Author Topic: Buildup: My quest for NA 280 hp (Read 156613 times)

Boyracer · « **on:** August 21, 2008, 08:09:31 AM »

Ok, this is the continuation for my first thread about my project "Buildup: My quest for NA 180 hp" http://www.m42club.com/forums/showthread.php?t=2971

This quote is taken from one of my posts in original thread:

Quote

Major rethink on my plans. There will be two engines:

Engine 1. (current one on car)

- Shrick copy cams
- Motronic chip optimized for Shrick cams
- lightened flywheel
- 2.5" custom made exhaust + cat

Should be around 165-170 hp when ready. This engine will be put on storage once engine 2 is ready.

Engine 2. (one I am going to build based on acquired bottom end)

- W�ssner forged pistons (comp ratio around 12.5)
- bored block to 86 mm
- well balanced crankshaft
- ebay CNC con rods/stock con rods with lightening and shot peening
- S50B30 ITB's
- Mildly modified cylinder head with possible 35 mm intake valves
- Glass/carbon fiber airbox
- Solid valve lifter/follower conversion
- bit stiffer valve springs
- Dbilas, Cat Cams etc cams around 300 degrees duration
- VEMS or Megasquirt engine management
- lightened flywheel from engine 1.
- 2.5" custom made exhaust + cat from engine 1.

Difficult to say about power... Engine should be ok to rev as high as 8500, perhaps even 9000. Honda has similar sized engines and they produce 180 to 240 hp on road trim, altough they have VTEC but on the other hand they do not have ITB's.

I think I now consider engine 1 to be ready, all modifications apart from lightened flywheel have been done.

This new thread is about engine 2. I hope to start the build soon and have engine atleast part ready next spring. Power target is way too optimistic for 1882 cm3 engine but there is always possibility for miracle to happen ie. I could find M47 crankshaft from somewhere upping the displacement to about 2050 cm3... Then 280 hp is propably possible but then the engine most certainly is not street legal.

When I started the project I had a goal to keep the car street legal and in everyday use but that has now changed. Car has no interior anymore, it has bucket seat (only one), soon 6 point harness and it has been relegated from daily driver duties to track day car. I try to keep it road legal but at some point is might not be possible anymore.

So, this is it then... I will report here the progress I have made with the engine 2 in same way as with engine 1. It will be long and expensive but also interesting road ahead

nuvolarossa · « **Reply #1 on:** August 21, 2008, 09:01:06 AM »

I was playing until now with a great virtual engine simulator (@ builder's shop) for my turbo engine... and now I NEED to go there to play to see if your goals can be achieved with those mods

( I sniff HUGE head work to be done)

EDIT: first result says: piston speed VERY high! you will need to reach 8500rpm and even more to have that power!

Huge props for the project ( and passion) !

GrindCulture · « **Reply #2 on:** August 22, 2008, 09:21:19 AM »

This could be the first attempt that I've seen to replicate S42 type figures!?

Madness

Good luck.

nuvolarossa · « **Reply #3 on:** August 22, 2008, 10:11:23 AM »

MM reached those values in a S14 with 13,5:1 CR, but that has 37mm inlet valves and 33 exhaust... 35mm is really the maximum for intake valve in our M4x?

but thinking that S42 used 35mm/32mm valves, it not worth the money!
Last evolution of s42 used 5mm steam valves...
how much details have those documents that you bought time ago on ebay? in terms of plenum size, runner lenght and those things that nobody wrote on the net?:rolleyes:

Boyracer · « **Reply #4 on:** August 22, 2008, 10:56:28 AM »

Quote from: nuvolarossa;55304

MM reached those values in a S14 with 13,5:1 CR, but that has 37mm inlet valves and 33 exhaust... 35mm is really the maximum for intake valve in our M4x?

S14 had far bigger bore then M42/S42 so it could also accomodate bigger valves too. Here's some S42 data (I have posted these earlier):

S42 had 35 mm inlet / 32 mm outlet valves.

280 hp from 2,05 liters is veeeery challenging task (and right now I am missing the crankshaft to give me even that displacement). If I don't get the crankshaft I must be very happy with 220-240 hp.

The guy from who I bought the forged pistons developed S50B30 to give 375 hp (around 120 hp/ liter) with reworked head, larger valves etc. If I could reach same level of tune I would still be at 240-250 hp range. BUT! He only revved the engine to 7500 (peak power was at 7000) and I hope to have some 1000 rpm more in use which always helps. The problem is to get enough flow from the cylinder head to support such revs.

I think 8500 rpm is reachable with good quality parts and careful planning and assembly. The areas that I am more worried about are cylinder head cooling and bottom end lubrication. S42 had modified cooling system which had 4 coolant in or out ports on cylinder head connected by metal pipe just below intake port. How can you replicate that? Also, what kind of modifications bottom end needs to sustain high revs reliable? New oilways on crankshaft, oil squirters on block walls? Lots of questions!

I need to split this to smaller tasks, if I wait until everything is ready it will be a long time before the engine runs! So I have thought about plan like this:

Fall/winter 2008:

1. ITB's ready (adapter plate started already, need airbox etc)
2. Megasquirt engine control ready

Those I can already use and test with my current engine to see how they work.

Spring/summer 2009

3. Bottom end (forged pistons, block boring, new con rods, M47 crankshaft if possible, general overhaul)
4. Clutch (lightened stock flywheel and stock clutch or custom flywheel and multiplate clutch)

I can use this new bottom end with stock head I have now with ITB's and Mega.

God knows when?!?!?!

5. Cylinder head (bigger valves, porting, long duration cams, stiffer springs, new guides etc etc etc).

This is simply the most important and expensive bit of all and it must be just right :eek:

Frankie · « **Reply #5 on:** August 22, 2008, 01:57:36 PM »

Me like this a lot...

Btw, check this site out. They use M42 engine on their Roadsport car. It generates around as N/A 250hp.

http://www.prospeedracing.net/

ose30 · « **Reply #6 on:** August 22, 2008, 03:56:02 PM »

Any idea what ITB's they used?

These ? http://www.specialmotors.fi/lapparungot.htm

kiulu · « **Reply #7 on:** August 22, 2008, 04:04:48 PM »

Quote from: ose30;55312

Any idea what ITB's they used?

These ? http://www.specialmotors.fi/lapparungot.htm

They had those ITB's and I bought them.
Now they use TWM ITB's.

Boyracer · « **Reply #8 on:** August 23, 2008, 01:31:33 PM »

Quote from: Frankie;55309

Btw, check this site out. They use M42 engine on their Roadsport car. It generates around as N/A 250hp.

http://www.prospeedracing.net/

They also perform preparations for M42/M20 engines

I think that team is in Ahvenisto track tomorrow taking part to Historic Grand Race. I'm going there too and with a bit of luck I get to chat with them and ask about details.

kiulu · « **Reply #9 on:** August 23, 2008, 01:38:00 PM »

Quote from: Boyracer;55350

They also perform preparations for M42/M20 engines

I think that team is in Ahvenisto track tomorrow taking part to Historic Grand Race. I'm going there too and with a bit of luck I get to chat with them and ask about details.

They are not at Ahvenisto tomorrow because their engine broke up at Vauhtiajot.
Conrod broked and maked a few holes to the block.
I know the driver/team well.

halcron · « **Reply #10 on:** August 25, 2008, 12:15:17 AM »

Hi! Any idea whats the size of the stock valves for M42 engine? Is it 33 or 35mm?

Also, I am wonder what if we increase the lift instead of using a larger valve? Will that help?

nuvolarossa · « **Reply #11 on:** August 25, 2008, 01:20:40 AM »

Quote from: halcron;55436

Hi! Any idea whats the size of the stock valves for M42 engine? Is it 33 or 35mm?

stock valves are 33mm intake/30,5mm exhaust with 7mm steam in e30, 6mm steam same valve diameter in e36 M42 (only e36 '92 year had 7mm steams) and M44.

ose30 · « **Reply #12 on:** August 25, 2008, 04:06:11 AM »

Quote from: kiulu;55313

They had those ITB's and I bought them.
Now they use TWM ITB's.

I asked some information from the company who manufactures those ITB's. I am interesting to know how's the quality etc. I am looking for a set of ITB's for my other german made project. Any idea how those ITB's work on charged engine's ? Are your ITB's separate body ones? (that's the type i need) That company has not answered so far my questions i asked almost a week ago...

Boyracer · « **Reply #13 on:** August 25, 2008, 04:06:38 AM »

Quote from: halcron;55436

Also, I am wonder what if we increase the lift instead of using a larger valve? Will that help?

That goes without saying, new camshaft will increase lift too. But there is a point where increasing lift does nothing to flow anymore, intake port is flowing as much as it is going to flow anyway.

But when you increase valve diameter you can also increase diameter of intake port. And unlike increasing lift (that only really helps on high lift area), increasing valve size really helps on low lifts.

So in ideal world you should try to increase both lift and valve diameter

halcron · « **Reply #14 on:** August 25, 2008, 08:49:02 AM »

Quote from: Boyracer;55450

That goes without saying, new camshaft will increase lift too. But there is a point where increasing lift does nothing to flow anymore, intake port is flowing as much as it is going to flow anyway.

But when you increase valve diameter you can also increase diameter of intake port. And unlike increasing lift (that only really helps on high lift area), increasing valve size really helps on low lifts.

So in ideal world you should try to increase both lift and valve diameter

Oh IC. Thanks for the explaination.

I am curious about how you are getting 35mm valves for the M42. Cause I remember reading from another thread that M62 valves are 35mm but shorter in length, thus it won't fit.