M44B19 Racing Engine

[Deyan]

Past few Weeks I was gathering lots of Info and now I would like to share what I've learnd and what I am planning:
 

Bottom-End
Crankshaft + Bearings from Diesel: 88mm Hub (16.6kg) Stock 13.2kg
Eagle Forget Conrods: 135mm (22mm pin, 540g) Stock 532g
Wiseco/Mahle Forget Pistons: 86mm (22mm pin, 320g) Stock 446g
Headgasket M44: 1.74mm

=> CR = 13.06:1 /1.85mm over deck/
     Discplace: 2044.7cc = 8.6x8.6x8.8x3.14159  (511.17cc per Cyl)

Eagle Forget Conrods are the cheapest on the market: round 400$
Lucky for us the Mitsubishi Evo after 92' are 85mm with 22mm pin.
The Evolution 86mm Forget Pistons: round 520$, but Stock (good for more than 300 hp) they cost something like 75$ each.

About the Pistons: I've made some messurment and what I found:
88mm hub + M44 Piston + 140mm M44 Rod = 2.25mm over Deck
M44 Pistons got 30.4mm Comp. Hi.
The Evo Pistons Comp. Hi. is however 34.7-35mm.
which means:
88mm hub + EVO Piston + 140mm M44 Rod = 6.85mm over Deck
88mm hub + EVO Piston + 135mm Eagle Rod = 1.85mm over Deck

=>
1.85mm = 10.7cc
M44 Chamber Volume = 33cc
M44 1.74mm Gasket = 10.1cc
Evo Pistons (9.3:1) = 10cc  /there are 9.0:1 and 8.5:1 ... so lots of choices/

CR = 1 + {511.17/[(33+10.1+10)-10.7]} = 13.06:1

CR with 2.04 M44 Gasket = 12.57:1

I just don't know what would be safe as a size above deck, but I think a thicker gasket and little bit shaving the pistons would be enough. I am looking forward to at least 12:1 CR

----------------------------------------------------------------

M44 Head
35mm Intake Valve
31.5mm Exhaust Valve
Catcams
Reworked Head
Stiffer Springs (dbilas or Catcams)


Int Valve from S54 (E46 M3) /117mmX6mmX35mm/ reworked to the same length as M44 Valve.
Ex. Valve from Supertech

There are 2 Options for the Cams:
I. Catcams 283/284 (PartNr: 1301701) - used with O.E.M Parts
II. Catcams 312/304 (PartNr: 1301752) - used with Stiffer Springs and Solid Lifter (Pushrods)




As for the Stock M44 Head:
Beehive Valvesprings /37g/
Int. Valve 33mmX6mm /47g/
Ex. Valve 30.5mmX6mm /47g/
Hydr. Pushrod /45g/

Alone here everything is much lighter than the M42




So I would be glad to have a little discussion about the Camshafts. For how much RPMs is the Option 1 good (284/283 with O.E.M parts ... probably stiffer springs) and up which point does Option 2 make sence?

[Deyan]

There is also an EVO Piston with Comp. Hi. 28,7mm and Dish 21cc
In this case: 140mm Rod => 0.55mm above Deck
=> CR = 1 + 511.17/[33+10.1+21-3.2] = 9.4:1 /0.55mm above Deck/

[Boyracer]

I just don't know what would be safe as a size above deck, but I think a thicker gasket and little bit shaving the pistons would be enough. I am looking forward to at least 12:1 CR

I think stock pistons come 0,15 mm above the deck. Stock head gasket is around 1,7 mm thick (correct me if I remember wrong!) so distance between piston top and cylinder head is 1.7 mm - 0.15 mm = 1,55 mm.

However there should be atleast 0,7 - 1 mm allowance for rod stretch on high rpm! So in stock setup and in high RPM the distance between piston top and cylinder head can be as little as 1,55 mm - 0,7 mm to 1 mm = 0,85 mm to 0,55 mm.

So you can see that the piston cannot come much above the deck with stock head gasket and cylinder head.

Do you happen to know what is the chamber volume of M42 cylinder head?

[Letsplayskatch]

Not that I post much on here but; my catcams came with new springs and retainers as they're fairly aggressive. No need to source from other companies. But thats if you decide to go for the 312/304 degreed ones like me.

GL with the build!
Scott

[Deyan]

M42 Head has 33cc Volume too.
(S14 - 42cc /// M50B25 - 34cc /// M52B25 - 36cc /// M3 USA S50 - 32cc
/// M3 Euro S50 - 32cc /// S54 M3 E46 - 33cc /// M5 S38 - 34cc)

It is very interesting, but the ///M Power after S14 got smaller Chamber Volume. :confused:

Everything about the BottomEnd guilt for M42 too.

The good thing is, that you can buy stock Evo Pistons for 100$, and they are very strong and forged from the factory. Together with second hand diesel and 135mm second hand M20 Rods ... you can stroke the Engine for under 1000$ and It will still be very strong.

Letsplayskatch, where did you order your Catcams? Tell me what are your impressions .... idle, power, where does the power come?

I can choose between: M42 1st Gen., M42 2nd Gen. and M44 ...
I would go for M44, because after all I've read, the Head is better, it is 85mm bored from the factory and I think the stock head can rev more, than M42. And in my case this car will be for fun and track, so I can go for the most agressive setup, that could probalby be ok for few thousands km.

[Letsplayskatch]

Check your PMs Deyan

[nuvolarossa]

check valve pockets, especially with the high lift cams... (angles are differents between BMW and Mitsu head.


-> don't trust my numbers in threads about 4g63 pistons here or in BF.c

[Boyracer]

M42 Head has 33cc Volume too.
(S14 - 42cc /// M50B25 - 34cc /// M52B25 - 36cc /// M3 USA S50 - 32cc
/// M3 Euro S50 - 32cc /// S54 M3 E46 - 33cc /// M5 S38 - 34cc)

Great info! I have M42 head and 12,6 CR pistons that are meant for S50B30. Because the volumes of M42 and S50B30 chambers are so similar CR's should be pretty similar too. Actually it is good that M42 head has slightly bigger volume, lowers the CR a bit.

It is very interesting, but the ///M Power after S14 got smaller Chamber Volume. :confused:

I think that is partly because S14 had vastly bigger bore (atleast 93,4 mm) than later S/M engines (max 86,5 mm).

I can choose between: M42 1st Gen., M42 2nd Gen. and M44 ...
I would go for M44, because after all I've read, the Head is better, it is 85mm bored from the factory and I think the stock head can rev more, than M42. And in my case this car will be for fun and track, so I can go for the most agressive setup, that could probalby be ok for few thousands km.

If you are talking about bottom ends only, M42 is better. M44 has little bigger stroke but the crankshaft is cast and it has only 4 counterweights

M42 crank is forged (stronger and has better fatigue resistance) so it can be revved higher, also it is fully counterbalanced (less vibrations) which also helps in high revs

[strypt]

Also beware of the trigger wheel bolted to the M44 crankshaft. It has exploded twice on my friends racecar with 8k+ rpm. (Fully built M42/M44 combo, almost 250 bhp N/A)
Edit: The trigger wheel sits inside the engine, not in the front like M42. It is bolted to the crank thou, but apperently hard to balance it without it. Maybe possible if you add weights.

[Deyan]

strypt: Does your friend use 88mm Crank from Diesel?
If he got issues with the trigger wheel, why doesn't he convert to M42 trigger wheel?

Boyracer Yes M42 does have stronger Bottom-End, but if you go for Stroke with 88mm Crank, it is better M44 (my opinion).

nuvolarossa This is why, I would go with used Evo Pistons first. We will see how much should they be reworked.

[nuvolarossa]

strypt: Does your friend use 88mm Crank from Diesel?
If he got issues with the trigger wheel, why doesn't he convert to M42 trigger wheel?

http://www.stalheimmotorsport.se/page.php?p=40

". Efekt ca 240 hk vid 8350 rpm varvstopp 8500 rpm" :eek:

[strypt]

strypt: Does your friend use 88mm Crank from Diesel?
If he got issues with the trigger wheel, why doesn't he convert to M42 trigger wheel?

No he uses the M44 83.5 mm crank to get lower piston acceleration and less torsional vibrations.
The problem is that the M44 trigger wheel is bolted onto the "throw" (don't know the english word sorry) of the crank at the 4th cylinder. Completely different from M42. Removing it will require adding weights to the crank to be able to balance it.

[strypt]

". Efekt ca 240 hk vid 8350 rpm varvstopp 8500 rpm" :eek:

248.3 hp was the exact number

[Boyracer]

No he uses the M44 83.5 mm crank to get lower piston acceleration and less torsional vibrations.
The problem is that the M44 trigger wheel is bolted onto the "throw" (don't know the english word sorry) of the crank at the 4th cylinder. Completely different from M42. Removing it will require adding weights to the crank to be able to balance it.

8500 rpm with cast M44 crank is good and useful info! As M42 crank should be even more durable as it is forged.

I think they are called counterweights? To offset the mass of piston and con rod. M42 (and M47) has 8 and M44 only 4 so in theory M42 should be better balanced.

Piston speeds and hence accelerations are interesting subject. The longer the stroke the larger the acceleration and resulting forces. M42 has same piston speed in 8500 rpm as S50B32 (E36 M3) in 7400 rpm!

That is why I am not too big fan of increasion the stroke. You will gain some torque and power but in the same time lose some ability to rev high. With shorter stroke you can compensate by running engine to higher revs, gaining power if the cylinder head flows enough. But to have most out of high revving engine you need to change you differential ratio to shorter etc.

The choice is really down to design goals and limitations of engine design. My engine will be only 1882 cm3 but it will rev like a food blender. If the head will flow enough and tune is good it should be capable of doing around 250 hp

[Boyracer]

Ooooh, interesting photos from Strypts friends site!

Broken off trigger wheel on M44 crank:



Aftermath:



It's not pretty