Stroker question

[quattro84]

Objection! Are these formulas and the Excel file controlled by THE engineer???

Ok, jokes aside i will have a look and also see how would the 158 rod, 95,5 stroke i am planning compare to the original 3B ect setup.

Yup, approved by An engineer

Seems like he used the E30M3 file as a source that has been floating around on Motorgeek for some time, (including a file of the goniometric for piston desaxation)
and that just works fine.

[Jamo]

This is what 034 say:

This is a typical if more rod ratio is good, a lot more must be even better, I don't agree. To make an 86.4 work in a tall deck 236mm block, you would need a very long rod, at least in the 165mm range, which gives a ridiculous rod ratio of 1.9 or more, to run a shorter rod means a ridiculously tall and heavy piston. The right crank for a 236 block is the 92.8 for a high revving motor, and you could end up with a good 1.75 rod ratio, perfect for a 10k+ rpm motor.

Frankly, Audi had it right on the stock motors with 1.66, this ratio gives the perfect piston speeds for longevity and also the right piston acceleration speeds to and away from TDC for great cylinder filling and exhaust scavenging. Its not a myth, its simple mechanic, if you want to run such a short rod ratio, you just can't rev it if you want the motor to last. You can take a stock rod ratio motor and rev it to 10krpm no problem, with the right head and components in the bottom end, its a great match.

The 92.8mm in the 220 block is a nice motor, like what we put in Christian's Coupe, that motor sings to 8krpm day in and day out on track and makes great power up there with about 500 quicker spool up on the turbo, that's a 1.55 ratio and its about as low as I'd go for an 8krpm motor.

Going with a ratio like 1.9 slows the piston down so much it can really affect power production at lower rpms and there is no reason for it.

On the other end of the scale, I've seen a lot of problems with 95.5mm cranks in 220mm blocks, most don't last long and trash the rings and piston side skirts. I personally have never had luck revving one of these motors much past 6500rpm. Not sure what length rod the 2.2 Issam referred to ran, but in any event, can't be much past 1.5 rod ratio, I cannot imagine revving that motor past 7krpm much less 10k.

http://www.motorgeek.com/phpBB2/viewtopic.php?t=22345

Now Javad worked at Eurospec developing these engines

Now testimonials of people who actually used the engine not theoretical like the spread sheets

Thoughts on the build...
If you like torque and can afford a 2.6...DO IT! Don't over turbo the engine. A GT35R might "seem" better for the displacement and will put up bigger bragging #'s but The powerband will be narrower and you're already limited to around 6500 redline. (Unless of course you don't mind replacing engines on a regular basis.)

[/quote]

http://www.motorgeek.com/phpBB2/viewtopic.php?t=15035&postdays=0&postorder=asc

Highlights of the thread

This car "was" a completed project, however, the rings decided to quit on the bottom end, so it is once again back in the garage awaiting a new engine.

I am done with the stroker builds...this is the 3rd time this engine has been apart and I am going to go with something that is proven now. A 2.2L bottom end with stock pistons will be more than reliable for the horsepower level I am going for

So are you keeping the long stroke with a stock 2.2 bottom end vs the high deck height block? Just wondering what the reasoning is.

I wish I didn't have to touch this car! I *thought* everything was cool until I started going through a quart of oil every 300 miles...

After talking to Swanson today, I found out the block I have is the same deck height as a standard 2.2L, the crank is what is different. The block has been clearanced to compensate for the longer stroke, but OMG, it is crazy the angles those rods must be at!

http://www.motorgeek.com/phpBB2/viewtopic.php?t=18533

This is a reoccurring theme on motorgeek with 220mm blocks and 95.5mm crank

IMO the guys that have used it say limit it too 6500rpm if you want to follow the spreadsheet have deep pockets!

[quattro84]

As previously said, this setup eats pistons & rings (like you quote from Motorgeek). Sidewall forces are becoming rather large. It's up to the enduser to take the step to go stroker. I agree with you, there is enough information around these days to make a well-thought decision. Spreadsheets are good way to get an idea of potential numbers and forces.. but taking it into practice is another (big) step. All i know i'm not the first to pay expensive learning money on this subject...

[EBR]

I know about all this Jamo, and that's why I'm planning on staying under 6500rpm almost the whole time

But do you know what pistons and rings these guys where using? Did they use a top ring with 1mm thickness?
And did they stay under 7k rpm or did they go close to 8k, wear out their engines and then saying 95.5mm crank in 220mm block is crap??

And if the guys in Norway have exactly the same setup as I do and rev their engines to 7300rpm, and that on trackdays which is pretty heavy, then there are also examples of these engines that work!!

Like I said earlier I will make a threat about my car and post up some pictures! And when I have driven my car a little bit I can post my experience and if the engine only lasts few thousand kilometers I will tell you so

I'm not doubting that having a tall block is much better, but it must be possible to live with the 220mm block, at least I hope so since I got me one

Regards, Eiríkur B. Rúnarsson...

[stiglet]

Ok, I have an AAB diesel block which I beleive is just the same as any 236mm block but with a smaller bore. I will bore it out though, but that's trivial.

I think the crank is still 95.5, but i'll be ok revving to 7,000rpm, right?

BTW, this won't be for a turbo, so the con rods will be slightly longer to raise the CR.

[Wizard-of-OD]

As previously said, this setup eats pistons & rings (like you quote from Motorgeek).

Are you speaking from experience because it sounds to me like this is hear say....

Sorry for the late response to this but I was referred to this thread this morning. Bone stock 9A 16V was a 92.8mm (1.55 rod ratio) engine in a 220mm deck block. I know COUNTLESS people that have taken 16V MKII engines to 9000+ rpm's on a solid lifter conversion. No damaged to side walls of the pistons or eating of bearings / rings.

We have 2 cars locally that are running a 95.5mm diesel crank in a 220mm block with a 144/20mm connecting rod (1.51 rod ratio) and they have been running since June 2009....
We are also campaigning 2 lotus's with the same 2067cc displacement motor (1.8T stroked here). Think for a single minute what the difference in stroke between a 95.5mm crank and a 92.8mm crank really is.
Its a radius of 1.35mm.......

Happy motoring.

[porkkis]

Ok, I have an AAB diesel block which I beleive is just the same as any 236mm block but with a smaller bore. I will bore it out though, but that's trivial.

AAB lacks the machined surface for the flywheel sensors and also there is no place for the heater hose flange. And also no place for the knock sensors but that's equal to all the diesel blocks I think.
I've done a 10vt tall block engine using an AAB block.

[PaulJ]

Hi All

Very interesting reading, What is the engine code for the tall block 236.5mm I think
with the normal bore, I quite fancy this as a project, On reading its probably the 1 Jamo is using amongst others with the longer 158mm ? rods. I'll see if I can pick 1 up at the right price locally

Cheers Paul J

[Jamo]

Are you speaking from experience because it sounds to me like this is hear say....

Sorry for the late response to this but I was referred to this thread this morning. Bone stock 9A 16V was a 92.8mm (1.55 rod ratio) engine in a 220mm deck block. I know COUNTLESS people that have taken 16V MKII engines to 9000+ rpm's on a solid lifter conversion. No damaged to side walls of the pistons or eating of bearings / rings.

We have 2 cars locally that are running a 95.5mm diesel crank in a 220mm block with a 144/20mm connecting rod (1.51 rod ratio) and they have been running since June 2009....
We are also campaigning 2 lotus's with the same 2067cc displacement motor (1.8T stroked here). Think for a single minute what the difference in stroke between a 95.5mm crank and a 92.8mm crank really is.
Its a radius of 1.35mm.......

Happy motoring.

Speak to Javad at 034, Eurospec had a hell of a time with this setup also speak to Pnanassy

It's not being said the setup doesn't work, it's just very hard working on the engine, the 1.35mm whatever isn't the factor you've got piston with a very small compression height on them and the rings are subjected to some serious stresses due to the high rod angle. The amount of clearancing needed on the block for the rods is a give away.

PaulJ you can use any rods size you like inbetween 155mm to 159mm.

Mine are 155.xx mm to keep the compression height of the pistons the same as OEM where as the longer rods reduce the compression height

Not saying this is better as there are more than one way to skin a cat.

[Wizard-of-OD]

Speak to Javad at 034, Eurospec had a hell of a time with this setup also speak to Pnanassy

I am 034 of Canada & UK. Dont really need to speak to Javad or Eurospec Jamo.
Fastest Audi in North America ran a bottom end built by us so I know what works and what does not....

It's not being said the setup doesn't work, it's just very hard working on the engine

2+ years running strong on 95.5mm stroke
again , once the rod ratio is over 1.5 then you are more than fine.
144 / 86.4 = 1.67
144 / 92.8 = 1.55
144 / 95.5 = 1.51
144 / 100 = 1.44

150 / 86.4 = 1.74
150 / 92.8 = 1.61
150 / 95.5 = 1.57
150 / 100 = 1.50

[killa]

Good morning,

It's scary how the years move and we are still on the same page, I remember putting these setup together back in 2000 then breaking records in 2004. I used to hear nonsense back then while i knew that it wasn't true because i did it and had similar motors in the Honda Camp doing the same.

fellas, the 95.5mm crank is not a good crank for everyday driving but can work, would work best on the tall 236mm block thus allowing you to run the taller rod.

To think that we have 1100whp cars here with 1.55 rod ratio and you're discussing little things is funny, but let's be real, today's experts were looking to run 99mm strokes yesterday, no motors ever built though

[Wizard-of-OD]

but let's be real, today's experts were looking to run 99mm strokes yesterday, no motors ever built though

I am not sure which way to take this post but yes lets be real Paul.

2005 != 2011.

My GTI runs a 2067cc bottom end in a 220mm block .
Stefan A4 runs a 2067cc in his A4 (A Motor I built) since 2009....
Todd runs a 2067cc kit in his GTI (boomdaddymack on forums) since whenever.
Yves runs a 2042cc kit (82.5mm bore) since July 2010 in his race car.

These are a few off the top of my head. I am onto my 3RD 95.5mm Custom JE piston batch and I am sure more will come.The only issue with the 95.5mm cranks vs the 92.8mm cranks is the additional weight in the rotating assembly which you yourself once said is a mute point in discussion.

[x6rs]

what do you think of the CR in a tall deck,155mm rods and oem pistons?
is it 8.7:1 0r 10.7:1?

have you used this setup too?pro cons?

[RallyQuattro]

155mm and oem pistons it will be 9.8:1

Here in Swedish:
Blockhöjden ökar med 236-220=16mm
Staklängden ökar med 155-144=11mm
Den ökade slaglägden gör att kolven kommer (95,5-86,4)/2=4,55mm högre upp.
Alltså kolven kommer att svänga 16-11-4,55=0,45mm lägre ner än orginal.
Orginal förbränningsvolym 81²*pi*86,4/4000/(9,3-1)=53,6cm3
Förbränningsrummet ökar med 81²*pi*0,45/4000=2,3cm3
Nya kompet blir (81²*pi*95,5/4000/(53,6+2,3))+1=9,8

[JP]

A stroker can be made to rev reliably it all comes down to how deep your pockets are and what the final intended usage is.

If you are rebuilding every race or season then it is unimportant to make the engine last. If using it on the road that's a whole different ball game. I've seen in engines build by very reputable companies some of whom are regularly mentioned and my ten year old can do better. The problem is the end consumer is not using it for racing they are using it as a high mileage daily, so all the factors that should be taken into account haven't been resulting in short lifespan engines which are fine for the racing scene but not the average daily hack.

The biggest issue is the thrust forces that occur at the pistons maximum point of acceleration during the stroke.

FOR EXAMPLE when using narrow top rings like 1mm you can look at them under a microscope after use and see where they have been twisting within the ringland. So realistically 1.2 to 1.5 steel top ring is a minimum requirement for reliability on the street to reduce torsional fatigue.

Next you will benefit from running a longer sideskirt with a narrower bore to give more piston stability when the max forces occur. The downfall is more surface contact on the bore so they are more prone to ovalling on the stock cast grey.

So next you use ductile liners, less bore distortion, less flex, less piston wear.

Depending on the rod ratio you have to start looking at whether the downward forces are still in effect when load is being distributed onto the big end cap bearing. 16v n/a engine with a 100mm crank used to eat big end bearings for breakfast everytime it went on track the issue was only resolved once sputter bearings where not only used on the rod side but also on the cap side. As it was literally crushing the softer cap bearing (no physical contact - just compression) causing the sputter bearing to touch the crank journal which is not so forgiving as they are more brittle.

Add a turbo to the equation and a couple of bar of boost and you compound any of these problems.

At the end of the day anything can be achieved unfortunately we live in a society where everyone wants everything for cheap. The end result being that sometimes the shortcuts work and sometimes they don't.

As for a given rpm on a stroker 1.66 rod ratio for the street and 7200 continuous with 7500 peak would be considered reliable for numerous years, want to rev more and be prepared to dig a bit deeper. Go less and it will rev up quicker but the forces increase exponentially and you want to start dropping the peak rpm value.