smoke on over run :-(

Post by **katanaman** » Mon Dec 28, 2009 12:19 am

yes but the shaft hasn't been out and rotated 180 deg or something like that? If the shaft is upsides down I think it can spray oil directly at the valves if memory serves. Maybe not, it was just a though.

kiwicar · Post by **kiwicar** » Mon Dec 28, 2009 8:09 am

endoscopes on Ebay (funny to find one there!

) an example here
http://cgi.ebay.co.uk/Tube-Snake-Scope- ... 3a54e60087
but many others.
Mike

Post by **Coops** » Mon Dec 28, 2009 11:42 am

katanaman wrote:yes but the shaft hasn't been out and rotated 180 deg or something like that? If the shaft is upsides down I think it can spray oil directly at the valves if memory serves. Maybe not, it was just a though.

no mate not stripped down,
fitted straight to the 4.6 as they came off the 3.9.
glad its got everyone puzzled

Post by **Coops** » Mon Dec 28, 2009 11:53 am

kiwicar wrote:endoscopes on Ebay (funny to find one there! ) an example here
http://cgi.ebay.co.uk/Tube-Snake-Scope- ... 3a54e60087
but many others.
Mike

cheers Mike,
just seeing if the boss will let me get that one,

will keep you posted

if i can get it it is always here if anyone needed to borrow it,
or i could hire it out

kiwicar · Post by **kiwicar** » Mon Dec 28, 2009 4:57 pm

"i could hire it out "
yes you could. . . but have you thought what it might get used for

?

Mike

Post by **Coops** » Mon Dec 28, 2009 5:55 pm

kiwicar wrote:"i could hire it out "
yes you could. . . but have you thought what it might get used for ?
Mike

ramon alban · Post by **ramon alban** » Mon Dec 28, 2009 10:45 pm

thev8kid wrote:yeah i must get round to doing this, but bit hard with the christmas period, not allowed into the garage to tinker,

did get an email from someone saying they had a similar thing, they was using 15/40 oil and when they changed to 20/50 it stopped, could that happen?

Tony, No doubt a change in oil might make some diff, but that suggestion, like many of the ones honestly made in this thread amount to no more than tinkering around the edges until you get some time to run the basic diagnosis for bore/ring damage.

Now, having seen the compression test results for cylinders # 4 and # 8 it seems to me you can be pretty sure the engine has internal damage or unbedded rings.

Your # 4 and # 8 compression result is getting pumped up OK to high levels due to all the oil flooding the bores/rings thereabouts, but that same oil is is burning off on overrun and even more oil is being sucked up by the high inlet depressions on overrun. Even very high vacuums, if my earlier postulations are correct.

The suggested leak-down test would surely confirm the problem.

Sad to say, its prolly time to get stripping I'm afraid.

Post by **Coops** » Tue Dec 29, 2009 12:34 pm

ramon alban wrote:
thev8kid wrote:yeah i must get round to doing this, but bit hard with the christmas period, not allowed into the garage to tinker,

did get an email from someone saying they had a similar thing, they was using 15/40 oil and when they changed to 20/50 it stopped, could that happen?
Tony, No doubt a change in oil might make some diff, but that suggestion, like many of the ones honestly made in this thread amount to no more than tinkering around the edges until you get some time to run the basic diagnosis for bore/ring damage.

Now, having seen the compression test results for cylinders # 4 and # 8 it seems to me you can be pretty sure the engine has internal damage or unbedded rings.

Your # 4 and # 8 compression result is getting pumped up OK to high levels due to all the oil flooding the bores/rings thereabouts, but that same oil is is burning off on overrun and even more oil is being sucked up by the high inlet depressions on overrun. Even very high vacuums, if my earlier postulations are correct.

The suggested leak-down test would surely confirm the problem.

Sad to say, its prolly time to get stripping I'm afraid.

cheers Ramon,
thing that confusses me is if its that bad why is it not burning oil any other time?
normal driving etc no oil burning,
and the comp test was done two days after the car had run and was cold,
have sent Paul an email regarding ordering 2 piston ring sets,

Post by **Coops** » Tue Dec 29, 2009 3:45 pm

going to have ago at making a leak down tester while im at home,

found some instructions online,
and handy thing is i have the parts to hand,
http://www.max-boost.co.uk/max-boost/Le ... tester.htm

once made how much should i pump into the cylinder?
190psi as per comp test?
and what do i need to look for?
how quick the gauge drops? and if i hear hissing in the inlet/exhaust and rocker cover?

ged · Post by **ged** » Tue Dec 29, 2009 4:02 pm

Hi Tony,

I hope you don't think I'm trying to teach you to suck eggs. But if your going to put 190psi in the cylinder with it in gear to stop the engine turning, you'd better have a good handbrake & chock the wheels as well.

Post by **katanaman** » Tue Dec 29, 2009 4:12 pm

I would agree that a leak down test is the better test but I don't agree with Ramon on this occasion. There shouldn't be that much oil washing the bores on the starter and you will have the throttle wide open so no vac. If there was so much oil getting ontop of the pistons to seal the rings the car would be burning oil like a Salamander stove and it doesn't seem to be doing that. I am positive even if there were some limited sealing happening you would still see a fair drop in pressure even with a compression test. Of course I could be wrong here and a leak down test will confirm but it doesnt fit my experience with several auld shager engines.

Post by **Coops** » Tue Dec 29, 2009 4:13 pm

i was hoping some one was going to say, put x amount of psi in the cylinder and watch for the following

Post by **katanaman** » Tue Dec 29, 2009 4:19 pm

put whatever your compressor can handle (150 PSI?) in and time the leakage to 0 PSI. It doesn't really matter so long as you use a reasonable amount else you wont be able to time it and obviously they should all be to the same level. You can also have a listen and if you have leaky valves you can hear which ones. As to pressure and needing a good handbrake, na just leave it in a high gear to stop the pistons moving. The pressure in a running engine is way higher than you will ever get with a compressor.

Post by **Coops** » Tue Dec 29, 2009 4:23 pm

cheers guys,
i will get to the bottom of this ferkin problem

unstable load · Post by **unstable load** » Tue Dec 29, 2009 4:40 pm

Tony,

A bit off topic but related...
In piston aircraft there is a scheduled inspection that involves a cylinder blow-by or leakdown test where the engine is run up to temperature and then one set of plugs is pulled and a tool is used to test the amount of cylinder blow-by as a percentage of the amount of air put into the cylinder.

here is a link to an example... http://www.nichols.nu/tip420.htm

We are happy to see 65 - 75 percent and a max 5% difference across all 4/6 cylinders. Anything less is call to check valves and if needed, to pull a jug and have a look-see inside.