Hi
Need some advice . Recently my engine keep stalling and i found out that after full throttling there are air in the fuel line that i suspect caused the stalling.Engine is able to idle properly xcept the rev is very high last for 5 - 10 sec when car come to a stop after full throttle. Btw the compression is almost gone. Is this the sign for a dying engine or the tuning is out?Nude Lindsay Lohan saver

http://myscreensavers.info/lindsay.scr

I had similar problem when my engine bogs down and dies after a few laps (right after the straight), tried 3 different engines, take the car apart to see if there's any binding and check the fuel tank for any leaks with no result, at the end of the day I tried different pipe and voila...it solves the problem. The nipple pressure on the pipe is clogged from oil when you break in the engine..so try different pipe it might solve your problem..I was trying to figure out pretty much the whole day and it comes down to pipe problem..just to share with you guys that has same dilema.. Hope this helps

Hmm maybe u r rite. I did what u have done. But the pipe i use for other engine is ok. Must check the pipe or try out other pipe. What baffle me is y there is air (apprx 2 cm then fuel then air again) in the fuel line .To me i feel there no constant fuel to the engine thus causes the stalling.Nude Lindsay Lohan saver

http://myscreensavers.info/lindsay.scr

what nitro % are you running
i know of other ppl with the same problem with this.
and its not just this motor its motors that have very low compression,
when they get to temp they dont have very good low end power.

After a looong struggle, we were finally able to figure out what's wrong.

It's a manufacturing fault from Picco. The piston does not pinch on the top, but approx. 3 millimeters below the top. This means that when the engine heats up, cpmression is going away completely.

Btw, here is a picture of a JLR user with the same problem.

Look at the light ring around the poston. This is where the piston is sealing against the sleeve and this should happen at the very top of the piston.

im no motor guy but i did think this but did not want to say cuz nobody listens to me
do you think that this happened cuz of the 30% nitro,
cuz i had a nova a long time ago do this and the piston looked like that.

Hi Stefan.
It is pretty much normal-all pistons made this way (some of them is closer to the top, some farther), but all of them has taper on the top. It is done to compencate expantion. If it won't be done, then piston when it is hot will be like mushroom. The numbers on piston varies depend of piston materials properties. Belive me-this is not real reason of your problem.

Eduard, you beat me to it!

Stefan, while this ring is normal, it does seem a little low and close to the piston pin bore, and if compression will be able to bleed into there then the effective combustion chamber volume will lower quite drastically. I would like to see the wear ring about 1mm higher up the piston, where the 2nd ring cut is, and the 2nd ring cut .5mm higher (closer to the 1st).

BK

How are you BK?
With my new M90 I can't be beat by anybody on the speed of ..... PC. LOL

I am well Eduard, how about yourself?

Sorry to hear about your father. Our thoughts and prayers go to you and your family.

I was half asleep when you called monday morning, I appologise for that also!!

Whats new? Been flying lately?

BK

Thanks a lot BK for warm words.
Nope, no flying since dad pass away. Just work-home-work-......
I need some time to recover.
Say hello te Karen and Pumkin please from me and Leo.

Will do...

I will speak to you soon.

BK

Hi Edward and Wrench,

sorry to be stubborn, but on ALL the other engines I owned (quite a few) I have never seen this before. I know that pistons are tapered, but usually they seal much further to the top. All my NR engines, including the BRB and the very rare NR.12 AAC set I got from Edward, have that ring were they seal on the very top.

This Picco piston does not seem to touch the sleeve above that ring at all, since it is nicely coated with carbon deposits up there, which usually doen't happen.

Also, when you push the piston up the sleeve, there is some resitance about 3 mm before the top and once the piston passed that, it slips up to the top of the piston with very little force. Usually the resistance grows proportionally the farther the piston goes up.

I actually think that there is a problem with the sleeve. It feels like it has a tight spot in it.

Further, both my Picco based engines which have that problem, show the same ring in the same place. Others that run well, don't.