cam install... advise requested
Thread Starter
Melting Slicks
Joined: Mar 2008
Posts: 2,300
Likes: 1
From: Quincy IL
cam install... advise requested
'85 L98 4+3, Stock cam, engine is still in the car. I have a bit of knowledge, but I do have some help that is more knowledgable. Cam is already out of the car. After the lobes are greased and cam is installed, lifters and push rods are in... intake, fuel rails, runner tubes, plenum are installed, distributer is put back in (Top dead center on cylinder #1)..... fuel lines are hooked up as well as any vacuum lines, as well as the front of the engine and radiator etc... Is there anything else I need to double check or wise advice before we go to starting the car and doing the 20 minute, 2,000 rpm break-in? Any thought are welcome... I would prefer being a little more knowledgeable when this happens next week. (Weather permitting)...
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Here are a few things I thought of:
I KNOW you're running new lifters on a new cam, right? You are using the correct break-in moly-grease, on both the cam and the lifters, right?
If the cam is a flat tappet, don't use synthetic or regular engine oil. Use something like Rotella because of it's added zinc content. Newer oils are lacking in zinc - and maybe some other mineral as well - that's badly needed when running a flat tappet cam. There have been a whole host of flat tappet cam failures attributed to the absence of zinc.
I ALWAYS pour in a bottle of GM EOS (Engine Oil Supplement) available at your GM dealer, on every new camshaft install, even rollers. It has special additives to help prevent scuffing, etc.
I assume you meant top dead center ON THE COMPRESSION STROKE, right? Remember, the #1 piston is at TDC twice during each full stroke of the engine. Once on Compression and once, again on Exhaust.
Lifter preload: Did you set lifter preload? If so, what method did you use? There are a few different ways. The big cam companies, like Crane and CompCams, recommend the E/O, I/C method. How to do it that way should be posted in the Tech Tips area on this Forum.
If the engine runs badly, shut it down and find the cause. Most times it's: One or more lifter preloads too tight; a crossed plug wire or incorrect base timing.
If any, and I mean ANY, problem develops on initial start up, shut down the engine to make the correction/fix. Don't let the engine idle or you run the rish of wiping a lobe(s).
Watch your oil pressure and coolant temp like a HAWK. The engine should fire instantly and R's brought up right away.
Be sure to double, or even triple, check all your connections and settings before you turn the key for the first time. I can't emphasize this enough. I've read far too many posts of "Oh, I forgot to connect the (fill in the blank)", or "I set the lifters too tight", "My timing was off" etc.
The first start-up is the most critical time for a new cam.
Change your oil and filter after the break-in has been completed. Only use oil with high zinc content to help prevent premature wear.
And during break-in, keep those R's UP and change the RPM frequently to allow oil splash to hit different areas.
Hope this helps.
Jake
I KNOW you're running new lifters on a new cam, right? You are using the correct break-in moly-grease, on both the cam and the lifters, right?
If the cam is a flat tappet, don't use synthetic or regular engine oil. Use something like Rotella because of it's added zinc content. Newer oils are lacking in zinc - and maybe some other mineral as well - that's badly needed when running a flat tappet cam. There have been a whole host of flat tappet cam failures attributed to the absence of zinc.
I ALWAYS pour in a bottle of GM EOS (Engine Oil Supplement) available at your GM dealer, on every new camshaft install, even rollers. It has special additives to help prevent scuffing, etc.
I assume you meant top dead center ON THE COMPRESSION STROKE, right? Remember, the #1 piston is at TDC twice during each full stroke of the engine. Once on Compression and once, again on Exhaust.
Lifter preload: Did you set lifter preload? If so, what method did you use? There are a few different ways. The big cam companies, like Crane and CompCams, recommend the E/O, I/C method. How to do it that way should be posted in the Tech Tips area on this Forum.
If the engine runs badly, shut it down and find the cause. Most times it's: One or more lifter preloads too tight; a crossed plug wire or incorrect base timing.
If any, and I mean ANY, problem develops on initial start up, shut down the engine to make the correction/fix. Don't let the engine idle or you run the rish of wiping a lobe(s).
Watch your oil pressure and coolant temp like a HAWK. The engine should fire instantly and R's brought up right away.
Be sure to double, or even triple, check all your connections and settings before you turn the key for the first time. I can't emphasize this enough. I've read far too many posts of "Oh, I forgot to connect the (fill in the blank)", or "I set the lifters too tight", "My timing was off" etc.
The first start-up is the most critical time for a new cam.
Change your oil and filter after the break-in has been completed. Only use oil with high zinc content to help prevent premature wear.
And during break-in, keep those R's UP and change the RPM frequently to allow oil splash to hit different areas.
Hope this helps.
Jake
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Another thing I just thought of: Prime the oiling system before turning that key. You want immediate oil pressure and not have to wait for it to build. You'll need an inexpensive priming tool; AutoZone may rent them for free.
When priming and as you're priming, manually turn the engine over periodically until you see oil squirting out of all the rockers. Do until until you no longer see any air bubbles at the rockers. This could take a while so a 1/2" drill would be best to handle the continued load.
Jake
When priming and as you're priming, manually turn the engine over periodically until you see oil squirting out of all the rockers. Do until until you no longer see any air bubbles at the rockers. This could take a while so a 1/2" drill would be best to handle the continued load.
Jake
Last edited by JAKE; Feb 22, 2009 at 10:15 PM.
Thread Starter
Melting Slicks
Joined: Mar 2008
Posts: 2,300
Likes: 1
From: Quincy IL
Jake, Thank you very much for this info. I will learn greatly from it. This is something I've never done before but I'm looking forward to learning (hopefully not the hard way). I'm going to study out your advise thoroughly. Never heard of Lifter preload before. Thanks again!!
Lifter preload - website I found http://www.gregsengine.com/hlift.htm
Lifter preload - website I found http://www.gregsengine.com/hlift.htm
Last edited by vette54728702; Feb 22, 2009 at 03:11 PM.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Jake, Thank you very much for this info. I will learn greatly from it. This is something I've never done before but I'm looking forward to learning (hopefully not the hard way). I'm going to study out your advise thoroughly. Never heard of Lifter preload before. Thanks again!!
Lifter preload - website I found http://www.gregsengine.com/hlift.htm
Lifter preload - website I found http://www.gregsengine.com/hlift.htm
Right, many times it's mistakenly referred to as "setting the valves" or "adjusting the valves" but what you'd actually be doing is setting lifter preload.
Let me know if I can help further.
Jake
