Hi, So I purchased new steel cylinder liners, 81.5 bore to go with my new JE 10.0:1 pistons. Problem is the liner O.D. looks to be about .002" oversize. Would you recommend turning down the O.D. of the liners , or honing out the spigot I.D.? The original Nikasil liners were what I would call a hand press fit, i.e. light tapping with a plastic mallet would seat them. The steel liners will barely start into the spigots, and when I mic them the O.D. is definitely oversize. Thoughts Thanks Jeff
You are asking for all kind of issues. What engine are we discussing here? 308? You could have a tool and die machine shop cut them to match the originals and see what the bore looks like after you install them but I would think that may be sketchy.
Yes, 3.0 liter QV in an 83 Mondial. Pistons, and I.D. of liners are fine. Just the O.D. of liners are aprox. .002" oversize.
Have the machine shop check the block and fit the sleeves it’s better to have them mate if need each sleeve some might need to be cut others might not what does the specs say about fit Tolerances Sent from my iPhone using FerrariChat.com mobile app
I doubt the bores are so bad as to need the sleeves custom machined to fit. If the sleeves are .002 on the big side, get them cut down. Like I said, a tool and die type shop would be my choice as precision is appsolute on a job like that. Cutting .001 off of a 3+ inch sleeve is a high precision job. Set up will be critical. I have an outstanding lathe and that is not a job I want to do. Not that I can't, but the time and set up would make it expensive. It should be done with a four jaw chuck adjusted to zero runout, (each sleeve would need to be set up this way) and then a tail center with a custom made insert to have it dead centered when you make a cut that is a 1/3 of a human hair. On the plus side, if they slip in easily, (cut a little too much), it is not the end of the world. They are stepped and can be sealed in place. 355 sleeves slide in by hand.
Guys, Thanks for the responses. I believe part of the issue is I cannot find a spec for O.D. of the liners. Any thoughts? Thanks Jeff
The specs for a QV engine hole where the liner goes in are: 93.000 - 93.022 mm at the top and 87.000 - 87. 035 mm at the bottom. For a slip-in fit, the maximum spec for the liner must be 0.001 of an inch less than 87.000 mm. Give that spec to the manufacturer and tell him "your problem, not mine"
Gents, I measured an old, and new liner. I got them from Superformance. Thanks Jeff Image Unavailable, Please Login
Guys, I measured my spigots: averaging 92.85 mm for the top hole, and 86.75mm for the bottom hole. Jeez, now what. Jeff
I'm sorry Jeff is going through this, but I must say that I have ordered a number of things from Superformance for my '77 308 over the years and most of them did not fit on my car even though they said that they would.
OK, it is what is, tomorrow, I will pack up the block, and liners to go to the local machine shop, I am going to ask them to machine the block to allow for a transition (push) fit between the block and liners. Since the liners are in spec. I don't expect much help from Superformance, so just going to get it done. As far as my block goes, since it is under spec, i.e. it never met spec. I guess **** happens. Thanks Jeff
That’s good to know do you use Loctite for a sealer when they are at that point Reason I’m asking I have been in the market for a 348-355 and pretty sure anyone I get will probably need a big service hopefully not sleeves but if they do I’d like to know my options Sent from my iPhone using FerrariChat.com mobile app
Great thanks for that info I know about the valve guides and ready to do them on either car I end up getting but you never what you might find when you take a engine apart Sent from my iPhone using FerrariChat.com mobile app
I have changed a few liners on F355 where the valves burnt out and the owners continued driving on it.
I agree that you need to talk with the guys you bought the parts from. I don't know about these engines. But I do know that in machinery there is such a thing as an interference fit. Is that a possibility in this case?
Most of the parts I've ordered for my engine rebuild required some sort of adjustment. In most cases I cannot say for sure if the supplier was wrong or if there were some manufacturing update on our car. At the end of the day if the additional machinist cost is not outrageous, I just make it do. Bringing back these pistons skirts to spec did cost less than sending them back and forth to the UK. 500€ for the first piston, half an hour (50€) for the remaining 11... Image Unavailable, Please Login I must say, that I had no such issue with Superformance, all their parts have been trouble-free (so far). Their back-order management is frustrating though... At the end of the day we have to bear with our suppliers: if it were not for their hard work, our cars would be stuck in the parking.