Part 2: The Components Needed For A Cam Swap
The following are the recommended/required components needed for doing a cam swap. The valve train is not a good place to cut corners with. In terms of doing the valve train it is recommended to do it right the first time, so it can all be done one time and one time only.
A. Valve Springs:
Purpose: Keep the valve in control.
Benefit of Upgrading: Upgrading the valve springs is ABSOLUTELY mandatory in doing a cam swap. The stock valve springs CANNOT handle any more lift or RPM than the stock cam puts out as well as a cam with a more aggressive lobe design.
Popular Choices: Crane Dual Spring Kit 10308-1 (includes locks, retainers, shims), PAC Beehives 1218 or Comp Cams Beehives 26918.
Note: Make sure the valve springs you purchase are matched to the camshaft you plan to run. You do not want the valve springs to go into coil bind which is maximum compression of the spring till its solid because this will cause a major failure in the motor.
Along with valve springs, you will need locks, retainers, shims, and valve stem seals (16). The LT4 valve springs located in the LT4 "Hot Cam" kit should NOT be considered to be run with any cam due to the fact they are known to be very weak and only have a max lift rating of .540 which is not high enough for most off the-shelf camshafts.
B. Roller Rockers:
Purpose: Transfers the motion of the cam along the pushrods and assists the valves to open.
Benefit of Upgrading: Upgrading from the stock 1.5 stamped steel rockers to 1.6RR's will increase the lift that the camshaft is putting out as well as producing an extra degree or two of duration at the valve and increased overlap.
Ex: Lift of cc503 w/1.5 RR's = (.503/.510) divide by 1.5 then multiply that number by 1.6 to get lift with 1.6RR's = (.537/.544).
Required?: No, but highly recommended.
Popular Choices: Crane Golds, Comp Cams Magnums, Comp Cams Pro-Magnums.
SA or NSA?: Self-Aligning should work fine for some of the smaller camshafts that do not see revs past 6200/6300rpm. Non-Self Aligning is cheap insurance that can handle high rpm rev's better because the use of guide plates will ensure that the rockers cannot slip off the valve tips. NSA use 7/16" studs which is stronger than the 3/8" studs that most SA rockers have. Non-Self Aligning will require the use of hardened chromemoly pushrods, studs, and guideplates (8).
Purpose: Transfers the motion of the cam to the roller rockers.
Benefit of Upgrading: A stiffer pushrod helps to reduce pushrod flex and along with the valve springs helps to keep the valves under proper control and away from valve float. Upgrading the pushrods is important for durability of the system and should be done when upgrading the cam.
Required?: No, but highly recommended.
Popular Choices: Chromemoly 5/16" or 3/8" outside diameter. Hardened chromemoly pushrods are required if using guide plates. The Trick Flow’s tend to be the most popular and proven choice.
Note: Pushrod length should be checked on any camshaft or change in the cylinder heads. There are a lot of variables that can change the length of the pushrods needed from camshaft base circle, deck height of the block, milling the heads, valve job height and valve length. If the pushrods are too long or too short they will cause premature wearing of the guides and valve train failure could be possible. LT1's with stock heads (assuming none of the mentioned changes have been done) will more than likely still use stock length 7.200" pushrods. It is so easy to measure pushrod length that it should be done regardless. A very easy to use tool to measure pushrod length is the Comp Cams pushrod length checker part# (7702-1).
Purpose: Rides along the lobes as the cam rotates around and follows cam up the lobe ramp which pushes the pushrods up.
Benefit of Upgrading: Over time with higher mileage motors the lifters tend to wear out.
Required?: No, highly recommended for higher mileage motors.
Popular Choices: GM LS7 lifters, Comp Cams hydraulic roller, Crane Cams hydraulic roller.
Note: Yes the LS7 lifters will work in an LTx motor, they are one of the only interchangeable components between LSx and LTx motors. If you go to your local GM dealer to order lifters for your LT1, they will give you LS7's because they are the newly revised replacements.
Gaskets: The following gaskets will be needed:
Front timing cover gasket, optispark seal, crank seal, water pump drive seal, egr gaskets, throttle body gasket, intake manifold gaskets, valve cover gaskets, water pump gaskets.
Timing Chain: Over time the stock timing chain wears and can develop slack. It is highly recommended to swap out the chain for a new one. A stock LT1 replacement chain from GM will do just fine for most.
Note: An LT4 timing chain will NOT fit on LT1 sprockets.
Valve Stem Seals: Worn out valve stem seals will allow oil to come up through the valves which leads to accelerated oil consumption and blue smoke coming from the exhaust. The perfect time to replace them is during a cam swap and for the low cost of them it should be done every time without doubt.
Optispark: If the optispark has not yet been changed it is a good idea doing so at this point. Whether you're doing the cam swap yourself or having it done by a shop, the optispark distributor has to come off. Therefore, it is the easiest time to replace it and will save you time and effort in the long run. If your having a shop do the swap it will not cost you any extra money to have it installed considering the old one comes off and gets re-installed again which will save you money of having it done again down the road.
Water Pump: Same goes for the water pump as with the optispark. If the mileage is getting up there or the pump is starting to show signs of leaking this is the time to replace it. It will save you time, effort, and money to do it at this time. Another alternative would be to run an EWP (Electric Water Pump). EWP's use the stock waterpump housing so hold onto your stocker in this case. EWP's have been dyno tested on LT1's to produce about 10hp/10tq at the wheels as well as cool your motor down during track runs better than the stock pump will. They are not for everybody so best to do your research on them before running one.
Your typical cam swap will run roughly $1,000 in parts alone. That’s not including if you replace the Optispark or Waterpump etc. Labor depends on the shop and part of the country you live in but figure $600+. Tackling a cam swap yourself can easily be done with the right tools and patience. It is smart to start with bolt-ons before at all considering a cam swap. Without the proper intake and exhaust modifications a cam will be choked hindering performance greatly. If the car is auto it is highly recommended to put a stall converter in the car before a cam. Drivability will be poor and performance marginal without the use of a proper sized stall matched to the cam. Lastly, a tune should be on order after any cam swap. Poor drivability and performance will be the result of leaving the stock tune in while running a cam. I hope this guide proved useful to you and good luck with your cam swap! If you have any questions, concerns, etc. feel free to contact me.
StealthFormula @ LS1LT1.com
'97 Formula WS6
18,000 Original Miles
Stock Bottom End - LE2 Heads - 224/230 cam - Most Boltons - 4K Stall - 3.73's - UMI Suspension
11.47 at 119
Last edited by StealthFormula; 04-03-2009 at 12:27 PM.