Smoking / Oil soaked plugs
11-24-2015, 09:14 PM
#1
9 Second Club
Thread Starter
Smoking / Oil soaked plugs Fresh motor-- less than 300 miles on it.
11.8:1 383 (Wisecos, heads are heavily ported/decked 5.3s with 54cc chambers), th400, etc.
Melling high pressure, high volume oil pump.
10w30 60psi idle.
Rings are gapped .026/.028
It went through typical break in: Check for leaks, flog it on the dyno.
The car would always smoke a little on start up, assumed it was oil leaking down the bolts from the trunion upgrade.
The car saw a handful of WOT pulls, 2-3 on a 250 shot.
The car was not smoking during high rpm pulls.
I dropped the car off at the tuner for some NA drivability tuning, and when I picked it up he said it was leaking oil. I threw it on my lift and saw it soaked the rear cover, and was dripping from the starter and oil pan.
I cleaned it up, did a test pull (N/A) and it would smoke bad above 5k.
Back on the lift, removed the trans, replaced the rear main and the rear cover, replaced the old "PCV" that consisted of each valve cover T'ed into a breather with 6AN hose with a 10AN bung welded into each valve cover, with its own K&N filter breather, and then also replaced valve cover gaskets.
Cleaned everything up, and went to the dyno today for nitrous tuning. First motor pull, it smokes BAD... then it starts smoking at idle. Drained catch can, did another pull to see if it was a fluke.. Smokes just as bad @ WOT & idle afterwards. Oil spewing from rear of the motor and on the ground. It is not leaking from oil pressure sending unit or cam sensor.
The crazy thing- it was not down on power at all. It actually picked up 5 rwhp from pull 1 -> pull 2.
Removing oil cap and cracking throttle you can't feel any blowby or excessive pressurization through the oil filler.
I pulled a few plugs, and 1,2,3 were all oil soaked.
Any ideas? This motor was freshened up (rings, bearings, valves, sleeve in #8, and pistons in 3 & 8) after eating a few ground straps earlier this year. The car was built for 300-400hp of spray, so the rings are a little loose-- but what would cause them to 'unseat' ?
11.8:1 383 (Wisecos, heads are heavily ported/decked 5.3s with 54cc chambers), th400, etc.
Melling high pressure, high volume oil pump.
10w30 60psi idle.
Rings are gapped .026/.028
It went through typical break in: Check for leaks, flog it on the dyno.
The car would always smoke a little on start up, assumed it was oil leaking down the bolts from the trunion upgrade.
The car saw a handful of WOT pulls, 2-3 on a 250 shot.
The car was not smoking during high rpm pulls.
I dropped the car off at the tuner for some NA drivability tuning, and when I picked it up he said it was leaking oil. I threw it on my lift and saw it soaked the rear cover, and was dripping from the starter and oil pan.
I cleaned it up, did a test pull (N/A) and it would smoke bad above 5k.
Back on the lift, removed the trans, replaced the rear main and the rear cover, replaced the old "PCV" that consisted of each valve cover T'ed into a breather with 6AN hose with a 10AN bung welded into each valve cover, with its own K&N filter breather, and then also replaced valve cover gaskets.
Cleaned everything up, and went to the dyno today for nitrous tuning. First motor pull, it smokes BAD... then it starts smoking at idle. Drained catch can, did another pull to see if it was a fluke.. Smokes just as bad @ WOT & idle afterwards. Oil spewing from rear of the motor and on the ground. It is not leaking from oil pressure sending unit or cam sensor.
The crazy thing- it was not down on power at all. It actually picked up 5 rwhp from pull 1 -> pull 2.
Removing oil cap and cracking throttle you can't feel any blowby or excessive pressurization through the oil filler.
I pulled a few plugs, and 1,2,3 were all oil soaked.
Any ideas? This motor was freshened up (rings, bearings, valves, sleeve in #8, and pistons in 3 & 8) after eating a few ground straps earlier this year. The car was built for 300-400hp of spray, so the rings are a little loose-- but what would cause them to 'unseat' ?
12-05-2015, 09:04 AM
#2
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There is a number of things that could have been overlooked one or more may apply;
If heads were ported there could be a leak true the intake rocker bolt into the intake port, this along will do it, the fix is easy just put tread sealer on the intake rocker bolts.
Excessive wear on the valve guides and/or bad or missing valve stem seals.
There is a draw back on Nitro build engine blocks due to the extra 6 to 8 thousands extra gap on the piston two top rings, this can be compounded and exaggerated by the use of low tension oil control rings. This combination is very often broad about by machine shops and builders alike thinking that low tension oil rings will yield extra horse power, is really the opposite you can't make power you can enjoy with an smoking engine and wet plugs, i sincerely hope this is not your case but if it is, is worth going true the hassle of fixing it.
The fix high tension oil control rings and be sure the nappier second ring is properly oriented if not will sent the oil to the combustion chamber instead of the oil pan.
I hope this helps good luck and please let us know what it was.
If heads were ported there could be a leak true the intake rocker bolt into the intake port, this along will do it, the fix is easy just put tread sealer on the intake rocker bolts.
Excessive wear on the valve guides and/or bad or missing valve stem seals.
There is a draw back on Nitro build engine blocks due to the extra 6 to 8 thousands extra gap on the piston two top rings, this can be compounded and exaggerated by the use of low tension oil control rings. This combination is very often broad about by machine shops and builders alike thinking that low tension oil rings will yield extra horse power, is really the opposite you can't make power you can enjoy with an smoking engine and wet plugs, i sincerely hope this is not your case but if it is, is worth going true the hassle of fixing it.
The fix high tension oil control rings and be sure the nappier second ring is properly oriented if not will sent the oil to the combustion chamber instead of the oil pan.
I hope this helps good luck and please let us know what it was.
12-05-2015, 09:43 PM
#3
9 Second Club
Thread Starter
part of the mystery has been solved... The oiling under WOT & at idle appear to be from oiling down the intake. The catch can had filled and was also installed backwards. (The filter material was on the clean side)
I pulled apart the fast and cleaned it out, put new plugs in it, plugged the intake PCV hookup, and installed a breather filter on the valley cover.
While it was apart I redid all of the rocker bolts with permatex thread sealant since the heads are heavily ported and I figure my startup smoke was coming from that.
No smoke on startup or idle-- but the oil leak is still there. I ordered a replacement rear cover and will also replace the freeze plug in the back of the crank since it's an eagle 4" crank and they're apparently known for leaking.
Thanks for the feedback so far and I'll be sure to update the thread with the final resolution.
I pulled apart the fast and cleaned it out, put new plugs in it, plugged the intake PCV hookup, and installed a breather filter on the valley cover.
While it was apart I redid all of the rocker bolts with permatex thread sealant since the heads are heavily ported and I figure my startup smoke was coming from that.
No smoke on startup or idle-- but the oil leak is still there. I ordered a replacement rear cover and will also replace the freeze plug in the back of the crank since it's an eagle 4" crank and they're apparently known for leaking.
Thanks for the feedback so far and I'll be sure to update the thread with the final resolution.
