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Discussion Starter #1
Greetings all,

I haven't posted in awhile and I would love to visit here more, but I haven't had time to work on the Cougar as much as I would like to.

Several years ago (about 6,) I had the heads rebuilt and I've noticed that I have quite a bit of smoke blowing out the PCV hole (when I take the valve out) and the breather hole. It does it when the car is cold and hot. I put a plug where the breather should be, but now I have oil gurgling out the dipstick tube top. That stops if I take the oil cap (plug) off. I'm going back to using a breather on the driver side, but it just seems like too much smoke as far as I'm concerned. What is normal ventilation suppose to show? I really have zero mileage on the car since the rebuild, so for all intents and purposes, components should still be new.

Any help would be greatly appreciated.
 

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It is indicative of too much crank case pressure depending on how much smoke. There is always some so you should not block off the crank breather. Running the pvc is best bet. Now as for the potentially excessive pressure on a newly rebuilt engine, if bored there might be too much over bore. If not bored then there is too much wear and the rings are not holding the pressure. What kind of rings did you use and has the engine run enough to seat them? The crank case pressure is mostly a result of compression slipping by the combustion chamber and ring to wall clearance (excess) is usually the cause. Could be a cracked piston but that usually goes catastrophic not long after beginning to seep pressure.
 

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Discussion Starter #3 (Edited)
I didn't rebuild the bottom end. Cylinders looked good, so I just went with a head rebuild. After head rebuild, compression was good (although I don't remember what it was.) You're the second person that suggested rings, and I'm hoping it's not that. I really don't have the funds to tear back into it at this point. Could it be as simple as a valve adjustment?

***Edit*** Let me add that there is no smoke coming from the exhaust, other than normal.
 

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If you haven't driven it much ,I would suggest doing so to set the rings, then if the problem still exists,install breather filters, 1 on each side on the valve covers, that should help the blowing issue.
 

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Your fresh heads are putting increased pressure on your bottom end. The rings are being overpowered by the increased pressure. You can live with the problem for a while, but you need to pull the heads and check the cylinder bores. You may be able to hone the cylinders and install new rings. Otherwise you may have to have the cylinders bored and replace the pistons.
 

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From the beginning of time, WHEN YOU DO A VALVE JOB, YOU HAD BETTER LOOK AT THE MOVING PARTS BELOW.

As a kid in the 40's dad was good with engine's, and he walked away from so many requests to do a valve job, WITHOUT looking at the lower end. STILL holds true today.

Dale in Indy
 

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My first cougar had a 289 in it. I didn't know much about much back then and wanted to hot rod the car up a bit. rebuilt the top half, heads were tightened right up with new springs lifters, valves and all. Spent a lot of money for a 17 year old kid on the intake heads and carb. Never touched the bottom half. Goofing around one day against a 72 nova, blew the bottom right out! Ole man was pretty cranked over that. Never again will I build half an engine! I think your top half is probably to strong for the bottom and you have a lot of blow by on the rings also.
 

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Not to start a pissing match but the lower end must have had problems to begin with. There is nothing wrong with doing head work on any engine as long as the lower end is in good shape to begin with. I have never had any lower ends fail after head work or suddenly start burning oil and or have excessive blow by in 30 + years working as a auto technician. Most Ford engines use very high quality piston rings from the factory and their engine blocks are made from quality materials unlike the other guys. Most usually still have crosshatch and no ridge if well maintained even at 200K miles. I put a head on my wife's 97 Escort about a year ago (dropped a valve seat @ 174K, common problem) and there was no cylinder wall wear at all.

Bill
 

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I stand by my statement. Your statement of, " There is nothing wrong with doing head work on any engine as long as the lower end is in good shape to begin with", well, that sums it up. You too agree that it is SMART to determine such before performing the head work.

I don't agree at all that Ford is using QUALITY materials, and the other guys aren't. Just about ANY engine will perform for an extended time period if as you state, "if well maintained", and not abused. I know of NO knowledgeable engine person that will state that the SBC isn't a quality piece, period. I like Ford stuff too, but they don't own quality all by themselves.

Dale in Indy
 

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I stand by my statement. Your statement of, " There is nothing wrong with doing head work on any engine as long as the lower end is in good shape to begin with", well, that sums it up. You too agree that it is SMART to determine such before performing the head work.

I don't agree at all that Ford is using QUALITY materials, and the other guys aren't. Just about ANY engine will perform for an extended time period if as you state, "if well maintained", and not abused. I know of NO knowledgeable engine person that will state that the SBC isn't a quality piece, period. I like Ford stuff too, but they don't own quality all by themselves.

Dale in Indy
My post was not meant for you directly but several other posts that seem to say doing head work on a older motor will cause lower end problems. Some kind of voodoo or something.

From the hundreds of engines I have disassembled I stand by what I said. Chev engine blocks are not quality pieces. Most of these engines are from the 60's, 70's and 80's. I would hope GM has improved in the last 20 years. Engines in general seem to have less problems now days so I lack usable info on newer stuff. Besides most engines in later model years that have problems fail in a big way and its cheaper in most cases to replace. 9 out of 10, rough guess Chev V-8 engines I have torn down have massive cylinder wall wear. This is most likely caused by poor quality materials. Another possibility is poor cooling system performance aka cylinder wall temp is incorrect. Most likely running too cool causing excessive wear. Lack of maintenance is possible but that would mean Ford owners take better care of there stuff than Chev owners do.

Back to BigBullitt's problem, Is the PCV valve functioning correctly? Vacuum at the valve? The engine should stall or nearly stall if the valve is removed from the hose at idle, does it? Is it the correct PCV valve? With the engine running if you place your finger over the valve cover side of the PCV valve you should hear a click followed by another click when you finger is removed. The clicks should be consistent. Is the vent side of the PCV system clear? If all this checks out do you see blow by out of the vent side at idle with the PCV valve installed? A tight engine should have a slight vacuum in the crankcase at idle if the PCV system is working correctly. A small piece of paper should lightly stick to the vent side of the system at idle. How many miles are on this engine and what mods have been made? If this engine sat for an extended time its possible the rings are no longer seated. If this is the case the problem may correct it self after a road trip. Vary speed often to load and unload the engine. S*** got to go to work, see ya

Bill
 

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wonderwrench, I can only say there are MILLIONS of folks that will/would disagree with your statement that GM blocks aren't QUALITY. Most engineers of any worth have stated that the SBC is one of, if not the greatest engine to ever be developed. Look how it has progress since the 50's, and how popular it is today, it ain't no Voodoo piece.

I respect your right to present your opinion, I just don't think you are right in making such a statement.

I like my Ford too, and the SBC certainly has my respect.

Dale in Indy
 

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Dale is right.
Never add compression to a hi-mileage engine or one that isn't in tip-top condition.
The increased compression will overpower the rings and cause ring blow-by.
 

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Dale is right.
Never add compression to a hi-mileage engine or one that isn't in tip-top condition.
The increased compression will overpower the rings and cause ring blow-by.
Wow this keeps going, care to explain how basic head work is going to increase compression over what the engine had before it needed head work? Excessive milling of the head deck surface is the only way its going to happen. An engine found to have excessive blow-by after head work had excessive blow-by before the head work and it was missed by who ever was doing the work.
 

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wonderwrench, I can only say there are MILLIONS of folks that will/would disagree with your statement that GM blocks aren't QUALITY. Most engineers of any worth have stated that the SBC is one of, if not the greatest engine to ever be developed. Look how it has progress since the 50's, and how popular it is today, it ain't no Voodoo piece.

I respect your right to present your opinion, I just don't think you are right in making such a statement.

I like my Ford too, and the SBC certainly has my respect.

Dale in Indy
Different manufactures have different weak spots. Its common knowledge, at least in the old days that Chevy blocks were soft and or the cylinder wall temp ran too cool causing excessive ring and cylinder wall wear. Early 70's 307 blocks were the worst, they needed rebuilding every 60 to 80K. Older Chevy engines also have weak cam and crank shafts in most if not all non HP or HD applications. Drop and old Chevy OE cam on a cement floor and see what happens. Cams are cast and not hardened. That's why so many Chevy cams went flat back in the 80's. The old OE cams are also know to snap and drop down on to crank causing catastrophic damage. Chevy's cast cranks are weak unlike Fords cast cranks. It was common to see Chevy cranks broken though a main bearing. In most cases the vehicle was driven in to the shop making one hell of a racket. Even HD engines with forged cranks that used belt driven PTO's broke cranks. In most cases Fords cast cranks will hold up well under any use in stock form. Mildly built engines using cast cranks seem to hold up even under under extreme conditions. Ford has its weak spots though entirely different. SBF are prone to main bearing problems. In 1974 Ford lightened the 302 passenger car blocks to save weight. This weakened the blocks which caused main bearing wear do to block flex. This was fixed in the mid to late 80's for the most part in a revised casting. Fords also seem to spin rod bearings more than Chevy, drop valves more than Chevy.

I have nothing against GM and have owned five 73-77 Chev Monte's, a 74 Buick Apollo, 77 Buick deuce and a quarter and now drive a 98 Pontiac GP. I have owned about as many Fords and 2 Toyota's. If it gets me from a to b I'll drive it. Not a Mopar guy though, never owned one. For me its like petting the cat backwards though I would take a 68 Coronet RT for the right price.

Oh and is the Chevy small bock the best engine design ever ? It is a sound design that has been made near forever. It has huge aftermarket support. Is it the best engine ever? IMHO no. That honor would go to the 221, 260, 289, pre 74 302 and 351w or Buick's 3800. If the Windsor and 3800's did not exist Toyota's 2TC or Fords 300 six would be neck and neck.

Bill
 

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care to explain how basic head work is going to increase compression over what the engine had before it needed head work?
You had the valves ground, correct?
A valve job will raise the compression due to better sealing valves.

That is my opinion anyway.
 

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How many miles are on the bottom end?
 
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