T Mack 1 - FSO wrote on 01/12/10 at 18:40:06:


I hope you don't do black powder rifles.  

I have considered putting a 1/8 NF pipe tapped hole to the front of my oil gallery on the spare engine so as to run a simple short braided line to the handle bar oil pressure gauge (mounted up on the handle bar) so I will know what I am getting on the actual top end gallery oil pressure at all times.

Why do this?  Because if you are running damaged journals with opened up gap clearances your effective idle oil pressure at that head journal area will be greatly reduced due to increased "leakage" out the increased gaps around the cam journals.

We likely need to run a higher idle speed after a damage event just to get the same very minimal oil pressure at the bearings as we have got increased gap leakage that works against us ....

Taking the oil pressure at the lower case gallery does not tell the same story as ONLY THE PRESSURE AT THE CAM GALLERY COUNTS FOR ANYTHING AS ONLY IT APPLIES TO ANYTHING THAT IS "HEAD DEATH" SIGNIFICANT.

If you had a blocked oil passage or misplaced gasket, this would tell you the tale.  If you had enlarged gaps and were running low on idle speed pressure because of the gaps this would tell you the tale.

Think of this all as a calculus "related rates" problem.  At low engine speeds your supply rate at the head can be lower than normal due to oil pump wear, partially trash blocked passages, etc.  On the pressure consumption side of the equation the cam to journal gap has increased by 2x or more, greatly increasing the volume of oil that can exit the upper gallery pressure zone.


((flow pressure in) minus (flow pressure out)) = remaining oil pressure to support bearing function


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All older savage engines have cam journal damage to some degree.


Yep, yours does too -- you jest don't know about it yet.

Ok if you want to talk oiling the cam journals why not take a lead from the oil cooled GSX-R generation.  When they built a hypo head they would add extra top end oiling two ways.  First they tied the cam oiling together through and external line shown here.  Note the silver line across the side of the head.



Now before you blast me with we only have one cam shaft you dumb....    Take note of the second step they would do.  The next step in the upgrade chain was a tie that also dropped a line straight down to the pump port on the lower right side of the engine that was used to check/confirm oil pressure in the shops.  So what they did was run a line basically straight up from the pump to the cam galley so that that expensive top end got oil the minute the pump started turning.  

Now looking at the Savaqe manual on the same page Lancer posted this would be equivalent to running a line out the bottom or front threaded fitting and into the small plug (drill out and tap for a banjo bolt or fitting) that exists on the right end of the cam galley on the head cover.  (there is one on the left side also.)  There is also a plug on the top of the engine case on that side also that could be used for a cleaner look.

This way you shoot oil straight up to the cam galley and bypass the long slow route through the back of the engine.

If anyone doesn't undertand from looking at the picture I linked to I can try to find a better one that has the full kit.

Thoughts??

verslagen1 wrote on 01/13/10 at 18:28:38:



Two items.  If you come out the the small plug on the top of the case that I described that would be after the filter.  Second, if the  cam journals are a high pressure drop application then it would only get the oil it needs and not short anything else.  If it were a lower pressure drop application then it might drop pressure to other parts of the engine.  At this point the cam bearing surfaces in the head are the only oil related failures then maybe they should receive the oil.  The other areas of the engine don't seem to have any failure problems.  I agree a higher volume oil pump would be nice but at this point no one has found one that fits.  This design is fragile if you can wipe out a head by droping the idle to where it still runs but doesn't provide enough oil pressure to lube the top end.

Smok'n

You got it -- if we drop our idle speed too low then we die the death of 10,000 little scrubs.   Too many did this while learning about the idle speed trick (some just liked the loping sound of a very low idle speed).

Suzuki recommends a 1,000 to 1,100 rpm idle speed, but after a cam event like Lancer just had he will require a slightly higher idle speed as his head will leak more oil out the enlarged bearing gaps.

Verslagen is correct, we have flow and pressure issues out of our oil pump at low rpms.  Our oiling system is a minimal system, it has no over pressure regulation at all so it was designed to pump at max rpm a designed flow that could exit the system through the existing passages.  It can pump too little at idle and too much at max rpms.

Take me for example, I am a wicker with a stage 2 cam.  I run me some high RPMs and I suffer from extreme oil pressure making the side cover oil gallery at the top of the case difficult to keep pressure sealed and leak free.  So you see we can have issues at both ends of things because of the oiling system the bike comes with.

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The stage 2 cam from Web Cam has had the steel cam journals dressed down a bit to slightly below the Suzuki factory diameter specs so I have "increased journal clearances" for that reason.  I need to run a sightly increased idle speed to make sure I keep good oiling going on when sitting at a stop light.

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Lancer will also possibly have some additional issues setting his valve clearances as the extra gap he now has is an appreciable percentage of his intake valve clearance number.

"Durn, I set it and it was right, I come around again to check it and it's way too (tight loose)."  

(you pick what happens this cam rotation turn around)