What to check after a few hundred miles on a rebuilt engine?

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Bl1zzard

Bl1zzard

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Hey folks,

I've got a few hundred miles on my 1974 Dart that had it's first start in many years this spring. It has a rebuilt 360 sometime since 1984. I can't verify how long ago because it was 2 previous owners ago.

I've checked compression on all cylinders and it's good at ~125psi. Plugs are nice and clean with a grayish brown. It runs well when warmed up, hard to start after sitting for a couple of days.

It's leaking a little oil on the drivers side head which got me thinking. What should I be checking on this engine now that it's been run for bit? Do the heads need to be retorqued? Should I be going over valve train, etc. or just run it as it stands? I would like to stop the oil leak, but it looks like I need to pull the headers off to get at the head bolts. I don't relish the thought of doing that, they are not nice, Hooker headers, almost impossible to get at the bolts without some fine wrench wrangling and only getting one small turn at a time. Took me about 3 hours to install new exhaust gaskets. The oil is of course dripping on the headers and makes for a nasty smelling drive after an hour or so.

I'm just curious what I should be doing next. There's lots of threads on how to break-in an newly rebuilt engine, but not much on anything that needs to be checked after it's been broken in.
 
I can't imagine why you would need to retorque head bolts for an oil leak. Do you mean valve cover fasteners? If so, yes you can try that, sometimes the gaskets can shrink from disuse and fasteners become loose. But I'm thinking it may already be too late for that. It takes a light touch on stamped steel v. covers. If the cover rail has become distorted from previous over tightening, you'll have to straighten it first, then replace the gasket.
 
rustycowll69 said:
I can't imagine why you would need to retorque head bolts for an oil leak. Do you mean valve cover fasteners? If so, yes you can try that, sometimes the gaskets can shrink from disuse and fasteners become loose. But I'm thinking it may already be too late for that. It takes a light touch on stamped steel v. covers. If the cover rail has become distorted from previous over tightening, you'll have to straighten it first, then replace the gasket.
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I'll attach a picture of where it's leaking from, hopefully it makes sense. This is the drivers side back of the engine, right in the most impossible place to reach because of the headers. I don't believe it's coming from the valve covers. I wiped everything down and that bolt is the only place that get's oily after it is driven and warmed up.

I'll look up the torque specs on the head bolts and see if I'm willing to attack removing the headers and reinstalling them. It's really not my favorite place to wrench on the car. Give me stuff to do on the passenger side all day, no problem.

IMG_20200612_122952.jpg
 
Not for an oil leak, but typically on a new rebuild, you check head bolt, intake manifold, exhaust manifold and accessory bolt torque. Not back off and retorque either. Just set the torque wrench at the required value, and check the tightness in the correct torque pattern.
 
Bl1zzard I am reading your original post, if the car engine was rebuilt sometime back in 1984 and driven for some time so its past checking torque. If something major was gonna loosen up it would have done it already. What I was recommending was for a newly rebuilt engine.

Maybe it is as simple as a leaky valve cover gasket, or loose valve cover bolts.

Btw if you want to correct the fact that it cranks rather long after sitting a few days, ditch the stock mechanical fuel pump, put a block off plate, install an inline electric fuel pump designed to work with a carburetors lower pressure requirement, then switch the pump on, let it run for about 30 seconds before you pump the gas to set the choke and fire it up. Something like what's in the pic below

Screenshot_20200612-144320_eBay.jpg
 
Last edited:
moparmat2000 said:
Bl1zzard I am reading your original post, if the car engine was rebuilt sometime back in 1984 and driven for some time so its past checking torque. If something major was gonna loosen up it would have done it already. What I was recommending was for a newly rebuilt engine.

Maybe it is as simple as a leaky valve cover gasket, or loose valve cover bolts.

Btw if you want to correct the fact that it cranks rather long after sitting a few days, ditch the stock mechanical fuel pump, put a block off plate, install an inline electric fuel pump designed to work with a carburetors lower pressure requirement, then switch the pump on, let it run for about 30 seconds before you pump the gas to set the choke and fire it up. Something like what's in the pic below

View attachment 1715544869
Click to expand...
Thanks, I've been thinking about replacing the fuel pump for an electric one.

To be clear, the engine was rebuilt sometime since 1984. It has not been run since this spring. We bought the car non-running and with the help of my friends here at FABO my son and I got it running. It still had assembly lube everywhere when we bought it, so I'm sure it never ran until March of this year. I'll check the torque on all the bolts and accessories as suggested and see if the leak goes away. I'm almost certain it's not the valve cover gasket or bolts, but I'll got over them all again.
 
if it was built a long time ago, the valve cover gaskets may be old technology. They made a grey rigid silicone gasket that is far superior to older gaskets, especially when they are in close proximity to header heat.
 
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