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stew205

2088cc Mi Bottom End

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B1ack_Mi16
the 16v crank is fully counterweighted, so yes, it's less prone to whip (flex) at higher rpm's

 

BTW, are you aware of that the T16 crank actually is like the XU11D crank, with just 4 counterweights.

Makes me believe it's not a problem running high revs with the T16 / XU11D crank either.

The bonus is that those cranks are forged (possibly the reason for why they only made them with 4 counterweights).

Edited by B1ack_Mi16

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Kev-G
BTW, are you aware of that the T16 crank actually is like the XU11D crank, with just 4 counterweights.

Makes me believe it's not a problem running high revs with the T16 / XU11D crank either.

The bonus is that those cranks are forged (possibly the reason for why they only made them with 4 counterweights).

 

Neither of these engines were really designed for sustained high revs though....

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B1ack_Mi16
Neither of these engines were really designed for sustained high revs though....

 

Well.. I thought the T16 had the same rev-limiter as the Mi16?

But maybe it's lower?

 

I really think it's a bit random what cranks is fitted to what.

2.0 8v turbo engine has a fully counterweighted cast one, like that was designed for much revs? :P

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Mandic
Well.. I thought the T16 had the same rev-limiter as the Mi16?

But maybe it's lower?

 

Mi16 redline begins at 6500 and at 7200 fuel cut occurs.

 

But T16 (has redline at 7000, don't know about fuel cut) with its higher R/S ratio is capable of running lower piston speeds. But the crank is still the problem. So I think it's not a question of which can rev higher, but how long can it sit at the redline.

 

So Mi16 will experience higher piston speeds but having fully counterweighted crank, the bottom will be able to take the punishment easily...

 

Cheers

 

Ziga

Edited by Mandic

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easypug
2.1 Mi16. I found the car more tractible & also give it a wider power band. One thing i dislike about the 1905cc , it they are breathless low down, need to be thrashed to get 100% out of them. Others tuners scoff at 2100cc, due to being cast block, but they are stronger & not really that much heavier than the 1905cc. The YAnks are right , you cannot be Cubes. The increase CC allows the head to flow better. 1905cc Suffer from a lack of low down torque due to oversize inlet ports (low port volicity). That larger piston improves that. For me, i,d go 2.1, good low down grunt, with the lovely :D 4500rpm + powerband. from an marketing point of view, very want to invest on the unknown, which is a shame Should be finshed our 2.2 Mi16 , by the end of the month.

 

BTW, before you ask. 88mm stroke , 88mm bore.

 

Any comments to make on the 2.2 Mi16 engine? Have you tried a 92mm stroke and 87mm bore, any experiences?

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mos

hi,

been speaking to a number of engine builders over the past week or so (including a couple of company's associated with this forum) about the 2.1/2.2 litre bottom end for my 2.0 mi/s16 block.

most are willing to take on the project, but prefer me to have already sourced the crank.

1.9 mi16 cranks are very difficult to come by so i though i may use an 1.9 8v crank.

couple of the engine builders suggested that diesel cranks (which are much more plentyful apparanetly) may be a better solution, anyone any thought or reccommendations on this or which particular crank to use

 

thanks

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Bono

8v isn't fully counterbalanced, i am using what i think is a diesel crank.

Its not from an mi16, and it runs on standard S16 bearings.

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Hilgie

XUD9 dieselcrank is the same item as a 1.9Mi16 crank.

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Guest andymr

Hi Guys, this thread seems to have gone quiet since last summer with a few members mid upgrade. How did they all turn out.

 

Reason I ask is my 205 2330cc upgrade split a pot on the dyno bench, block was a steel diesel. Now my man :blush: (I just drive it! :D ) tells me that taking the bore from 83 to 88 made the metal to thin because there is a water channel between pots on the diesel block.

 

We are back on the dyno today using a later steel petrol block which only had to go from 86 to 88 and has left plenty of solid metal, will let you know how it goes!

 

Andy

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Sandy

Fingers crossed!

Edited by sandy309

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Guest andymr

Sandy my man , good job I didn't slag off you guys!!!!!!!!!!!!!!!!!!

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Sandy

Haha! I'm hoping to get down there tomorrow to see it on the Dyno, but i'm frantically trying to finish my own car. The initial signs with the engine were good, it was taking loads of fuel and was making good torque by half throttle, it'll be an entirely different delivery to the 1930cc one.

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B1ack_Mi16
Hi Guys, this thread seems to have gone quiet since last summer with a few members mid upgrade. How did they all turn out.

 

Reason I ask is my 205 2330cc upgrade split a pot on the dyno bench, block was a steel diesel. Now my man (I just drive it! ) tells me that taking the bore from 83 to 88 made the metal to thin because there is a water channel between pots on the diesel block.

 

We are back on the dyno today using a later steel petrol block which only had to go from 86 to 88 and has left plenty of solid metal, will let you know how it goes!

 

Andy

 

Interesting.

 

The 86mm bore petrol blocks also has a small drilled hole between the cylinders, also 85mm bore diesel block got this.

 

By the way, what stroke are you running?

 

I've got a 88mm bore and 94.5mm stroke (2299cc) engine myself, but only just started it some times yet so don't know it it will last for long.

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Sandy

It's 2238cc 92mm stroke.

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Guest andymr

Sandy this is the spec Colin sent me:

 

2330cc 16v

88mm bore- 92mm stroke

steel crank and rods

forged pistons

ported mi 16 head

solid lifters, double valve springs with titanium caps,

45mm throttle bodys with 8 injectors

4-1 exhaust manifold

dta engine management

 

:D:P:)

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B1ack_Mi16
Sandy this is the spec Colin sent me:

 

2330cc 16v

88mm bore- 92mm stroke

steel crank and rods

forged pistons

ported mi 16 head

solid lifters, double valve springs with titanium caps,

45mm throttle bodys with 8 injectors

4-1 exhaust manifold

dta engine management

 

:D:D:)

 

Nice spec, same crankshaft as me then apart from my offset-grinding.

So recon about 230-240bhp, maybe 250? :P

 

Would be nice to see pics of the cracked block if that's possible, if you could get some taken when the block is dismantled.

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Sandy

It's definately 2238cc, slight slip of the number keys there maybe. We'll find out later what power it makes all being well, the priority is mid range though. The old 1930cc was making 229bhp and the car was a record holder at many events with that. A wider spread of torque will improve times by making some gear changes unnecessary and pulling better out of slow corners.

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Sandy

I've just got back from the Dyno, i'll wait until I hear the final results later (they were still tweaking when I left), but it's comfortably over 200lbft :D

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B1ack_Mi16
I've just got back from the Dyno, i'll wait until I hear the final results later (they were still tweaking when I left), but it's comfortably over 200lbft :lol:

 

Cool! That's impressive, I was hoping for around 200lbft on mine, Engine Analyzer Pro was indication approx 205lbft at maximum torque for my setup, but I thought that might be a bit more than really was realistic.

 

Is it mapped on a "accurate" RR? :D

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Sandy

On the bench Dyno, DIN corrected. We saw 205lbft just over 5k. Certainly a big smile genrator after the dissappointment the other day and a tribute to Colin's hard graft over the last few days to rebuild it, not forgetting the lifeline of the nameless legend that bored another block so well, at such short notice.

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Livelee

My mi16 has just suffered it's 2nd headgasket failure in under a year. Rather that fix it again i'm going to buy an s16 engine. With the 2 engines I have i'm thinking of using the best bits from both and rebuilding it all together.

 

Given the bits i'm going to have what would be the best combination? The car is track only. I'm only going to be using the standard air intake system, not carbs or TBs.

 

Many Thanks

 

Dan

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Doof

Sorry to bring this topic back up but its really useful and i'm a bit stuck with a question I have given the following info from pumaracing:

 

If the bore/stroke ratio is altered (for a given capacity) but the head stays the same then the power curve will hardly change. The engine won't rev higher or lower just because the stroke changes. It's still the same swept volume breathing through the same head and it will rev until it becomes strangled for lack of airflow.

 

Engines don't make lots of power because they rev high. They rev high because they are making lots of power and that's determined by airflow. If a head can flow 5000 litres/min it will supply a 1 litre engine for 5000 power strokes a minute (10000 rpm). It will supply a 2 litre engine for 2500 power strokes a minute (5000 rpm). The 2 litre engine can't be forced to do 10,000 rpm with that head and even if the components inside were very light or didn't break it still couldn't breathe at those rpm.

 

Attaining high rpm isn't a goal, it's a natural result of improving flow.

 

Basically, the standard gti head is capable of flowing at least 130bhp right? the 1.9 shows this (lets not argue factory claims here). So, given that everything is based on the flow of the head as is stated above and which is the same on the 1.6 and the 1.9, why doesn't a 1.6 rev beyond the 1.9 to the limits of the common head? Based on the above I would expect the 1.6 to make the same power but at a higher rpm than the 1.9 given the correct cams to allow it to do so. We can discount the entire inlet and exhaust system here because clearly they both flow well enough for 130bhp.

 

Anyone? My only thoughts are that we are thinking of two seperate things, peak power and maximum revs. If the bottom ends and valvetrains could handle infinite rpm, a 1.6 would presumably rev to a slightly higher absolute peak rpm than the 1.9 because the restriction would be in the head...but why can it not make the same peak power at a slightly higher rpm?

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Sandy

The natural rev range of the engine is determined by far more than what the head will flow and stroke is an important aspect of that. Friction and inertia are affected by what bore/stroke combo you choose. Cam profile is also a very important component of this and the way the piston moves towards and away from TDC affects the way the engine sees the cam profile.

Edited by sandy309

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Paul_13

Do you have to machine any material off the pistons to be able to run the 1.9 16v/diesel crank? i.e would the rod move more side to side?

 

And what thrust bearing do you use? I heard diesel bearings fit but the thrust bearing is a PITA

 

Paul

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blackpug

I'm all very confused by this. Here's a list of what i have/can easily get:

 

1.9 Alu MI16 in need of a rebuild (tired high miler)

1.9 8v fresh engine with new bearings and 1600 pistons

Can easily get diesel blocks/engines (which ones?)

 

So what could i build out of that lot? For road rallies so i'd have to keep the std MI16 injection system and inlet (injectors, ecu can be changed). Sorry for the blunt question, just read the whole thread and got kinda lost in it all!

 

Edit: I dont want to spend alot of money on it - as much OE engineering as possible (new bearings rings etc though)

 

Cheers,

 

Ad.

Edited by blackpug

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