FastEddie313

I have a 1980 454 that is completely stock and seems to have 75k original miles on it in a 15k lb P30 class A motorhome..
I had to replace the hot air choke with an electric unit, did a carb gasket, replaced all the fuel lines, cleaned the carb a bit and put in a new filter..
It runs pretty darn nice and quiet, no engine noise, seems solid..

Besides standard tune up items, is their more major freshening up I should do to the engine to really be able to trust it? Things like..
Headgaskets? Should I put new head gaskets on it just because the old ones are old? Do they last forever or should they be updated?
Bearings? Should I put new main and rod bearings into it? Are their better ones available today for it? Is it about time mileage wise to replace them maybe?
I don't know what sort of lifters it has but they sound quiet so I haven't even pulled the rocker covers..
Should the lifters be removed and inspected?

Or should I just leave it alone? How reliable would you expect a seemingly good running old engine to be?

I don't know these engines very well but I know engines pretty well.. If that makes any sense..

oilcanhenry

Why mess with something that's not an issue? As long as its running well, and has good oil pressure, you don't
need to replace things which are best left to a full-overhaul or a crate-engine. The 454 cubic inch is reliable enough.

Unless you want more power, I'd leave it be. Change to synthetic fluids, particuarly the motor oil, if you want more protection
from engine deposits and sludge build-up. Use a very good oil filter (not Fram's) like Wix, Purolator, Mobile 1 or Royal Purple.

FastEddie313

So you would just trust it heavily loaded with a lot of your valuable things and family from Michigan to Arizona just do it it'll be fine?

I think I can do all sorts of work to it with the block in the vehicle but pulling the block would be a huge job, quite an insanely huge job broke down somewhere in the middle of the country you have never been before, if it decided to throw a rod through the block, or spin a bearing, it would make for a catastrophically bad situation..

I might be interested in some "power" upgrades if they were a reasonable part of reliability upgrades. Like lifters and rockers..
I don't really know..

Pretty reliable you figure?

I plan to atleast watch the AFRs, make sure they are right beforehand obviously, to make sure it doesn't hole a piston climbing a hill or something..
It feels like it runs good, smooth and quiet, but with an old carb I think it could be all over the place and I wouldn't feel that..

How about the 400 turbo trans?
Fluid and filter change? Anything else?

kevinkpk

Anything mechanical can and will fail anytime regardless of "new". Turbo 400 is a great transmission. I pulled a back hoe with a one ton chevy with a 454. I also agree if it's not knocking runs fine, what can you do with it? If you want to tear it down, go for it. I currently have a 455 in an Olds that has 170K with nothing done to it with a turbo 400.

oilcanhenry

Like kevinkpk said, anything mechanical can break at any time. The 1980 454 was a low compression "smog motor", so you might have around 280 HP, which is low for such a large displacement engine, but GM had to meet the emissions standards back then, so 8 to1 was typical for compression ratios in most engines back then,and exhausts were very restrictive, with small catalytic converters and smog-pumps jamming up the combustion flow through the motors. Lots of people were modifying their cars back then, if they didn't need to pass a smog test.

Even the stock 350 CI V8 only ran about 200-220 Hp or so back then. Hell, my high compression, VVT, DI injected 2015 Malibu motor would flat out blow away most 1973 to 1984 vehicles if I time traveled in time to back then with it, (Where are you Doc Brown?) Hehehe!

I'd love to pull up to Burt Reynolds in that 1977 Pontiac TransAm he supposedly drove in "Smokey and the Bandit" .I'd "smoke" the Bandits' car low HP TransAm easy with today's high compression, high horsepower vehicles.

Having said that, the 454 was a nice motor for its time and there is nothing wrong with its reliability at all. Just take care of it and it should be as fine as cab be expected.