SBC motor suggestions/help

[smf]

So I have a SBC 400 with about 108k on the rebuild. I runs pretty good, some pings at WOT but strong other than that. I just changed the rear diff and xfer case fluid and noticed oil coating the under side of all the running gear. I have traced it back to the timing cover/oil seal.

Question: While i tear into this should I replace some more of the bolt on stuff, pwr steering pump, pulley to wide serpentine pulleys etc? The parts are old and could be replaced as well as hoses and just general clean up.

Should I even get into it or just get another motor? I know is sounds crazy but how many more miles can I get on a rebuild? This is my first rebuild so I really don't know what to expect. I would guess if done properly it should last just as long as a new motor if taken care of but judging by some of the decisions made by the previous owner, I am a nervous.

Should I just fix the seal and run it.

Thanks for the input on what you would do.

 

[fieldsken1]

if you are that worried about it just rebuild it then you know its good its not that much money. better safe then sorry

 

[inkpot]

Howdy! That seal is about $10. Replace it and see what happens. I'd keep running it as long as it all performs OK. Good maintenance and easy on the throttle may get you another 50K miles. John

 

[F-junker]

Attention to heads. I believe that 400 was prone to head problems, cooling I think. I'm not 100% sure on this but look into it.

 

[dgangle]

Fix the seal and run with it. I ran a 400 SBC in a 40 back in the day with a zillion miles on it and it ran hot. It had gobs of torque and even with the age and wear it performed well. They are known to have head and cooling issues as because of the bigger bores (over a 350) there is no room for a water passage between cylinders 3/5 & 2/4. I don't recall exactly, but the head issue has to do with water/steam passages.

Unless you just want it rebuilt and have the resources, I'd just run it. 'Not that much money" can = $1000-3000 depending on what it may need or what you want to do to it. Your call, but I'm into not spending it where I don't have to.

 

[inkpot]

Attention to heads. I believe that 400 was prone to head problems, cooling I think. I'm not 100% sure on this but look into it.

Howdy! The majority of the heat problems were due to people running heads (especially camelhumps)and head gaskets from 283/327/350's. None of them had the steam holes to mate with the ones in the block. This was needed to vent the area where the cylinder bores touch each other. John

 

[Downey]

I'm not opposed to the above suggestions to patch what you've got and squeeze some more miles out of it, but you might want to peel an eye for a later model fuel injected engine. This is not a great option if you have to spend $3-4,000 for it, but I get reports all day long from guys who found a $1,000 deal on a newer LT-1 or LS-1 motor----could happen!!!!!!

 

[Adventure Teq]

If you have the money then why not replace them to ease your worries. If not then I wouldn't hesitate to fix what's broke and run it. What's the worst that could happen, component failure? OH NO!

If I was worried about reliability of all the rebuilt components on my 40 it would never leave my driveway. If I started replacing everything with new I might as well replace the entire thing with something like a 200.

 

[FJFOOL]

I agree with the majority, you said it still runs strong, I'd replace the seal, take a good look at the hoses, and keep running it.

 

[smf]

thanks for all the advice. I will just fix the seal and run it.

 

[Hobbs]

Buy a new truck.

 

[zebrabeefj40]

If I were that far into the motor I'd at least swap in a new timing chain. That many miles means a stretched chain for sure. $30 for a parts store replacement or $70 for a high quality aftermarket true double roller set. I would not bother swapping to the serpentine stuff unless you have it lying around. R&R the hoses, gaskets and belts is all I'd do otherwise.

Nick

 

[orangefj45]

how about starting with the basics like doing a compression test?! that'll tell you some stuff about the engine.

i say if the comp test turns out well ( and i see no reason why it should'nt ), then put a new seal and timing chain set in it and run it.

jim ( downey) makes a good point. fuel injection would be a nice upgrade. a serpentine belt system would be a great upgrade as well. you could achieve both by finding a blown up TBI 305 or 350 and robbing all the parts off it. you will have to run a computer, higher pressure electric fuel pump and of course a wiring harness along with the other TBI parts on the engine to get the TBI to work properly. but those are options and possible upgrades. they do not need to be done but i'd put em on my "list".


if the engine runs good, does'nt make and noise and does'nt smoke, then do a comp test, replace the items listed above and keep oil in it. that should keep the cruiser on the road for quite a while...........

 

[pb4ugo]

If it runs decents replace the seal, and any other suspect parts. Back off the timing a little to eliminate the ping.

Then search for another engine to rebuild, rebuild it and change it out in the future, with minimal down time.

 

[smf]

Great advice. Will do on the timing chain. I also like the idea about getting another motor and rebuilding it. If I pull the flywheel, is there a seal back there to?

 

[7mag]

Run it till it quits. When it dies, build a 383 with you 400 crank. Best of both worlds.

 

[theoii]

Does the SBC have the same problem with reverse direction water pumps as some other vehicles? If you just steal the parts off another you may need the water pump too.

 

[F-junker]

Run it till it quits. When it dies, build a 383 with you 400 crank. Best of both worlds.

Yes this is the solution here!