SNAIL

P6 · Snailer Joined: 04 Apr 2008 Posts: 12 Location: Hilversum

Hi Snailers,

While building an engine I've checked the oildelivery to the cilinderheads and it gives more oil to the leftside head as to the rightside head. Looking with the frontside of the engine towards viewer. I did blow the oiltube with compressed air and it looks clean. Also the tube retaining bolts are correct with the big 2mm hole central and the smaller 0.7mm hole in the heads.

It is the common 602cc engine from let's say 1978.

Knows one of you if this differences is normal? All information is welcome.

Thank you.

Mark/P6

Bart · Posted: Sat Jul 09, 2011 6:22 pm Post subject:

How big is the diffrence Mark?
I would say a difference is normal cause the oil pipe to the right right side (seen from the front) is longer.
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P6 · Snailer Joined: 04 Apr 2008 Posts: 12 Location: Hilversum

Hi Bart,

Simply clever what you wrote, thanx, maybe thats the clear point of it, the difference in length of the tube. Fluidfriction goes with length, is that physicslessons?

Then maybe is an engineupgrade with equal length tubes a good idea to make Andre's machine better?

The difference in delivery was around 2:1

Someone knows if this really is a standard thing on our flat twin?

Bart · Posted: Mon Jul 11, 2011 7:12 pm Post subject:

If you would like to balance it out, maybe a banjo bolt with a bigger hole would help, otherwise, equal length tubes should do the job.
However, I would think Andre and his team developed it such that the standard setup garanties enough oil for the right side.
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dyanut · Posted: Mon Jul 11, 2011 10:10 pm Post subject:

P6,
what was the engine speed at which this difference was noticed?
If it was at tickover, the system oil pressure at that engine speed is much lower than what it will be at full chat.
(1 bar vs. 5.5/6.5 bar?)

I think you will find that Citroen chose the sizes of the restrictions in the banjo bolts to ensure that there's very little difference in the flow rates to each cylinder head at higher rpm.
When the pressure in the lines is higher, any reduction in flow rate due to wall friction will be much less significant.

Not that you'd want to test at high speed, with the risk of losing a fair amount of oil... Wink

Ken

Olli · Posted: Tue Jul 12, 2011 9:11 am Post subject:

In some engines (I would say early 70's) there is 3 sizes of those banjo bolts. Big on the middle, middle size on long tube (left) and small for short tube (right).

-Olli

EDIT: Year matching post Wink

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dyanut · Posted: Wed Jul 13, 2011 1:32 am Post subject:

Olli,
do you know if Citroen marked these fabled banjo bolts 'D' and 'G' to avoid any confusion, in the same way as they identified right and left side cylinder heads? Rolling Eyes

Ken

P6 · Snailer Joined: 04 Apr 2008 Posts: 12 Location: Hilversum

The engine was standing on the table without the sparkplugs and it was rotated by the drillingmachine, so less rpm. But in a while on the left side it filled a small tin of beans. The right side was a half filled tin.

It's also true that 7million engines can't be wrong.

Maybe they used 3 different holes till they've found out that is doesn't mather that much?

Ken, Olli & Bart, thanx for this.

Mark/P6

JuanNavarro · Posted: Thu Jul 14, 2011 11:27 pm Post subject:

According to citroen manual, the lubrication tube retaining bolts at both cylinder heads side have 2 holes of 0.7mm diameter.

Probably you are also measuring the oil delivery without this callibrated hollow bolts, try using the bolts at the end of the lubrication tubes, using a nut to secure it, probably this makes the difference (thats why they are there, to ensure the right flow)
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