M42 stroker build begins

[i8ur911]

Color is an attempt at Lime Rock Fire Orange on the e92 Lime Rock M3. Looks pretty badass. Definitely need a kicking motor to go with it now though.

Dropped the Dbilas idea as they have really sucked to deal with

[i8ur911]

Flywheel is in hand. Lightened, resurfaced and balanced to clutch kit. Cost me about $400. Sounds like a lot, but the workmanship is second to none. Will post pics ASAP. Dbilas is also back in the game. Finally got back to me with good news and a better deal. Things are finally coming together.

[mabeer]

Sounds great!  Did you get your head back? I'm waiting on mine still .  Hopefully some updates soon.  Sorry to jump in on your thread, our concurrent builds make me feel a sort of kinship.  I look forward to your updates, gives me some motivation.

[wazzu70]

I look forward to both your updates. Give me motivation to finally get my car finished and running! My engine is not nearly as cool though.

[i8ur911]

Head should :fingers crossed: be in my hands in the next few weeks. I can't wait to get this thing together, but have a feeling it won't be finished/installed until first part of next year

I'll keep updating as there are changes. I'll also post a pic of the flywheel

[i8ur911]

M20 "lightweight flywheel" completed today. First impression......disappointment. Everyone says this is a "must do" on M42 cars, so maybe my expectations were sky high. I notice VERY LITTLE difference. Now I've only driven the car 40 miles, but I just thought the engine would rev up quicker. We'll see if my opinion changes as time goes, but right now I wish I invested the money elsewhere

[318is91turbo]

i had been curious about this. glad i didnt do it haha. im sure you have better clutch holding power tho. where exactly does your engine stand? just lightweight flywheel now?

[Slowered318]

M20 "lightweight flywheel" completed today. First impression......disappointment. Everyone says this is a "must do" on M42 cars, so maybe my expectations were sky high. I notice VERY LITTLE difference. Now I've only driven the car 40 miles, but I just thought the engine would rev up quicker. We'll see if my opinion changes as time goes, but right now I wish I invested the money elsewhere

I did a similar flywheel conversion and shaved a few pounds off my drivetrain. I will agree it's not a significant difference, unlike swapping for a lightweight wheel/tire package for example. On the downside running the A/C might give you trouble and you end up with excess gear box noise (I have to hold the clutch in at drive through windows), on the upside the car doesn't coast like a Lincoln Town Car and shifting gears is a little more predictable. I think it's important to swap for an electric fan if you are installing a lightweight flywheel to get the optimal effect. This is somewhat theory but the RPM will drop a lot faster between shifts with the lighter flywheel, if your fan clutch is engaged then the RPM will occasionally drop even faster. By removing the drag on the front and back of the engine it should be more responsive to throttle input and more precise when shifting gears.

All thing considered, I wouldn't suggest a flywheel conversion unless you absolutely need to replace one or more of the clutch components.

[bmwman91]

You guys went from a stock M42 clutch/FW to a lightened M20 setup and did NOT notice a difference?! I must be sensitive or something lol. I noticed a big difference in peppiness (as well as obnoxious tranny rattle at idle and while engine braking particularly in 5th gear).

[wazzu70]

You guys went from a stock M42 clutch/FW to a lightened M20 setup and did NOT notice a difference?! I must be sensitive or something lol. I noticed a big difference in peppiness (as well as obnoxious tranny rattle at idle and while engine braking particularly in 5th gear).

No, I think the other guys are crazy I definitely noticed a huge difference in revs with a little throttle blip. Heel-toe is much easier, ect.

When you just stomp on the pedal you won't feel much difference, but actually driving the car you will notice a huge difference during gear changes.

[i8ur911]

Didn't drive the car today. Oddly after conversion, my windows and mirrors don't work? Someone mentioned something about the different M20 starter?

I finally ponied up today and ordered my Dbilas kit! I'm running Alpha-N as well because I want to run the itb's "open". Can't wait for these to get here. I know these will help give me the snappy throttle response I'm looking for.

The head should be done in another week or 2. With ordering the Dbilas kit I'm going to hold off on the bottom end until this time next year. I'll install the refreshed head, Cat cams, Supertech springs, lightweight lifters, 19lb injectors and itb's first. Once tuned it should add a nice punch. One of the guys i work with is very familiar with Alpha-N too. Can't wait to start taking some photos of progress

[MLM]

It will be intersesing to see how much the stock pistone need pocketing for the new cams (assuming your keeping the stock piston) It looks like an extra 2mm based on the cam spec.

[wazzu70]

Im jealous of your Dbilas!

I think the cams are made for factory pistons. Of course, always measure before starting the engine!!

[Jmorganix]

You guys went from a stock M42 clutch/FW to a lightened M20 setup and did NOT notice a difference?! I must be sensitive or something lol. I noticed a big difference in peppiness (as well as obnoxious tranny rattle at idle and while engine braking particularly in 5th gear).

When I did my M42 hot rod, I used a flywheel from a 2002 tii (and clutch) lightened it further and cut it down to accept the M42 ring gear.  I needed to use the "323" throw out bearing.

WOW what a difference.  In fact it was so light (and tough) that the car wanted to die most times when coming down to idle on its own.

WHICH M20 flywheel do you use in your concept?  Clutch?  Bearing?

Jenn

[i8ur911]

Im jealous of your Dbilas!

I think the cams are made for factory pistons. Of course, always measure before starting the engine!!

You are correct sir. No additional pocketing necessary. Already confirmed with machine shop too