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I didn't take a picture, but I'm torn on whether or not to install new rings in my new 401.
The rings are seated, the bores still show some crosshatching, and there is no "glazing" or ridge in the cylinder. But the plugs showed signs of oil use and there was some carbon on top of the pistons. I'm not sure if it's from running rich or from oil consumption.
However I think that while I'm in here I might as well. I can get a flex hone and new rings for $200.
And if I do hone it would I do it before or after I send it out to be cleaned?
Yep, while heads aren't hard, I've found that a guy that laps valves for a living does them as good or better than I do and in half the time. Last time I paid to have it done it was only $80 a head, too.
Since I know you love to tear into stuff, a cheap, fun, and educational thing you could do instead while farming out the heads is get yourself some plastigage and check your bearing clearances on the rods and mains.
Edit>>> to add another nearly free thing you can do while the heads are off is get a long screwdriver and soft faced dead blow, and spend some time knocking the left over casting sand out of the water jackets. Neither baking nor boiling the block gets that crud out, only some secret solvent they used in the factory (that didn't work that great) or elbow grease does the trick. I've gotten at least an 8oz cup worth from every AMC I've cleaned up, and I'd bet a nickel it's a bigger cause of 401 overheating then over boring them.
Last edited by REDONE on Wed Apr 05, 2017 9:57 pm, edited 1 time in total.
79 J-10 (Honcho Mucho) KE0LSU
304/Performance Fuel Injection TBI/MTA1/SP2P/Magnum rockers
T18/D20/D44s&4.10s/33" Mud Claws
Grizzly Locker Rear
4" front spring drop, 5" rear shackle flip
Chevy style HEI (ECM controlled)
Dolphin "Shark" gauges in a fancy homemade oak bezel
3/4 resto, rotting faster than I've been fixing it.
REDONE wrote:Yep, while heads aren't hard, I've found that a guy that laps valves for a living does them as good or better than I do and in half the time. Last time I paid to have it done it was only $80 a head, too.
Since I know you love to tear into stuff, a cheap, fun, and educational thing you could do instead while farming out the heads is get yourself some plastigage and check your bearing clearances on the rods and mains.
It's low mile enough that I don't think the heads need anything beyond valve stem seals. And only because they're split. I'll probably lap them while I've got the valves out just for fun.
Have you seen the trick with a piece of hose and a drill? I did that on the Cherokee valves and they turned out very nice. Need better compound to get the finish I want but the Cherokee has compression numbers from 138-144.
REDONE wrote:
spend some time knocking the left over casting sand out of the water jackets.
Interesting... but in a more than 20 year old engine!!!
I had to search and yes, some people are having issues in gas engine (diesel engines have coolant bypass filter)... elements are not id'ed, could be breakdown of coolant and silicate ... when not enough water or worn out coolant, sounds like muffler bearings and blinker fluid jokes, but yes coolant looses it protective effects.
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)
REDONE wrote:
Have you seen the trick with a piece of hose and a drill? I did that on the Cherokee valves and they turned out very nice. Need better compound to get the finish I want
REDONE wrote:
Have you seen the trick with a piece of hose and a drill? I did that on the Cherokee valves and they turned out very nice. Need better compound to get the finish I want
REDONE wrote:
Edit>>> to add another nearly free thing you can do while the heads are off is get a long screwdriver and soft faced dead blow, and spend some time knocking the left over casting sand out of the water jackets. Neither baking nor boiling the block gets that crud out, only some secret solvent they used in the factory (that didn't work that great) or elbow grease does the trick. I've gotten at least an 8oz cup worth from every AMC I've cleaned up, and I'd bet a nickel it's a bigger cause of 401 overheating then over boring them.
The only time I hone is right after I've re-ringed an engine. Are you certain your rings are seated properly, and clocked properly? Whenever I have an engine rebored I ALWAYS have them use torque plates, otherwise the rings might not seat correctly. Keep close tabs on your oil consumption. Install new plugs and them make a few full throttle runs then check them to see if there's an excess of carbon on them, or if they're wet with gas or oil, they should be tan in color and dry.