454 Tear Down - When to Stop?

[Rat72]

It's been a long saga but the seller of the motor said it was freshly rebuilt about 10 years ago and then garaged. I got it running (barely) but it had almost no vacuum and I had to run it way advanced to keep it idleing. When I pulled the plugs, everything was fouled so I put some new plugs in it and tried to set the timing to something reasonable. But it didn't run any better.

So I pulled the manifold and found that one of the lifters had come apart. I installed a new cam and lifters but went to check the plugs before reinstalling the manifold and two of the plugs had oil on the threads and the tips were covered with carbon. This is after running it for about 2 minutes. The other plugs looked OK including the plug where the bad lifter was. So I hate to button everything back up if there is a bad ring or valve or head gasket. Whata you guys think, do I have a problem or is it just the remnants of all the bad timing and previous fouling? My thought is to run a leakdown test on her? Thanks in advance for any insight.

Whit

[65-72 chevytoys]

If it is out of the truck pull it apart and do a rebuild just to make sure. A rebuild is the only way to be sure.

[GREASEMONKEY72]

if theres oil on the plugs it could be the vavle guides are bad and its leaking/burning oil, i hope you get it figured out and goodluck with it

-steven

[bill_in_sd]

Could also be burnt rings. Cars that sit that long have problems with the valve guides and the rings. A compression test will confirm.

Somewhere I read that you can leak down some kerosene or mystery oil in the cylinders a few days before starting the first time to help the rings, but of course I found this out after starting an old Datsun with a little shot of ether to really get it going. One cylinder was an absolute mess since the rings fell apart after that.

YMMV.

Bill in SD

[stllookn]

On motors that have sit for a long time I like to get oil pressure to the bearings, lifters and rockers before starting by removing the dizzy and driving only the oil pump. I then pull all the plugs and turn it over with the starter to see if it will generate oil pressue under the starter. I also find that valve guides can dry out and rings can stick. I usually run them for a while before doing a compression check. It can take a long run before the rings will free up and the engine will stop smoking. You should break in the cam at 1500-2000 rpm for about 20-30 minutes, I believe depending upon the cam spec. This is difficult to do when you cannot get it to run properly.

Did you check to make sure the dizzy weights are free and the vacuum advance is working? A vacuum leak and stuck weights will keep it from advancing. Just some thoughts.

[Rat72]

Great input all. I've decided that if the heads have to come off, the motor will go through a complete overhaul. I'll run the leakdown test and see if there is anything compelling there. If not, the comp cam kit I bought came with new seals and springs so those will go in. Slap everything back together, prelube it, break in the cam and then go blow all that old carbon crap out.

If that doesn't work, I'll kick the dog, pull the boat anchor and start over.

Thanks,
Whit

[Boog]

There ya go Whit. Ya gotta have a plan.

[Rat72]

Part of me says to hang it up and buy an all aluminum 572, add a whipple supercharger, fuel injection and be done with it. Yee haw.

Whit

[mjrmn]

Originally Posted by Rat72

Part of me says to hang it up and buy an all aluminum 572, add a whipple supercharger, fuel injection and be done with it. Yee haw.

Whit

DO IT!!!! Just make sure to post pics so we can all drool!
Oh and feel free to just drop off that boring old 454 at my place too!

[68GMC454]

might as well rebuild it since your messing with it anyway..but then the 572 would be better...at least we can drool then..