Hot Rod Forum : Hotrodders Bulletin Board - Reply to Topic
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Hotrodding Basics> Rod Cap groove??
User Name
Password
lost password?   |   register now

Thread: Rod Cap groove?? Reply to Thread
Title:
  
Message:
Trackback:
Send Trackbacks to (Separate multiple URLs with spaces) :

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Additional Options
Miscellaneous Options

Topic Review (Newest First)
04-04-2013 02:37 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 11:30 AM
painted jester 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!

Jester
04-04-2013 10:32 AM
oldbogie
Quote:
Originally Posted by Jordan_Sullivan View Post
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
Ignore it, most likely new bearing sets will not have the matching notch so they won't feed any oil into the groove. If it becomes functional because you happened to get a set of NOS bearings with the notch it's no big deal if one works and the others don't.

Bogie
04-04-2013 09:49 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 08:13 PM
birkey i wasnt planning on it. haha thanks for the info
01-20-2012 12:13 PM
oldbogie
Quote:
Originally Posted by birkey
should there be a matching groove in the rod as well?
No, but to get them to work there needs to be a half round hole on the mating edge of the rod bearing insert that is open to this hole, otherwise their will be no oil flow. These were discontinued a long time ago, modern bearing shells haven't included this feature for many decades.

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.

Bogie
01-19-2012 09:20 PM
birkey should there be a matching groove in the rod as well?
01-19-2012 09:18 PM
Centerline 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.



Centerline

HotRodsAndHemis.com

"That's about as useless as a snooze button on a smoke alarm." - Jeremy Clarkson
01-19-2012 07:26 PM
cobalt327
Quote:
Originally Posted by birkey
i thought it was fishy because there were major burs on the outer part. should all of them have it
All the rods should have them. They helped lube the cylinder walls and cam but were found to be unnecessary.

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 07:21 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 07:08 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 07:07 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 06:32 PM
birkey None others had this in on them.
01-19-2012 06:31 PM
birkey
Rod Cap groove??

what is this?

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -6. The time now is 06:42 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.