Ford Twincam + BMW m10 = hawtness
That's what this thread is about.


This is the project blog on the ford twin cam head mounted to a m10 block. It's not about "what a travesty of bmw heritage to do this".. "I'd never do this because every part that touches my car is NOS bmw tellie bag'd because I'm a purist"

This was started with this thread here.

http://www.bmw2002faq.com/component/option,com_forum/Itemid,50/page,viewtopic/p,426623/highlight,/sid,667bcc8050987ee7eb1a57cf465b6f4d/


There's pictures of headgaskets on the block here





Goals for the project

Head bolted on

Timing Chain Setup Worked Out
crank gear/cam gear/chain

Tensioner functioning

Cams Cut or "re pressed"






So I've been busy the last week or two. Got some progress done last night. Bolted the head to the block. It does bolt on. The smaller head bolts for the 02 will probably need to be replaced. They are the wrong size for the hole in the head. It could easily move. I will probably drill and retap the block later and run some stang arp studs. Probably the easiest.

It looks oh so easy from now but I know it's just the beginning. Let me explain how the cams on the twincam ford are driven. The Exhaust cam has two gears on it. One gear to drive the chain to the crank for crank to cam timing and another gear on it to drive the intake camshaft via a short little chain. The intake cam only has one gear on it and a spacer block to shim a bolt. That gear is for the exhaust cam chain drive. In between the two cams is a hydraulic tensioner. This slides between the top and the bottom of the chain that links the two cams. Once pressurized it pushes out to maintain pressure on the cam linking chain. The cam to crank chain gear is offest out from the head a little far. My initial goal in this is to utilize the mustang tchain, crank gear and cam gear. I feel this is an easier start than the 02 one. As for the crank magically fitting onto a bmw crank. NO luck. It's about 1/2" diameter difference. Right now I'm leaning towards something like a speedy sleve on crack. basically a steel spacer to adapt the two diameters. The mustang chain is also a little long. About 4 links removed will fix it though. The construction of the chain though is just a bunch of links and the pins are just mushroomed on the ends. i don't think shortening the chain will be a big issue. If the chain sits to far out on the tensioner I'll just have to lathe some material off the stang cam gear and put a washer between it and the bolt.

Still lingering out there is the cams. The factory cams are pressed together so I may be able to un press them. rotate and repress them together although I'll be the first to say that's incredibly harder than it sounds. There's alot of pain in that one.

As for the ports and runnners. The ford twin cam head is kind of goofy. Each intake port is different in size and shape. It almost looks like they used a staged injector and cut off one runner below a certain RPM. One port is round and smallish. like 1.4" diameter and has no notch for injectors to spray so it must have been mounted further up. It's dirty on this used head. The valve is covered in carbon and looks like 50k miles of crud. The second port for the other intake valve is square, large CSA, and has a notch for an injector to spray. This port looks "as cast" new. I bet these ports generate a bitchen amount of tumble and swirl.
Just by looking at the head I can tell that a little bit of lift will easily carry this thing upto high RPM life. In comparison. My SR20det head ports are maybe 30% smaller.

Modular pistons. Well the forged mahle motorsports pistons arrived last week. They weigh in at 365 grams for a flat top. It's hard to find a partial skirt strutted piston with that kind of love for as cheap. With that light weight you could easily rev much higher on the same con rod. Realistically I'm hoping for a 8k RPM stable 02 with a nice idle. Hopefully I can wiggle this into some autox class and pwn everyone.