Originally Posted by allansmith859
Ok guys I am wondering if I can use a roller cam in my sbc350. It is not a roller block(3930010). Can I use roller lifters. I have never messed with roller applications before. Only Flat tappet.
First off when we talk about a roller cam we mean a cam made to operate with a rolling element lifter against the lobe as opposed to a flat tappet can that uses a sliding fit between the the lobe and lifter. Roller cams are made from better materials because of how the roller loads the lobe and the total timing is in the lobe which makes even a mild roller cam look very aggressive compared to an equivalently timed flat tappet cam. The flat tappet lobe is tapered over the top because the time it takes for the top of the lobe to sweep the lifter diameter is a substantial part of the duration at peak lift.
The 010 block is not factory designed for a roller lifter cam. This leads in several directions non of which are simple or cheap.
The standard for many years before the factory went to roller lifter cams was the aftermarket. These were intended for maximium performance engines not as a solution to mandated reduction to removal of chemistry in motor oil such as Zinc Dithio DiPhosphate (ZDDP) that the factory rollers are in response to. The aftermarket cams being essentially a race item are made from steel billets and use bar linked roller lifters. Both of these are expensive solutions, in addition the steel cam has a steel distributor drive gear which is not compatible with the steel gear used on distributors. This pushed a bronze gear for metals compatibility but the bronze gear is sacrifical and needs to be replaced on a regular basis which isn't very street driven maintenence friendly. Today's technology has developed a carbon/epoxy distributor gear which exhibits about twice the life for about twice the price of bronze. The factory has developed a heat treat/conversion coating process called Melonizing that is used on steel gears that makes them compatible with the steel gear of the camshaft which exhibit long life necessary to street use. The SBC flat tappet blocks do not use a thrust plate to manage the fore and aft forces on the cam, they depended upon the normally angled lobes and convex shape of the lifters which is there to cause the lifters to spin in their bores as also a means of pushing the cam back into the block till it engages the backside of the aluminum cam drive gear into the casting of the block to carry the thrust loads. Since none of this configuration exists with a roller liftered camshaft the old fatory block has no way to react the thrust movements of the cam, so the adftermarket industry came up with a thrust button that is attached to the nose of the cam and through a tight clearance to the timing cover maintains the cam in lateral position within a few thousanths of an inch when properly set up. This is not easy to do! The trust buttons come in metal with needle bearings or plastic. The plastic is easier to set up and more forgiving of clearance errors but doesn't hold up long enough for extended street use.
GM started the conversion to roller cams in 1987 with passenger cars. Truck blocks prior to 1996 can be a mixed bag of blocks with no provisions or blocks with provisions and sometimes even an OEM roller cam. These 350 blocks of the period are not provisioned casting numbers 10054727, 14079287, 14088548, and 14101148. These 350 blocks from the period are provisioned roller tappet blocks look for casting numbers 10243880, 14011148, 14088526, and 14093638. Any of these blocks can be a 2 or 4 bolt main. Be careful of these close casting numbers that are very different blocks the 14101148 is a flat tappet block, while the 14011148 is a roller provisioned block. These are all one piece rear main seal with passenger side dip sticks. These engines will bolt in to earlier chassis and when including their flywheel or flexplate will bolt to the older transmissions. So swapping the newer one piece rear seal block into 1986 and older chassis is not a problem except these newer engines will need an electric fuel pump as the manual pump provisions are not machined. The big differencces between older and the newer unprovisioned blocks and the provisioned blocks is that the provisioned blocks have taller lifter blocks by nearly a half inch to support the taller roller litfers used in the 90 degree blocks, there are three bosses added to the main oil galley casting to fasten the spider. The spider has eight legs each of which supports a dog bone. Each of the 8 dog bones join a pair of lifters keeping them aligned to the cam lobes, these perform the same function as the tie bars on aftermarket lifters. The timing case is modified to include the bolting provisions of a thrust plate to react camshaft longitudinal movements. The OEM cam has an extneded nose of reduced diameter that passes through the thrust plate to secure the cam drive gear. The timing set gears and chain are unique to the roller cammed engines to provide space for the thrust plate between the cam gear and block. The push rods are .3 inch shorter to accomodate the taller factory roller lifter. The provisioned blocks can use the older flat tappet cam and lifters along with their older timing set and longer pushrods with no other changes except putting the older flat tappet parts into the roller provisioned block. It is not so easy to put the factory roller cam into the older or not provisioned blocks but it is doable.
The old way of doing this was to use a factory roller cam with a modified thrust plate and the roller cam timing set. The thrust plate has it's bolt ears cut off so it just becomes a thick washer between the cam gear and block. Thrust has to be taken with the old trusty thrust button. The spider is mounted by drilling and tapping three holes through the main oil galley and using a stack of washers to align the spider. By using the shorter lifters from the 60 degree V6 engine the length issue of the lifter boss is solved, these are Delco #HL118. These are what you pay the big bucks for to get in a retro kit. Be forewarned that this does take some creativity to make it work it isn't a straight drop in.