m42 build up...

[small_m]

I just wanted to share one of my current projects. I am building up an m42 for a friend. Its going in an e30 but I figured that as I have a ti and most ti's have an m42 then I'd share my pics and progress.
The motor is going to go in a track car, but also driveable on the street. The specs are as follows

-87mm (3mm over) 11:1 compression, JE pistons (custom made to my specs)
-ARP head, main studs and ARP rod bolts
-Cometics MLS headgasket, also custom to 87mm
-6mm m42 valves and guides (7mm right now) to reduce weight
-MM sport intake cam
-MM beehive valve springs and retainers

here are some pics of where I am at right now. Everything has had its first clean and I am trying to get rid of all the old oil tarnish with my soda blaster.

-Pistons



-block is ready to go to the machine shop, mains are torqued and I will be getting a torque plate made up.

[small_m]

-rods are clean and torqued ready to get the small end honed out for the new wrist pin


-cylinder head has had first clean up and is about ready for the new valves and springs to arrive.



-notice how bad the seats are pitted!!! valve job is needed!


and my messy garage with too many engines apart!!!

[ChItalian1027]

Looks good, are you going to turbo it sometime in the future?

[small_m]

I dont think my friend has plans for that. Also with 11:1 compression its not very FI friendly. Although i could always fit a fat headgasket.

[small_m]

I also want everyone to know I build engines as a side job so if anyone is interested in getting any work done please let me know. I used to build indy and nascar motors from 2004-2007

[xxxJohnBoyxxx]

Thumbs up on the crank, I have always stroked my motors and they do show good results. That sure doesn't look like you are putting any boost to that motor, just a mean torque 3,000-5,252 and good HP from 5,252-7,500+. I sure would love to see some rods in there for 8,200 but a few rpm won't matter.

Best, John Smith

[ChItalian1027]

Do you know what timing your going to run it at?

[small_m]

This will not be a stroker motor. Just a 3mm over on the bore size.
When you ask about timing as you asking about cam timing or ignition?

[xxxJohnBoyxxx]

Originally Posted by small_m

This will not be a stroker motor. Just a 3mm over on the bore size.
When you ask about timing as you asking about cam timing or ignition?

Ah stupid me. I didn't think about it. The 87mm is for the 2400 - 6? I need to read better before typing BS. I think I have a 88mm in my I-4 which is the stroker. Sorry about that, I hate giving bad information

[dave45056]

I just love M42 engines. They look like an engineering marvel. I like what you are doing, but be careful with the Cometic Gasket. I had one and it failed after a year-ish. I used standard head bolts using the standard tightening procedure (torque-twist-twist). The area which wore out was in the the area between the cylinders. At 87mm bore, that section will be even smaller. My replacement HG was a stock one. It has worked perfectly. I'm not sure if you have any other options for a custom HG, but I thought I'd let you know my experience.

Edit: Here is a link with pics:
http://www.318ti.org/forum/showthread.php?t=22701

[ChItalian1027]

Originally Posted by small_m

This will not be a stroker motor. Just a 3mm over on the bore size.
When you ask about timing as you asking about cam timing or ignition?

Sorry for not being so descriptive. I meant both cam and ignition timings

[pdxmotorhead]

Amazing resemblance to a little Cosworth.... BDA

Dave

[small_m]

Originally Posted by pdxmotorhead

Amazing resemblance to a little Cosworth.... BDA

Dave

If you check the little engine closest to camera with the red block. That is an old 65' cosworth MAE (1.0l 4 cyl with 3 main journals lol). It went in a Ginetta G4 that we took to the land speed runs at the salt flats. After a mis shift at13000rpm it broke the flat tappets off into the block . So round 2 will be built soon.

Anyways. I got the block back from being bored and honed 3mm over. The deck was 0.002 out so I had it cut. I ground all the rust off till the block looked polished. Its now painted and just needs a final clean when the paint is set.
I have all the MM stuff now. The retainers are cool looking and alot smaller than the stock stuff. I should have the head done soon with the new 6mm valve guides installed. I was very surprised to see that MM does not supply a cam spec sheet. I had called them to ask what the cam should be degreed at. They told me to just use the stock cam locking tool. This being a "race" motor I really dont like that approch. It should be listed so that it can be set exactly at say "106deg atdc at max lift" or so on.
I will take some pics and update it when I get a second.
Lee

[small_m]

Measuring installed heights to calculate the shim needed for the valve spring. I installed the spring at 70lbs compression and 180lbs at full lift.

This is the shim I made to help figure out my installed heights

Block is bored and honed for the nice shiney JE pistons

Ring cut and installed.

MM valvetrain is all laid out and clean ready to install

[small_m]

bottom end is in and together. ARP main, head and rod bolts/ stud

Exhaust valvetrain is in, intakes are next

Crank is installed with the ARP studs