I have a 392 -with 4000-5000 miles on it -compression is 90-125 Looks like bore needs hone and rings - what do you guys thinks ran a lot of carb on break in-thanks
I tore it down because of the fouled plugs - its runs rich with the carb set -up - I think I washed down the rings on break in
Pig rich. I would have retested the compression after I put a drop of oil in each cylinder. Since you have it apart, might as well hone it and install new rings.
It's hard to tell if the oil was getting by the rings or guides. I guess it's too late to ask if you did a leakdown test
Looking at the cyl pic there is no cross hatch to seat the rings re hone it try some Hastings rings. also the motor has to get up to temp 180 and if you are running weber carbs that could add to if the jetting is wrong and dont forget dist timing.
The scuffing on the cylinder wall is probably because it was so rich, it washed the oil film off the cylinder. You need to get it burning correctly (much leaner mixture) or I think you will be back to the same problems. New rings and a nice cross-hatch pattern to match the ring type would be good before putting back together.
I am running the Webbers have leaned them down since the break - in was never thinking about the temp -the motor runs at 140 most the time I was thinking the same about the hone - would a flex /ball hone do it any thoughts on 1) Grit-180-240-400 2) Rings and gap Thanks guys
How you hone it depends on what you use for rings. crome rings for instance need a more course stone than cast rings. I am going to guess they you washed it down pretty good, common thing to do especially with a multi carb or injection setup. I have been doing this a long time and I still try to fire one and break it in on a stockish setup then switch to the multi or injection setup and start dialing it if at all possible. Maybe I am just paranoid. Perhaps you should take a ball hone to is and then mic it before you decide what parts to throw at it. Make sure your cylinders are going to clean up. Check for round,piston clearance etc. That is what I would do. it may take you an extra day but save you another tear down.
I bought a 400 grit Ball hone and Seal Power rings any comments on this selection - may be too fine ??
Those are just cast rings correct? You should be alright. The fine hone may take a while to get rid of the scuffing but it won't take as much meat out as quickly as a course hone.
The cheap and easy way always comes back and bites you in the butt.I would do it the right way because the cylinders will be tapered.I tried that method on a 350 chev and it lasted a short time and started using oil again.
Man, I would check skirt clearance, looks like a lot of metal transfer to the bore. Were the plugs fouled with as or oil?
Good point - I need to look At that - Plugs fouled with oil which I would think , would make it look very rich also
I question piston to wall but all the scuff is most likely due to too much fuel and too low temp, I believe that piston should be around .005 piston to wall I'd pull it and hone it Good luck! What is up with the rods, welded? Also, run cast rings that "K" at the end of the number indicates ? I used to put a 525 stone on the cylinder finish for a cast ring and a reduced cross hatch to hold the oil on the walls longer. That was a long time ago, maybe some newer info now days .
The K indicates moly rings 34Toddster. I had to do a bit of a search on that one. Those scuffs look pretty deep and I'm not sure that a ball hone will clean them up. I've used ball hones a lot and they work great on smooth cylinder walls during a rering job using cast rings but may not be what you want for those moly rings.
Are those piston skirts knurled or is it just the way they look in the photo? If they are, it could be why they are scuffing your cyl. wall.
I thought either chrome or moly that's ok I'd still hone it in a Sunnen machine or equal. If the skirts have been knurled they may be a bit loose anyway. I think I might look at the guides in the heads too.....see there I go spending money again!
As far as I'm aware , the only reason to knurl piston skirts is to tighten up a loose piston fit. You need to measure close before honing, as even a ball hone will open up the cylinder a bit.
What kind of pistons are those? I don't know about the knurling. You may want to check with the piston manf & find out what their suggested wall clearances are & if it's ok to knurl them. Did you contact your builder yet? Does he have experience on Hemi's?
I've knurled alot for pistons and if any thing it should have helped hold oil on the skirts. The bigest problem with knurling is most shops do it wrong knurling should only be done on the non thrust side.
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