TBucket Engine Project (Dart SHP)

Do a compression test on a warm engine (say, 140-160 water temps) followed by a leakdown test with the engine still warm. Brian says the numbers may be all over the place due to the detonation. Write them all down as you test. (all this per Brian)
 
Indycars said:
So which came first the chicken or the egg...... the detonation or the oil consumption?:confused:
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The oil consumption is causing your detonation.
On the first go around with my 334 SBC, I used Total Seal rings. The car started using oil right after break-in and never tapered off.
I was positive that the rings never seated. As time wore on, it started using LOTS of oil, up to the point that it would spray raw oil
out of the tailpipe and onto the bumper of whoever was parked behind me at work. Kinda like a Wagner power painter. Yet it passed
the compression test with flying colors. And there was a "tick" inside the engine that I never could find. That's when I parked the car
18 years ago with 19K miles on this engine. I don't know if I really did have a ring sealing problem, or not. What did happen was that
due to insufficient valve retainer to seal clearance, the cam lobes and lifters went bye-bye, and all that metal went through the engine,
destroying everything. It badly scratched the cylinder walls, embedded in the sides of the pistons, bearings, crank journals, etc.
While the valve seals were new, there was no noise. In time, as they hardened, a very light "tick" appeared.
The cylinder wall scratches were not at the top, so it would therefore pass the compression test. I'm not saying that this is YOUR problem,
but if so, then don't spend too much time troubleshooting, because you will be doing more damage. A compression test with the pistons at
BDC should reveal this problem.
When I rebuilt, I used regular Hastings moly piston rings and I now have miles of clearance in the valvetrain.

Again, not saying that this is your problem, and I know you checked, double-checked, and triple-checked everything.
Even so, shit like this sometimes just happens. Seems like always to me. I hope it's a minor problem in your case.
 
I forgot to add to the above that along with my oil consumption problem, I had detonation. It was revealed
when I pulled the engine apart. My rod bearings no longer had their outward crush and just fell out of the rods.
That is an indicator of detonation. I have a good ear, and always listen for it, but I never heard a thing!
 
 
Grumpy said:
easily 60% of detonation is not in the normal adult humans hearing range
Click to expand...
That is why I want to modify a knock sensor/Electronic Spark Control module to flash an LED when knock is detected
so I can then manually retard the timing.
 
There may be hidden hot spots inside the motor. Measure each cylinder head with an IR pyrometer to see. Brian was having some issues with hot spots, solved them today. (per Brian)
 
Loves302Chevy said:
I forgot to add to the above that along with my oil consumption problem, I had detonation. It was revealed
when I pulled the engine apart. My rod bearings no longer had their outward crush and just fell out of the rods.
That is an indicator of detonation. I have a good ear, and always listen for it, but I never heard a thing!
Click to expand...

That's scary if I can't here the detonation. Looks like I will have a project to do this
winter. In the meantime I will need to use an octane booster of some kind. I checked
at Lowes and Home Depot, could not find Toluene. So not sure what direction I will take.

Thanks for your comments
 
At $26/gal for Toluene it's kinda high, I can buy 110 octane gasoline for
$7.80/gal. Toluene must have really gone up lately for it to be so high.
 
price seems to vary,between stores ,Ive seen it cheaper at the auto paint store recently, I bought several gallons a couple months back for $18.99 each
I tend to pour a couple gallons in the tank of the 1985 corvette when I intend to use the nitrous , as a safety measure ,but rarely other times
 
the high octane is just a band-aid.
Considering how much $ and time you spent in that engine, you should do more testing and find what is the cause(maby pull the engine and dis-assemble...), before running it too much and maby doing intensives damages.
 
mathd said:
the high octane is just a band-aid.
Considering how much $ and time you spent in that engine, you should do more testing and find what is the cause(maby pull the engine and dis-assemble...), before running it too much and maybe doing intensives damages.
Click to expand...

I agree with Mathieu. Pull your oil filter and cut it open before you run it again.
Or you could have an oil analysis done. You MUST find out where your oil is disappearing.
If I remember correctly, your DCR was about 8.3:1. Should be fine for pump gas.
So did the weather make that much of a difference that you now need more octane?
 
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Mathieu,
The band aid is only until I can get to the colder months and can't drive. What tests would
you suggest to determine the cause???

I wonder why the plugs don't show specs of aluminum, is this not a good indication of
detonation at any level???

Love302Chevy,
It's not leaking oil and the exhaust does not have that much smoke that would indicate the
kind of oil usage I'm seeing. None of the transmission fluid go thru the radiator, so I'm just
wondering what's really happening.

How is cutting the filter open going to help, what would I be look for?

DCR is 8.27 ..... good guess, very close to 8.3.
 
Brian says he suspects pre-ignition leading to detonation. Eliminating all hot spots in cylinderhead water jackets will help. Bring water temp down to 140-160 F. Or drop hot driving water temp 10-15 f. He says he'll elaborate more after the first of the month when his ban expires. Every engine has hidden cooling system flaws. Pre-ignition leading to detonation or just detonation super heats the oil around 400-800 F.
 
Indycars said:
How is cutting the filter open going to help, what would I be look for?
Click to expand...

The oil has to be going somewhere. Learn from my mistakes and incorrect assumptions with the 334.
Waste an oil filter. Cut it open to make sure that something mechanical did not fail. If so, then metallic
chips will be in the filter. If not, then continue with what you are doing. If there is metallic debris, then
every revolution that crankshaft makes is killing all of your hard work.
I should have cut open the filters on the 334. I assumed that the engine was mechanically sound, so while
I was looking in other places, I was actually doing more damage. The inside of the filter would have revealed
that the cam & lifters were failing. I would have stopped and found the cause.

It is possible that your piston rings have lost their seal. All of your spark plugs show oil deposits.
 
Drawmain said:
Brian says he suspects pre-ignition leading to detonation. Eliminating all hot spots in cylinderhead water jackets will help. Bring water temp down to 140-160 F. Or drop hot driving water temp 10-15 f. He says he'll elaborate more after the first of the month when his ban expires. Every engine has hidden cooling system flaws. Pre-ignition leading to detonation or just detonation super heats the oil around 400-800 F.
Click to expand...

Rick, have you ever taken a timing light and verified/graphed your advance curve?
Are you sure that the outer ring of your balancer has not slipped?
 
Drawmain said:
Brian says he suspects pre-ignition leading to detonation. Eliminating all hot spots in cylinderhead water jackets will help. Bring water temp down to 140-160 F. Or drop hot driving water temp 10-15 f. He says he'll elaborate more after the first of the month when his ban expires. Every engine has hidden cooling system flaws. Pre-ignition leading to detonation or just detonation super heats the oil around 400-800 F.
Click to expand...

He makes a good point here. I think I just saw a post on Grumpys where the impeller separated from the shaft
inside the water pump. So while everything seemed fine from the outside, the water pump was not moving any coolant.
 
The piston rings will seal up again once the pre-ignition/detonation ceases, your smoke and oil consumption issue will be gone (per Brian)
 
Rick, a multi level approach here may help!
one factor you may be having is that some coolants don,t contact the inner engines micro surfaces without a wetting agent added to the coolant ,and, I know you did a good job tunning the cars engine, but something may have changed,
Id start by verifying the fuel pressure, ignition timing, coolant levels , I'd look for vacuum leaks,and check the oil level, inspect the oil filter internally, and you may want to consider retarding the cam timing an additional 3-4 degrees and checking the piston to valve clearance, as this effectively reduces the dynamic compression, and moves your whole torque curve about 200 rpm higher and IF , anyone is reading this thread, and having a similar issue and if your car, does not have an oil cooler, transmission cooler,7-8 quart baffled oil pan, radiator fan shroud, and an adequately sized radiator,and oil temp gauge's that keep you aware of the fluid temps. you might want to install those, as those parts are all effective in reducing the thermal loads on the engine, keep in mind reducing the operational temps reduce the potential for detonation. you might want to recheck the ignition timing curve advance, has not changed, and a 160F t-stat with several air bleed holes added might help as a test, but as youve already proven , increased octane levels will potentially help avoid the issue, and filling the fuel tank with the highest level of octane fuel at the gas station ,may seem like its increasing the cost of vehicle operation, but its dirt cheap insurance spread over a life of the car, vs the cost of replacing a detonation damaged engine if you select lower octane fuel in a false effort to save cash flow.


the links and sub links will be helpful
http://garage.grumpysperformance.com/index.php?threads/water-wetter.2140/#post-11172

http://garage.grumpysperformance.co...steam-holes-posted-by-dennyw.2991/#post-57455

http://garage.grumpysperformance.com/index.php?threads/unwanted-engine-bay-heat.12186/#post-59072

http://garage.grumpysperformance.com/index.php?threads/how-radiator-caps-work.7718/#post-26294

http://garage.grumpysperformance.com/index.php?threads/octane-boosters.613/#post-46230

http://garage.grumpysperformance.co...ow-to-reduce-its-likely-hood.9816/#post-49741

http://garage.grumpysperformance.co...octane-for-compression-ratio.2718/#post-35581

http://garage.grumpysperformance.co...n-you-plan-for-quench.11298/page-2#post-51599

http://garage.grumpysperformance.co...et-it-to-last-cam-install-info.90/#post-57942
 
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