Smokey 455

D

DB

Guest
I recently completely rebuilt my 455 and it runs unbelievably good. However, after I start it up and it runs for a few minutes, it starts to smoke (bluish tint) through the exhaust. I used new .030 Forged Pistons with Chrome Moly Rings from TA, had the heads and block completely redone by a very reputable machine shop. It doesn't smoke when I first start it, nor does it smoke excessively (that I can see in the rear view mirror)as I am driving. I haven't messed with carb jetting yet and it smells very rich. Could this be the carb loading up and just appears to be oil? I have been told the chrome moly rings pretty much seat as soon as you start the engine, but could they still not have seated all the way? The engine has about 200 miles on it since I started. Any help would be appreciated.
 
Don't remember the gap. I had the machine shop install the rings on the pistons for me. I did check them once I put the pistons in the holes and I do remember them being almost dead on.

Broke in was done as usual. Started the engine, ran it for 20 minutes at about 2800 rpm, rapping the throttle occasionally. Drove it varying speed for about 100 miles and changed the oil. Still varying speed, but getting into the carburetor at little now. Have noticed the oil is already dark again. Thanks for the reply.
 
Sorry, forgot to add that it has used about a quart of oil since I changed it the first time, but I have had engines use oil at firts after rebuilding which eventually quit so I wasn't too concerned about it until now.
 
DB,

First thing to do would be to adjust the idle mixture and see if that helps. (It might also be something else, but first things first)

I assume you are using a Q-jet. Was it rebuilt too?

To tune the idle, hook up a vacuum gauge, and turn the idle mixture screws (one on each side) until you max out the vacuum reading for that screw. Then do the other side. Then double check each side.

If that doesn't help, we'll start looking at compression readings, etc.

-Bob Cunningham
bobc@gnttype.org
 
I am running a 950 HP series Holley double pumper.

As soon as the weather breaks, I am going to install a MSD 6AL ign box and jet the carb down.

Hopefully that is all it is, but I have a feeling I may have glazed the cylinder walls.

I appreciate your help and I'll let you know what I find. After I complete the above, I make take it on an extended drive (2 hours or more) and see if that helps. Thanks again!
 
Chrome moly rings do take longer to break in.(Which is why I avoid them like the plague!) I prefer cast iron.

That said, I would give the engine a bit more time to break in. One other thing, did you stagger the ring gaps properly? I have seen ring gaps lined up that can cause this same problem.
 
950 is a lot of carb for that motor... is that gonna be a race motor?

You may be suffering from an over-carb'ed motor, which means you'll have a very inefficient idle.

-Bob Cunningham
bobc@gnttype.org
 
I installed the ring gaps 180 degrees apart so I think I am okay there. The chrome moly rings are what TA recommended with the Forged pistons. I was hoping someone else had an opinion on how they seated.

I had the heads ported and polished extensively and I am also running a pretty big cam and an single plane intake. Yes it is a big carb, but it takes every bit the 950 puts in (air and gas) without a hint of stumble or bog.

It will smoke the tires at a 30 mph roll in Drive and pulls hard to 5500 rpm. Only took it that far upstairs once, but man what a ride! Thanks for the help. I'll let you know how it does after I re-jet and install the MSD box.
 
I can't say, as a shade tree mechanic, that I have a lot of experience. I stay away from chrome rings because I have had problems with seating.

Did you have your motor bored with a torque plate? I think that chrome rings are possibly used for dirty enviroments to resist wear, like a racing engine without much of an air filtration system. If you didn't bore with a torque plate you must use a conventional iron ring to seat into the malformed cylinders, chrome rings don't seat and therefore need a good round bore.

I could be wrong, but I am sure someone will explain the pros and cons after this post.
 
On another note, I have been told that the best way to break in a set of rings is under a heavy load at low - medium RPM for about 20 - 30 minutes. A climb up the Rocky mountains comes to mind.

-Bob Cunningham
bobc@gnttype.org
 
I can recall that GM had a similar problem with the 55 Chev small black when they were first released. Their cure was to pour some Bon-Ami down the throat of the carb slowly! That roughed up the cyl walls.

I don't think that is what you need to do. If the engine is properly assembled, just put some miles on it, and hopefully it will cure the problem. Vary the RPM, and drive it around town. Not much fun with a single plane manifold, but it will get the engine broken in.

Good ol' cast iron rings seat faster, last longer, and are a lot cheaper. Chrome moly is great for a Nascar engines, but then, they only have to last about 6 hours.
 
Thanks to all who have replied! I appreciate the help.

To be honest, this thing makes so much power down low that you cannot even tell it has a single plane intake on it. It makes awesome power through the whole power band.

But, we all know that's what Buick big blocks are known for. Can't wait to take it to the track this spring and spank some Chevys and Fords with it!
 
Great! And if the smoke doesn't clear, you can always rent it out down here in Florida as a misquito fogger!

Did you by chance retard the cam? That will kill some of the bottom end torque, and give it back to you on top end. Let us know what she turns.

What is the rest of the "package"? Body? Trans? Rear?
 
It doesn't smoke that bad, just a slight hint that is more or less aggravating since it is a new motor. I installed the cam at 4 degrees advanced (as recommended by TA) and it has a nice chop through full exhaust. I think I need all of the torque I can get to get the big pig rolling.

The motor is in a '72 Skylark Custom. It's backed by a built 350 turbo tranny w/3500 stahl and a 12 bolt out of a '70 Chevelle with 4.11 gears (local track is only 1/8th mile), electric fans, 160 deg. thermostat, March underdrive pulleys, drive shaft loop, B&M ratchet shifter, Poston full length 1&7/8 headers with Flow Master two chamber mufflers and Southside Machine lift bars. Best of all, the air conditioning is still hooked up and blows cold.

I also have air bags, 90/10 front shocks, rear sway bar and trunk mount battery kit yet to install before I hit the track. I'll let you guys know what kind of 60ft., E.T. and MPH it runs (track opens in early April).
 
Did most of my NHRA-AHRA racing in your area at Bunker Hill and IRP. As I recall, New Albany is north of Ft. Wayne? I ran there once or twice.

That combo should put you into the 6's in the 1/8. Should pull about 106. Mine did, but it was a C-S/A. (70 GS Stage1).
 
Actually, New Albany is about 100 miles south of Indy. I run it at Ohio Valley in Kentucky (Fort Knox) about 30 miles Southeast of here. I'd like to take it to a 1/4 mile track, but with 4.11's, I think I'd run out of gear. Kind of scared to take it over 5800 (Buick big block). I also have a set of TA Stage II alum heads. Those will have to be put on later due to expense of setting them up and buying new headers. Those should really wake it up, I hope.

I was hoping for mid 7's, but 6's would really be fun! I'll have to put a cage in it if it runs that good.

Worried the stock drive shaft will explode when I put my slicks on and it finally hooks up. All this writing about the car is making me want to drive it, but the snow won't go away long enough.
 
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