304 Engine Ring Question (right bank smoking).

I know I might get flamed for this but...

My son has a '74 CJ and the right bank is smoking after it gets hot.

We are going to pull the valve cover on Tuesday and check to see if the drain back holes are clogged as well as putting new valve stem seals in and checking compression.

My question is (since he doesn't have much money after buying etc etc. although he could save) if we find a bad cylinder, can we just pull that piston and replace the rings?

Also, would we have to pull the intake or can we get away w/leaving it and re-sealing it up (that is if the valley pan doesn't give way).

Thanks,
Jim

 

you could pull just one. not the best idea and no to pull the head the manifold has to come off.

 

What's the compression? You should be able to localize a bad cylinder by looking at the plugs. I would be surprised if you have poor oil control and good compression, if the oil control ring is the problem.

You could do one hole, but it's not that much more effort to do all eight. Price difference is minimal too.

There are only a few ways that oil can get into the combustion chamber - in the fuel, by the rings, down the valve guides, through a bad head gasket, or through a crack in the block or head. If your PCV system is not working, it will pressurize the crankcase and force more oil into the combustion (ie around the valve stems).

 

Thank you all.

We will do a compression test on Tuesday and I agree, while there, do all eight.

Should we leave the bearings (one on the crank) or change them out?

Again, we will know more on Tuesday.

Changed the PVC Valve, still smokes big time when he was driving it down the road and gave it a little gas.

 

Question, what MFG of rings should he buy?

Thanks,
Jim


Sent from my iPhone 4S

 

A good brand, like Sealed Power.

He wants cast iron rings - no chrome or moly. Cast iron is the standard quality. Cast iron rings will seat in old, crooked bores, more expensive rings will not. You'll need to hone the bores to a cross-hatch pattern, so that the new rings will seat. You'll also need to cut the ridge off of the tops of the cylinders to get the pistons out.

 

Wow, thank you. I didn't know that. While we are at it, Ashley's ('80 CJ7/304) engine as well. She is going to a Edelbrock 4bbl intake etc and wanted to replace the head gaskets/valve seals so I guess we will do her engine toooooooooooooooo.

I will look to see what Summit has or Napa.

Thanks again for all the help,
Jim

 

There are main bearings and rod bearings. Main bearings will not come out unless you remove the crankshaft, with the engine out of the car.

You could possibly replace the rod bearings. Rings, rod bearings and a valve job is an old-school "overhaul." I would also replace the timing set, unless it's obviously new. The overhaul is less common today than the complete rebuild.

If you aren't familiar with this stuff, you should do some homework. Here's a good place to start - http://www.amazon.com/Engine-Builde...33552&sr=8-1&keywords=engine+rebuilders+guide - it's comparatively easy to do a 'complete' rebuild - fewer choices to make. It is more difficult to patch up an engine, because you need judgement and intuition about what is needed, and what is not.

I would certainly evaluate the oil pressure and compression, and do a leak down check before I took the engine apart. Look at the spark plugs. Once the engine is apart, you can no longer do the dynamic testing that tells you a lot about the condition of the engine. If the engine is just tired, you'll likely be better off to buy a remanufactured engine and swap it out.

 

Question, what procedure should they take to break them in?

And, should I put assy lube on the cyl wall when I slide them in and then coat the top of the cyl after they are in ?

Thanks,
Jim

 

RockAuto (cheap), or your local automotive machine shop (informative). Maybe that's your local Napa.

 

You really need an experienced friend to help you, or do some more research. The book I listed is a good start.

IIRC you dunk the pistons in engine oil. You'll need a ring compressor.

 

Thanks you,

 

Called the machine shop today.

Long block - $1800.00

Short block - $1200.00

Still proceeding w/the compression test tomorrow.

 

Has anyone scene this DVD ?

About to buy the book posted earlier and saw this.

Sounds like a winner, 3hrs long.

http://www.amazon.com/gp/product/B000F39P3K/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

http://www.amazon.com/Basic-Engine-...dp_top_cm_cr_acr_txt?ie=UTF8&showViewpoints=1

 

Likely has a lot of good info. I would rather read than have people talk at me. If you prefer that format, it could be a good start. The reviews seem positive.

Is this something you want to do again some day, or are you just trying to get by the current problem?

AutoZone has good prices on engines. Check them out - that will likely be your cheapest source for a complete engine, other than another used engine.

My advice would be to figure out what the issues are with the engine before you decide to rebuild, repair or replace. What's the oil pressure like? The hot idle OP is the most telling. That's full operating temperature (maybe after a run on the highway), at the factory specified idle speed. These engines tend to develop low hot idle OP when they are tired.

 

The title also comes with a book - if you buy it that way.

http://store.boxwrench.net/How-To-R...ook-with-Basic-Engine-Building-DVD_p_107.html

 

Thanks again for all the Help Tim. Ya it is good to have the books & I was also thinking of the dvd to show a little more just in case.

Yes we are doing a compression test today. We also have looked at the O'Reilly engines and I know the guy there. He said he sold 20 of them so far and only two have come back. One that he knows of, and one the district mgr knows of-3 yr unlimited mileage.

Check this out-he said if I bring in the 304's core he would sell me the 360 long block in its place for the some price. He said besides the heads and block (no guts) that those are the only used parts, everything else is new, not rebuilt.

So he can get a 360 & my daughter is thinking of it as well. She has a 304 in her '80 CJ7.

Question, is the 304 intake the same as a 360? Reason I ask is my daughter just bought a new/used Edelbrock intake (so she can go from 2bbl-4bbl) for the 304 off someone elses 304.

Also, IF, she/he goes this route, what yr had the most HP of the 360's that would work. THey all should bolt up. So I was thinking, IF, they went this route, to get the one that had the most HP even though it might not be that much.

We were pricing things for the 304 verses the 360 and the 304 costs more, not sure why.

One more thing I hater to report with all sadness-my son, well, he is thinking of swapping out his entire drive train (304/manual trans/D20/Ramsey winch w/PTO) and trying to put a short auto in there and either reuse the D20 or find a D300. I had a set up at one time in a 5 like that (still have the 12" drive shaft) and it is tight.

So we will see.

Thanks again,
Jim

 

The 360 is the same crank as the 304. The blocks are different castings, and the bore size, pistons and rods are different.

Much of the power boost with the 360 comes from its better cylinder heads, with bigger valves. The smaller bore of the 304 requires smaller valves, so the 304 heads are different from the 360/401 heads.

A 360 will bolt in easy as pie - but the engine balance is different. The 360 uses a different flywheel and harmonic balancer, so you will need those parts too.

304, 360 and 401 manifolds all interchange.

360 cores are a lot more plentiful than 304 cores, and there are more 360s than 304s still on the road. So I'd expect a discount if I traded a good 304 core for a 360. The discount on the 360 might pay for the new flywheel and balancer you'll need.

Re power/performance, earlier is better. First year for a 360 in a Wagoneer is 1971. Main difference is in the camshaft and external plumbing, so I think the year of a seasoned core does not matter really. The best seasoned core is a virgin core, which has not yet been machined. But the 360 and 304 are plain gray iron blocks, and will go 60 over, if you find a core that has already been bored.

 

Thanks. I didn't think of a 401 I'm sure he would do that to but for her it might be to much.

I forgot about the flywheel (80 buck I think if memory serves) & didn't know about the balancer.

Good info and we will see how things go.

Will Update:

 

Good 401 cores are expensive. They can't be bored much, typically. A 401 core that has been bored once often has to be sleeved.

A 401 is a different animal. It's about as large a bore that can be used in a block that size. The block is special high-nickel alloy, for strength. The crankshaft and rods are forged steel, unlike the 304s and 360s with cast iron cranks and rods.

401s are cool, and can make monster power. However, a 360 swap is easily the single best bang-for-the-buck hop-up for the 304. Cam, compression, carburetion and cubic inches - the 4 Cs.