My 440 rebuild thread

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Have the heads looked over good.
MH engines typically were run pretty hard if the vehicle saw regular interstate use.
I’ve had several sets here that had some pretty serious exhaust valve seat recession, and/or cracks in the exhaust seats.
They’re also known for cracking externally under the two center exhaust ports.

They might be fine...... but take some time to look them over pretty good.
 
Pulling the heads today. I went to the machine shop yesterday and spoke with their head guy, and he's gonna go over them. He's going to check for cracks, check the seats, guides, new valves, springs, retainers, etc.

First glance after removing the intake is ugly. I'm not trying to be judgmental, but it doesn't seem like whoever put this together really knew what they were doing. There's silicone smeared in places that don't even mate with anything. I also noticed the heat crossover wasn't blocked, which isn't big deal, but the passenger side doesn't appear to have been sealing.
4fVZogmzT2yXMHrPIg6+qQ.jpg
 
Well, here's one potential problem I found after pulling the heads. When I dropped them off at the machine shop, I noticed the #7 exhaust spring had part of the inner spring sticking out like this
DBA7206B-D72C-44AE-B679-E639008E8091.jpeg
I took this picture while waiting to speak with the machinist, but then forgot to point this out to him. Does this look like a problem?
 
Well, here's one potential problem I found after pulling the heads. When I dropped them off at the machine shop, I noticed the #7 exhaust spring had part of the inner spring sticking out like this
View attachment 1715819151 I took this picture while waiting to speak with the machinist, but then forgot to point this out to him. Does this look like a problem?
Well yea, that’s a problem. And likely indicative of more valvetrain issues you’ll find.
 
That stuff just needs to go.

I’d take a hard look at the cam lobe & lifter that goes with that spring.

If the exhaust valves are the two groove variety, I’d be replacing them with the passenger car 4 groove type(or replacing all the valves with aftermarket single groove SS pieces).
 
At this point I'd be declaring pretty much all the head hardware (springs, retainers, locks, dampers, seals, valves) for scrap and starting over. If the heads don't need any machining it might be cheaper to get them redone with new parts but Stealth heads are $1200 for a pair, last set of BB heads I did for my cousin I got decked, valve job, guides reworked, all new hardware installed ready to bolt on and they came out to about $1500... and that was around 2012 iirc.

I have a set of 346 casting heads off the 1973 440 I'm rebuilding that I don't need but they're "virgin" high-mileage pieces, likely need to be fully gone through though...
 
Okay, it's been a while since I've updated the thread, so I thought I'd check in.

I had the heads looked over and the shop said basically all of the valves were leaking. They machined the seats/valves, replaced all the springs, and replaced the rotators for standard retainers. Reinstalled the heads and test drove, and the car runs much better.

Finally I'm able to cruise the interstate! However, the same popping/stumbling/detonation (?) is still occurring, only at a higher RPM (~3400 instead of 2800). At the risk of having too many threads going on about the same engine, I'm going to put this one on pause until I actually decide to to the rebuild.
 
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