M103 Crankshaft

[Don M]

Does anyone know if the M103 crankshaft is forged?? I dont have one to look at or I would not ask.

Finally, if it is forged, is it a twisted forging? I do know the journals are induction hardened.

I want/need a strong crank for this project Im starting. Since I am going to have rods made I want to see if the crank is going to be forced into the budget as well.

Anyone with crankshaft knowledge, please post. Alloy specs, etc. I suppose I could chem check the alloy, but would like to have any knowledge available.

Anything.

Thanks in advance,

Don~

[t walgamuth]

i would think forged, yes. i don't have the specs here though.

tom w

[Don M]

Anything you find out and add would certainly be appreciated.

[300EVIL]

No, the stock crank isn't forged, the rods are though. Like you said, it is induction hardened and is plenty strong. How much power are you looking to make? Be prepaired to spend big bucks on a custom crank. I just polished, balanced and cryo treated mine.

[Don M]

Originally Posted by 300EVIL

No, the stock crank isn't forged, the rods are though. Like you said, it is induction hardened and is plenty strong. How much power are you looking to make? Be prepaired to spend big bucks on a custom crank. I just polished, balanced and cryo treated mine.

My goal is 700 rear wheel HP measured on a DynoJet. A cast crank is a bad idea, IMO. Dang it.

[300EVIL]

That means you need to make over 800HP at the crank. What's your application? You may just want to pick a different engine if your looking for street use.

[Don M]

Very limited use. I want to go the Texas Mile with the car.

I know I can have a crank made, but that is expensive. I wonder if more than one person might be interested in getting a crank made up and share the cost??

More info on the texasmile is here:

http://www.texasmile.com/EventRulesAuto.asp

[300EVIL]

My guess is around $3K a piece for a billet crank even with a group buy. PUMPISH, is going for 800+HP on a stock crank. You may want to check with him and see if he's done yet. A few years ago I may have been interested but I have spent way too much money on this project already and still have a long way to go.

[AustinsCE]

3-3.5K sounds about where I had them last I was looking. The best place I found mostly had chevys and I'm going to guess they're a bit shorter, so I approximated more like 4.

[Don M]

Yes, Winberg seems to charge about 3500 for a Hemi stroker crank. I bet a 1 off type thing for a M103 will be very expensive. Im having "shoppers shock" as I type.

The bean counters never liked me.........


I am very interested in your project and want to absorb anything you do on the Megasquirt set up. I planned on the same system to replace the CIS-E. LOL

On valvetrain and camshaft I can add knowledge, grinding, and even cores to experiment with. I know we could add some ponnies with a good profile but it would take a ton of testing to dial one in.

[300EVIL]

Sure thing, I'd be glad to share info on the Megasquirt. I was totally unimpressed with the Megasquirt I but the new Megasquirt II has a lot of potential. I also have my Ford EDIS parts all ready to go except for the 36-1 tooth trigger wheel. I found a guy that's going to make some for me. If anyone is interested in running EDIS on the M103; Let me know and we can get a group buy on some trigger wheels and VR mounts. Like under $100.

[300EVIL]

This is what I had done to my cam. For both intake and exhaust, I had the duration droped to 250 degrees from the original 262. I had the lift increased from .275 to .295. I also added .020 to my valve stems to compensate for the grind and keep the geometry neutral. What do you think of that profile?

I am also interested in getting some stiffer springs and titanium retainers made. I want to redline safely at around 8 grand with 20 PSI max boost. I purchased some Shrick valve springs thinking they had more seat pressure. Unfortunately that was not the case. If I remember correctly the stock spring is almost 300 LBS open which is not bad but could be at 8K RPM with boost pressure. Then again the titanium retainers will help a lot with the possiblity of float.

[Don M]

If I need that trigger wheel or tone ring thingy to run the MegaSquirt. I am in for a group buy on those. Sign me up.

Typically a turbo cam is split duration. Not always though. Longer open times on the exhaust side is the norm. A wider LSA ( lobe sep angle ) is almost always needed to avoid exhaust back pressure from making its way back into the chamber after the piston pushes out what it can.

I like the idea of a short intake on a turbo engine! This helps keeps the LSA wider with what cam core you have to work with. I dnt know how much meat is on a M103 stick, but there is a pile of them down at the grinders shop and will look at them in the coming weeks.

Do you have the opening and closing points of the profile in degrees @ say .050"?

I think you went the right direction with less on the intake. Maybe keeping the Ex side longer might better. Testing is the only way to know for certain.

Once you pack in 20 PSi of stoich fuel and air, you will have a large amount of yukkies to get rid of on the blow down side.

[300EVIL]

You can run Megasquirt off fo the stock trigger on the flywheel but a 36-1 tooth wheel on the balancer will offer far more accurate injection timing. More importantly, this will allow you to run Fords distributorless ignition system, EDIS. I picked up all the parts I needed at a junkyard from a ford suv for $30. Well worth dumping the distributor to me.

As for the cam, yes, opening and closing points at .050. Yeah, I think your right about the exhaust profile a little more duration to get the extra volume out would be better.
Cams are a real rocket science for me but I'm learning. I'm willing to spend the time and money on used cams when I'm up and running to find the perfect profile. I'm sure we could get something close enough with three or four trys.

[Alan Cottrill]

What kind of signal does the stock trigger produce?

Thanks,
AL