Head oiling, something Pat said...

[Havoc]

I talked to Randy about this, his opinion is... that we don't need it on our street bikes.....
Randy has his own ideas on top end oiling. I noticed that he does not use the Hank Scott top end kit on his race cars.
Randy has a trick he uses where he adds a extra chamfered groove to the cam bearings for extra oiling.

I have a couple of questions regarding top end oiling on FJs. Now I really should have sussed this out over the last years, but my head has stayed with 'it works', meh.
1. How is the left side of the head fed(right side in picture)?



I can see the oilways to transfer oil to the head up the stud ways on the right side.



Can't see any on the left.



Does the oil cross the cam tunnel through the hollow cams?

2. When we talk about cam bearings, is that the bearing surfaces on the caps and head or is there a shell convertion or something? I like the idea of grooving the holes in the bearing surfaces of the head to hold a larger volume of oils against the surace of the cams without changing pressure or anything. Like a crank shell.

Not going to pull it apart for this first run up but for the future, sounds good

[SlowOldGuy]

Not sure I totally understand what you're saying, but if you groove the bearing journal, you will actually be REMOVING bearing oil film surface (not sure that's the correct word).

Putting a groove of oil around the journal does nothing to improve oil film protection.  It does just the opposite.  You remove bearing surface area which causes the pressure (stress) to increase on the remaining surface area which, in turn, squeezes more oil out of the bearing.

It's oil PRESSURE that provides oil film protection in a plain bearing surface.  The more bearing area you have, the more oil protection it provides (under pressure).

DavidR.

[Havoc]

Thank you sir, yes, that makes sense. Wonder what Randy grooved to improve oiling?

[racerrad8]

1) Does the oil cross the cam tunnel through the hollow cams?

2. When we talk about cam bearings, is that the bearing surfaces on the caps and head or is there a shell convertion or something? I like the idea of grooving the holes in the bearing surfaces of the head to hold a larger volume of oils against the surace of the cams without changing pressure or anything. Like a crank shell.

Not going to pull it apart for this first run up but for the future, sounds good

1) Yes. The oil is supplied up the stud on the right through the galley circuits on each side of the head to the cam journal. That journal of the cam have a grooved surface as well as two feed supply holes to fill the cam and keep the other three journals lubed.

2) There is no "bearing" on the cams. It is a cam to head clearance fit that by Yamaha's tight standard does not require grooving. Yamaha also restricts the amount of oil to the top end in the case and head galley's. If the oil restrictors are not removed then the grooving of the cam will actually lower the oil pressure and possibly oil starvation at the final oil galley.

Now, if you remove all of the restrictors, add some clearance to the journals and groove the cams you will get the results similar to the groove crankshaft main bearing.

I am grooving because I open up the head journal and the additional oil, via grooving is required to keep the cam centered in the bore.

Putting a groove of oil around the journal does nothing to improve oil film protection.  It does just the opposite.  You remove bearing surface area which causes the pressure (stress) to increase on the remaining surface area which, in turn, squeezes more oil out of the bearing.

DavidR.

David, not quite when dealing with the cam specifically. The lobe is constantly pushing the cam away from the valve forcing it against the cam cap. When the oil restrictors are removed you have a much higher volume of oil available to the cam journals. When you groove the cam you ensure there is a "full circle" of oil around the cam at all times to cushion the cam from bearing forced away from the valve. The reason we have to open the cam journals up on the race car is too eliminate the bind of the journal as the engine is mounted in the car side ways and the back of the engine sees much higher temperature ranges. If the head is not clearanced broken camshaft occur all the time.

Randy- RPM

[Havoc]

1) Yes. The oil is supplied up the stud on the right through the galley circuits on each side of the head to the cam journal. That journal of the cam have a grooved surface as well as two feed supply holes to fill the cam and keep the other three journals lubed.

Randy- RPM

Thanks for that man, appreciated. Glad I was in the right area. May I ask your opinion on my head feed. 1500 Billet block so possible heating issues, fitted a HSR top end oiling kit feed through a cooler to try and reduce temp a little with cooled oil. Do the race car guys block the feed from the block up the stud tunnels or is the feed 'additional'? Hoping you're going to say the later.. Ta

[racerrad8]

Thanks for that man, appreciated. Glad I was in the right area. May I ask your opinion on my head feed. 1500 Billet block so possible heating issues, fitted a HSR top end oiling kit feed through a cooler to try and reduce temp a little with cooled oil. Do the race car guys block the feed from the block up the stud tunnels or is the feed 'additional'? Hoping you're going to say the later.. Ta

Most builders do block the factory oil holes and run the external only, I do not block the factory galley. I can say if you did remove the restrictors in the head, you could put a 1" hose up to it and it will only let the restricted volume of oil through...

Do you have the stock studs of aftermarket large diameter studs?

If you have the thick aftermarket studs then you need the external oil feed.

Randy - RPM

[Havoc]

Do you have the stock studs of aftermarket large diameter studs?

If you have the thick aftermarket studs then you need the external oil feed.

Randy - RPM

Using aftermarket APE studs and have the HSR head oiler in place. Haven't blocked the OEM feeds



Also need to quiz you about the dogs in the box, been on your site and seen what's available. Wish I'd found it a year ago..

[racerrad8]

Using aftermarket APE studs and have the HSR head oiler in place. Haven't blocked the OEM feeds

Also need to quiz you about the dogs in the box, been on your site and seen what's available. Wish I'd found it a year ago..

Well, once you put the turbo to that, it will probably break a stud or pull a thread or two from the case.

Here a couple of topics regards the aftermarket studs;

http://www.fjowners.com/index.php?topic=3088.0
http://www.fjowners.com/index.php?topic=479.0

Shoot me an email if you have questions about the trans. Now that you found me here I am...

Randy - RPM
randy@rpmracingca.com

[SlowOldGuy]

Uh, just ignore me.  Do what Randy says!  This hopped-up FJ stuff is way out of my league!

DavidR.

[Havoc]

Cheers for that chaps, read both of those. My previous area is oilcooled GSXR nitrous drag bikes, always used rolled APE studs, they don't stretch like the OEM one's at 250bhp +, that's the point. Case strength wasn't an issue pre-explosion, but the explosions were inveriably caused by bad math re-AFR and NOS...and rider error 

Unless you are building some sort of forced injection intake system where you will be building significantly higher combustion chamber pressure, you do not need "better" studs; they will only lead to other failures.

Randy - RPM

I am Randy. I do think I need 'better' studs. I have used Time-Sert to reinforce 2 threads in this motor but the others seemed fine, I never use Helicoil, consider it a bodge. Also used HD bolts around the crank, 1 Time-Sert required but everthing else seemed strong. I'll be disappionted if the case material won't support my power expectations, they are quite low at this stage. I'm using a 2mm copper gasket to reduce CR, so the designed in expansion mentioned of OEM Yamaha studs I would have thought would be adequately compensated in the 2mm soft copper base gasket in my case? we must only be talking about thousands of an inch here surely. I am here to learn, cheers Randy for your input and correct me at ever turn.

I'll continue to update the Project thread, let you all know how it does, and if it holds together. Thanks chaps, Tom