I have a '71 Imperial with an engine leaking oil...

[USSMOPAR]

keep the block heaters, great for cold weather 40F starts
remove an accessible freeze plug and see how corroded it looks, evaluate
there are freeze plugs in the heads
replacing the oil pump is a waste of money unless the rotors are chewed up
pull the oil pan, install a windage tray
Use a valley pan with NO crossover, do not listen to the bad advice, the car needs to be tuned for today not yesterday 1970 whatever.
Timing chain and gears
Flowcooler water pump 195 degree thermostat
new engine biscuits try to find nos
valve seals,
pull the heads? no use a bore-scope and look! probably not, a properly tuned engine will not eat the valve seats even on todays fuel. don't look for trouble
change oil sending unit use nos

 

[ayilar]

@hootothecore -- would love to see more photos of your car, and hear about its history. The 1971 Imperials are great cars, and we don't see /hear about them often enough.

PS: I would not mind seeing pics of your 1970 Challenger 'vert either

 

[Boydsdodge]

A couple of pictures...

Thanks for the intake gasket p/n. Regarding freeze plugs. This car had block heater plugs. I'm not sure I want to remove that option even though I've removed (and kept) the plug-in cable.

I suspect the oil sender as the main leak, but it has made a mess, so engine out for cleanup.

Also, if I pull the heads, should I have hardened exhaust valve seats installed?

View attachment 637826

View attachment 637827

Imperial with a Vanishing Point Challenger. Woo Hoo.

 

[Boydsdodge]

If you pull the fuel pump, make sure the push rod goes back in the same way you removed it. Is the new fuel pump working now, if not it might be pump push rod.
Valve covers are notorious leakers. Now you have me thinking to pull my Engine, I have a pair of heads being rebuild now and was just going to do that along with chain, pan, rear main seal. Etc....

 

[hootothecore]

More pics...

 

[mopar preferred]

That Challenger is the perfect color combination for me!
My sister had a '69 Olds 442 in the same colors, but also blue pinstripes and blue vinyl top.

 

[Jakter]

How are the freeze plug heaters held in place and do they have a o-ring on them to make the seal?

 

[3175375]

100% change those freeze plugs !! they cost next to nothing but can ruin your day when they fail. As 413 mentioned, with the engine in the car it´s almost impossible to get to all of them.

Including the freeze plugs in the heads. The ones at the back of the heads are extremely difficult or near impossible to replace with the engine installed.

 

[hootothecore]

Ok, follow up to this thread. I've decided to do a full tear down and rebuild of the engine. I have pulled the heads and rotating assembly from the block. I will have a machine shop clean the block, hone the cylinders, new cam bearings, and freeze plugs. The heads will be cleaned and freeze plugs replaced.

I will do new piston rings as I have a set of standard sized rings.

Since this is a low mileage engine, I don't feel the need to machine valve seats, do any cam work or crank work. Now, can I replace bearings without doing any machine work to the crank? Since I've gone this far, I plan to replace all bearings. I just don't know if the crank has to be machined/polished when going with standard sized bearings. I can have the main and rod journals checked for roundness. There is no obvious wear and the bearings looked fine.

Any opinions on reusing the rod and main bearings? My plan is to replace, but just want some opinions.

 

[ayilar]

@saforwardlook @Xenon @CBODY67 @david hill @71Polara383 @Boydsdodge @cbarge are some of the good FCBO folks who have advised me in related matters. They might chime in here too.

@hootothecore -- would love to see the fender tag of your Imperial.

 

[Dads300]

Wow, that’s a snowball you got rolling there. You could honestly clean and reassemble as long as it all checks out. I would replace all of the bearings since they’re pretty cheap. I would make certain the rods and mains are standard though, and not .001 undersize or something from the factory. Be aware that the middle cam bearing often ends up tight where the cam won’t go back in, have your machine shop verify its size after install since they have the tools to correct it easily. I would 100% replace the timing set, and all freeze plugs. I would check the exhaust seats, they can get pounded out of shape and not seal well. It’s easy to check since you’re this far in. I would also reuse the oil pump if it looks good (I would bet money it’s perfect).
Travis..

 

[hootothecore]

@saforwardlook @Xenon @CBODY67 @david hill @71Polara383 @Boydsdodge @cbarge are some of the good FCBO folks who have advised me in related matters. They might chime in here too.

@hootothecore -- would love to see the fender tag of your Imperial.

I added cruise control and power door locks. Funny thing about the cruise, when I went to install the brake switch I found a factory cruise harness stuffed up under the dash with firewall grommet and all wires and connectors.

 

[hootothecore]

Wow, that’s a snowball you got rolling there. You could honestly clean and reassemble as long as it all checks out. I would replace all of the bearings since they’re pretty cheap. I would make certain the rods and mains are standard though, and not .001 undersize or something from the factory. Be aware that the middle cam bearing often ends up tight where the cam won’t go back in, have your machine shop verify its size after install since they have the tools to correct it easily. I would 100% replace the timing set, and all freeze plugs. I would check the exhaust seats, they can get pounded out of shape and not seal well. It’s easy to check since you’re this far in. I would also reuse the oil pump if it looks good (I would bet money it’s perfect).
Travis..

Yes, I will replace the timing set. Don't want to put that nylon toothed cam sprocket back in. Do you recommend double roller or single tooth sprocket and gear?

 

[Dads300]

A standard replacement set should be 100% fine. At the rate you’re going, you’ll never wear this car out.
Travis..

 

[CBODY67]

In one respect, ANY steel sprocket timing set can work. A duble roller will have the "bicycle chain" noise when the engine is running, BUT the rest of the engine will be worn out before the timing set will cause any problems. Think 400K+ miles in one of my motors.

Plastigauge the crank and bearings. Let that be the determining factor there, other than measuring the crank journals, too. Just mark the ones that are removed as to location, so they can be re-checked for clearance after the crank journals are "light polished", if needed.

As to the standard-size set of rings, that will determine how the cyl walls look and what size they might be after a little light honing. NO guarantee things will still be "standard" after the touch of the honing stones, if needed. These would be judgment calls from the machine shop.

As to the cyl heads, the exh seats are the ones which unleaded fuels can degrade more due to the heat. Having good valve guides can help keep things positioned correctly in this situation, too. Which is where adding the bronze heli-coil guide inserts can come in handy. This, like the roller timing chain, are "insurance items" to me for long-term engine performance into the future. Upgrading to the trimmed Chevy 454 orange silicone valve seals can happen at this time, too.

I fully realize the intent to just freshen things up at minimal costs, but as you mentioned "piston rings", one thing which can unlock power is to get the block "plateau honed" and then put some Mahle pistons in with the new "MM" ring package on them. Less friction from thinner rings on a lower-wear (it seems) bore finish can result in power not needed for the rings to do their job, results in more power at the flywheel.

I learned of that item on a Lake Speed, Jr. video the other night (about 96 minutes long) where he talked about some of his Dad's old Cup engines they dyno'd and refreshed. Then followed up with a YouTube video that Rottler did on how the process worked and why it was better than common honing we have become familiar with. It will work with the current thin rings or the older wider ones. BTAIM

Only thing about the Mahle pistons is that you might need to use thicker head gaskets to keep compression near what it currently is.

Might need to wait on the measurements from the machine shop and then determine how to proceed.

Just some thoughts,
CBODY67

 

[david hill]

Ok, follow up to this thread. I've decided to do a full tear down and rebuild of the engine. I have pulled the heads and rotating assembly from the block. I will have a machine shop clean the block, hone the cylinders, new cam bearings, and freeze plugs. The heads will be cleaned and freeze plugs replaced.

I will do new piston rings as I have a set of standard sized rings.

Since this is a low mileage engine, I don't feel the need to machine valve seats, do any cam work or crank work. Now, can I replace bearings without doing any machine work to the crank? Since I've gone this far, I plan to replace all bearings. I just don't know if the crank has to be machined/polished when going with standard sized bearings. I can have the main and rod journals checked for roundness. There is no obvious wear and the bearings looked fine.

Any opinions on reusing the rod and main bearings? My plan is to replace, but just want some opinions.

Your decision to rebuild is correct. No mention was made of exact mileage on the car. With no engine teardown having been done. I would caution you that a ring replacement only may not give you the results and quality your looking for. The same goes for the crankshaft. In crankshaft precision measurement of the crankshaft is a must. New bearings are a must. Cam bearings are a required. You may be able to use standard bearing. However if the crankshaft requires machining, just do it. The same goes for connecting rods. Check them for size and if required have them done. Shortcuts will have catastrophic results. As for camshafts, if you have plans on keeping your car long term, Melling makes some of the best US made replacements around. With new cams they will need new lifters. You have covered timing chain and gears so enough said. Oil pumps weren't mentioned so again unless your a pro about checking its overall condition. Replace it. Again melling is a good source that I use w/ 100% success. Lastly to cover piston ring only replacement. If the cylinder bores show any ridge wear or thrust surface wear a piston ring only replacement will give you poor results and wasted money. Bore the cylinders. Machining the cylinders to 0.30 over should bring it back on spec. Oversized pistons can be found on the internet for under 400.00 a set. Any questions PM me.

 

[hootothecore]

Your decision to rebuild is correct. No mention was made of exact mileage on the car. With no engine teardown having been done. I would caution you that a ring replacement only may not give you the results and quality your looking for. The same goes for the crankshaft. In crankshaft precision measurement of the crankshaft is a must. New bearings are a must. Cam bearings are a required. You may be able to use standard bearing. However if the crankshaft requires machining, just do it. The same goes for connecting rods. Check them for size and if required have them done. Shortcuts will have catastrophic results. As for camshafts, if you have plans on keeping your car long term, Melling makes some of the best US made replacements around. With new cams they will need new lifters. You have covered timing chain and gears so enough said. Oil pumps weren't mentioned so again unless your a pro about checking its overall condition. Replace it. Again melling is a good source that I use w/ 100% success. Lastly to cover piston ring only replacement. If the cylinder bores show any ridge wear or thrust surface wear a piston ring only replacement will give you poor results and wasted money. Bore the cylinders. Machining the cylinders to 0.30 over should bring it back on spec. Oversized pistons can be found on the internet for under 400.00 a set. Any questions PM me.

Mileage is 44663. Given the condition of everything, I believe that to be correct.

 

[david hill]

Mileage is 44663. Given the condition of everything, I believe that to be correct.

Your engine teardown will reveal the truth. Post photos of your teardown and inspection. @ayilar's Buttercup was supposed to be in good condition and if you follow the thread it was one of the best running 440's in such poor condition internally I have seen in the last 30yrs.

 

[ayilar]

Thank you for posting the tag. YM43T1C171763 is a beauty. Love the GB9 on this car.