PaintedRat
NOTE: For those using this for search info, the Egge 343 pistons are listed on their site under Rambler, and are slightly shorter than listed. These will provide CR over 10, but quench isn't perfect, read for details.
I tried install my pistons into my block today. The bore is fine, and the rings fit. The counterweights on the 360 crank contact the piston skirts at the bottom of the stroke. What do I do now?
I'm thinking the easiest would be to have the counterweights taken down, then rebalanced, but I don't know if you can do that. One suggestion was to machine the pistons, but that sounds like it would take more effort and money.
jeepsr4ever
This is common when your fitting a custom set of pistons. You will need to cut the skirts either grind them or mill them doesnt matter.
PaintedRat
Is this something I can do with a dremel and file or should it go to a shop? How much clearance do I need? Can it be done on the rods, and should I remove the rings (both for the purpose of not trapping debris in bad places)? During removal/reinstall of rings, I'm afraid I'll break another ring and have to order new ones.
jeepsr4ever
at least .035 of relief...you can use a dremel. How bad is it?
PaintedRat
It is solid contact, but at the very bottom of the stroke. I think a hair off and it will pass. I will try to do this today on the first piston and see if I have any trouble.
Oh, and I see a lot of orange/red, blue, and black blocks, so I thought the green shown above would be a fun color for my first engine build.
jeepsr4ever
Sweet looks like AMX Big Bad Green :t:
AMX69PHATTY
Interesting.
I have a stock 343 4V piston sitting here beside
a TRW replacement cast 360 piston.
On the TRW 360 piston, the part of the skirt that goes
from the side of narrow part farthest down on the skirt 90* from the pin
to the cresent shaped flat surface 90* away, below the pin
is what differs from the stock 343 piston.
On the 360 piston this area comes down almost flush with the cresnt shaped flat.
Looks like on each 343 Piston, in ( 4 ) places, you would need to blend / grind this area
so the skirt transition from the 2 skirt "tips" becomes almost, but not quite,
flush to the cresent shaped flat area above the pin.
May I ask if you have 360 pistons to sit besdie and compare to the 343's ?
PaintedRat
I had the machine shop chuck the 360 pistons after they were removed from the rods, so no side by side comparison. I'll try to get a pic of the 343. I don't know what brand they are, they were bought through the machine shop.
AMX69PHATTY
Not the greatest pictures, but the camera I have is really old.
73hornut
I would have them rebalanced afterward. Your going to change the weight of each piston.
PaintedRat
It is hitting the area below the wrist pin marked in the pic. Should I take material off both sides of the piston, or just the side that contacts the crank?
If I can get away without rebalancing, I would prefer not to spend the money. I'm pretty much pushing my budget to finish this motor as it is.
AMX69PHATTY
Wow, I don't know. That area does look thicker in your pic.
That ledge is about .20 thick on the ones I have.
From piston top to that surface is about 2.40 on the 360, 2.45 on the 343.
Guess this is over my head and I'd better drop out and let the proffesionals.
Goose
Well I am not sure on the clearance issues but I can tell you 2 things to keep in mind.. Rods stretch and shrink.. so If you are going to clearance the pistons.. make sure you have a little extra clearance, cause at operating speeds that piston is really moving when it hits the top and bottom of the stroke.. and what looks like enough now, won't be.. (as to the amount.. beats me maybe MC and the fast guys know..) but the second is.. If you grind material off those pistons.. spend the bucks.. rebalance. balancing an engine is the single best dollar you can spend.. It will increase power and longevity more than any other money spent on a bottom end..
jeepsr4ever
How much is hitting? If you have to take off a small amount I wouldnt worry about re-balancing. Your not going to hit and hold 7500+rpm are you?
PaintedRat
I didn't have a good mic handy at the time. I don't think it is much material, but I'll put one rod/piston on the crank after work to measure before I do anything to the piston. Too much drama yesterday to do anything more than paint the tins (and my hands).
I hope to never hit 7500 RPM. This is an offroad rockcrawler that I will be driving to trail this season, trailering starting next year. It will be idling a lot, and staying in the lower RPM range, but it'll run higher compression if it matters.
BTW guys, I appreciate the input. My book shows the steps, but not what to do if things don't fit. If not for Bulltear I would have already smashed everything.
ironman_gq
you'll probably be fine if you try to take the same amount off of all the pistons.
1980_Cj7
PaintedRat wrote
Wow, if we put that in our engine compartment...you wouldn't be able to see it, ha, ha. It would be camouflaged, or however you spell in French.
jeepsr4ever
Frank is goona flip! Hey Pat remember when we stole Frank's jeep after the shots of Icehole? Doesnt that stuff lead to trouble :?:
Mudrat
OMG!!! (In a pseudo California Girl Voice)
Yeah I remember dragging Frank outta the rack (tent?) to fire up his truck, grab the trailer and come salvage his ride. What was it 12:30 ... 1AM when we finally made it back to camp?? :mrgreen:
That engine would DEFFINATELY get lost with the same color has his Jeep.
Frank, remember, GREASE is your friend - use more of it :wink: :?
And remember the spelling grEAse, not to be confused with gOOse . While he may be a friend, he won't keep your hubs from sparking and melting #-o
jeepsr4ever
:?:
Anyways, love the color!
