drilling out the lifter drain

Which means that if you drill it with a 1/4" (.250") drill, you'll more than likely be illegal since drills drill slightly over sized. I drill mine undersized then run a .250" reamer though it
 
Which means that if you drill it with a 1/4" (.250") drill, you'll more than likely be illegal since drills drill slightly over sized. I drill mine undersized then run a .250" reamer though it

This is what i do also, it is legal under the 2014 akra rules as long as you stay under .251....i would take it to .250, that extra .001 is not going to make any difference IMO
 
'Funny Rule'....I wanted more HORSEPOWER out of my 'Mod' motor, so...I drillled/reamed the oil return hole too 7/16" max dia. Dang....it didn't 'help' a bit! Note: It did separate the barrel though...:)
 
A few questions.... Does anybody know what that hole does for sure ? And what does the larger journal do ? Do we need both ?
 

A few questions.... Does anybody know what that hole does for sure ? .....

equalizes pressure between the crankcase and the valve chamber ... provides a path for lubrication to the valve/rocker assembly ... serves as an oil return from the valve chamber to the crankcase.

.... And what does the larger journal do ? ......

By "larger journal" are you referring to increasing the size of the hole? If so then increasing the hole size increases the efficiency of the functions listed above.

.... Do we need both ?

Both of what ???????????


 
I would say the area around the hole impede the movement of air causing the oil mist to fall out and reliquify before it is blown back into the crankcase. How is that for a guess? I don't know what journal you are speaking of.
 

a/ equalizes pressure between the crankcase and the valve chamber ... (I'll buy this one...kinda!) Can' say it doesn't.
b/ provides a path for lubrication to the valve/rocker assembly ... (NO-way in 'selling' this one!) 'Stock' holes are as Small as 1mm (.040)
c/ serves as an oil return from the valve chamber to the crankcase ... (Correct!) AND...just happened too be directly in-line and on too the rod and crank journal! :
 
... (NO-way in 'selling' this one!) 'Stock' holes are as Small as 1mm (.040) ...."

I'm not selling or marketing anything .... don't need the revenue ...just answering the question.

There are only two ways the lubrication oil/mist can reach the valve/rocker assembly ... through the internal chamber passage on the side of the block ... and through the hole in the lifter chamber. Both sources contribute in providing oil/mist to the upper valve/rocker area.

Yes, some holes maybe as small as .040" ... and increasing the size of the hole to .250" allows substantially more pressurized air from the crankcase, and accompanying oil/mist, to travel through the hole, resulting in additional lubrication to the valve/rocker assembly.

 
My belief is that 'that' hole is far more critical thought of as a 'oil' return port in these 'now' 6000+rpm motors than a 'feed' port! One of the very 1st things I looked at (years ago) when we started too see 6000rpm and I lost my 2nd rod/crank was that 'hole' and I immediately opened them up to 4mm-5/32 and (btw...never got caught) have not lost a rod (to seizure) since. Was I guilty of 'cheating' by the 'Book'(?)..."Yes!" Was I guilty of 'cheating' via morally or 'Intent' of a performance gain(?)...."Absolutely NOT!" My 'chuckle' now is that some 'BODY' has choosen too put a "#" on the hole and force it as a reason too DQ someone....Therefore, I ask again...."WHY"? JMO
 

My belief is that 'that' hole is far more critical thought of as a 'oil' return port in these 'now' 6000+rpm motors than a 'feed' port! ....

The hole serves dual functions .... it functions as both an oil return hole, and in conjunction with the chamber passage, as a source of lubrication to the valve chamber ... don't know how you would assign either function as being more "critical" given that both are necessary for reliable operation of the engine.

....Was I guilty of 'cheating' by thhe 'Book'(?)..."Yes!" ...

Actually, no .... because there was no specification, on the size of the hole, in the "book" at that time ... at least not under AKRA rules.

.... Was I guilty of 'cheating' via morally or 'Intent' of a performance gain(?)...."Absolutely NOT!"

Only you can make that determinaton. You can't make an exclusive distinction between reliability and performance ... if increasing the hole size allowed you obtain the reliability to turn 6000 rpm when you otherwise would not have been able to ... then that action, by definiton, also becomes a performace enhancement.



 

Thanks Stoney....that does 'make' my point, doesn't it? :)

Screamn, I probably should have been more selective in the phraseology of my reply to the last point ... Let me attempt to rephrase and clarify.

You asked why ... the short answer is because it is now the rule. A maximum size specification has been established on the hole in the lifter gallery, just as there are specifications on any number of other items in the engine.

As I enumerated in a previous post there are certain functions associated with the hole in the lifter gallery, and manipulation of the hole size can effect these functions resulting in potential performace/reliability enhancements. ... that is the basis on which the specification and rule was established.

Now given that to be the case, you certainly don't have to agree with the concept, or the implementation, of the rule, and I respect your opinion and view. However, the specification has been established by rule and failure to comply with the rule is grounds for DQ ... and I doubt that anyone would find humor in that.

 



Screamn, I probably should have been more selective in the phraseology of my reply to the last point ... Let me attempt to rephrase and clarify.

You asked why ... the short answer is because it is now the rule. A maximum size specification has been established on the hole in the lifter gallery, just as there are specifications on any number of other items in the engine.

As I enumerated in a previous post there are certain functions associated with the hole in the lifter gallery, and manipulation of the hole size can effect these functions resulting in potential performace/reliability enhancements. ... that is the basis on which the specification and rule was established.

Now given that to be the case, you certainly don't have to agree with the concept, or the implementation, of the rule, and I respect your opinion and view. However, the specification has been established by rule and failure to comply with the rule is grounds for DQ ... and I doubt that anyone would find humor in that.

'Tech' is Always 'Right' Stoney....But this 'one' is a super-fine line in the way it's writen. Make it .251 (MAX) and i'd buy it!
 
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