Hot Rod Forum banner

Engine still smokes

2K views 19 replies 8 participants last post by  red65mustang 
#1 ·
Hi, This is deno again. I changed the850 demons, to 650 demons and the engine does not run rich now, but smokes a good white oil smoke when warmed up. I think that it should be re-ringed. What do you guys think? Thanks deno---
 
#2 ·
deno said:
Hi, This is deno again. I changed the850 demons, to 650 demons and the engine does not run rich now, but smokes a good white oil smoke when warmed up. I think that it should be re-ringed. What do you guys think? Thanks deno---
Did you change your oil after the carb change that was rich, and washing the rings ? in some cases I have run into this situation and a good oil change with quality oil helped . How's the valve seals ?
Normally "white smoke "is antifreeze .........
 
#3 ·
re: engine still smokes

I didn't change the oil, but the oil is new and does not smell like gas. I lit the dip stick with a lighter and had no flash of fire. One thing is that the blower gets hot, and the spark plug wires pop off the plugs. I have new suppression wires with a Mallory 3748201 Dist. that uses a resistor. I installed a Accel super coil after. I have new positive stop seals on the intake valves to see of the guides were bad. Do you think I should put the same on the exhaust valves to see if the guides are bad also? The smoke is oil. No water in the oil, and no oil oil in the water. Thanks deno---
 
#4 ·
Blue smoke is oil, white is water, or anti freeze and black smoke means its running rich.

Just because you dont have water in your oild or oil in the water doesnt necessarily mean you dont have a leak somewhere. depending on how big the leak is you may never have water in the oil.

Check to make sure your intake manifold is torqued down and that your heads are torqued down. If this is a new build and you just broke it in.... the gaskets may have settled and after a few miles or so they need re-torqued.

I've seen people come into the shop pulling their hair out over situations like this after they just rebuilt their engines and all it needed was gone over and the bolts tightened down.

That may be where your problem is.

Also, keep an eye on that Accel coil. they are notorious for going bad. Not saying yours will, i've known them to last a long time without any problems. but i've seen them fail more times then not.

:thumbup:
 
#6 ·
If you would of had enough of gas in your oil you wouldn't
had to try and ignite it with your lighter, the engine would of
been a small fragmental bomb .

When ever a super rich condition is causing what you explained
it's washing the rings and the oil is impregnated with hydrocarbons
and other things that dilute the oil . "I was just guessing that may
be the problem" however, if your plug wires were popping off the
spark plugs and the blower was getting hot, I would think you
have a problem other than just white smoke.
I would do a compression test, vacuum test, read the plugs, do a
leak down test , recheck the timing, carb F.A.Ratio, pressure test
the cooling system and slowly start over. It sounds like something is a mis. :thumbup:
 
#7 ·
deno said:
I didn't change the oil, but the oil is new and does not smell like gas. I lit the dip stick with a lighter and had no flash of fire. One thing is that the blower gets hot, and the spark plug wires pop off the plugs. I have new suppression wires with a Mallory 3748201 Dist. that uses a resistor. I installed a Accel super coil after. I have new positive stop seals on the intake valves to see of the guides were bad. Do you think I should put the same on the exhaust valves to see if the guides are bad also? The smoke is oil. No water in the oil, and no oil oil in the water. Thanks deno---
Just a quick question...
Do you have a stock mounted fuel pump ?
the reason I ask is that I have seen the fuel get
mixed with the oil because of a leaky diaphragm.
Just a thought....something not to overlook..
 
#8 ·
re: engine still smokes

Hey guys, I am just trying to find out the problem before I take apart the engine.The smoke is white with some Gray and the smell of oil. When I bought the car I had the same problem. The engine had day one plugs in it, and it started up with no smoke. I had to get to work, so I had the delivery guy drove the car into my garage. There was no smoke because the engine had not heated up yet. When he started up the car, I heard the starter grinding. The owner then told me that he would send me a new starter. He never sent it to me. The starter is OK, but the timing was to far advanced. This is a high performance starter. To 1939P7 . I had the dip stick out,and away from the engine when I lit the oil up on the bottom of stick. I did a compression test and all came out with 125 LBS, I did a leak down test at 100 LBS, and received a 5% loss at 95 LBS. The wirer's were on tight, why would they be popping off ? Could the coil be to strong for the ignition ? Can I take the belt off the blower and run the engine to see if there is Any other problems
 
#10 ·
Do you have access to a radiator pressure tester ?
if not borrow one and do a cooling system test,
one cold and one at operating temp. if you have a
leaky head gasket that should tell you. Like with diesel
motors it's difficult to trace a small head gasket leak
or a cracked head, one sure sign is air bubbles in the
over flow tank after it's shut down and white smoke
while running.
Again: Do you have a stock mounted fuel pump ? :confused:
the reason I ask is that I have seen the fuel get
mixed with the oil because of a leaky diaphragm.
Also if you have an auto trans with a modulator
it could be drawing ATF into the intake, I ‘ve
seen that drive me nuts once . If there isn't a rough
idle or cylinder/s not firing correctly then it may be
something internal .

Have you changed the oil yet ? NAPA has an oil test kit that they sell and you may have the results in about 4 days depending where you live, that's DNA for an engine . :thumbup:
 
#11 ·
Deno, your convinced it's oil....how many miles to need to add a quart?

Another possible oil burning source is no baffles in the valve cover for the PCV, the rockers can be squirting oil into the pcv and on into the intake manifold.

redo the leak down test with the pistons only half way up the cylinder on a compression stroke, this will tell you if a wall is scored or the cylinder walls are worn bowed and the rings are not sealing. There is almost no wall wear at TDC cause the piston is close to centerline with the crank

The spark plug gap determines how many volts from the coil is needed to jump the gap, the coil will only put out just enough, not the max possible unless the plug is very wet/fouled/worn. Old points car coils were 20-30,000 volts but actually used about 1/2 their max with plugs gapped about .032". New cars plug gaps are 40-60 for a bigger flame, and are doing fine with 40-50k coils, outputting maybe 2/3's of their max.....very little chance your coil is part of your problem....

can't tell you why a spark plug wire will jump off (new one for me) but I can tell you the boots would have to be way to loose, allowing an air gap along the ceramic which can/will cause mis-fires, now your super dupper coil will put out max volts and jump from the plug end (first possible path) to the head

agree with the above....retighten the intake bolts, if the heads were milled .020"+, the stock manifold ports are not parallel, they form a inverted "V"
 
#12 ·
red65mustang said:
redo the leak down test with the pistons only half way up the cylinder on a compression stroke, "

What is your suggested way to hold the piston at that position with 100 psi in the cylinder? That would be 1256 pounds of pressure pushing on 4 inch piston multiplied by the crankshaft leverage. Putting a wrench on the crankshaft bolt the engine would be unscrewing it.
 
#13 ·
xntrik,
unless the walls and rings are a perfect seal at mid stroke it won't hold the 100psi (and move the piston?=no oil getting to the comp rings?)
it will start leaking past the rings at ex:60lbs??? (based on his 125psi comp results) and you can hear it if the walls are really bowed/worn and/or the rings are shot

"IF" he is burning oil (white-grey?).... his TDC comp and leak tests and plugs read good.....leaves rings and walls?

what this test is best for is checking for a scored (wrist pin loose?) clinder wall, much lower leak point value than the rest...won't show up at TDC
 
#14 ·
re still smokes

I just went thru the same thing with my t/a. come to find out it cracked several oil control rings. no blowby, good compression, good leakdown test. my motor was for lack of a better word, 11.7 compression and it really didnt like being whaled on running pump gas, silent detonation finally caught up to me.. with your blower application , and you said it was hard to start from advanced timing, same thing may have happened.
 
#15 ·
red65mustang said:
xntrik,
unless the walls and rings are a perfect seal at mid stroke it won't hold the 100psi (and move the piston?=no oil getting to the comp rings?)
it will start leaking past the rings at ex:60lbs??? (based on his 125psi comp results) and you can hear it if the walls are really bowed/worn and/or the rings are shot

"IF" he is burning oil (white-grey?).... his TDC comp and leak tests and plugs read good.....leaves rings and walls?

what this test is best for is checking for a scored (wrist pin loose?) clinder wall, much lower leak point value than the rest...won't show up at TDC

So how do YOU do it?
 
#16 ·
xntrik,

plugs out,
dist set to 0 deg advance, dist cap off, dist base marked for cap contact align (so you know your before) TDC reference for rotor/which cylinder is coming up on TDC,
thumb on the spark plug hole, rotate till you feel some pressure (both valves closed)(and rotor before TDC)
screw in your comp tester hose with disconnect,
attach to an air press regulator with gauge (mine is off an old paint gun), dial up the pressure till you hear it leak
 
#17 ·
re: engine still smokes

Thanks guys for all the input's. I will try all of your suggestions. The first thing I will do, is get a history of the engine. The engine is a stage 2 from Big AL,S TOY BOX. I received the original buyers phone #, but the engine was taken out and sold to someone else. I am trying to contact him now, Thanks again deno---
 
#20 · (Edited)
Deno, I'll ask again... how many miles to a quart of oil? Your convinced it's oil but I'm not convinced it's not water or tranny fluid cause it is grey/white and your plugs are tan

BDC tests: ? cause the piston skirts are hangin' out of the bores and the rod/piston is at an extreme angle and there is probably (normally) no major pressure due to (normal?) valve close time during the upstroke and bores wear less than max at the bottem.....I have no idea what the results would tell you????

TDC
( )-mid stroke: represents (?) the bowed wall wear on a worn cylinder wall ,worn oil rings are most relaxed at approx mid stroke allowing the comp rings to scoop excess oil off the walls to burn.....which normally shows up as thick baked on black deposits on the steel inner part of the plugs (with tan insulator) with "some" wall wear/weak oil rings

Maybe somebody here can tell ya how many miles rings last with the blower boost pressures?
125psi (hot-throttle open?) comp= roughly 8/1CR which in a normal stock motor.....rings and walls can last (?) 250,000 miles

If this motor has been sitting un-used for a long time (yr?), there can be alot of water condensation/contamination/etc. in the block, the pcv sucks it out when the oil temp is hot =grey smoke....hope that's it.....drive it on the hwy (hi-vac/low load) to burn it off and then change the oil
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top