Another M20 Storker - I'll call it 3.1L+

[Justin B]

Oh I forgot. I got my crank and ARP rod bolts in yesterday from the UPS guy. ARP doesn't make bolts specifically for the S50 application, but I read that the kit for the LS1 fits. They're 3mm too long, but the threading is .8" IIRC so there's still full thread engagement.

After I got home from work I took off the tranny, clutch and flywheel then mounted it up on another engine stand.

Here's how they sit right now. Ignore the messy garage :P

[PiercedE30]

Do NOT buy a Spec clutch. I just recently had my Spec St. 3 pressure plate blow up and put nearly a dozen cracks in my transmission bellhousing and a hole the size of the end of a pencil. Just a warning.

[Justin B]

OOh, that's ugly. Thanks for that. I'm still going to try the stock one, they can hold about 200 hp, and that's about what I'll have but in a much lighter car too. It also won't be nearly as much of a problem to swap out as on an e30 from the 02, only the essentials are there, especially no stupid heat shields etc to get in the way of getting at everything.

[golde30]

dude, im running the stock 200K miles diff on my s50 swap, and i drive the piss outa my car. hasnt failed me yet...

[StereoInstaller1]

Storker?

[golde30]

^^^haha, i didnt even notice that. but i am sorta dislexic, so this makes sense.

[Justin B]

lol. I didn't either. Oh well!

[nando]

some thoughts:

the stock clutch is probably fine. But I'd consider a sachs 618 PP - it ups the capacity of the stock disk to 330ft/lbs and is still streetable. I have the sachs sport clutch and 618pp, it takes 6k awd clutch drops and I also daily it - it's "grabby" but still smooth; it's still a sprung hub.

I disagree with jim on the cam (I've had the same ~1hr long conversations with him as you've had, haha), but it really depends on what you're after. you wouldn't have a hard time idling with a 288 - but schrick cams aren't as agressive as they look on paper. but if you want the rally cam, that's just fine. :)

valves - I agree with jim that oversized valves aren't neccesary. are you sending your head to them? I would highly reccomend having them back cut - this WILL increase flow. Jim does something similar to their valves, he has a special step cut they use, but it's basically the same idea. a nice side effect is the valves end up a little lighter.

porting - avoid much porting to the intake. I would focus on smoothing the bowl with a dull finish on the walls. you can go a little more on the exhaust, but leave a step from the exit of the port into the header, 1-2mm should be enough. polish the exhaust with a mirror finish, I would also polish the combustion chamber, and deburr the piston crowns (especially the deep valve pockets).

what version of MS are you going to use? you can break the motor in on motronic, it will run okay (i'd reccomend a stock chip), but you'll be missing out on good power until you switch to standalone.

[nando]

whats a good aftermarket clutch to use? I am doing a similar stroker right now.. 3.1L with high flow head, 272 cam.... etc. I was going to use my stock clutch because I heard it would hold up.... but I would rather be safe with a beefier setup in there.

you aren't going to be happy with a 272 cam on a motor that big; although it will have truck like torque it's going to peter out after ~6000rpm. of course if you want truck like torque... :p

[Justin B]

Nando, we'll see about the cam, I could always just buy a schrick and sell this one if I want. The schrick actually has a little bit less lift overall so the pistons still should clear at any point. At this point I dont plan on sending them my head, I'm going to have machine work done around here then do the major assembly myself. If I want more flow I may have that all done at a later point, but I can at least know that there's still a little bit left to have and the motor isn't just 'done' with tweaks. ITB's will help a lot too.

The megasquirt version I have is MSII/Extra on the V3 board IIRC. I cant use motronic to break it in since I will have a different ignition set up getting rid of the distributor and even though I could keep it, I'm machining down the harmonic balancer, pressing on a 36-1 wheel, and rebalancing it. That makes the engine rotating mass a little lower too.

I'll may do the light port/polish myself too, depending on how much the shop would want to have that done.

[Justin B]

dude, im running the stock 200K miles diff on my s50 swap, and i drive the piss outa my car. hasnt failed me yet...

I'm talking about my 2002 Cary. This motor I'm building is going in the deuce. They have TINY diffs. That break, and very easily under a lot of power. I'll have a moderate amount.

[nando]

Nando, we'll see about the cam, I could always just buy a schrick and sell this one if I want. The schrick actually has a little bit less lift overall so the pistons still should clear at any point. At this point I dont plan on sending them my head, I'm going to have machine work done around here then do the major assembly myself. If I want more flow I may have that all done at a later point, but I can at least know that there's still a little bit left to have and the motor isn't just 'done' with tweaks. ITB's will help a lot too.

The megasquirt version I have is MSII/Extra on the V3 board IIRC. I cant use motronic to break it in since I will have a different ignition set up getting rid of the distributor and even though I could keep it, I'm machining down the harmonic balancer, pressing on a 36-1 wheel, and rebalancing it. That makes the engine rotating mass a little lower too.

I'll may do the light port/polish myself too, depending on how much the shop would want to have that done.

why would you downgrade from a 60-2 wheel to the 36-1? the 60-2 wheel has nearly twice the resolution, which means more accurate timing and fueling. if you're going to run EDIS, I can sort of understand, but it's just as easy to run wasted spark with the stock toothed wheel.

I would at least back cut the valves -shouldn't cost too much, and there's a good flow increase. a stock head with ITBs might not be so fun. :p

[Justin B]

I never really had thought about the resolution, but I was thinking aboutusing EDIS. Or at least having the MS control the coil packs without the EDIS brain (I think) and using wasted spark, and never thought of keeping the 60-2. I suppose I may. Perhaps if I get my flywheel resurfaced, which I really should, I could ask them if they could lighten the front harmonic balancer by a lot if I decide to use the original wheel...

You think any competent machine shop that can do head work will be able to back cut the valves properly? What area exactly would they cut and how far back anyway? I never really considered having a 100% stock head as far as ports and flow is concerned.

[Justin B]

Oh and by the way, I got my S50 rods in the mail today! Woot.

That's the good news.

The bad news is that the head bolts that I bought from Summit that I read somewhere from someone who is on this site as well (dont care to name names, it was just the wrong part and they were told it would work from someone at ARP), that would work on the S50 rods actually do not work, the thread pitch is WAY finer than the S50 rod bolts. Same diameter it seemed like, and just like it said 3mm longer, but the entirely wrong thread pitch. If anybody wants a brand new set of LS1 rod bolts lemme know, or I'll just send them back to summit or maybe sell them later.

[nando]

yeah, any shop can do it. just what I found on a quick google search:

http://www.chicagolandmopar.com/techtips/backcutvalves.asp

wish I had known about it when I built my head. next time maybe?

I would seriously consider using the 60-2 wheel. few people do EDIS with these days, it was more popular back when it was a fuel only solution or before it supported more than 1 coil driver. technically you can do 6 with MS2/e, but there's no real benefit there. :p