piston no.2 on f7p engines

[treishu]

what is happening with theese engines - is there an lubrication problem on theese engine types because my engine destroyed the crankshaft at the conrod no. 2 and i have a friend that had exactly the same problem in exactly the same place. is this a bug of the engine and can something be done?

[MAXIBOY]

no not as far as i'm aware..if these engine have an oil issue its usually rod bearing no.1 that fails..

[treishu]

i'm telling you... i know of 3 engines that have problems with the rod bearings no.2 .

can this be solved by increasing the output of the oil pump by changing the inner resort with an 1,9 dti one and grinding out smth...(i've seen a sketch from renault sport about doing this somewhere but don't remember exactly)

[MAXIBOY]

i have it..but thats done for very high rpm engines..

i have built a few now and one runs over 8000rpm very often..yet too have an issue with a standard oil pump..

could ask stan @ apd and danny @ gdi for another opinion..

[stan]

standard oil pumps are fine.

What was your oilpressure like?

I must admit, the failures do tend to be on no.2, but the ones I have seen have been pressure or cleaance related.

[treishu]

i was on a mountain road with my r5 and there were many tight hairpins on which i went very fast... after another 10 miles or so the engine stopped with the crank bearings being one over the other :)

[MAXIBOY]

need a baffled sump to stop oil surge then..

[treishu]

will weld some alu plates inside the sump.

[MAXIBOY]

thats what i did.. :D

[volymmannen]

I changed the original baffel on my F7P to a better from a F3r mounted around the oilpump..
P7p on the left F3r on the right
http://i55.photobucket.com/albums/g159/volymmannen/DSC00419.jpg

[Laine_16v]

Lol i have the baffle on the left, my engine will die soon then :D

[richy]

my f7p came with the baffles on the right.

[number1]

I got chatting to an AA man a few years back, he worked for renault when the williams came out, had the same williams back in 2 times with piston failure on no.2 or 3 cant remember what he said now, had 3 replacement engines! from renault, After the second failure he pulled both the blown motors apart to find out why, The the gudgeon pin circlips were missing, Took the new sealed from renault engine apart to find the same thing! He rectified there little error and never saw another failure the same way again!!

[treishu]

what is a gudgeon circlip?

[col]

Its the circlip that holds the shaft which go,s thru the piston.......in simple terms :wink:

[treishu]

ok. and what's got that to do with the conrod bearing failure?

i have all the circlips in their places.

is there anything else to try?

[col]

Gudgen pins have been known to fail .ie seize

you have oil injectors screwed into oil rail , are they working.......they cool pistons from underneath....by squirtin oil upwards under the crown.

[treishu]

as above... the problem isn't with the piston or gudgeon pin or the oil squirting thingys...

the bearings between the crank and the rod went one over the other...
i don't really know the exact term but the retaining thingy for the bearings broke and they turned inside the conrod.

[col]

Your big end went yea ?.........con rod has big end an little end.........did bolt snap?.......or bearing ran dry...............ive had it happen on me jeep .

[stan]

No bolts snapped, most likely an oil supply issues, imgonna have a closer looksy when I get back into work next week.

Will post any findings :D

[col]

Ye interested in your findings Stan...........as an when..........

[treishu]

it happened at the big end of the conrod. where it is "connected" to the crankshaft. :)