I am in the process of several upgrades to my LT4. I purchased the LT4 hot cam, but have never installed a cam, so I was hoping to get some pointers from this forum. Here is were I am at: I have the engine on a stand, the balancer, hub, timing cover, Intake manifold, valve covers, timing chain and sprokets are already removed. Now for the questions:

1) According to the manual, after I remove the roller rockers, rods and valve lifter retainer, I will need to remove the lifters. The manual indicates that some lifters may be difficult to remove and will need some special GM tool to remove the stuck lifters. Should I expect some of the lifters to be stuck, and if so are there any tricks to remove them, or do I need to get this specialized tool?

2) When pulling the cam out, should I twist it back and forth, rotate it clockwise, rotate it counter clockwise or just pull it straigh out?

3) Same question as #2, only when installing new LT4 hot cam.

4) I was told that since I have an LT4, I do not need to replace any lifters or springs. Agreed?

5) When installing the new cam, I need to lube up the lobes with a cam lube, any suggestions on which product?

6) Manual says I should apply motor oil to the Journals of the cam before installation. What are the Journals, and is this a good idea?

7) Should I put any lubricant on the lifters when I replace them and if so, what type?

8) What did I forget? Anything else a novice should be aware of?

Thanks in advance for combined wisdom of the forum.

God Bless America,
Chris Thomas - 1996 LT4

 

Well, I haven't done my cam yet but here are a few things that come to mind:
Get a magnetic wand to remove lifters easily.
When installing the cam be careful to not score it on the journals.
The only lube for a roller cam is motor oil.
Mark all parts so they go back where they came from.

 

I'm not a professional mechanic, but I did a Hotcam in my LT4 earlier this year:

1) They shouldn't stick. On flat-tappet cams, sometimes they stick because the bottom of the tappet can get 'mushroom' shaped with excessive wear. That's not a problem with roller lifters.

2) you can rotate it in either direction. Just make sure to pull it straight out or you'll damage the cam bearings. If you screw a couple long bolts into the timing chain bolt holes, it makes a great handle.

3) Same as above -- be very careful of the berings.

4) Correct, unless you have a lot of miles (more than 50K). Inspect everything for wear.

5) Mobil-1. I used 5-30. Also, make sure you clean the new parts (cam, timing chain, etc.) very well with a degreaser, and then oil it up.

6) The journals are the round parts of the cam that sit on the bearings.

7) Yep -- Mobil-1

8) Just keep it all clean! If you didn't get a new timing chain, you should. Mine had 40K miles and the factory timing chain had a lot of slop. I used the GM Extreme-duty LT4 timing chain. Also, I'm assuming you're replacing all of your seals when you reassemble it.

Hope that helps!

 

everything thats been covered is accurate, i will add that when you begin removing the cam, keep the cam sprocket bolted to it so you will have leverage to keep the back end of the cam aligned and so you don't score or knock a cam bearing out. once the cam is out far enough to take a solid grip i would grab the cam itself. use a very slow twisting motion and do not force the cam in any manner, when its lined up she will slide through each of the journals like warm butter on bread. i did my first one 2 weeks ago, in the car! fun fun fun, but out of the car you should be able to maneuver much better and have alot better angles for manipulation the cam for both removal and installation.

as far as installing the hot cam, use mobil one on the journals and don't be shy with it, get them oily!! then use the same technique as used for removal, a slight gentle twisting motion, and go slowly, as the jounals come to each bearing you will have to align them before they go through, take your time don't be hasty, make absolutely sure your lined up before proceeding, its not hard just tedious!! but you can do it!

hope this helps!
chris

 

Just a word of advice, Chris. Based on the kinds of questions you've asked I fear that you may be getting in over your head. Get a buddy who has an understanding of what needs to be done to give you a hand when you begin the swap.

Naturally we'll all be here to give you information and help on your project, but there's no substitute for having someone right there with you.

I'm not trying to discourage you - have at it! - I'm only trying to save you an aweful lot of frustration and additional work down the road.

Hope this helps.

Jake

 

Thanks for the advise and especially the tips. Having never torn apart a motor to this extent, I am learning alot and having fun at the same time. Since this is a project car and not a daily driver, I have the luxury of taking my time and only working on it when I get the urge (which is more often than the kids allow). The advise and tips from those on this forum that "have been there, done that" is invaluable! I will be the first to admit that many of my questions are that of a first timer, but this is the best way for me to learn. Thanks for helping me out. In addition to the LT4 hot cam I am doing several other mods while I have the motor on the stand. They include:
- Clean entire engine, since it is covered with oil/grease.
- Heavy Duty Timing Chain and sprockets
- Head gaskets
- Intake, exhaust, valve cover, oil pan, oil filter assembly and timing cover gaskets.
- Throttle body gasket kit
- optispark
- waterpump
- alternator
- serpentine belt
- several sensors
- Harmonic balancer

lcvette, it looks like you have recently done many of the same mods that I am in the process of performing. I hope you don't mind if I call on some of your experiences as I go along.

Thanks again guys,
Chris - 1996 LT4

 

Well,
I'm right behind all of you on this upgrade path...so I'm glued to these posts. Quick question, if you're doing the head gaskets at this time why don't you have the heads worked on too? You gotta pull them off to replace the gasket, find out how much a machine shop will charge to do a valve job, bowl blend, port match, all that good stuff. Or do we not do these things to LT4 heads?
Another question, can enough of the head be clearanced to lower the compression for a blower or NOS? Or should that be done with the pistons only?

Sam