Engine block boring: Special or no big deal?

Discussion in 'Technical Q&A' started by Horsefly, Apr 22, 2004.

  1. Horsefly

    Horsefly F1 Veteran

    May 14, 2002
    I was wondering if the boring, honing, and general block prepartion of a 308 V8 or an older V12 is something that any decent(!) engine rebuilding shop could handle? A cylinder bore is a cylinder bore whether it's inside a Chevy iron cylinder block, a Chevy aluminum block, or a Ferrari aluminum block. Most engine shops have the proper cylinder boring, align boring, etc, equipment to rebuild most any modern internal combustion engine. Is there anything "special" in a Ferrari engine block that would prevent a competant(!) engine shop with knowledgeable personel from rebuilding, or at least prepping, a Ferrari motor? If somebody were to tear down the engine themselves, deliver the block to an engine shop, provide the shop with the required bore specs, couldn't they prep the block for essentially the same cost as any other V8? Or 50% more for a V12 block? Or course we're assuming that the shop in question knows what their doing. I know of several local shops that do excellent rebuilds on Chevy, Ford, etc, engines for racing and restoration. Couldn't they handle a simple Ferrari block bore and prep? And of course it would probably be best to deliver the new pistons with the block for proper fit.
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  3. pma1010

    pma1010 F1 Rookie

    Jul 21, 2002
    Full Name:
    Some of the V8s and maybe some of the 12s have Nikasil liners which I do not believe you can bore out, you'd have to re-liner.

    On your general point, I think the answer is "it depends". For me, it would depend on competance of the shop. Some one like David Bean Engineering would be well qualified (they build all John Weinberger's racing engines, focused mainly on Lotuses, but I think they could do it) as would John H's hope in Indiana or Wayne Obrey's shop in Neenah, WI.

  4. mk e

    mk e F1 World Champ

    Oct 31, 2003
    The twilight zone
    Full Name:
    The Butcher
    Sure they can be bored by any good shop, as long as it has iron liners like the 2v 308s. The QV and later are nikasil liners, they can be replated and just drop in.
  5. tbakowsky

    tbakowsky F1 World Champ
    Professional Ferrari Technician Consultant

    Sep 18, 2002
    The Cold North
    Full Name:
    Must be sure the have the propper deck plates aswell so they can simulate the head as it would be torqued down on the engine. This is a very important step to insure the accuracy of the bore job. Engines like the 308 have cast iron cylinder liners. These liners can be bought or custom made for cheap. More then likely the best way to go would be to replace the liners with standard sizes thus you don't have to replace pistons, and everything will be back to stanard sizes.
  6. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    Make sure shop has correct Ferrari line bore tools. This cannot be faked IMO. The only one I have ever seen is at scuderia ramparte in bolder colorado. Search the FC members under Dave Helms 303-938-9000. Tell him you were sent by the IMSA 348 admireer and maybe you can send your block to him.
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  8. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    Also check with Joe san paolo @ concours auto. 562-697-4188 La Habra , Ca. He may have the correct tools too. He builds really hot race Ferrari motors.
  9. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    As far as boring is concerned, you can just remove the old cylinder liner and insert a new liner. The Ferrari block is not like an american block where the liners are cast into the block with the rest of the material. If you want to bore the liners while in the block, you need a special tool that holds the liners in place while the cyliner bore does its job. This tool will look like a torque plate for an american engine but sized for the Ferrari block.

    As far as line boring is concenned, you just need the bore of the correct diameter.

    It has been said that any 'competent' machinest can turn a cyclinder liner, however, you end up working with very small tolerances, and the cost to buy these liners is not as great as the cost to have one turned out. For the F355, the interior bore dimensions are NOT the same throughout the bore, but taper towards smaller clearances towards the top of the liner.

    Don't forget to replace the valve guides and check the valve seats during the rebuild.

    As to the V12, make sure the shop has the ability to deal with the 60 degree bank angle as most are setup for 90 degree only.
  10. Fiat Dino 206

    Fiat Dino 206 Karting

    Apr 19, 2004
    Full Name:
    Most competent shops can probably do most anything on a Ferrari engine if they have the proper equipment and specifications ... most shops don't care to buy specialty tools for a single job. Align boring bars of the correct dimension for the cam saddles and crank come from Ferrari and are probably not inexpensive for a single job.

    Many areas don't have a sufficent concentration of any one model of Ferrari to justify a machine shop spending the time and money in anticipation of having an Independent Technician send them a job.

    The liability of scewing up a Ferrari is somewhat greater than screwing up a Chevrolet which discourages some shops from taking on machine work on Ferrai engines.

    I speak from experience. I had a need for head work on a Dino (Fiat) 206 engine. Within one-half mile of my house is a small machine shop that does custom work building parts for racing cars and motorcycles ... he wouldn't touch my engine. He could have done it the needed work in his sleep, but didn't want to run the risk.

    Best wishes
  11. Matt Morgan, "Kermit"

    Matt Morgan, "Kermit" Formula Junior

    Nov 12, 2003
    Ferndale, WA
    It all depends on how good of a total motor you want. Personally I prefer to do it the following way: Bolt on a deck plate, with a good used gasket in place. Make sure to follow the correct torque pattern, etc. I use a 1" thick custom made 4130 (chrome moly, for strength) deck plate that is surface ground for true flat. This immitates the condition that the cylinder will be in in actual use. It is not uncommon for there to be slight out of roundness after bolting the deck plate on. Piston ring seal will be greatly improved with this done. Secondly, make sure the shop you use has the type of equipment that locates the block by the crank journals. This assures that the piston will run true with the crank. Liner finish is the next area of importance. I prefer what is called a "Plateau" finish. This is done by honing to within the last .0005", then finished with a 500 or 600 grit stone to produce a very smooth surface, with a hint of the coarser stones marks still visible, as they help maintain oil film. Bear in mind that the area of the most friction in any motor will be the pistons movement. Takeing the time on that area will reduce parasitic losses, and the result is more useable powerout of the same amount of fuel/air. A bonus is, this method results in a very short break in time needed, and a better ring seal for the life of the motor.
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  13. Peter

    Peter F1 Veteran
    Rossa Subscribed Owner

    Dec 21, 2000
    B.C., Canada
    Matt (and anyone else for that matter), have you ever used Flex-Hones (carbide balls at the ends of long, plastic fingers) for honing? Its claimed (I've got no experience with this product) to provide a better surface, knocking off the sharp ripped edges, flattening the surface while keeping the ridges for oil retention.

    I'm surprised that you are using such a fine finish on bores, I thought the norm was really no greater than 220 (for iron rings, coarser [180 or less] for harder moly/chrome rings)? Or am I mistaken?...
  14. Matt Morgan, "Kermit"

    Matt Morgan, "Kermit" Formula Junior

    Nov 12, 2003
    Ferndale, WA
    Peter, That is part of a popular misconception. First off the "ball type" is convienent, but it does not adress and deviance from straight walls, as straight stones do.
    Todays technology in piston rings has come a long way since the old days, where coarser cross hatch patterns were necessary to wear them to each other. The down side of coarser stones is multiple: Liner wear as they break in, particulate matter floating in the oil as a result of the parts "mateing". And finally ring end gap, as it increases with the break in, thus encourageing blowby.
  15. Smiles

    Smiles Moderator
    Moderator Owner

    Nov 20, 2003
    Pittsburgh, PA
    Full Name:
    Matt F
    A really good machine shop can do ANYTHING.

  16. Peter

    Peter F1 Veteran
    Rossa Subscribed Owner

    Dec 21, 2000
    B.C., Canada
    Great points, thanks dude.

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