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383 Stroker with blow by PCV problem

22K views 31 replies 12 participants last post by  64nailhead 
#1 ·
Bought a C10 with a 383 installed. It had a blow by problem with the oil breather/catch can installed. PCV was removed and capped. I installed a PCV connected to air filter and blow by problem still present. I now have a double pcv system. One going to air filter the other to intake. I adjusted timing to 12 btdc at idle and 34 at 3000 rpm. I ran it up the freeway today to check timing and got on it. Pushed rpm up to 4100 to check timing, power, etc. When I exited freeway I filled the street up with white smoke. It looked like the truck had caught fire. PLEASE I need help to figure out this oil pressure problem. What could I have done to cause this smoke? It was not present before the pcv system was installed.
 
#3 ·
sounds to me like the excessive blow by is now getting sucked into the engine, and the smoke you saw was the excess blow by (oil) burning in the cylinders. There should not be that much blow by. I run adrag car with no PCV or header evacuation, and the motor has extra ring gap for nitrous, and I have very little blow by at all.

chevyguy13
 
#7 ·
First you had no pcv then you installed a pcv wrong by hooking it to the air cleaner. Pcv hooks to manifold vacuum source. Then you have a breather which can be hooked to the air cleaner or the breather can just draw air from the engine bay.
Pcv on one cover, breather on the other.
Pcv uses vacuum to pull fresh air into the motor which mixes with the blowby fumes and into the motor to be burned.
2 pcv's won't work if one is hooked to the air cleaner like you have now. The other one has no air supply.
 
#10 ·
After the engine is warmed-up real good, remove both pcv valves. Either chock the wheels or have a friend hold the brakes while its put in drive. Does a lot of smoke come out of the pcv ports? If it does it may need compression and leak down testing done to see if rings are worn too much.
ssmonty
 
#11 ·
I agree and disagree with RWENUTS.Some engines did have one going to the aircleaner, with out a PCV on it, just basically a vent from passenger side valve cover to a little filter inside the air cleaner. While on the drivers side would be a pcv valve in the valve cover hooked to manifold vacuum. It does not pull in fresh air! It pulls out blowby, moisture and other gases created by the combustion process. It pulls it out and sends it back through the engine to get "re burned" no matter what you have for a pcv system you should not have that much smoke. You have other issues.
 
#12 ·
True! Some have a line hooked to the air cleaner. Some have a breather. You need some where to get air in to the motor to mix with the fumes. Plug off the breather hole and the pcv shuts on the other valve cover. A vacuum can't pull on a vacuum. It deadheads. That's why you need to supply some air with the breather to mix with the fumes.
 
#15 ·
When you ran it up did it detonate really bad? Last time I ran my blower car at the strip, third run it layed down at 1,000 feet, and instant blowby. Had to drive it home 50 miles like that, looked like I was on fire. Found 7 pistons burned and pounded so bad I couldn't pull the rings (C&A gapless) from the grooves, couldn't hear detonation that killed it.

Before that I had no PCV system, but didn't have any issues with blowby. When I rebuilt the motor I did go with PCV. This is worst case, but just sayin...do a compression check.
 
#17 ·
It did not detonate. I think I am going to try a breather source. After I check the valves and rings.
Check the valves and springs for what? What are you looking for in that area related to excessive blowby? Worn valve guides maybe??
 
#18 ·
383 Stroker with blow by PCV problem

Ok, let's make this easy. install a PCV valve on driverside valve cover. Run vacuum hose to the large fitting on carburetor. Install a breather cap on passenger side valve cover. The PCV valve will pull fresh air into the engine thru the breather cap when pulling a vacuum. You can also use a breather cap that has a fitting for a hose to run to the Crankcase Ventilation Hose Connection under the Air Filter assembly. Most aftermarket Air Filter asemblies provide this fitting.
 
#19 ·
leak it down......you got ring/cylinder seal problems sounds like.......pvc....yeah, ONE hooked to the engine vac source, but ya gotta have an inlet too, so a breather on the opposite side works good. this allows fresh in, and blowby back into the intake to be burned......disconnect pvc, remove breather, start motor....wat happens? oil/vapor fumes? is there enough that alot of pressure can be felt when you put your over the open hole?
 
#23 ·
Not too sure

I am taking it back to Phoenix and tearing it all down. I bought the motor and transmission in Fresno. Ran it around and now its time to take it down and see what I have. I will keep everyone updated and thanks for the help. Ii am looking at some new heads just in case. Brodix makes a decent set any others you all prefer that are under 1300 dollars?
 
#29 ·
This is a rather drawn out story, but true, and expensive.......
On my blown 406, the block didn't come drilled for a dipstick. It's a Rodeck 350+ Aluminum block that came out of a sprint car. Rodeck wouldn't even drill it. I had/have a Milodon 7qt drag pad on the motor and was looking for a way to keep an eye on the oil qty. I figured I could run around for one season without, just change the oil a couple of times. Anyway, I decided to go from Pleasanton to Sacramento, only 100 or so miles to the Golden State Nationals. Mind you, I had driven it around Pleasanton quite a bit. Well, I got about 20 miles out of town and she started to rattle the lifters and the oil pressure started to drop. Shut the car off and wait about 30 seconds, I fire her up and away we would go. I got to Manteca which was about 30 additional miles. We had to stop 2 more times. Since I couldn't check the oil, I dumped two more quarts into the pan. We left my buddies house and headed to Sac. We had to stop more times. Now, the drive home, which should of taken 1.5 hours took 6! The next day, I drained the pan, only had 3.5 quarts of oil left out of 7 or 9 depending on how you look at it. The engine never smoked a lot, just a little haze if you were looking real hard. The next winter I freshened the motor and had the valley drilled like a normal SBC for the oil to drain back, and removed a screen that was plugged with epoxy on the drivers side by the rear main cap. I also installed a Steff's sight glass in the oil pan to monitor oil quantity, and had the pan powder coated. Put her back together with the same rings in the same cylinders in the same positions (only 500 miles on them), but with new bearings. I changed the oil at 100 miles and everything seemed good. The oil looked new. After changing the oil things got worse. It was using more oil than before. One night before the Good Guys West Coast Nationals. I was at my buddies house in Brentwood. We dicided to pull the blower, he had a boroscope from work, so we looked down the intake runners an they were soaked/pooled with oil. I had already rerouted the PCV and we felt this wasn't the problem. We then pulled an intake stud out and the threads were completely soaked with oil. The anti seize had been completely washed off the threads. We cleaned up all the intake rocker studs and re-installed them with black RTV. The massive oil issue solved. But, things were still not Kosher. Remember the oil pan powder coat? The pan had trapped glass beads which by now had worked themselves loose and almost destroyed the lower end. Rebuild No. 2, removed the "O" rings in the deck and changed over to Cometic head gaskets and new rings and bearings. Now, everything is *****en and she runs scary awesome. No more leakage!

Keith
 
#26 ·
there are a few ways to determine how much head flow you need.The most simple but not most accurate is take the CFM air flow on the intake side of the heads and double it,,,IE: if a set of heads flows 250 cfm it will support 500 plus HP.It doesnt mean you will have 500 hp,just that if you use the correct combination of matching parts then the engine has potential to generate 500 HP. The exhaust side of the heads ideally will flow 75% or more of the intake figures.
 
#27 ·
Thanks for the great information, not just for this post, but all of your post. I think I've learned more things about making an engine go fast and hold together in the last 6 months by reading your posts and a few others than I have in the previous 57 years when I was thinking I knew a fair amount.

Thanks Again Vinnie
Ray
 
#28 ·
So I tore it down

Found out I have some 60's fuelie heads old enough that the valve seats are not hardened. I guess it IS time to start shopping for some new heads. I am going to post fuelies with casting number for some number matching restorer. They are the 202 with the angle spark plugs.......very rare for 50 year old heads. Ha ha! Thanks for everyones help. I will post again when I am done re re re building the 383.
 
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