During my recent head/cam install, I modified by lifter retainers by drilling 1/2" holes to help expedite oil drainage to the sump. I found that using a Unibit provided a perfect method to drill the holes without cracking or compromising the strength of the retainer. The holes come out perfect.

Here's what they look like:



Here's the Unibit that I used, I marked right above the 1/2" step with a black marker so I would know when to stop drilling:


Here's a close up of the holes:

 

interesting does it actually help??

 

No way to know for sure, Wheel to Wheel recommends this modification.

 

o well then im gonna do it to mine since i got it out
if they said stick a potato in the air box to go faster i would probly do it
they build some badass stuff

 

Do you drill both sides of the retainer? Or is the 2nd pic just a stock retainer and the top picture has both drilled?

 

I only drilled one side, the side that points down when installed in the engine. The background being the same color as the retainer masks this.

The top picture shows a drilled retainer v. an undrilled retainer.

Sorry for the confusion.

 

After spinning a lifter in its bore, I bought a new set of lifter trays and planned to do this mod. Then I read somewhere that it works well in a dedicated race environment, but not as well on the street. I went the following method because it wasn't my daily driver at the time, but that changed a month later. No problems so far, but the heads have to come off to change the cam.

mod

Installed

 

Super nice, who makes those? I looked for a revkit but couldn't find one for the LS1.

 

They're in Texas, but they're not a sponsor Don't know if I can mention them, so PM me for more info.

 

Could you explain for the people who don't know what a rev-kit is? I assume you put that in and don't use lifters? Wait, that can't be right. Is it similiar to this?

http://www.airflowresearch.com/hydra_rev.php

 

Yes, same premise. Keeps the lifter on the lobe via the helper springs. When I spoke with Tony Mamo at PRI, he liked the idea of the rev-kit for the LS1 also. Others suggest they are bandaids for other valvetrain components which aren't setup correctly, such as valvespring pressure.

I had to shave down the underside of the top a bit so it would fit flush against the head, but there are shims included. IIRC, I shaved it the same amount the deck was surfaced, .020.

 

Yea thats a rev kit for a SBC. This is the first I have seen in terms of a rev kit for a LS1, and its pretty interesting. From what I understand is that a rev kit helps control the lifters without adding spring pressure to the valve and pushrods. From the looks of it the lifter trays were scrapped to place the rev kit, yes?
Deffinatly want to hear more about where you got it, looks like something a lot of people would be interested in.

 

Yes, this kit replaces the lifter trays. Bolts to the stock tray mount location. Needs to fit firmly flush against the underside of the head so that it doesn't rock. As I said before, once this is installed, you can't keep the lifters up for a cam swap, so the heads must come off to change the cam. Most around here aren't interested in that extra work

Kit cost $425 last summer. I already gave Aaron the URL to the vendor, but will post it if a moderator says its OK. Some more pictures...

top

bottom

 

You just cant post contact information, but regardless, send me a PM.

 

Interesting, how stiff are the springs?

 

I was told once but I didn't document it. For some reason I want to say 60lb/in, but that may not be correct.

 

Any issues from those who have performed this mod a year later?

 

I have the drainback modification on my turbo PU truck daily driver. I put the engine in the truck in 2003 and it now has 90,000 miles with no problems.

Kurt

 

A little over a year later and 13,000 daily driver miles without issues.

 

What confirmed issues have been caused by not doing this mod?