IE 3.0 L stroker kit - any good/worth it?

[Madhatter]

You dont need a piggy back engine management system, the motronic unit can supply more than enough fuel for the engine, the only issue can be ignition timing and just what adjustments you can make/need to make. Different engines are going to respond differently to a whole host of things (from compression ratio, fuel, deck heights, cams, chamber design, air temps, air density, the list keeps going) which will change just how much timing advance you need to run to stop the motor from pinging. As others have done in the past, if you need more you can fix it by rechipping the existing ecu. Its something you have to cross when you get it tuned because you arent going to know any other way.

If you wanted full and total control over ignition and fuel you could run a megasquirt for very little money.

[SA E30]

I've got 3 mates, and myself who make more than 250hp at the crank... all ranging from a 2.7lt - 2.9lt , our lowest reading is 157WKW, and highest is 163WKW ... None of us have really radical setups.

No itb's or anything, granted 2 of us run stand alone management, but the other 2 use a Dastek unichip. Ok, I will say we run pretty wild cams... 288,288, 292 and 300. IMO I think it is possible 2 get 280 - 290 out of an M20 with a S50B30Euro crank, 86mm pistons, ITB's ... and Worked head...

[madjurgen]

i thought the euro crank had different bearing sizes and therefore would not work with a m20?

[FredK]

The euro crank has the same sized mains as the US engines (60mm), but the rod bearings are 50mm instead of 45. So, as long as you use euro motor connecting rods, you should be OK.

[DrMcDave]

are there any benefits of using a euro crank over a Us crank? Aside from the rod bearing sizes which i assume would be stronger.

[nando]

probably a longer stroke, but the difficulties and cost of finding one in the states probably aren't worth it for an M20.

[madjurgen]

decided what crank/rod combo youre going to go with nando?

[DrMcDave]

probably a longer stroke, but the difficulties and cost of finding one in the states probably aren't worth it for an M20.

hmm considering you can use the s52 crank i don't see why that option is even considered. There is a guy in ohio running a 3.2 in his ix, and he said its working out well so far. Although jim at MM said the one guy that has one who build it on his own has had a lot of problems. Poor build i guess.

[nando]

decided what crank/rod combo youre going to go with nando?

it's still up in the air, the crank will probably be one of the last parts I buy. I don't think the loss in revs between the 84mm and 81mm crank would be all that much though. I've been playing with a piston kinematics calculator and there really isn't much difference between the two. It'll probably come down to what I can find locally, I don't really want to buy a crank sight unseen or have it shipped.

[SA E30]

it's still up in the air, the crank will probably be one of the last parts I buy. I don't think the loss in revs between the 84mm and 81mm crank would be all that much though. I've been playing with a piston kinematics calculator and there really isn't much difference between the two. It'll probably come down to what I can find locally, I don't really want to buy a crank sight unseen or have it shipped.

It's not really a loss in Rev's... the car will still happily spin up 2 7000rpm, it's just that is looses some of the speed in which it does, and the power starts dropping off a little sooner thats all...

One thing that the guys here like 2 do is take the entire m52b28 internals and transplant them striaght into the M20.

Another thing that is gaining popularity here in SA, is to take a 330i (m54) crank , on 86mm pistons ... gives u a 3.1lt , and oodles of torque... I'm thinkin of building a motor like this with a big Huffer attached

[JJGBMW323]

It's not really a loss in Rev's... the car will still happily spin up 2 7000rpm, it's just that is looses some of the speed in which it does, and the power starts dropping off a little sooner thats all...

One thing that the guys here like 2 do is take the entire m52b28 internals and transplant them striaght into the M20.

Another thing that is gaining popularity here in SA, is to take a 330i (m54) crank , on 86mm pistons ... gives u a 3.1lt , and oodles of torque... I'm thinkin of building a motor like this with a big Huffer attached

M54 crank eh? Interesting....Q: With the m52 how many MM is the crank and what rods do you use?


I think Matthatter's long thread on the stroker m20 3.0 liter is right on the money...but its up to the owners to decide what they want to run, and the resources that they have.

I have the 81 mm 524 td crank (knife edged), MM forged pistons,
and a built 2.8 liter stroker with lightened 325i flywheel for my 79 323i.

With the 2.8 liter I am using the m20 rods.

I also have acquired a s50 crank, which is 86mm, and I intend to use the s50 rods and forged pistons for a 3.0 stroker someday down the line.

I dont think I want to use anything bigger than the s50 crank as Jim at MM says with the S52 you need both custom rods and pistons...

He charges 1500 for the rods and about the same for the pistons...
so as usual he is expensive..

[SA E30]

M54 crank eh? Interesting....Q: With the m52 how many MM is the crank and what rods do you use?


I think Matthatter's long thread on the stroker m20 3.0 liter is right on the money...but its up to the owners to decide what they want to run, and the resources that they have.

I have the 81 mm 524 td crank (knife edged), MM forged pistons,
and a built 2.8 liter stroker with lightened 325i flywheel for my 79 323i.

With the 2.8 liter I am using the m20 rods.

I also have acquired a s50 crank, which is 86mm, and I intend to use the s50 rods and forged pistons for a 3.0 stroker someday down the line.

I dont think I want to use anything bigger than the s50 crank as Jim at MM says with the S52 you need both custom rods and pistons...

He charges 1500 for the rods and about the same for the pistons...
so as usual he is expensive..

U use the M52 crank with S50B30Euro pistons. u can uses the M52 rods, but u need 2 get offset small end bushes. Or u could use M40B18 rods, which r 3mm longer, and u don't need offset bushes. Cause whne using the S50B30Euro Pistons, they have a dish in them, and u need 2 cut them down 2 make a nice high CR... with the longer rods u can cut them down 2 a flat top piston, which would give u around 10.5:1 CR... Another trick for a higher CR is 2 cut the pistons out the block, but cause of the head design and the fact that u can pretty much only get a 84mm gasket... u have 2 chamfer the sides in 1mm 2 fit inside the gasket... It works well.

Actually spoke 2 a guy 2day. For when I build my race motor... Gonna make me a 324td crank, and weld it up 2 94mm, with a built up block... (sort of a custom long block) and 86mm pistons... Gives u a 3.3lt M20... Sounds cool with about a 12:1 CR that would be a rocket on the track

[madjurgen]

^^^
thats not a very rev-friendly rod ratio

[JJGBMW323]

again please

U use the M52 crank with S50B30Euro pistons. u can uses the M52 rods, but u need 2 get offset small end bushes. Or u could use M40B18 rods, which r 3mm longer, and u don't need offset bushes. Cause whne using the S50B30Euro Pistons, they have a dish in them, and u need 2 cut them down 2 make a nice high CR... with the longer rods u can cut them down 2 a flat top piston, which would give u around 10.5:1 CR... Another trick for a higher CR is 2 cut the pistons out the block, but cause of the head design and the fact that u can pretty much only get a 84mm gasket... u have 2 chamfer the sides in 1mm 2 fit inside the gasket... It works well.

Actually spoke 2 a guy 2day. For when I build my race motor... Gonna make me a 324td crank, and weld it up 2 94mm, with a built up block... (sort of a custom long block) and 86mm pistons... Gives u a 3.3lt M20... Sounds cool with about a 12:1 CR that would be a rocket on the track

Ok. Can you explain this last part to me again.
324td crank = 524 td crank = 81 mm.
S50 crank = 86 mm.

Bore out the 2.5 m20 block to 2.8 liters = 85 mm

According to what i have heard the s50 and m20 rods are similar.

So what does "weld it up 2 94 mm - mean?"

My forged MM pistons M20 325i rods, and knife edged 524 td crank
is a 2.8 liter and has a 10:5:1 CR ratio.

I have heard that using the S50 crank, and S50 rods,
you can have a similar ratio with custom pistons, and this yeilds
aprox 3.0 m20 stroker and 240 HP.

[SA E30]

The welded crank is exaclty what it says... they take a crank build it up to make a stroke that is a lot longer than the stock one... ? Dunno if that makes sense. He makes new Big ends, and Journals, and pretty much extens the legth of the stroke... I was lookin at a 324td crank that is out of his son's M20 he has stroked it 2 86mm... like an S50B30 crank.

With a 85mm bore and 81mm stroke, u barely a 2.8lt... it's actually 2757.8 cc ... In south africa thats not really done, cause we have a 2.7lt from factory, that was used for race purposese (it's very similar 2 Alpina B3 2.7lt)

That makes 155kw.

I actually can't remember the legth of the S50 Rods but I've got a set at home, that I will look at. I do know that the big ends on the S50 are bigger, while the small ends r smaller, than a regular M50 or M20.

Mad jurgen... I don't know why u say that... the rod ratio is still inside the accepted 1.6