|04-04-2013 03:37 PM|
|TucsonJay||I remember those from many years ago. I've done Chevy sixes, smallblocks, and 348/409s. I know I have seen them, and was also told they were to oil the cam.|
|04-04-2013 12:30 PM|
oldbogie Post #9 is right on the button Ill add this: The main purpose in racing applications of the oil groove was so the oil squirted on the pistons could absorber and dissipate forged high compression piston dome heat (keeping pistons cooler), the groove on the rod isn't needed in lower compression street engines. My pink rods in my 12:1 302 have the grooves, I had to add the groove to my new inserts.
Some of the top racing engine builders add remote oil squirters to lubricate and cool piston undersides. Especially on turbo or supercharged engines. If you depend on strictly splash lubrication to pistons, cylinders and rings? that's a decision for the engine builder or the engine owner to make!
|04-04-2013 11:32 AM|
|04-04-2013 10:49 AM|
|Jordan_Sullivan||Hey guys, i just took my motor apart and my motor has one, what should I do? there is only one.. disreguard it and use a different rod cap?? thanks|
|01-20-2012 09:13 PM|
|birkey||i wasnt planning on it. haha thanks for the info|
|01-20-2012 01:13 PM|
Unless this is an engine that is going to see very heavy duty use putting an oil stream on the cylinder wall and the bottom of the piston just isn't needed there's plenty of throw-off from the rod journals.
In heavy duty truck and racing applications you still see squirters but these days they tend to be tapped off the main bearing oil supply and directed with a nozzle to the underside of the piston. Some engines use a drilling through the rod shank to direct oil against the piston's underside, found in upscale racing engines and hard working diesels these days.
Using this puts a lot of extra work on the rings as they have to manage the normal throw-off plus this indexed stream, it gets to be a lot of oil. I wouldn't encourage the use unless there is a big need as has been described for heavy duty use or distance racing where the engine runs for long periods of time at high power settings.
|01-19-2012 10:20 PM|
|birkey||should there be a matching groove in the rod as well?|
|01-19-2012 10:18 PM|
Absolutely. All early hemis had spit holes in the rod caps. Here's one from the 331 I put in my truck. The one in my Deuce has them as well.
"That's about as useless as a snooze button on a smoke alarm." - Jeremy Clarkson
|01-19-2012 08:26 PM|
If this is a SBC, those rods w/the oiler or "spit holes" weren't used after about '64 or so. They were commonly seen on the small journal SBC rods with 11/32" rod bolts. There were other engines besides the SBC that used them, too.
|01-19-2012 08:21 PM|
|engineczar||IMO for performance applications your better off without them. If it squirted at the bottom of the piston it might be helpful but the way those squirt they end up just overloading the oil rings.|
|01-19-2012 08:08 PM|
|birkey||i thought it was fishy because there were major burs on the outer part. should all of them have it|
|01-19-2012 08:07 PM|
|engineczar||That groove is an oil squirter. If it's only on one rod then you have a mis-matched set.|
|01-19-2012 07:32 PM|
|birkey||None others had this in on them.|
|01-19-2012 07:31 PM|
Rod Cap groove??
what is this?