Here is what happened:



- Changed the valve covers for ones that had no PCV valve and breather. Engine ran for about 2-3 minutes and started to hiss like crazy through the oil dipstick tube and the water in the radiator/water pump was "bubbling". So, I shut her off. Next startup, the engine ran for 30 seconds, revved really high and dies. Engine started to leak oil at the rear of the oil pan (gushed), but stopped.



Here is what I did:



Step 1: Removed intake manifold/valve covers, did a visual on pushrods/lifters/valves, compression check on all cylinders, adjusted the timing (visual) to TDC.

Result: All cylinders at 150, cylinder 5 at 90 on compression check and made a loud rattling noise on the upstroke (not good, I initially thought) and everything else checked out ok.



Step 2: Removed the oil pan and did a visual on the bottom end, playing close attention to cylinder 5. Did another compression check with oil pan off. Retorqued complete bottom end. Noticed the rear oil pan seal went bad as well as the front. Timing belt chain and cam looks great from the bottom.

Result: All checked out ok, to my surprise cylinder 5 now has 150 and noise has stopped. No cracked piston, connecting rod, no metal parts anywhere in the oil pan. Nothing! Engine turns sweet.



QUESTION: Because there was no breather and PCV valve, did I have an over compression of air in the bottom end that was not able to release due to the lack of a breather/pcv valve? Because I checked everything (as mentioned above) do you think I should just go ahead and put everything on and test fire with the old valve covers? Or did I miss anything else? Does this have nothing to do with the new valve covers? I did not break the seal on the heads and don't want to remove them if I don't have to. I would have broken the seal if I still had problems with cylinder 5, but that mysteryously went away.

BTW, not that it matters, but this is a 390 stroked to 427. 427 bottom end with EDC development heads and a 427 medium riser dual quad intake with dual Holley 850 double pumpers. Top end nothing fancy, just a mild/hot comp cam and standard rods, lifters, rockers for durability/longevity, and Sanderson 427 hugger headers. Runs a 10 - 11 second 1/4 mile on 98 octane pump gas. This one is going in my grave with me!

Thanks,



David

First, the stroke of a 390 and 427 is the same at 3.784". Why would you take away the source of crankcase ventilation? All engines have some form of PCV, whether it is a road draft tube, breather cap, or PCV valve routed to the carburetor base or intake for burning of crankcase gasses. You need to plumb some kind of positive crankcase ventilation system, or at least re-install a breather, either on the manifold, or in valve covers. The blow-by of your rings will continue to blow out the gaskets, and create leaks everywhere. Joe-JDC.

I saw these really cool solid valve covers that did not have any ventilation whatsoever. My carbs and air filter do not have any provision for hooking up the tube from the PCV valve, so Ive got it hidden behind the intake manifold where I have a bothersome oil leak, so I was glad to get rid of it.

Although I have built several engines in my garage, I did not really know the real reasoning behind PCV and just never did any real research on it. Honestly, I thought that it was just some emissions stuff that I could get rid of anyway. Besides, I liked the look of solid valve covers without that bothersome breather or PCV valve/tube coming from the valve cover.

PCV means positive crankcase ventilation. The positive is actually critical here. To everybody else who may not understand, including the person who originally posted, as several have already noted, the crankcase gets pressurized although the how may not have been explained properly. The volume of the crankcase does not increase and decrease as a cylinder does. That is to say that a piston going up and down does not increase or decrease the crankcase volume due to the fact that for every piston at the top of the bore there is another at the bottom. Basically in a V8 there are two pistons at the top, two at the bottom and four somewhere in the middle so the basic volume does not change. What does change is crankcase pressure. Unless you have stumbled upon a major discovery that nobody else knows about, a piston ring is only about 90-95% effecient, that is to say that some pressure will slip by no matter how good the engine is. This is what causes the problems and there are definitely more than one. The first and foremost in this case is a pressurized crankcase. This results in spewing oil through every seal and hole. Blown main seals are common as are lost dipsticks as they eject themselves from the pressure. The next issue is less of a problem but can happen and that is so much crankcase pressure that engine effeciency is affected. And finally the biggest long term issue is oil contamination. Combustion byproducts end up in the oil. It is a fact. That is why oil turns black, it is carbon. The real problem is moisture and acids that form when combustion gasses mix with oil. These acids, and the moisture, damage bearings and wear surfaces and cause shortened engine life. The PCV was not invented as an emission reduction device. It was developed in the 1950's to improve engine life and customer satisfaction with new cars. It has a purpose and anybody that tells you that it is just a smog device has a lot to learn about cars. Hawkrod

Hawkrod

39 Ford Deluxe Coupe
59 Tbird 430
60 Lincoln Premier
(2)62 Tbirds
(3)68 Cougar XR7-G's
69 Cougar 428CJ 4 speed
77 1/2 Ford F250 4X4 w/460 swap
86 SVO mustang
76 F250 Crew Cab
1969 Mach I
look at my cars past and present at superford!

I simply did not want to get into a long lecture about the science of engine dynamics if he could relate to a simple answer. Joe-JDC.

I think Joe was just typing too fast when he included a road draft tube in his quick definition of positive crankcase ventilation. A road draft tube is actually "negative" crankcase ventilation, but requires the vehicle to be moving to be most effective.

I also agree that the PCV system was developed long before pollution concerns. However, in (1968?) it became the preferred (required) choice of federal regulators.

1954 Ford Customline 2-dr. sedan 390 4-speed
1955 Ford Fairlane Victoria 2-dr. hdtp, 292
1962 Ford Galaxie 500, 4-dr. sedan, 292
1968 Ford LTD 2-dr hdtp, 390 auto. (rough but driveable)
1970 F-100 360 auto (owned since 1985)

pressure to go. Helped a friend build a major 302 that kept blowing out gaskets. When I asked him if he checked the PCV he said he didn't have one. We actually ended up installing a vacumn pump system. Most repair manuals have a basic diagram.....RW

http://www.network54.com/Forum/74182/thread/1121640447/Why+didn%27t+this+work


Feel free to ignore one poster's outrageous comments (PCV = blowing up engines) unless you plan on running heavy loads of nitrous and then a PCV valve isn't appropriate. Adding a version of Ford's old style road draft tube to the back of your intake should work and allows the continued use of your solid valve covers.

ventilation explanation....if there is 427 cubic inches above your pistons...there is the same cubic inches below them !!!!without any exhaust valve to let it out !!!!!

it that simply.....Merry Christmas RW

true John and all that air PLUS the normal piston ring blow-by has to go somewhere.



Say, did you run a PCV on your cammers (the wagon?) or just breathers (road draft tube or merely a breather in each valve cover)?

the only pressure is from blow by past the rings.If two pistons are pressurizing the crankcase then another two are sucking on the way up.All there has to be is a vent system,pcv or open like the road draft tube or a couple of breathers on the valve covers in his case there is none.

compression thing sounds like a temporarily stuck valve that contacted a piston. Is this a new motor? I just put new heads on a motor I built and it ran fine until it reached operating temp, then 4 valves stuck and hit the pistons and bent, "a loud rattling noise on the upstroke". The head guy had made the tolerances too close in the bronze guides.
Good luck

Hollis Franks
Black 63 1/2 XL R Code
Gray 65 289 Falcon Ranchero

I built these EDC heads a few years ago and have never had problems with them. I am not sure if the noise I was hearing was blowby because of all the pressure that was in the bottom end. The top of the piston and the spark plug were wet (fuel smell) and I first thought that it was a broken intake valve. But, I was surprised that the cylinder went back to 150 once the pressure was released in the oil pan. The "weird sound" was only on this cylinder and during the up stroke. At first I thought that the piston wasn't making it all the way up and I was anticipating either a broken valve, connecting rod, or piston. Again, biggest surprise is that I found no mechanical problems, which is why I am now thinking that there was so much pressure that the noise was simply ring blowby that was making the wierd sound. Only other wierd thing was that it was only one cylinder on the side that was missing the breather. The side with the missing PCV valve was ok. But, this could be because of the "two pistons being up" theory, so one had to make some noise.

Did you have a couple of them lying around?
Might be a bit more than needed for a street/strip 390 motor. LOL

Mike G

I know it sounds like a hell of a lot of CFM (1700), but they really work well believe it or not. Remember, I've got extra big intake valves running the EDC heads that are ported and match the 427 mid-riser intake. I've got some decent sized exhaust valves and the EDC's are matched to the FF427 Sanderson headers. The torque is fantastic and it revs really quick too. I get through the gears pretty fast. Not bad for stock without NOS or blower.

Wouldn't 1150s fit?

fuel mileage. Seems like over kill to me as well, especially the DP's but if it runs well then use what you have.

is better than todays new toys. Why should I spend all the money on new dual carbs when I've got these two handy. Hey guys, so NOS or a blower is NOT overkill?

relatively mild (compared to many around here)and some headers and slightly bigger valves don't justify that much carb. If this was a flat out drag motor, then perhaps. Not knocking it if it works, just saying I wouldn't have gone there. It's a lot of trouble to sideways mount a pair of carbs as well, although the cool factor counts. Got any photos?

This was more for the looks and the fun factor. These are both automatic choke doubler pumpers. The secondaries rarely open because I never get a long run where I can open it up that much and it doesn't take much to spin the big hoosiers anyway. I've got two electric fuel pumps and two separate fuel lines to the fuel tank. This is on a 1930 model-a chasis, tubbed, shortened drive shaft, and a 9" (what else). All together its only about 2500 lbs. It reminds me of a 80's model Pinto or Mustang, very light. I don't know the gears exactly because it was a doner from the junk yard. Hey, I know I could've gone with 2 450's or 650's even, but the looks of the 2 850's with dual feeds to both does get a lot of wows at the local cruise in and shows. Most people stop and spend more time looking at mine than the blowers because they just aren't as interesting. Lets face it, blowers and NOS are great for drag racing, but useless in daily drivers. So my only options to get the wow factor is a big block with rare EDC heads and two enormous carbs jutting out of the top. Most people can't tell a BB chevy from a ford other than the placement of the distributor or because of the car it is in. For me its also nice to have a Ford in a Ford because most streetrods are all sporting chevy 350's. They get all nostalgic in having a 1930's Ford, but its got a GM drivetrain! So, that's where mine stands out.

I've never heard of 850's with automatic chokes unless they are a spread bore? Either way it's more than double what should be used and probably hurts driveability over two 600 vacuums.

If that's a dual plane Medium Riser intake you shouldn't really have them sideways. Mounting them that way makes awful distribution.

Is that the car in the little picture ? The red one? Pretty cool, nice to see Ford powered hot rods

I never mentioned sideways. Holley has/had 850's with automatic choke. Come on guys, give me a break. What's all the fuss about me having two 850's?? I never complained about the streetrods sporting blowers that were never meant for the street or the NOS guys who just have it and never use it. So what if I've got two 850 carbs. Hey they look fantastic and the car runs just fine. Isn't a blower on a street car way more over the top than just me having two big carbs??

on a M/R intake in traditional inline position. They are just too long due to the secondary metering plate. I've also never seen the DP with automatic chokes. No need to defend your use of them, I'm just curious how you made it happen. Like I said earlier, how about some picturs of your car and setup. Sounds pretty cool to me at any rate.

how it's explained, the engine will not run unless the crankcase is vented in some way. Don