Hi everyone, Working on my 206 Dino 2-liter 135B000 engine, I'm stuck. I've ordered from Superformance quite a batch of new parts (crankshaft, bearings, pistons, liners, con-rods) - everything nominal, and now the machine shop got confused. On top of that we cannot find the information anywhere. The new liners has interference fit with the block of around 0,04” (0,1mm), which in the shop opinion is way to much, even for wet liners without the seal rings. I would really appreciate if someone will share the information: 1) What should be the interference fit (or outside diameter) of stock liner? In short - how much bigger the diameter of the liner should be than the hole in the block? 2) As it's no seal ring liner, what should be the fit procedure? Heating the block and freezing the liner? 3) The liner should be mounted with zero protrusion (so no sticking out of the block), or there should be some value? 4) Maybe someone could share the mounting procedure? Thanks in advance, because we are blind here.
The earliest manual I have is for a 2V 308 GT4. it states: "Liner protrusion from the gasket face, without seal ring A, must be between mm. 0,01 ± 0.05 and it should be equal for all liners of each cylinder file and near 0,03. Use gauge 542-CS-6768 for this checking" This manual does not state how liners are inserted into block.
.1mm = .0039 inches, or rounded to .004 inches. That's much smaller than the .04 inches you post. Regardless, I'd also say that .004" is quite a bit of interference that will result in the wall collapsing. Here is the WSM: http://www.dinospider.com/dino_manual/dino_2_4_Ferrari_manual_complete.pdf EDIT: just noticed you said 206 Dino and not 246
If all else fails, buy and read (factory issued) shop manual. Honestly, why would anyone even start a job like this without one on hand ? Copies should be readily available.
The liners need to protrude above the surface of the cylinder. The need to contact the fire ring on the head gasket in order to provide a good seal. Too much protrusion will cause the gasket not to crush enough and it will not seal around the coolant/oil passages. It all depends on the type/manufacturer of head gasket. The interference fit on the liners has a great deal to do with what they are made from,as the coeficient of expansion of the liners has a large impact on this value. Someone with experience building these motors with the head gaskets that are presently available will know how much interference fit and protrusion you will need. But that comes with time and experience, so getting that information may require that they build the engine. What does Superformance and the manufacturer of the liners recommend? How much experience does the machine shop have with Dino motors?
You also need to talk to Dave Helms at Scuderia Rampante in Eire Colorado. Dave has got his new Head gaskets for these cars, as well as all the Carb Ferrari's up and in production, that finally fixes the leaking head gasket saga. He has had excellent results.
Thanks for the hints. I've been in touch with Dave Helms, as well as with Superformance. It seems that the situation is a mystery. Dave suggest, that they are press-fit liners with the fit interference between 0,0020" - 0,0025". The workshop manual doesn't says anything about liners replacement, so we cannot base on anything here. Superformans sub-supplier says it should be 0,0015" press-fit with a sealant. Well... hmm...
The difference between .0015 and .002 is minimal. Temperature change can make the difference. What type of sealant go they recommend?
.002 is just right. Any more and they will be very difficult to install. I'm not totally against hitting the outside of the liners with a very light sandpaper, say 1000-1500, wet sanded to meet spec. I would not think removing that additional .0015-.002 too difficult.
This is Wade Williams. In my experience, on that style block, .0015-.0020 is the proper press for the sleeves. Finishing the bore after the sleeves are in will the issue. The main web is so close to the sleeve bottom, it is very hard to hone the bottom of the hole without making the middle too big. As for the sealing part, I use a liquid type silicone sealer that has a pretty long set up time. This allows you to get the sleeves in and set before the silicone cures. I do all my own machine work and I am happy to help you if I can.
repec range is: .07 to .11 MM with the ideal being .09 MM this is done AFTER the deck has been reground using the center line of the crankshaft as your god reference position The squaring of the block is then 30 degrees off of the vertical mid-line-which means you need a precision grinding apparatus I use an 856 Kwik-Way with custom center-less ground, size for size housing bore bars to mount the block into machine. The squaring is done with Swiss precision instrumentation (Etalon), or Mahr (German) This dimension is found in all wet liner Ferraris from the early 1950s to the late 1980s.....(been doing machineshop repairs on these since the 1970s, so this isnt my first rodeo) The REAL problems are sealing in the headgaskets.... good luck there....