Cam suggestion... and can I do this myself?

[russg]

I don't know what's currently in it, previous owner said when HE bought the car along with other performance parts it had a cam change but he does not know what's in it.   Basics right now are 383 motor with Holley 670 SA carb, Eddy 383rpm performer intake, Headman headers and 2 1/2 inch pipes, 3.55 gearing.  It takes off kind of sluggish and when finally hits about 3,000-3,500 rpm it pulls like mad.  I'm quite sure I need to make a cam swap to enjoy more bottom / mid range.

1) what is a good streetable cam for my current setup
2) can a reasonable DIY garage mechanic (myself) do this?  Is there a good step by step write up here or a good guide available?

Thanks guys, love this site!

[bordin34]

Compliments of RD when I asked how to change the timing chain and cam
well, since i have done two cam swaps in two weeks, here you go while it is still fresh in the mind:

First of all, you will need -

- oil change (go with royal purple, or racing oil, 5-6 quarts)
- timing cover gasket set
- camshaft lube (should come with cam kit)
- coolant (2 gallons)
- silicone
- permatex gasket maker
- a double roller timing chain set (summit sells them on their brand $50.00 i think)

Now what you will need to do... in order:

1. run your car to operating temperature, shut off and remove all the oil (like you are changing it) to include the filter [hint: when putting on the new filter, put oil inside it, will hold about a quart, so that your engine has oil to scavenge from on the start up]

2. bring your engine to TDC on the compression stroke on the #1 cylinder (AND LEAVE IT THERE)

3. remove coolant from radiator

4. remove fan shroud and fan, belts, and w/p pulley

5. remove radiator

6. disconnect battery

7. remove alternator and power steering pump (take a picture at this moment so you do not forget how things go back together!!!)

8. remove water pump housing

9. remove harmonic balancer using removing tool (you can rent these from autoparts stores)

10. remove timing chain cover (dont forget the two bolts on the oil pan that screw into the bottom of the timing chain cover)

11. clean all mating services (this point, your front oil pan gasket will need to be cut away and replaced, the timing cover gasket set will have a cork replacement, you will need to cut it so that it fits fine)

12.  replace the front main seal in your timing cover

13. remove your timing chain (5/8" bolt), but before you do make sure the two "dots" line up with one another

14. put on new chain, making doubly sure the two dots line up PERFECT (bring in cam bolt to hold the larger sprocket in place... gently tighten cam bolt so that larger sprocket will slide onto the camshaft easily), then tighten to 45 lbs

15. put in lower oil pan gasket (the one you cut to fit), and the timing cover gasket by applying silicone to both sides [make sure you have put some grease on the front main seal to ensure no splitting of the seal upon startup], apply silicone generously wherever there are two separate gaskets meeting one another and then reinstall timing cover

16. install w/p housing with gaskets and silicone

17. then everything else in reverse order

NOW...

if you are wanting to put in a camshaft:

to remove a cam you can do it two ways, keep the intake on or remove the intake... i recommend removing the intake since it will be your first one.

to remove your old cam (assuming we are at the stage where you just removed your timing chain)...

1. remove your distributor

2. remove your distributor gear (using a big flat tip screwdriver, insert tip into slot and turn counter clockwise)

3. remove valve covers, rocker arm assemblies, and pushrods (good time to visually inspect your pushrods, or just buy new ones)

4. remove your intake (take a pic to see how your linkage is set up to include kickdown) and valley pan tray (six bolts, 3 in front and rear on the hold downs)  [now is the best time to clean all mating surfaces between the intake, heads and block]

5. remove all lifters

6. remove your fuel pump, the fuel pump rod will hold your cam in its place

7. remove your cam shaft by put in a 8-10" bolt can be 1/2" or 9/16" bolt and SLOWLY GUIDE OUT YOUR CAMSHAFT MAKE DAMN SURE YOU DO NOT SCUFF UP YOUR CAM BEARINGS WITH THE LOBES OF THE OLD CAM!!! Grin  nice, slow, and sure is the name of the game

8. lube the crapola out of your cam on every single lobe and journal (to include your cam gear that meshes with the distributor gear)

9. SLOWLY PUT IT BACK IN USING THE SAME TECHNIQUE

10. get a clean container (i use a oil bottle cut in half) that has oil in it. put your lifters in one at a time and with the usage of a pushrod, pump them up with oil

11. install each lifter in each lifter bore, after each one is in, apply cam lube to where the pushrod will meet the lifter

12. reinstall pushrods and rocker arm assemblies making sure that the pushrods WILL NOT touch the heads at all (if they touch the heads, the rocker arms are not in the correct order, yes there is an order) torque down to specs (cant remember right now)
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go to timing chain installation at this time
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13. apply silicone at the corners where the heads and the block meet, and along the block where the valley pan hold downs are bolted in

14. use permatex gasket maker around each intake runner port (more or less wherever the valley pan will touch the heads)

15. put on valley pan tray, hold downs, and bolt down front and rear

16. apply permatex gasket make around valley pan tray that will touch wherever the intake manifold and it meet

17. bolt down the intake manifold (dont forget the last two bolts on the drivers side can only go on after you have the throttle linkage in place, those bolts hold it down)

18. replace distributor gear, applying cam lube directly onto gear (there is a slot in the distributor gear that you used to remove it, that slot needs to be parallel with the position of the camshaft in order for the distributor rotor to line up properly)

AND THE REST IS SIMPLE BUTTONING IT UP...

HOPE THIS MINI-THESIS HELPS YOU.

[russg]

Great writeup Bordin34, I'm thinking I would like to try it myself but out of curiousity what would most shops charge, or how many shop hours should an experienced shop take to change it out?

[bordin34]

I have no idea, and just to give credit, all I did was copy and paste the write-up. RD wrote this all down for me sometime last year.

[TexasStroker]

Check your compression and think of what you want out of the car.  If your main goal is a friendly driver with good street manners you might consider a 268 cam.  This is an all around perormer that has excellent low end power and will have a nice curve.  It should work well with a basic 383 with typical upgrades like you've got.  You can certainly cram something bigger in, but keep in mind while the 268 won't sound as radical as say the 292/509 MP stick, it is much better matched to your 383 and will subsequently be much more enjoyable to drive and if I had to take a guess...outrun the mismatched combo.

I'm sure others can offer better advice, but that is my  fwiw.

Keep us posted on what you go with and how the install goes. 

[russg]

How do I check current compression?  I use this car for weekend fun/ mainly street driving but might wish to once and a while drive it to the local track for a pass or two.  With the 3.55 gearing I don't spent much time on the highway.

[russg]

One more thing.. would it make sense while I'm in the top end doing a cam swap to pull the heads and have a local machine shop port or flow the heads, could I see a reasonable gain in hp for the money spent on this? 

[TexasStroker]

Track down or borrow a compression gauge...they thread into the spark plug hole.  Simply remove one plug at a time and go across all 8 cylinders.  This will give you some insight as to the condition of the motor and what the combo can handle in terms of a cam etc.  Just have a buddy crank the car while you monitor the gauge and record the readings.  This will let you know how to match the cam.

For what you are doing I think a 268 would be a good choice.  It should get you all around power, driveability, reliability, and enjoyment from a well matched combo. 

You probably don't need to go in and rework the heads (port and polish, valve job etc) unless you are really planning on milking everything you can out of the car, which doesn't sound like that is your goal...By the time you got all the full tilt work done on the heads you'd be very close to a brand new set of aluminum heads that would likely flow similar, if not better out of the box and shed some front end weight.

My advice is until you have to have a world beater to just keep it simple with your 383 and enjoy the car 

[firefighter3931]

One more thing.. would it make sense while I'm in the top end doing a cam swap to pull the heads and have a local machine shop port or flow the heads, could I see a reasonable gain in hp for the money spent on this? 

With a mild 383 the stock heads are just fine. As long as the valvejob is good you don't need to port the heads unless you plan to be spinning up to 6500+ rpm and want to make power there.

As for the cam ; i would go with something a little more modern than the old MP 268 grind. It's a descent cam but you can do much better and not lose any street manners. For a build like yours i Like the Crower HDP271 grind with the split pattern lobe design.



Ron