196 flathead troubleshooting

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   Nice Vinny, yeah I don't have an external leaks so not sure if Radiator stop leak will help. Just got my thermostat switched out, was concerned I wasnt getting any circulation but I think I'm good now. Threw a bottle of the head gasket leak in, what the heck.

so the interesting thing is there some smoke on start up (like always) goes away once it gets close to operating temperature, then the thermostat opens, and I get a steady light white smoke. I assume that's coolant and whatever burning off wherever the head gasket crack is at.

so I'm gonna keep running with this junk till she seals. then I'll probably buy another.... then I'll think about tackling the head gasket but dang.. this is my only ride right now so a head gasket repair would suck haha

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59SeattleSuperSix Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Mar/27/2020 Location: 98023 Status: Offline Points: 72	Post Options Post Reply Quote 59SeattleSuperSix Report Post Thanks(0) Quote Reply Posted: Apr/13/2020 at 1:25am
	Nice Vinny, yeah I don't have an external leaks so not sure if Radiator stop leak will help. Just got my thermostat switched out, was concerned I wasnt getting any circulation but I think I'm good now. Threw a bottle of the head gasket leak in, what the heck. so the interesting thing is there some smoke on start up (like always) goes away once it gets close to operating temperature, then the thermostat opens, and I get a steady light white smoke. I assume that's coolant and whatever burning off wherever the head gasket crack is at. so I'm gonna keep running with this junk till she seals. then I'll probably buy another.... then I'll think about tackling the head gasket but dang.. this is my only ride right now so a head gasket repair would suck haha

farna Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19676	Post Options Post Reply Quote farna Report Post Thanks(0) Quote Reply Posted: Apr/13/2020 at 7:06am
	If the hole in the block is the only issue, it is an easy fix. Just epoxy a piece of sheet metal over it -- or even seal and screw it. That's the thin non-stressed side of the block. If the bottom of the bore isn't cracked or broke out it's not a problem -- replace the crank and rods with the ones from the flat-head and good to go. Chances are that the bottom of the bore (or the cam) IS damaged though, or the bore is badly scored and would need sleeving. As long as the bore damage isn't into the water jacket a sleeve will fix it. No way to tell until you pull the pan and take a good look. I bought a parts car that had a flat-head engine that threw a rod (apparently) at high speed. The rod broke and went through BOTH sides of the block, ripped the oil pan, and broke a piece out of the cam! Nicked the bottom of the bore on both sides good too. It really thrashed around! It had been recently overhauled (new bearings). One of the rod bolts either broke or wasn't torqued down good, because it was gone!
	Frank Swygert

oddballracing Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Fan Joined: May/30/2020 Location: Canada Status: Offline Points: 4	Post Options Post Reply Quote oddballracing Report Post Thanks(0) Quote Reply Posted: May/30/2020 at 7:21pm
	I'm taking my flat head out of my '58 starting this weekend. I've farted around with this thing for a few years, but never really got too serious about it until last year when i couldn't get it to start, only to find out my carter dropped the throttle plate (I'll admit, a first for me). Inspection camera showed nothing n the intake "manifold", so I put a Holley 1946 from a '79 mustang 200" on it with a custom aluminum adapter plate only to experience what i believe to be a stuck valve a few weeks of sitting after getting it running right. I recall my compression numbers prior to this, being in the 110 - 120 range across the board, but don't have my notes on hand. If there is anything i can do to help while i got the brick out, just let me know. I'm going to be doing a serious look over it to determine if she's going back in or a suitable 4-cyl & 3/4spd swap is in order. Being up here in Canada, I'll I'd likely have to sell a few shop trucks to pay for a full rebuild, so I can't go that route, but if a bit of valve stem caressing and general cleaning is required in addition to a gasket set, I can stomach that. I'd hate to let the old motor go, but cannot justify throwing thousands at it.

1960American Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Fan Joined: Feb/05/2019 Location: Wilmington, NC Status: Offline Points: 14	Post Options Post Reply Quote 1960American Report Post Thanks(0) Quote Reply Posted: Nov/19/2020 at 7:10am
	I recently did a compression check on my flathead--- warm day, engine warm, was told it was rebuilt about 20,000 miles ago, 145 in all cylinders.

tomj Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jan/27/2010 Location: earth Status: Offline Points: 7544	Post Options Post Reply Quote tomj Report Post Thanks(0) Quote Reply Posted: Nov/19/2020 at 9:59pm
	Nice! I'm looking forward to building a flathead starting this winter.
	1960 Rambler Super two-door wagon, OHV auto 1961 Roadster American, 195.6 OHV, T5 http://www.ramblerLore.com

farna Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19676	Post Options Post Reply Quote farna Report Post Thanks(0) Quote Reply Posted: Nov/20/2020 at 6:00am
	A stuck open valve (can't stick shut on a flat-head, not unless a valve is severely bent!) is usually caused by old gas residue from a tank that has at some point sat a while being dissolved by ethanol gas. This creates a sticky "tar" vapor that gets into the valve guide and eventually causes one or more to stick. Of course you could have found the throttle plate if it's an intake valve stuck open... You will have to remove the head either way. If it's a piece of throttle plate hopefully it hasn't damaged the valve and seat beyond a hand lapping. If it's stuck in the guide you may as well pull all the valves and clean the guides good with solvent. With the valves stick up in the flat-head you may be able to fill the pocket with a penetrating oil (50/50 ATF/Acetone works great!) and let it sit and seep down. Turn by hand to make sure they all work, then maybe use the starter (with head still off) to work them real good. Might just want to take them all out and have seats done while the engine is out (I think you mentioned it's out?) , or just hand lap them if engine is still in. It's tight on the right side though, hard to get the valves out and keepers back on with engine in the car. Oh, and I'd drop the gas tank and clean it with a good solvent before running much more if it was sticky guides. It may be mostly clean now with ethanol gas, but wouldn't hurt to make sure.
	Frank Swygert