086.jpg

The shape on the other head. Clearly it's come from factory like that, as it's the raw casting surface finish....
http://forums.pelicanparts.com/uploa...1510096126.jpg

Now interestingly, 5 of the heads have an identifier of "6" under the intake valve...(excuse the dirty grime - lapping paste that I only wiped off - full cleaning in the tank tomorrow)
http://forums.pelicanparts.com/uploa...1510096418.jpg

And the odd one has an identifier of "4" and also has less well defined Porsche part number on the left of the photo....
http://forums.pelicanparts.com/uploa...1510096479.jpg

No idea what's happened in the cars life for this to be the case - no point worrying about it, can't change anything other than buying a set of CNC machined heads.

Does anyone know how to stop the photo uploader service from rotating the pics 90º??I'm using the Pelican photo uploader now, rather than Photobucket (after their ludicrous $400/yr subscription in order to link photos...idiots...)

Good evening Spencer,
Yes, it is strange to see that, because normally breeches must be identical to have a well-balanced CR.
It is not very reassuring at first sight, but now you have maybe way(means) to improve the balance of the volume of breeches, there are no modifications to be made.
Not grave for the dirt, I know what what know how to work on an engine. :)

One of my veered astern before the reassembly of my engine. :)

http://forums.pelicanparts.com/uploa...1510176113.jpg