Gut Check- I Have Two Dead Cylinders

I had a buddy of mine come by and take a look at the Dauntless and after doing a compression check I have two dead cylinders. 4 cylinders were about 90 pounds, 2 were about 30 pounds. So now I need to determine if I should rebuild mine, or order a rebuilt motor

Anybody run into this issue?
What should I be looking to come out of pocket ($$$)?
Any particular place I should start looking?

 

The usual next test is to put some oil in each of the cylinders and run the compression test again. Oil on top of the rings will raise the compression, if the rings are worn. If the compression does not come up, there is another leak, like leaky valves or a hole in the piston.

At that compression, I would expect the engine to be really tired, and have blue smoke out the tailpipe and a lot of blowby from the crankcase.

If it's just worn out (likely), how much do you want to do yourself? How long do you want the replacement engine to last?

 

You didn't say which cylinders.
If they are side-by-each, I'd suspect the head gasket.

But 90# on the good ones ain't much.

 

Opposite sides. Whats the compression suppose to be on the dauntless, 120?

 

120-150, I would guess. +/- 10% on all cylinders, ideally.

 

A leak-down test would tell a lot more about where the losses are. A spark plug is removed and an air fitting inserted. When pressureized, you can tell where the loss is.
-Donny

 

I agree with the leak down test being the next move. Altitude can play a role in your compression readings as well. So 90 might not be terrible. I want to say my dauntless pressure tested @110 on most cylinders at 3300 feet

Technical Articles at Greg's Engine & Machine

 

In this area, 225 engine rebuild runs from $1,200-3,000. The low-end being a questionable machine shop just doing the machine work, maybe a short block assembly, you doing most of the rest. Also, they are not likely to warranty anything at that price since you assembled most of it. Upper-end is a high quality shop doing a full rebuild and assembly with a few upgrades (hardened valve seats, 3 angle valve job, squaring the deck, cylinder bores, balancing, etc.). Obviously you can pay more for performance upgrades, but hopefully this gives you a point of reference.

From time to time you can find complete "rebuilt" 225's for sale in the $1,200-1,800 range, but unless you get the paperwork and talk to the machine shop that did it, tough to know what you are really getting.

 

There are plenty of articles online on how to make your own leak-down tester. You'll need a compressor.

The cheapest route is finding a used engine. The 231 Buicks from RWD cars, even fire or odd fire, will replace the 225. Unfortunately the donor cars for these engines are getting pretty old, and you may have trouble finding one. You are in California, and old cars stay on the road a long time there, so maybe you could find a donor. I'd look for a connection to the car auctions - many of the cars that don't sell there go cheap to the pick-and-pull yards, so prices could be pretty low.

Next cheapest would be an old-fashioned overhaul: rings, valves, rod bearings. The main problem there is the cylinder bore taper, which will wear out your replacement rings pretty fast. If all you want is a few thousand miles a year for the next decade, that may be good enough.

 

If you are not into rebuilding the engine yourself, a possible option may be a long block from S & J Engines in Spokane. They want $1600.00 for a long block that comes with a 7 year/100,000 mi. warranty. Their price pretty much seams to fall in the middle of what others have estimated for cost.

rebuilt auto engines 1967 Jeep

 

Leak it down before you look at any replacement.........................May be something simple......like burnt valves / valve job or a head gasket.........Get yourself in a quite area to perform the leak down test.....including getting away from a noisy compressor.........as you'll be trying to hear the path of the air leaking once the gauge shows a leak...........making sure that your always at TDC on the compression / firing stroke.......for each cylinder before you test..........a breaker bar on the crankshaft nut is a good Idea as some loose motors may try to turn over when pressurized.................... rings/ noise in crankcase & breathers ......... exhaust valves / noise in exhaust system......Intake valves / noise intake manifold & carb.....................head gaskets can be tricky as you may want to have a piece of rubber hose standing by to stick one end near your ear and the other in the adjacent plug holes.....

 

you still drive it, as I understand, and it works well or it is ok for you?
why did you made this test?
you can try a valve cleaner, maybe it is a good idea ???
Then you decide your budget, you consider your technical capacities, cost of tools, cost of your time...
And what is the quality of the rest of your Jeep, gearbox, etc...
I spent money on my Jeep at pro shops to have something in good condition with a guarantee.
ut I don't make it a new one, cost too high, no need.

 

Doesn't everyone just have a dozen Buick motors to swap in???

 

Only you.

 

Just one still in the box..............

 

I was looking at them today. Cost OTD was $2505 including core. I messaged them to see if I could save some money by delivering my motor to them, that way I'd save about $600 and they said I could. They're about a 6 hour drive from me and their open 7 days a week which is nice.

If I went that route, I don't know if going with one of their rebuilds would be good or just have them rebuild mine. I think mine is numbers matching but I'm not sure if that means much for a Jeep?

I called a local machine shop here in town and they quoted me about $2,400 to rebuild mine.