Author Topic: 2.0l M42 (Read 59463 times)

mandarin · « **Reply #60 on:** March 24, 2010, 02:21:18 PM »

Quote

With 135mm rod,M42 piston, and no shaving, the piston would be about 1,35mm below deck and 9,3:1 CR but only with 1951cc.
With 135mm rod, S52 piston(86,4mm) and no shaving, the piston would be 1,35mm below deck, 9,8 CR, and 2064cc.

Hello guys I'm new to that forum, was reading some topics and I have next quiestion:

is it possible to shave 1.5 mm off the top of engine block??? in that case with 135mm rods we will have 0.15 mm above deck, and will have standard compression

is that possible or not???

wazzu70 · « **Reply #61 on:** March 27, 2010, 07:30:55 PM »

Is the S38 chain stronger and lighter, or just lighter? I know M42 chains seem to break more frequently than others.

You can get the VW solid lifters from 034 motorsport. If you want lighter hydraulic lifters you can use the hydraulic VW ones. don;t know the PNs off hand but if you search you can easily find.

The MM 360 bearings are just early M20 bearings if you want the 360� oiling groove. If you just want 360� thrust the new bearing kits include it for the M42 from places like pelican. You can also just use M50 bearings. I got PTFE coated bearings from VAC motorsport and I just requested the 360� thrust. No machining required for the M42/M50 bearings.

Redpolack · « **Reply #62 on:** April 01, 2010, 01:15:58 PM »

Quote from: hesgone2fast;59209

I have used:
-M42 E36 block
-M47 crank
-S52 pistons
-M42 E30 rods
-M42 E30 head,fully rebuilt,shaved 0,2mm, fully ported, 6mm valves, MM bee-hive springs, MM retainers and shims
-Schrick camshafts
-Schrick lightened hydraulic lifters
-MM heavy duty, trimetal, teflon coated rod bearings
-MM 360� main bearings
-MM head bolts
-E36 M44 86mm headgasket (thicker than stock)
-All new chain, guides, E36 tensioner, gaskets.
-E36 Serpentine belt system

In progress:
-E36 M3 (S50)inline throttle bodies

would you have some building pics?

mandarin · « **Reply #63 on:** April 10, 2010, 05:12:00 PM »

Quote from: mandarin;89969

Hello guys I'm new to that forum, was reading some topics and I have next quiestion:

is it possible to shave 1.5 mm off the top of engine block??? in that case with 135mm rods we will have 0.15 mm above deck, and will have standard compression

is that possible or not???

I calculated and in case of that we will have something about 10.5~10.6 CR, instead of standard CR 10.1.

my question again:

is there possible to shave 15mm off the to cylinder block?

P.S. in previous post I have mistake writing 1.5 mm, there should be 15mm.

Warsteiner · « **Reply #64 on:** April 10, 2010, 10:16:07 PM »

Please be more specific about what you're asking. WE have no idea what crank, piston, rods etc.. you're talking about.

Why would you want to cut 15mm of the block anyway when you can manipulate the crank throw, rod length and compression height on pistons??

As a hypothetical:M47 crank/ 138mm rods
CH = Deck - Stroke - Rod - Above Deck
30.15mm = 212mm - (88mm/2) - 138mm -.15mm*

NOW with -15mm deck height with stock crank / 135mm rods
x = 197 - 40.5 - 134.85
x = 21.65mm compression height: Not happening
With Stock 140mm rods it gets even worse.
x = 197 - 40.5 - 139.85
x= 16.65mm CH

~Ralph

mandarin · « **Reply #65 on:** April 11, 2010, 01:53:13 PM »

Quote from: Warsteiner;90687

Please be more specific about what you're asking. WE have no idea what crank, piston, rods etc.. you're talking about.

Why would you want to cut 15mm of the block anyway when you can manipulate the crank throw, rod length and compression height on pistons??

As a hypothetical:M47 crank/ 138mm rods
CH = Deck - Stroke - Rod - Above Deck
30.15mm = 212mm - (88mm/2) - 138mm -.15mm*

NOW with -15mm deck height with stock crank / 135mm rods
x = 197 - 40.5 - 134.85
x = 21.65mm compression height: Not happening
With Stock 140mm rods it gets even worse.
x = 197 - 40.5 - 139.85
x= 16.65mm CH

~Ralph

sorry not for noting that:

so my idea is:
M44 Pistons,
M50 (Non Vanos) 135mm rods
m44 head gasket
m47 crank with 88 stroke.
-15 mm from cylinder block

we will get 0.15mm over deck

we get:

85*85*3.142*88=1997cc
cylinder volume ~ 499cc
head chamber volume (33cc) + M44 gasket voume(10.1cc) + M44 piston compression volume (not sure : ~ 9 cc) = 52cc

so compression

(499+52)/52=10.59 compression.

so will that configuration work?

so maybe cutting of top of block is possible but what with in case that configuration piston lower dead position will be 8.5 mm lower than standard m42 (8.5 mm = (88-81)/2 + (140-135))

Warsteiner · « **Reply #66 on:** April 11, 2010, 03:21:53 PM »

To get .15mm above deck with your calculations.

M44 has 30.4mm CH

30.4 = X-44-134.85
X = 209.25mm
You need to only cut 2.75mm off the block. I wouldn't do it. Change something else.

Why are you so persistent with wanting to cut the block?

If you do your -15mm Calcs then :
30.4 = 197-44-135 -X
30.4 = 18 - X
X = -12.4mm "above" the deck.

Doesn't add up.

Where are you getting your information from? Why are you using this combination of parts? I'm very confused and don't think that I can help.
I'm Sorry:-(

Can someone else chime in and clear this up?

~Ralph

mandarin · « **Reply #67 on:** April 11, 2010, 04:02:10 PM »

Quote from: Warsteiner;90710

To get .15mm above deck with your calculations.

M44 has 30.4mm CH

30.4 = X-44-134.85
X = 209.25mm
You need to only cut 2.75mm off the block. I wouldn't do it. Change something else.

Why are you so persistent with wanting to cut the block?

If you do your -15mm Calcs then :
30.4 = 197-44-135 -X
30.4 = 18 - X
X = -12.4mm "above" the deck.
Doesn't add up.

Where are you getting your information from? Why are you using this combination of parts? I'm very confused and don't think that I can help.
I'm Sorry:-(

Can someone else chime in and clear this up?

~Ralph

Thanks Ralph for your reply, probably I had not correct M44 piston specs.

I just rechecked everything and understood that I had huge mistake, my mistake was thinking that I made mistake:( (really stupid from my side)

my calculations: standard m42 stroke is 81mm m47 stroke is 88
so in case of M42 crank and 140mm rods with M42 pistons (standard M42 engine) we have 0.15mm over deck
in case of using M47 crank, 135mm rods with m42 pistons we got:
(140-135)-(88-81)/2 -0.15 = 1.35mm below deck so to normalize to over deck (0.15), decided to cut block from top on 1.5 mm .

so in case of using M44 pistons to get 0.15 over deck will need to cut 2.75mm off block.

I chosen that parts because I can get everything used for cheap and budget of build will be quite small.

also I'm afraid about cutting off top of pistons because I'm not sure how well it will be done at machine shop. so much more simpler is to cut block. also in case of M44 pistons will need to overbore cylinders to 85.

so just 1 question why you don't recommend cutting off the top of block?

Warsteiner · « **Reply #68 on:** April 12, 2010, 01:03:52 AM »

YES! Now you're on the right track with calcs. I wouldn't cut the deck for structural purposes. I know it's not much.
I'm not sure where you live or what your availability is for parts, but if you will let your machine shop deck your block and bore it, then I think they could fly cut your pistons. Also we don't know what your budget is and where you're money is best spent. If you're going all out with a crank and rods and pistons, basically a complete rebuild with gaskets and who knows what else, I would make them work together for you somehow. Just my .02 worth.

Good luck with your decision and your build.

Cheers,
~Ralph

PS... You do have one option if you want to do some more math:-)
Figure out what your compression will be with .40mm above the deck instead of .15 with a stock M44 1.74mm HG and then with a 2.04mm HG.

mandarin · « **Reply #69 on:** April 12, 2010, 03:08:00 AM »

Quote from: Warsteiner;90738

YES! Now you're on the right track with calcs. I wouldn't cut the deck for structural purposes. I know it's not much.
I'm not sure where you live or what your availability is for parts, but if you will let your machine shop deck your block and bore it, then I think they could fly cut your pistons. Also we don't know what your budget is and where you're money is best spent. If you're going all out with a crank and rods and pistons, basically a complete rebuild with gaskets and who knows what else, I would make them work together for you somehow. Just my .02 worth.

Good luck with your decision and your build.

Cheers,
~Ralph

PS... You do have one option if you want to do some more math:-)
Figure out what your compression will be with .40mm above the deck instead of .15 with a stock M44 1.74mm HG and then with a 2.04mm HG.

Thanks Ralph Again

most interesting thing is that I'm not in US

I'm almost on opposide side of planet

I live in Georgia (Not US state)
so for us cutting pistons and then pocketing them for valves sounds frightening

so I was talking about cutting block because I have heared that some guys have done such manipulations here not sure about M42 block but they have done that on M20 and M50.

about budget that works will go below 300$ (including M47 crank, m44 pistons, M50VN or M52B28 135mm rods, with works). not mentioning price for new parts.

wannam42 · « **Reply #70 on:** May 25, 2010, 05:51:58 PM »

mandarin,

I'm wondering if you've factored in the compression height difference between the two pistons you're considering.

The stock M42 piston has 31.65mm while the M44 piston has 30.4mm - that's a 1.25mm difference and would cause the M44 piston to be 1.25mm lower than where the stock M42 piston would be. This will lower your compression ratio.

If you're using M44 pistons, wouldn't you need to shave just 3mm instead of 2.75mm?

Andy_Casey · « **Reply #71 on:** June 04, 2010, 01:17:29 PM »

Suprised that TimS hasn't been on this thread. He's got a 2.1 M42 in his E30, using an 88mm diesel crank and custom 87mm pistons by Metric Mechanic (I think, or JE). Engine is running mild cat cams, flowed head, bored TB and was on Megasquirt but also runs OK on Motronic with different injectors. Power was about 190-200bhp on the rollers and torque is great, especially low down, much better than the stock engine or even my M44, ideal for sprinting / autotest. There's also the option or running the 90mm crank for a torquier still engine. It was a lot of work but the results are worth the effort.

Letsplayskatch · « **Reply #72 on:** June 04, 2010, 03:33:55 PM »

Andy, what 90mm crank is that?

e30guydownunder · « **Reply #73 on:** June 07, 2010, 10:17:21 PM »

He is probably talking about the M47N crank which is 89.6mm and almost unobtanium

ziedas nr 1 · « **Reply #74 on:** August 14, 2010, 01:16:10 PM »

Quote from: hesgone2fast;58969

Hi there, well, first of all, let me ask you wt is your budget, because starting with that, we can consider what changes to do.
If you drop in the M44 crank (83,5mm) and S50 pistons (86mm), you would end up with "only" 1929cc, that�s far from your limit...
Using S52 pistons (86,4mm) would push you up to 1947cc, still not there...
But using the allmighty M47 crankshaft (pricey, but worth it) along with stock M44 (85mm) pistons, would put you on 1997cc, that looks much better, you would only need to shave the pistons 2,5mm, and your deck height would be set at "0" and CR would be 10,8:1.
Much more torque from the bottom, and nice and good compression ratio.
Cost? Well, If I were you, I would look for a full M44 spare engine, so you don�t have to look out for M44 pistons, and you wouldn�t have to bore out the block to fit the M44 pistons.
So a nice and clean M44 engine should cost no more than $400-$500.
I bought my used M47 crank off ebay for $500, shaving pistons should cost no more than $80. balance all together about $80, and rebuild gaskets, bearings etc... $300.
All adds up to $1500, decent price for a nice 2.0L motor with huge potential.
If you have some extra cash after this, drop in a set of S50 inline throttle bodies (only 4 of course...) I bought my set for $300 on ebay, and is a pretty much straight fit (minor work involved...) on our cylinder head.

This is just my thinking, someone else is very welcome to bring in more ideas or discuss my opinion.
I hope to have helped you kidneyboy.

question,whitch crankschaft you use, or m47 100kw,or m47 110kw engine?