News:

We have implemented a Photo Gallery for hosting images right here on SAACFORUM. Check the How-To in News from HQ

Main Menu

New engine rebuild smoking and oil fouling plugs

Started by cob4ra, August 03, 2019, 12:47:55 AM

Previous topic - Next topic

Bob Gaines

#15
Sounds more and more like a ring or honing problem as has been discussed before given process of elimination and the evidence so far. Lets us know how the engine guy handles it.
Bob Gaines,Shelby Enthusiast, Shelby Collector , Shelby Concours judge SAAC,MCA,Mid America Shelby

shelbydoug

#16
You are just to the point of needing to disassemble the engine.

There is a forth stupid thing...when you install the intake manifold, do not use the supplied cork block gaskets. They are too thick. The manifold won't sit down in the valley deep enough. Usually it will cause a misalignment of the water passages but it could also leave the bottom of the intake ports open to the lifter valley.

Use silicone there instead.

This is also related to the thickness of the head gaskets that you use. The thinner the head gasket the larger the misalignment is.

When disassembling, go slow. Look for indications of intake manifold gasket and head gasket leaks.
68 GT350 Lives Matter!

csheff

could also be from a bad hone job. if plates weren't used while honing bores may be out of round causing major blow by.

gt350hr

#18
   There are three potential sources for oil to enter the combustion chamber and cause smoking. Rings , valve guides , and intake manifold ( gaskets or PCV)
Piston ring alignment on initial start up is not a valid reason as rings are in constant rotation caused by the cross hatch pattern honed into the cylinders. Banking on the professional shops talent , and that it appears to be on one side , I am leaning toward gasket seal at the bottom of the ports on the driver's side. Something like a honing issue or broken ring would ( or should) have shown up on the dyno test / break in. You might try retorquing the intake manifold but it may be too late to regain seal at the bottom of the port , "if" that's where the problem is.
     Ramdy
Celebrating 46 years of drag racing 6S477 and no end in sight.

pbf777

     A simple test for an intake vacuum leak:  remove and plug P.C.V. and all other vacuum pluming to carburetor, leave P.C.V. or breather valve cover orifice open to atmosphere, remove opposite valve cover breather and insert butane torch nozzle (with bottle and contents attached), seal with rag, open valve mildly allowing butane to enter crankcase with engine operating at idle speed, engine will respond if leak is present in short order.      ;)

     Now for the caution, not that I have ever experienced such, as the density required to be released in the crankcase is small, and should not acquire such as to be ignitable, but, remember one is allowing butane, a flammable substance free without if only a "pilot flame", so be wary of unintended ignition, with improper handling or technique!       :o

     Don't forget the fire extinguisher!       8)

     Scott.

     BTW: the odor of burnt hair will be only temporary, and your eyebrows and the hair on your forearms will grow back!  As when one plays with fire................ ::)   

gt350hr

Celebrating 46 years of drag racing 6S477 and no end in sight.

cob4ra

I'll first ask Bill how much he has 6S852 insured for! Then I'm going to use my two headed heads only coin to flip to see who is going to do this ( I'm calling heads I win) ; I'm spoiled as 1680 runs perfect with no smoke or oil burning from its assembly!  So Scott can you please come over and do this for us ??  I know Randy can't wait to try it !!
1966 Shelby GT350 Hertz 1680 ( previously 6s1842;6s1818)                                                  2000 Saleen S281 Speedster.                              Previously two sunbeam tigers and have owned 24 mustangs ; 4 Mercury Cyclones and one 1960 Fiat 600!

SFM5S000

I'd consider paying a small fee to watch....
... from a distance of course.

Cheers
~Earl J

gt350hr

   There are "smoke machines" that can be bought on the internet.  I found a miniscule vacuum leak that turned on a check engine light with one. Saved me $500 that the dealer quoted to do the same thing No burnt hair either.
    Randy
Celebrating 46 years of drag racing 6S477 and no end in sight.


gt350hr

  My friend bought a slightly higher priced one as he uses it every day in his business. The one you show is perfect for the occasional user and can be used for checking power boosters , vacuum lines for climate control systems , and much more.
   Randy
Celebrating 46 years of drag racing 6S477 and no end in sight.

pbf777

Quote from: pbf777 on August 06, 2019, 12:17:27 PM

     as the density required to be released in the crankcase is small, and should not acquire such as to be ignitable,
   
     Scott.       

     All joking aside, this process does work, WITH PROPER TECHNIQUE, of coarse.  If one wishes to test functionability (word?), first test, leave P.C.V. system intact, note effect, you will realize that only a small amount of butane is necessary, and particularly with a vacuum leak drafting the crankcase, no great sum is allowed to accumulate; with this familiarization then proceed. 

     O.K, so perhaps O.S.H.A. wouldn't approve; after all, "strike-anywhere" matches were replaced by "safety-matches", as some individuals just shouldn't be allowed to play with matches!       ???

     And, you can trust me, as I'm also a guy who when mounting BIG truck tires and it comes time to "blow em up", the initial inflation and seating of the bead is accomplished with the use of acetylene and a match....., it works every time...., KABOOOM!       8)

     Scott.

     BTW: If you do screw-up and singe something, don't get pissed-off at me; you perhaps should not be allowed any matches!        ::)

   

shelbydoug

My son built his own machine. It caught fire.  ;D

We do have a real one here now and it works quite well. It's very useful on current production cars because of their extensive plumbing.

The machine requires you to plug it in to an air pressure line. Remember that the crankcase seals at best can hold 15 psi. Don't go plugging the device into your compressor with 150 psi. It will blow the seals out. That is depending on your plumbing.

Even if you disconnect the pcv system, if you have an intake manifold leak into the lifter valley, you are pressurizing the crankcase.
68 GT350 Lives Matter!

warwick

I have a Bosch smoke machine for late model EVAP, and other leak diagnosis. The smoke additive also leaves a UV light trace. The machine also has a gauge to measure the leakage amount.

You may want to try to borrow one-often local auto parts suppliers can but put tool mnfg field rep in touch with you. I'll bet they will be able to find/loan/demo one for you (often to demo-video). Once you see them, if you have dealt with probs, you want one.

They are not all that common-only shops that really focus on late model diagnosis have them or would consider them in my experience. Machinists want them but typically don't get them. The list over a $1k typically.

texas swede

When I rebuilt the 289HP in my 67 in Sweden 35 years ago, it smoked like a chimney. I found out the problem was in cylinder number 4 (passenger side closest to the firewall).  After removal of the head and oil pan it was obvious there was a scratch
in the cylinder wall. Took out the piston and it was the chrome-moly ring had a burr on it. A friend and experienced engine rebuilder asked if I hadn't deburred the chrome-moly rings as this was a known problem. I said the rings were new and he said
it doesn't matter. After honing the cylinder and deburring I switched the angles of the ring openings 150 degrees. It solved
the problem so I think Bob Gaines' suggestion it can be the rings is a very valid one to investigate.
Texas Swede