LT1 350 in a Roadmaster Wagon destined for $2016 Challenge glory.
The engine I rebuilt had 250k on the clock. After driving/tuning/racing for 600 miles, it developed rod knock and yielded a harvest of coppery glitter in the oil filter. Before the noise, the oil light would sometimes flicker at idle once hot. I didn't think much of it and never measured oil pressure manually. During the rebuild I did the following:
- Bearings (plastigaged all the things)
- Rings
- Ball hone job
- Every seal
- Timing set
- Aftermarket cam
- Valve springs for the cam
- Threaded rocker studs to replace press-in
- some head porting
I did NOT replace:
- Oil pump (possible source of failure?)
- Hydraulic roller lifters
And it was running GREAT. Just an awesome wagon. For a while... The new engine is from a 59,000 mile (supposedly) Cadillac hearse destined for the scrap yard. I am guessing I'll need to use at least its crankshaft and piston/rod assemblies. I plan to buy a new high-volume oil pump and new LS lifters (better direct replacement for LT1s).
--> How much of the donor engine should I use? Re-use its bearings if they check out or buy new everything? Should I even bother with the upgrades and just plop in the stock motor?
My car-nfidence is at an all-time low. Overall I feel like an idiot for messing up a simply rebuild like this. I mean, its a small-block chevy. I don't how I berked this up.
Obligatory gore photos
Donor acquired
FIRST Install said caddy engine,do the challenge,THEN replace parts. at 60 thou. that engine may need plugs not much else.Three things come to mind that can wipe out bearings,the light won't come on till 5 psi, That was 1,yea just a chebby,what could go wrong.
What upgrades did you do to old engine ?
I would be using the caddy engine as is. Apply any upgrades to it but don't go doing bearings or anything on a 60k mile motor. In my lemons experience the motors that cause the most trouble are the rebuilt ones. Junkyard motors applied in a stock fashion to the stock car hold up the best - once they run that is. Believe me when I say you are in crowded company having trouble rebuilding a motor for race use. I myself have had one major rebuild failure but I can blame it on it being a Quad4. But I know in my heart it was my fault.
don't touch it, put it in and get going. then worry about stuff.
Install as is. Dissect to original and then make a decision.
Good runner with 60k on it? Stab a cam in it and go.
you Know Not to go to a larger cam than 485 lift in those engines don't you.
In reply to GTXVette:
I did not know that. Why? My cam was .525...
IGNORE that RED warning light and you are asking for trouble.
And you got it.
Checking the pressure could have saved the engine and a lot of work.
Of course, I'm sure you know all that now.
In addition to a suspect oil pump, consider a thorough cooling system check. I had to tear down an LT1 because the fins in the radiator of my 95 Corvette were filled with caked dirt. The radiator didn't cool effectively, coolant and oil temps got too high and the oil gave up at an autocross on the hottest August day Tampa must have ever had. The Vette had an oil temp gage, so I knew what happened. Probably your Roadmonster only has an oil pressure light and you wouldn't have known oil temp was getting to be a problem.
Post mortem on your engine will probably show bearing problems at #6 or #8. I saved the radiator by cleaning the fins by hand with a pick because I was hard up for extra money after buying everything for the rebuild, but today I'd drop a new radiator in instead. The machine shop was able to recondition the crank and rods, and that was with one wiped bearing and one piggybacked, so yours can probably be saved too. The engine was good as new after we were done.
Coil Bind, the valve stem seals are different than early Small blocks,there is a kit that raise the retainer to get more room but do that to the other heads at a later date,or do the seals with another tool to use early style seals.check this I'm gettin Old.
In reply to GTXVette:
I think I fixed that for the cam with a set of valve springs with a shorter bind height. Everything looked normal when I watched it run without the valove covers. I don't think it would have lasted this long if coils were binding.
As for cooling, it was on the hot side for a while. Only 20 miles ago did I change the tune to turn on cooling fans at a much lower temp. That kept coolant temp well under control and helped the oil pressure light problem, but didn't fix it. May have been too late at that point. Tow-package cars have an external oil cooler. Mine doesn't. Might be worth grabbing one of those.
Cut apart the oil filter on the new motor and use what you find there to determine how deep to go. If the oil filter is clean I would not do anything but address leaks. Supporting gear must be up to the task, clean radiator decent exhaust, etc.
You don't mention what fuel system you are using, that needs to be happy as well.
In reply to maschinenbau: 80's ish caprice has a remote set-up that is pull apart cheep.you must have the spring and retainer I was thinking of. some folks don't know, and the little stuff will make you want to quit.
Hope you get it going for the challenge, it's one of the cars I was looking forward to seeing there
I'm with the guys saying just use the donor bottom end with your new cam and top end parts, if that's practical. Then you don't have to worry about something going wrong with the bottom end during the rebuild, and those engines will run just fine with low idle oil pressure if the donor bearings are a little worn. At 60k miles though, I don't think you'll have a problem.
Let me know if you need a hand with anything.
Thanks for all the help everyone. I have already removed the broken engine. I'm still unsure whether to use my cam and heads, or just slap the whole thing in completely stock. The latter would give me time to rebuild the cammed engine, but I will probably sell the wagon after the Challenge anyway. It would probably sell better with a dead-nuts reliable stock engine, I suppose.
