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Martijnus
Joined: 29 Dec 2006
Posts: 2019
Location: Netherlands
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 Posted: Fri Nov 27, 2009 10:24 am Post subject: Project Log |
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From Project Plans to Project Log 
This week I started the modifications to my new engine, which will be turbo'ed.
Block on the cylinder boring machine. Boring the cylinders to the size needed for the sleeves. Had to take out a few mm per cylinder, and I can't bore more than 0.75mm at once...so it took quite a while
Still boring... although more pics of this would really be boring 
You can see one cylinder finished. There's a collar in the upper part of the cylinder, for the bossed edge on the cylinder sleeve which prevents the sleeve from sliding down. Ofcourse the sleeves are in very tight... but you don't want to take any risk, hence the edge.
Machining final cylinder before fitting the sleeves.
Modified 931 head; combustion chamber. A small ridge near the spark plug hole has been modified a bit. Also, the intake and exhaust channels have been cleaned up a bit, removing bumps and edges. Not much material has been removed, and I'd like to keep it that way. Bigger sure isn't better.
Intake will be media blasted to roughen the surface a bit, combustion chamber will be polished a bit. I don't think I'll get all those small dents out because they're relatively deep which means I'll have to remove more material than I want. Polishing will be done to prevent thermal absorption as much as possible.
Exhaust channel... not really spectacular. Again, cleaned up a bit. Maybe I'll polish it too.
New valve guides will be installed soon.
Intake channel.. slightly more modified. The goal was to keep the bend of the channel as smooth as possible, without edges, ridges and bumps. Key is how the angle of the air flow is when it passes the valve dish, so the 'outside' of the bend has minor modifications.
Overall pic. I like the looks of that intake
Bottom view of the block, after fitting the sleeves. It looks like the sleeve on the right comes out further than the others, but that's just misperception. The used lubricant makes it look like it's longer/sticking more out.
All sleeves go through about 1-1.5mm. I've had the crankshaft in to check if it could touch that ridge, but it won't. There's a lot of clearance in between. Worst case the conrods will come close... but I'll notice that soon enough (when I'm installing the con-rods not when I crank the engine).
Again....
The sleeves are sticking out a bit on purpose. The edges will be machined off, so why take the risk of cutting too deep.
Overall pic, after fitting sleeves.
In the background you can see the spokes of a nice 30's Lagonda
(looks a bit like this one: http://log.autogespot.com/08-2008/kgweekoverzicht/lagonda_m45-tourer.jpg)
Again on the cylinder boring machine. This time the sleeves are being machined to the actual bore for the pistons. Not much (about 0.50mm) had to be taken out of each sleeve, so it went a lot quicker than boring the holes for the sleeves themselves.
Next step is honing all cylinders, but I'll have to wait until the pistons arrive. I waited with ordering the pistons on purpose; if fitting the sleeves went bad, I still could abort the project without having paid a lot of money for a set of pistons.
I'll take exact measurements of the (new) pistons and according to those measurements determine the final bore. at the moment I'm 0.05mm before the target 86.51mm (in theory... in practice it'll be determined by the exact piston size).
Boring all the sleeves to the final size (0.05mm before target, which is bridged by honing). The edge on top of the sleeve is also made smaller after this, to around 0.10mm above the mating surface. Going too far means I'll have to machine more off the mating surface, so a steady hand and full concentration was necessary
After that, a beveled edge was cut on the top of the cylinder for easier and safer fitting of the piston rings.
End result of the whole boring process.
Media blasted the engine to remove rust. I avoided the mating surface and cylinders, but it wouldn't be a problem if I accidentally blasted a piece of that too... both have to be machined anyway, so you'd have to be very reckless to really screw that up
When the block is nearing its completion, I'll spray the engine with primer and paint it 'cast iron gray', a darkish shade of gray which is the same colour as my current engine. Current engine didn't have primer though and wasn't blasted...so that paint is coming off again 
Won't happen this time 
Other perspective after media blasting.
I avoided the mating surface of the oil pump. That won't be painted, wasn't rusted and still looked great. No need to touch that.
Skimming the engine's mating surface...
This also definitely removes the edges of the sleeves on that surface.
Still skimming...
The surface wasn't bad at all. It was perfectly clean after taking off just about 0.05mm. It's hard to define how much has been taken off... there's a dial gauge on the machine, but the cutting stones wear too, so it's a guesstimate. That's good enough, 0.05mm won't have noticable impact on CR or other important things. On my current engine a whole 1mm was taken off to raise CR by ~1.0... 0.05 should raise compression by 0.05 in theory... so from 8.5:1 I'll have 8.55:1 in theory. not significant imho. There are more important and influential things.
Skimming finished. There's a small spot noticable between cyl. 2 and 3. This small spot can't do any harm, and removing it would be purely for opitcal/aesthetical reasons... I rather machine as little as possible off, knowing the spot isn't any problem, than machining a lot more off to be able to point at my finished engine and say "look! under that head and gasket there isn't ANY spot" 
Close-up of the mating surface.
Can you see the transition from sleeve to block? No? Right, you can't
Sprayed lubricants on the engine. WD40 on the outside of the engine, because it'll get in the pores and remove even more stuff and prevent new oxidation. Teflon spray on the machined surface to prevent oxidation.
When the pistons arrive, honing can begin. After that the engine will be chemically cleaned, washing out all the lubricants and remaining dirt.
Directly after that I'll paint the engine because the bottom side is done at that time.
New freeze plugs will be installed, new plugs for the oil gallery etc etc.
That's all for now. If my camera survives everything I'll keep shooting pics of the progress.
I'm very pleased with how it's going. Sleeving engines gives me some sort of weird kinky gut feeling. It just feels like the best thing you can do to make an engine better.
_________________
"Rule: Turbo's make torque, and torque makes fun." (C. Bell)
924 "50-jahre", 1981.
MSII/extra, LPG, ITB's, 5lug.
To be turbo'ed in a while.
Killed her at the Nurburgring, Porscheless at the moment |
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Min
Joined: 04 Nov 2002
Posts: 2368
Location: Vernon, British Columbia, Canada
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| Posted: Fri Nov 27, 2009 10:58 am Post subject: |
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wow, very nice, how much did the sleeves cost? .... do mine next?
Min
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Custom means it didn't come from a box.
1980 n/a with EDIS and Megasquirt II Injection. 7 different colors and counting. |
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Martijnus
Joined: 29 Dec 2006
Posts: 2019
Location: Netherlands
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| Posted: Fri Nov 27, 2009 12:47 pm Post subject: |
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| Min wrote: | wow, very nice, how much did the sleeves cost? .... do mine next?
Min |
dunno yet actually. my boss pulled them out of our stock and they were usable. I hijacked them instantly and whenever $-signs crossed my mind, I thought of happy places where money doesn't exist and everyone is naked.
They're actually for mercedes benz diesels (65 hp  ).
When I google the kolbenschmidt number, I only find russian sites 
Then again... they were the first in space, so they probably sleeve their mercedeses too.
The costs won't be in the materials though... the sleeves can't be really expensive, but it's just really really really labour intensive....and that normally costs a lot.
I'll know it soon
still...this whole project will be expensive like hell... I know more expensive ones but when I started this project I said to myself that I shouldn't do it... it's not worth it.
but it is. can't wait to crank this baby for the first time and compare it with my current engine. Rebuilt vs rebuilt.
_________________
"Rule: Turbo's make torque, and torque makes fun." (C. Bell)
924 "50-jahre", 1981.
MSII/extra, LPG, ITB's, 5lug.
To be turbo'ed in a while.
Killed her at the Nurburgring, Porscheless at the moment |
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9xx
Joined: 18 Jun 2006
Posts: 627
Location: Jarvenpaa, Finland
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| Posted: Fri Nov 27, 2009 4:18 pm Post subject: |
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Wow, I like this thread!
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Mikko
All gone: 931 '82 Alpine White, original option "220" G31 with LSD + 3 x 944 |
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morghen
Joined: 21 Jan 2005
Posts: 9095
Location: Romania
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| Posted: Fri Nov 27, 2009 5:29 pm Post subject: |
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excelent thread but does anybody else apart from me think that sleeving a performance engine is bad?
my dacia(renault) 1.3 50HP engine used sleves, it wasnt a performance engine and the godamn sleves always caused trouble.
what is the tightness tolerance that you used for inserting the sleves (H6/H7) ? i think tighter...right?
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Supercharger and EFI kits
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Dutch924-racer
Joined: 23 Jul 2007
Posts: 1081
Location: The Netherlands
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| Posted: Fri Nov 27, 2009 5:46 pm Post subject: |
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Fantastisch !!!
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937 trackday car
Series 2 engine
951S turbo and intercooler
Fast road camshaft
Forge recirculation valve + boost controller |
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Rich H
Joined: 10 Jun 2007
Posts: 2665
Location: Preston, Lancs, UK
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| Posted: Fri Nov 27, 2009 6:13 pm Post subject: |
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_________________
1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec |
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Martijnus
Joined: 29 Dec 2006
Posts: 2019
Location: Netherlands
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| Posted: Sat Nov 28, 2009 1:57 am Post subject: |
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| morghen wrote: | | excelent thread but does anybody else apart from me think that sleeving a performance engine is bad? |
I understand that thought Sleeves are especially good for durability. The performance shouldn't affect it really.. the load/forces are passed through just fine through the sleeve. The only thing that worried me was the material between the sleeves... if this becomes too thin, cracks can appear but I'm told (by the experienced coworkers) that there's more than enough in between.
The sleeves are meant for a low-output diesel, but on the other hand, diesels have a waaaaay higher CR, which involves high loads on the material too.
I'm totally not worried about the sleeves for performance. 200hp (rear wheel) isn't thát much, boost will probably be lower than a stock 931. Not much higher in any case.
As I mentioned (probably in the other thread), sleeves are made of a lot better suited material than the cast iron of the block itself.
| Quote: |
my dacia(renault) 1.3 50HP engine used sleves, it wasnt a performance engine and the godamn sleves always caused trouble.
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I'm not familiar with the specific dacia techniques and materials, but just like daewoo uses opel's design with a lot lower quality material, I expect dacia doing the same with Renault's stuff.
The experience I have with French (modern) cars is that they have some weird designs. They often use aluminium open deck engines, which causes severe deforming of the cylinders which in turn causes premature wear and other nasty problems.
Is that dacia aluminium? It surely is... they're not sleeving their cheap cars when they use cast iron blocks. Remember that aluminium expands wayyyyy more than iron/steel when the temperature rises. This is often the problem when aluminium engines are sleeved.
I once put my Honda XR600 cylinder in my oven, to cure the paint I applied.
After a while the whole aluminium casing dropped down from the cylinder sleeve itself. No problem, I quickly tapped it back in place, but it showed me what happens when these specific materials are heated.
Still, when that cylinder is fitted on the engine, the sleeve can't go anywhere.
If you decide to get the sleeve in tighter, the stress on the sleeve and the casing is massive when cold, but could be fairly good when hot. So there has to be a compromise somewhere between tightness applications.
Could be renault didn't design the tolerances right, or
| Quote: |
what is the tightness tolerance that you used for inserting the sleves (H6/H7) ? i think tighter...right? |
I'm not sure what you mean with H6/H7. I presume that's a measure for tightness tolerance?
I'm not familiar with those terms...and I don't have to be The butcher doesn't know every term for animal's body parts too, to be able to be a great butcher.
Weird comparision, but I think you know what I mean
The sleeves in my engine have a tightness of 0.06mm. This means the sleeve is 0.06mm larger in diameter than the bore in the block.
That tightness is ofcourse dependent on bore. A bore twice as small should have another tolerance... it's all relative. Same with bearing journals/clearance... all relative.
So I fully trust on the years of experience on these values. I'm only 2 years at this company and one thing I quickly learned is that they have so much knowledge and experience, no theoretical calculations will prove them wrong
I just love this job... I'm fascinated again every day by techniques which are applied, design choices from 1920 until now by engine manufacturers and choice of materials.
Bugatti and other old manufacturers where so far ahead of their time and had so much knowledge about engine building... today's manufacturers could learn a lot by looking back.
Another update:
got new valve guides. Weird that I couldn't get them for my NA head a year ago, and now I can... while the guides are the same 
They will be fitted next week. Pistons will be ordered monday I hope
Still not sure if they'll be forged or cast. I hope it'll be forged ones... those are the CGT ones. No cheap aftermarket stuff... mahle original. That's really a great fabricator.
_________________
"Rule: Turbo's make torque, and torque makes fun." (C. Bell)
924 "50-jahre", 1981.
MSII/extra, LPG, ITB's, 5lug.
To be turbo'ed in a while.
Killed her at the Nurburgring, Porscheless at the moment |
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morghen
Joined: 21 Jan 2005
Posts: 9095
Location: Romania
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| Posted: Sat Nov 28, 2009 2:18 am Post subject: |
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no aluminium in the dacia
anyway...i'm very curious of how this engine turns up...good luck !
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Supercharger and EFI kits
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Martijnus
Joined: 29 Dec 2006
Posts: 2019
Location: Netherlands
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| Posted: Sat Nov 28, 2009 2:27 am Post subject: |
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| morghen wrote: | no aluminium in the dacia
anyway...i'm very curious of how this engine turns up...good luck ! |
so they sleeved the cast iron engine, just like I did?
wow. There's only one reason I can think of; the material used to cast the engine is so low quality that it can't be used as a cylinder. Low-quality sounds a bit degrading... could be the material had very nice casting qualities, but due to those qualities it can't be used as a cylinder.
Weird that apparently it's more effective to put sleeves in... doesn't seem economical.
I'm curious about my engine too a part of the motivation is to check if my theories are right about what I did wrong on my current engine.
Which runs a whopping 1:8 on LPG now (averaged, so with traffic jams, city drives etc..) that's as good as it ran on kjet before I kicked the engine out.
_________________
"Rule: Turbo's make torque, and torque makes fun." (C. Bell)
924 "50-jahre", 1981.
MSII/extra, LPG, ITB's, 5lug.
To be turbo'ed in a while.
Killed her at the Nurburgring, Porscheless at the moment |
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morghen
Joined: 21 Jan 2005
Posts: 9095
Location: Romania
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| Posted: Sat Nov 28, 2009 8:51 am Post subject: |
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they did it like that probably because the materials were shit
never mind the damn thing
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bnoon
Joined: 12 Oct 2009
Posts: 607
Location: West Des Moines, IA USA
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| Posted: Sat Nov 28, 2009 11:30 am Post subject: |
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| Min wrote: | wow, very nice, how much did the sleeves cost? .... do mine next?
Min |
I just sleeved an iron 6.0 Chevy block and it was $150 (US) per cylinder including the price of the sleeves and machine work. The machinist mentioned that is his price no matter what brand of iron block you have. Aluminum blocks are quoted only after he can inspect the block to make sure it can be sleeved (because removing some factory sleeves can destroy certain blocks).
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'80 924 Turbo - SOLD!
1986 Porsche 944 Turbo - SOLD!
Porscheless |
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Arvidw
Joined: 20 Sep 2009
Posts: 227
Location: The Nederlands (Europe)
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| Posted: Sat Nov 28, 2009 5:57 pm Post subject: |
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Incredible, nice work Martijn!
I'ts incedible that you can not see the sleeves after milling the deck of the cilinderblok, it looks like it is made of one piece.
The heat transfer between the sleeves and cilinderblock is okey because you used a negative tolerance of 0.06mm to fit it ? I can imagine that you might want to use a conductive glue like a gap-pad between your processor and heatsink in your laptop... (or isn't this nessecary with sleeves?)
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Porsche 924 2.0 Kompressor 136.1wHp @ 5650rpm / 201.9wNm @ 3900rpm (dyno @ dp-engineering.nl) |
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Martijnus
Joined: 29 Dec 2006
Posts: 2019
Location: Netherlands
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| Posted: Sat Nov 28, 2009 8:22 pm Post subject: |
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There's nothing between the sleeve and the block that conducts heat bad (like air), indeed because of the tight fitting. This means the only loss between thermal conductivity is the difference in capacity of the materials themselves.
So, your comparision with the heat sink on a processor is very nice and obvious, but the difference with those is that there ís a gap (maybe only a few molecules thick) between heat sink and processor, and there's a difference in materials (so also in thermal conductivity; aluminium heat sink/silicon chip?). That's why there's a need for conducting paste. I guess when you'd press the sink on the cpu with the same force as what's on my sleeves, you probably wouldn't need paste anymore .
Since there's not much difference in thermal conductivity between the sleeves/engine block, the heat is transferred as good as stock
Still, it's good to mention it like you do
_________________
"Rule: Turbo's make torque, and torque makes fun." (C. Bell)
924 "50-jahre", 1981.
MSII/extra, LPG, ITB's, 5lug.
To be turbo'ed in a while.
Killed her at the Nurburgring, Porscheless at the moment |
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Martijnus
Joined: 29 Dec 2006
Posts: 2019
Location: Netherlands
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| Posted: Sun Dec 13, 2009 4:36 am Post subject: |
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Got the pistons for a while now, but forgot to shoot some pics:
Sideview, nice dish
Top view.
Sideview again...
Semi top view.
Engine block in primer... it'll be painted after this and then it'll get new freeze plugs. I guess it makes a lot of difference in appearance when the plugs are installed after painting, instead of painting new plugs too.
Somtimes you've got to accentuate certain things to display chronological order during the build.
Other side...
Can't do much... I'll measure the small-end bushes and determine if I'll replace them. I probably will and machine the bushes to a perfect clearance
After that, rods can be connected to the pistons, but I'll still have to wait for the oversized bearings from King... until I have those, I can't work on the crankshaft.
_________________
"Rule: Turbo's make torque, and torque makes fun." (C. Bell)
924 "50-jahre", 1981.
MSII/extra, LPG, ITB's, 5lug.
To be turbo'ed in a while.
Killed her at the Nurburgring, Porscheless at the moment |
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