Koda

Question, how much can you tell about the condition of an engine before you pull the heads?

When I get to mine, I plan to pull the engine, pull cam (it has some wild cam now), do new cam, lifters, timing chain, rebuild water pump, pull oil pan, replace pump, and check everything. Point being, the heads will still be on, and the rotating assembly will still be in that point.

Is there a good way to find out if you NEED to remove heads and pistons before you do it? Can I see enough with a light in the spark plug hole? Or, if a compression check is good and I can get it to behave and have good power, is that good enough? While I think I could pull main caps and remove the crank and pistons fairly well, I worry about head gaskets (I think this one is running on the original stamped ones) so I don't really want to get into that if I don't have to, but I guess that's more of a valve condition thing.

Car is a 67 442 with what seems to be the original 400, project car, odo indicates 55k, but thats probably 155. On one hand, do it all for peace of mind, on the other hand, it's easy to screw something like that up, and you lose compression.

oldstata

Compression test and leak down test tell the most unfortunately I am not the best to tell you what to look for u know general idea but not much hands on

Others will chime in

oldcutlass

In addition monitoring oil consumption/ leaks, oil pressure, timing chain condition, vacuum steadiness, temperatures, and overall running observations.

MDchanic

I agree with the above - if the standard checks check out right (compression, leakdown, vacuum, oil pressure, smoking, oil use), and you're not planning any changes, no reason to pull the heads.

You may also feel better if you look into each spark plug hole with a fiber optic scope - You should be able to find someone who can lend you one.

- Eric

rustyroger

You won't be taking the pistons out unless you remove the heads.
A leak down test will tell you more than just a compression test.
If you pull a mains cap and find the bearing is worn then it's a good bet the rest of the engine is worn too. On the other hand if the bearing is fine the rest should also be good.
I get the impression you are putting in a milder cam than the one you have now and having a mild or stock tune. If so you should get plenty of trouble free miles ahead of you.
It's very easy to go in much further than you originally intended. You may think "While I'm doing this I might as well go a little deeper and do that". Before you know it the engine is in the machine shop, the transmission is being rebuilt, the body is off while the chassis is being shotblasted......

And you only wanted to change the spark plugs.

If the leak down or compression test gives a good result stick with your original plan, especially if you have a limited budget and don't want your car off the road for long.

Roger.

Professur

And I though my kids had impulse control issues

redoldsman

I think pulling a valve cover and looking to see how clean the inside of the engine is will tell you a lot. If it is full of sludge it might be time for a rebuild. All of the above are things you should do also.

Koda

Thanks for the advice. I am not sure what cam is in it now, plus I need to get everything back to tuned as well. When I got the car, it was dead, so running and driving is an improvement, but I haven't been able to work on it in years.

I don't plan to drag race it other than maybe once in a rare while for fun, so I will, like Roger says, probably back off the cam a bit. The previous owner says it "has a w-30 cam", but the sticker on the top radiator plate says Crane Cams, so maybe he meant "cut to a w-30 grind." I figure, with modern cam grinds, I can get more power than stock, yet maintain manners and driveability.

The idea is to get it running well, cruise around like a dirtbag for a while, then restore the thing once I build my barn here in a year or so. At that point, I would do everything the engine and trans needed for the next 20 years, ideally.

Sounds like I need to do a lot of looking and testing and putting up pictures here for evaluation.

m371961

I agree to do comp and leak down tests. Any oil pressure trouble or smoking?
If those are good, pull valve covers and look for sludge and pieces of valve seals.
You do not have to pull engine to change cam or replace valve seals

Koda

Eh, it runs like crap at the moment. I don't see any oil problems either through behavior or aftermarket gauge reading. Does not smoke. I can pull a cover. Engine will get removed for frame off resto when I do it, but I'll get it thoroughly running right and diagnosed before then.

Octania

You certainly can leave the heads on and do a lot of other work. You can see a lot of the cylinder from the underside while the crank is out of the way.

Last time I semi-rectalled the engine, on the 403, 'cause I didn't want to disturb the head gaskets... I failed to check ALL the bearings, and that came back to bite me. knock knock KNOCK BAM BAM BAM.

Ended up with 100% teardown which found too much cam for the 4A heads, mitaswelled into a forged 330 crank, PO used an undrilled oil passage plug.... next assembly went much better.

So, how many times do you want to do it?