leak down

[PE857]

OK guys, need opinion,
Blown alc inj 505 bbc, started and warmed up best i could, still less than 100 degrees after idiling out 5 gal of alcohol at 1500 rpm. block just warm to the touch.
did leak down, results #1 18% #2 8%
#3 7% #4 10%
#5 6% #6 14%
#7 18% #8 10%
cranking compression all cyls 140# except#6 130# and #1 130#
motor has about 12 1/4 mile passes on it
tear down or not???????
Thanks

[058]

Run it.

[GofastRacer]

Teardown???, if you got good oil pressure, run the shit out of it!!.......

[hulshot]

your running alcohol, that is common to wash the cylinders clean of any oil because of the volume of fuel that is in the cylinders. sounds like your real rich at idle and just off. are you running water in the block or just in the heads or any at all? If yur really conserned about getting heat in the motor before a pass than run 110 octane fuel through it and be sure to shut your shutoff valve way down the lean the fuel mixture or run it on alc and shut the fuel down to lean on it this will cause a higher rpm and build up heat do to it being lean. I'm assuming its blown and injected??

[PE857]

yes, it is inj, and i'm sure it is pretty fat. oil pressure is excellent 90 idiling over 120 quick blip of throttle.
another friend of mine mentioned the cyl wall wash down possibility.
hulshot, im going to try the gas warm up thing next time. seems like no matter how hard i run that motor it will never get over 140 degrees. when im waiting at the in ramp i always fill the block with a small elec pump, turn it off, and go to the holding rope, make pass, and drive back to trailer still with no temp.
yes i do seem to have quite a bit of oil contamination. use castrol 20/50 oil, always have, but if youre familiar with that stuff it always looks like a milky mess at change time anyway. still have had good luck with it. change after every weekend of racing.
thanks for youre input. hoping to get away without a rebuild.

[PE857]

by the way, the boat is the red and blue kurtis hydro in the "race boat gallery" section under "drag boats" in the picture area.

[73kona455]

if u will lean it out with the shut down and build the temp to 180 it will run alot better . and the milk oil problem will go away alot.. boss has an alcohol drag car..
it makes alot more horsepower around 180 degrees.. up to 210 degrees..... above 210 power starts to fall off again...

[Infomaniac]

Where is it leaking rings or valves? What kind of rings did you use? I guess you used 100 PSI to check it.
[This message has been edited by Infomaniac (edited March 24, 2002).]

[PE857]

Info,
All of the leakage was in to the pan, checked it with a sthescope and could hear it plain as day.
Has speed pro file fit rings. Fresh hone, and best i can remember had .026 end gap. What ever Speed Pro recommended for blown applications.
Yes did use 100PSI of air.
Info, I have always valued your opionion on here, what would you do?

[058]

Those cyls. are still good. When they reach 30% leakage then think about freshening up the engine. Consider you are leaking a cold engine that has been fuel washed. If you still have doubts then do a "wet" test. Don't put too much stock in a leak-down test, rings work best when the engine is running.

[Infomaniac]

PE857: sounds like your barrel valve is way fat. As far as the compression test I would not be concerned. If it was mine I would check it reguarly, write down the readings to establish a trend. If one or two of them start to go away in a hurry, then start to worry. Those readings are OK. It is best to check it hot but is not always possible. I usually check mine cold because it will always be the same temp each time I check it. Cut the oil filter open when you change it and use that also to determine the health of the engine.

[hulshot]

If your milking the oil that bad yur flooding the motor and probaly loosing alot of power. on your next teardown install ZGS rings or total seal. this will almost completely rid the oil problem unless there is another problem, cracks,headgasket, and so on. What size pump are you running and what pressure is your idle check and your high speed poppit?? what kind of barrel valve do you have. what is the leak down on the barrel valve. so many questions. Isnt triing to make alot of power fun?
At the track I would run race gas in the pits and just before the water I would again go extream lean on the alcohol and try to get to 200+ on each head ( only ran water in the heads) I would let it start to steam out the lines, after a pass I would be down to 130 - 150 on each bank. I did not have milky oil either and I was still fat and happy
# 058 I may have run with you at one time. the number sound familiar. I had boat 757 Alc Flat HULLSHOT sound familiar.
PE 857 what kind of times are you running?