Bender Stage 2 spit a bunch of oil out .....

[77srxdude]

of the crankcase breather tube.

Bought the turbo used, installed and ran last week for 4 days straight over 600 miles. Ran flawless until the fourth day. Had 1/2 110 and 1/2 93 for the first two days at 16 lbs of boost and no problems.

Dropped it down to 13 lbs and was just runnin 93 the last 2 days.

Over the 4 day period I had to add roughly 1 1/2 quarts of oil and smelled burning oil often. I knew I had some in the turbo coming out of the compressor and in the chargetube and intercooler - the guy before me told me it did that some and he had the jet in the line.

Last day - we probably did 10 1/4 mile runs over 1/2 hour at 13 lbs and after the last run the sled pulled up and started dropping oil out of the belly pan.

Engine still starts and runs fine, no loss of coolant no, holes in the block - so good news there.

It looks like the oil spit out of the crankcase breather tube and filter - although I haven't completely taken out everything to see if maybe I have a bad line. Doing that thursday night.

I would say probably 1/4 quart of oil sprayed out and ended upon the ground - anyone else ever had this happen?

Otherrwise - this turbo thing is unfreakinreal!

 

[kaj]

read this post
http://www.ty4stroke.com/viewtopic.php?t=38888

 

[Srxspec]

13 lbs on a stock motor on 93 octane? If so not near enough octane for that kind of boost and compression!

10 runs within a 1/2 hour or one run every 3 minutes high water temp & big boost with not enough octane = boom. Remove head and replace #1 & #2 pistons and rings and have block renicasiled.

 

[BigDog05]

77srxdude: Hope its not as bad as it sounds, but the below boost calculator is pretty good reference reading.

http://www.ty4stroke.com/viewtopic.php?t=23214

Depending on elevation etc, about 7-7.5 lbs is about max for a Bender at 93 octane.

 

[Maddog]

Welcome to my pain. Get ready to rebuild. Look for the post motor rebuild?

 

[77srxdude]

I saw that boost calc - thought I read it as 12 lbs at 90 octane was OK - obviously I was reading it wrong and should have asked someone.

Live and learn - don't have time tonight but should know tommorrow night how much work it got.

I ran the thing for 140 miles hard on saturday at 93 without a problem. Sunday it ran for an hour all good then it happened. I guess I must have been lucky all day Sat.

Is it normall for me to be able to start it up a couple different days after that and drive it on and off trailers - even if it had holes in 1 or more of the pistons?

 

[givemeaboost]

The more you start it the better the chance of screwing up a cylinder. But you probably did it in allready. Do a compression check before you start tearing things apart. It takes a 10mm adapter to fit on a regular compression tester, Ken.

 

[FAMILYMAN]

10lbs at 93 octane with head shim or low compression pistons.

13lbs on a stock motor....only with racing fuel.

 

[77srxdude]

Finally got to put a compression tester on it - used two different ones to be sure - both read similarly.

Starting from the cylinder on the clutch side I have 165, 183, 183, 178.

Before I put the turbo on I had roughly 185 in each.

Significant difference from the first to the rest so I am going to tear into it. My guess is the oil was blowing out through the breather run after run and it finally started flowing out the bottom after that final run.

I have no problem springing for the 10:1 low compression pistons and my question is - should I just use the standard head gasket?

When playing with the boost calc - how do you compensate for the low comp pistons - just put 10 in for "stock compresssion" or is there more to it?

I want to be able to run 10-12 lbs on Pump gas and then max boost, which I believe is 15 lbs efficiently, with 50/50 93/110.

 

[Travis Moore]

Finally got to put a compression tester on it - used two different ones to be sure - both read similarly.

Starting from the cylinder on the clutch side I have 165, 183, 183, 178.

Before I put the turbo on I had roughly 185 in each.

Significant difference from the first to the rest so I am going to tear into it. My guess is the oil was blowing out through the breather run after run and it finally started flowing out the bottom after that final run.

I have no problem springing for the 10:1 low compression pistons and my question is - should I just use the standard head gasket?

When playing with the boost calc - how do you compensate for the low comp pistons - just put 10 in for "stock compresssion" or is there more to it?

I want to be able to run 10-12 lbs on Pump gas and then max boost, which I believe is 15 lbs efficiently, with 50/50 93/110.

Were you holding the throttle open when you did the compression test?

T

 

[77srxdude]

Were you holding the throttle open when you did the compression test?

T

Yes - I actually did it both ways and then also did it holding the slides up. Holding the slides up made no difference - holding the throttle all the way in made about a 5 lb difference in each.

 

[givemeaboost]

That seems like enough of a difference to warrant checking into it. When mine went down it was about 40# less and it ruined the cylinder to the point that it needed replating. The piston melted just enough to let the top ring land spread open and the ring was rocking when it went up and down. THis rocking scraped the plating off the top of the cylinder, Ken.

 

[77srxdude]

Tore it apart this weekend

Clutch side piston was the worst (165 psi) - but the cylinder looks untouched - gonna check for out-a-round to be safe.

Middle two were fine but brake side was a little lower psi than the middles - and it was missing a little on the front edge

Clutch side exhaust gasket leaking oil

2 pipe gaskets fried - the clutch side completely and the brake side about half destroyed - middle are fine.

Any suggestions as to what other problems to look for are welcome. Someone mentioned something about burnt valves but this is my first 4-stroke and not sure how to check that.

 

[givemeaboost]

Maybe you'll have some luck in that part anyway, Ken.