Mid- Engine Modified Sports

[Koncretekid]

So does the upper rod bearing have a corresponding groove?  should you make one?
Tom

[manta22]

Now that the rod bearing halfs are in the right places, things look OK. 

Regards, Neil  Tucson, AZ

[fordboy628]

So does the upper rod bearing have a corresponding groove?  should you make one?
Tom

No.  The proper bearing clearance will provide adequate flow toward the rod cheeks.

All that is required is the "flow" from the bearing surface to pass outside the cheek of the con rod, (both sides) and it will be "slung off" radially.    All the rod groove does, is to "direct" some of the flow in a particular direction, say the bottom of the piston.

Many V8 bearing sets are "directionally chamfered".    The big chamfer, or radius, has to face the rod journal radius, to provide clearance.   The other side is not clearanced as heavily, to add surface area and additional load bearing capability.


This is where the idea of:   "I can build an engine as good as anybody."   can get a bit tricky.     If you don't assemble engines all the time, your skill set can get rusty.   This is not intended as a criticism Neil.    It's just a "heads up" about the "little details".     There are a lot of "little details" and it can be frustrating to get them all correct.

Best regards and  
Mark

[Koncretekid]

I haven't built a V-8 since my high school days, but another dumb question would be which side does the notch face -- the journal or the other rod? (I would guess the journal side using the 50-50 rule.)

[manta22]

Mark;

Thanks for explaining the rod side clearance oil slinging. Your explanation was way better than mine.

The King XP rod bearings are not chamfered on one edge; instead, the locating tang is offset slightly in each bearing half so that one edge is inset in the rod to clear the crank radius. Looking at the bearings in the box they looked all alike, only when they were snapped into place did it become obvious that they were offset. Calling the manufacturer is usually a good idea when something isn't making sense.

Regards, Neil  Tucson, AZ

[floydjer]

I haven't built a V-8 since my high school days, but another dumb question would be which side does the notch face -- the journal or the other rod? (I would guess the journal side using the 50-50 rule.)

And you would be correct

[floydjer]

...and I would hope Crower would not drill holes in a rod cap

[fordboy628]

The oil squirter holes  that lube the cyl. walls are in the crank ??

With the amount of oil "flung off" the crankshaft and con rods, (even in "dry" sump systems), in most racing engines, cylinder wall oiling is typically NOT an issue.   In fact, with today's "low tension", thin section oil ring assemblies, the oil on the cylinder walls can easily "overpower" the oil removal capability of the ring and piston, forcing the 2nd ring into a "backup" role as an oil scraper.

Thin rings "re-capture" work otherwise lost to friction/drag power losses.    The trick is to minimize the loss component while retaining adequate lubrication and cooling . . . . .      There is some "disagreement" about this, but my opinion is that the bottom end components are mostly oil cooled.   The rings and piston land area transfer heat through the cylinder wall to the cooling system, but the skirt, not so much.

Yeah, your flathead powered lawn mower running low rpm levels with splash lubrication to the crank and rod needs a squirt hole to the piston/cylinder.   Your 6000+ rpm race engine, NO.   It's an "oil tornado" in that crankcase . . . .

 
M

[floydjer]

^^^ Concur...Those grooves location and orientation look to be more of a wrist pin oiler...and that is never a bad thing to have.  Carry on Neil.

[Koncretekid]

What about the oil squirters that are used in modern motorcycle motors?  I think they are to help cool the bottom, hence the crown of the piston but would they also help lubricate the piston pin?  I'm, of course, mostly concerned with air cooled motors.
Tom

[SPARKY]

I have run "crown oilers" in my BBC engines for over 10 years more and more engies run them now especially Turbo and direct injection engines

[wobblywalrus]

On the Triumph...heat related discoloration of the gudgeon pins and stains from oxidized oil on the undersides of the piston crowns showed signs of too much heat in that area.  This was with the eutectic cast OEM pistons and no thermal coatings.  Triumph has oil squirter holes in the rod big ends to send lube to that area.  This did not prevent the heat problem.

The cast pistons were replaced with forged ones that dissipate heat better and thermal coatings are used on the crowns.  At the same time the this done anal level pickiness was used to make sure the ignition timing was as retarded as much as possible while producing good power.  It is not excessively advanced.  Also, the mixture was adjusted to be certain it was as rich as possible without hurting power.  Lots of dyno work did this.

There are no heat discoloration marks on the pins.  There are no oxidized oil stains under the crowns.  The Carillo rods have no oil squirters.  The changes above were not done one at a time so I have no idea what worked and did not.  Together, one or more actions solved the problem.     

[manta22]

AGGRAVATION! 

Yesterday I installed both copper head gaskets after cleaning the deck and applying K & W Copper Coat around the coolant and oil drain back holes. Ditto on the gasket and I slid the heads over the studs on to the block. Fortunately, I only temporarily torqued the stud nuts to 35 ft lbs, intending to torque them to the final value, 70 ft lbs, today. This morning I installed the Crower roller lifters in their bores with some assembly lube and inserted all the pushrods into the lifters through the guide plates. One pushrod did not feel right. I could easily twirl all the pushrods around except #6 exhaust- it was tight. After checking everything I found that the pushrod was pushed over by the guide plate into the side of the pushrod hole. Apparently Dart had not removed sufficient casting flash from that hole to allow a pushrod to move freely.

I've removed the right cylinder head so that tomorrow I can use my die grinder to enlarge that hole (red line in photo). Now it looks like this may have been a problem last year.

Has anyone ever encountered poorly or unfinished head casting finish work? These are Dart Pro-1 aluminum heads.

Regards, Neil  Tucson, AZ

[ggl205]

Yup.

[Harold Bettes]

Neil,

The oldtime adage from long ago stated, "If it is not on time or doesn't fit, must be racecar parts..." still applies today. The finalization and detailed inspection of fit and finish is on the consumer, even if the parts are highly touted CNC super duper stuff. Important things such as valve seat concentricity are high on the hit parade for needing a detailed inspection to maintain any kind of QC. As I understand it you worked in aerospace stuff. The lack of QC is somewhat common in most (but not all) aftermarket parts. Buyer beware good old caveat emptor, my friend.

Looking at the bright side, at least you found the problem and it is easy to fix.

Continue being careful and it will always pay off.

Best of Luck!

Regards,
HB2