Bill B. or Brian or anyone else - Help A friend has what has a C4 engine with heads that are probably the original installed. Regardless they are stuck on. He we like to avoid removing the timing chest if possible. Tapping and general firm persuasion has not been effective. Out side fabricating a head puller plate(a lot of machine work) are there any tricks or techniques available? Is there a preferred way to fabricate a head puller plate? Thanks, Aaron
You are embarking on what can be one of the toughest jobs in Ferraridom. I just went through that on another motor so what I did in that case is still fresh in my mind. There are lots of different levels of methods depending on just how stuck they are. I'll tell you some of the methods so you can work out what combination to use. Different levels of success are experienced in different cases with different methods but I will tell you now I have and I have seen others have 30 or more man hours to remove one head. So be patient and keep a stock of beer around so you can just walk away and destress yourself once in a while. You should have at your disposal though one of those infared thermometers and a Oxy-acetelyne torch with a rosebud tip. I would be constantly soaking the area around the head studs with WD40 or similar just in the hope it will do some good. When you use the torch to heat the head keep the flame moving to heat it evenly and use the infared to measure your progress. You can get it up to 300 degrees and I have found in many cases that it took 280 or more to get the head to move. Also it help to have a couple of those electric heaters so you can set them in front of the motor for a couple of hours before you start to get the entire motor up to the first 125 degrees or so. It really will save you a lot of time. Often gently prying at whatever point is available that won't do damage to the block or head. The head puller plate is generally made of heavy steel stock 3/8 or 1/2 inch and should be bolted down to quite a few of the 8 mm and 6mm studs protuding from the top of the head to distribute the load over as many as possible. Then holes need to be drilled and tapped for long bolts to extend down to the head studs. Those bolts will be turned down against the studs to "Push" the head off the studs. That should be done with moderation. Also you might find it handy to have a large supply of metal shims about 4x4 to put under the head. Often when you get one end to move and go to the other, the first just rocks back down. With the shims you block the first end up so that it will not do that and you just keep rocking the head up a little at a time. Also I have had success several times with this. When you can detect that the head has moved, no matter how little put a half dozen or so head nuts back on and use them to push the head back down. This will help breakup the corrosion that is holding the head to the studs. Each subsequent upward movement will get easier. Take your time and good luck
Manifold together some spark plugs with no insulator and attach it to an air source. Screw in the plugs and pressurize the system. Make sure the cams are off so the valves are closed. Kermit says he's done that with a few 308 heads with great success. If the piston is 3" in dia, that's ~7sq.in of area on the head x 150 psi = 1060 lbs of force on EACH cylinder top. Multiply times 12 and you've got a lot of force there. Of course, if the head gasket leaks or valves then you'll just get a massive whistling sound!
I was just offering a suggestion, it's that first little bit of movement that is always tough. As I said, Kermit has reported success with this method on 308 heads which are infamous for corrosion around the head studs and being unmovable. Search for "308 Head Removal". There was a long thread that offered many suggestions for removing them. I'm guessing the 12 will be similar as far as getting them unstuck goes.
I don't know if it would work here, but Kroil is the best corrosion dissolver and penetrant I've used by a large margin. Expensive, but worth it, and a little goes a long way. Let it do it's work after squirting it on.
we use AeroKroil at work exclusively . the stuff is majic on dissimilar metals and metals affected by galvanic corrosion. try taking apart a landing gear on a plane based in a salt enviornment. i have used the exact opposite of the spec torque sequence to help remove large components. ferrari heads are famous for bieng a pain.
Just went through this process last week with my GT4.The head removal plate I made up was a little different and easier to use than the one Rifledriver explained but the end result was the same.I used a piece of 12mm plate with 10 studs approx.250mm long of the same diameter as the head studs and welded them to the plate in line with the Head studs.The plate had 4 holes drilled into it witch line up with the spark plug wells.Then I made up 4 studs aproox. 300mm long that had the same thread pattern as the spark plug on one side and another thread pattern on the other side.I Threaded the 4 studs into the spark plug wells and then placed the plate with the 10 studs over the head so that the studs lined up with the head studs and the 4 centre studs lined up with the 4 holes on the plate.Then I threaded the 4 bolts and slowly torqued them up.With in a little while the head came apart.Once I got it about 100mm apart it came of with just my hands pulling up on it.Note prior to this I used alot of wd40 and some acid to try and break down the corrosion.I thought of making the plate as rifledriver described but thought this one was easier to make.Hope this helps as I would think the process would be the same for a 12cyl.I also considered Kermits Idea with compressed air but one of he reasons for the engine rebuild was the valves were leaking so would the air I suppose
V12s are a different animal than the V8s discussed. Before it was Ferrari of Atlanta the dealership in Georgia was called FAF and they used to published a sketch of a cylinder head removal plate in their catalogue. You needed to fabricate two of them and they were simple but effective. Mine were loaned and never returned. i will try to figure out how to get a copy of the drawing posted to this site.
Yes I certinly agree that the compressed air method does not move the head usually more that an 1/8". But it breaks it loose, and that is usually the toughesst part. While I agree that once the gasket seal is broken the "push" tapers off quickly. Consider this: The last motor, a 2 valve had a hellof a hole from a sodium exhaust valve (#5 cylinder, so it was not a straight push)and it broke loose with no effort. The key is to hit it with air pressure fast, that is why I suggested a 3/4" "Ball" or quarter turn valve. I dont take anything away from the plate method, as it has worked for years, bo\ut it is a lot more complex to make, and if one hole is too far off center, the "pushing" bolt will slide off of the top of the stud, with not the kind of results that make ya smile...at all! Once broke loose, the head comes of much easier. HTH Kermit BTW: you can use 4 to 6 spark plugs, and fit damn near any motor, any valve count.
Aaron, Using a flame on aluminum scares me. I have tried to normalize heat-treated aluminum sheet only to wind up with a pile of brittle, crazed aluminum chips. Making a puller is more tedious but the results are much safer. I made two pullers, for my Series II 330 2+2, from ½ steel plate. They are hexagon-shaped, mounted on the studs of two adjacent rocker arm mounts and carry two bolts that push on the exposed ends of two studs. One could get by with just one plate, but two pullers permit a continuous removal process. Two or three lengths of pusher bolts are needed to pull the head completely off. I made mine with a hacksaw, a set of good drill bits and an electric drill (no machine tools). Jonathan Brent (Series I 330 2+2) built two pullers and documented that process on his website, http://www.jb330gt.com/HeadPulling.htm. His puller is more elegant than mine, but also more complicated. I think the same idea can be easily adapted to the C4. Tom
