Click on image for the lowdown. 
====
| | | Forums66 Topics128,051 Posts1,055,768 Members48,426 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Dec 2005 Posts: 1,026 'Bolter | | 'Bolter Joined: Dec 2005 Posts: 1,026 | I picked up a set of 906 Vortec heads to swap onto my 350 190 horse crate engine. While at it, decided to install a Comp Cam Xtreme Energy 256H cam and lifters. The heads came with a set of Roller lifters & PRW roller rockers. I didn't use the rollers lifters but did elect to keep the rockers. The problem I'm having is that I cant get the passenger side lifters/rockers to bleed.when priming the engine. The drivers side works fine, but the passenger side is dry as a bone. The heads were reworked at a local machine shop prior to installing. Any ideas?
Robert C. If it's true what they say, "You learn from your mistakes," I'm a Genius in the making. 1950 3600 | | | | | Joined: Feb 2004 Posts: 29,772 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,772 | Unless a distributor housing is installed, the passenger side lifter oil gallery will not pressurize. Some people use an old housing with the teeth ground off the gear to spin the oil pump during priming.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: Oct 2016 Posts: 916 'Bolter | | 'Bolter Joined: Oct 2016 Posts: 916 | wait....you bought a roller cam, but did not install roller lifters??? Am I reading this correctly?
Last edited by Norcal Dave; 03/19/2018 3:13 PM.
~ Dave
1950 Chevrolet 3600 3/4-ton with 261 engine & T5 Transmission
| | | | | Joined: Feb 2004 Posts: 29,772 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,772 | The Comp 252H is a flat tappet hydraulic cam. It also offers no measureable advantage on a dyno over a stock cam.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: Dec 2005 Posts: 1,026 'Bolter | | 'Bolter Joined: Dec 2005 Posts: 1,026 | wait....you bought a roller cam, but did not install roller lifters??? Am I reading this correctly? No, the block the heads came off of had a roller cam, lifters & rockers. I'm only reusing the roller rockers. The Comp 252H is a flat tappet hydraulic cam. It also offers no measureable advantage on a dyno over a stock cam.
Jerry It's the 256H. I'm running TPI & didn't want anything too radical, from what I've been told TPI doesn't like a wild cam. Also using the stock springs and they wont allow for too much more lift than that. This should get me over 300 horses which was the goal. Here are the flow numbers.
Robert C. If it's true what they say, "You learn from your mistakes," I'm a Genius in the making. 1950 3600 | | | | | Joined: Feb 2004 Posts: 29,772 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,772 | Of all the H-series Comp cams, the 260 seems to offer the best compromise between power and smooth operation, at least with the 20-some ones I've personally dyno tested. Around 268 degrees of duration where the "Magnum" cam series begins is where a noticeable idle lope starts happening, and power brake and other vacuum-related problems begin. A programmable computer chip that allows for some tinkering with fuel mixture and ignition timing advance is also helpful.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: Dec 2005 Posts: 1,026 'Bolter | | 'Bolter Joined: Dec 2005 Posts: 1,026 | Around 268 degrees of duration where the "Magnum" cam series begins is where a noticeable idle lope starts happening, and power brake and other vacuum-related problems begin. A programmable computer chip that allows for some tinkering with fuel mixture and ignition timing advance is also helpful.
Jerry Yep, vacuum issues was another thing I was trying to avoid. I'd sent off my chip to be reprogramed with the new cam specs. It should be back today.
Robert C. If it's true what they say, "You learn from your mistakes," I'm a Genius in the making. 1950 3600 | | | | | Joined: Oct 2016 Posts: 916 'Bolter | | 'Bolter Joined: Oct 2016 Posts: 916 |
~ Dave
1950 Chevrolet 3600 3/4-ton with 261 engine & T5 Transmission
| | | | | Joined: Nov 1995 Posts: 5,716 62401 | | 62401 Joined: Nov 1995 Posts: 5,716 | Nice to see you back with us, Robert! Any chance you can join us for Homecoming in April?
~ John A kid raised on Hotwheels, Matchbox and Tonka cannot be reasonably expected to own only one vehicle as an adult. 1949 Chevrolet 3804In the Legacy Gallery | In the Gallery Forum1973 IH 1310 Dump1963 Kaiser M38A12001 International/AmTran RE3000 "Skoolie"2014 Ford E-350 4x4 (Quigley) | | | | | Joined: Mar 2010 Posts: 10,272 Renaissance Man | | Renaissance Man Joined: Mar 2010 Posts: 10,272 | Nice to see you back with us, Robert! Any chance you can join us for Homecoming in April? Nothing more soothing than to hijack a John post while he is simultaneously hijacking a thread. Robert, if you do plan on going to Homecoming in April, PM me. A number of us are planning a convoy. Carl
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
| | | | | Joined: Dec 2005 Posts: 1,026 'Bolter | | 'Bolter Joined: Dec 2005 Posts: 1,026 | Lol! Hey guys, good to be back. I’ve been lurking around for a bit, just haven’t been posting much. Still on the mends from the crainotomy. Totally deaf in my left ear now with unbearable tinnitus but I’m here. Don’t think I’ll make it to Homecoming but I’d sure like to. Maybe next year!
Robert C. If it's true what they say, "You learn from your mistakes," I'm a Genius in the making. 1950 3600 | | | | | Joined: Feb 2010 Posts: 323 'Bolter | | 'Bolter Joined: Feb 2010 Posts: 323 | I’ve heard the Oem vortec heads were prone to cracking. I need to change out my 624s with something better. Where did you find yours?
These old bolts are in my blood. Hard thing is focusing on just one.
1937 Chevy 1/2 ton panel
1953 GMC 2 ton. future car hauler
| | |
|
|
