[MouseFink]

You should keep the valve spring pressure less than 80 lb. seat / 260 lb. open due to the lack of ZDDP additives in the oil. The ZDDP was eliminated from motor oil by the EPA because it plugs up catalytic converters.

Since the valve spring pressure must be so weak with flat tappet camshafts, the days of a high performance flat tappet camshaft are over.

[ap72]

Originally Posted by hcompton

Flat tappet cams are ok. Still biggest power cams are from flat not roller applications. Thank NASCAR for that one. They use solid flat tappet.

Roller retrofit is the only way to go and its costly. Also need new springs and maybe head machine work for larger cams. No point to go roller for low lift cam.

Roller cams are hardened steel, hyd. cams are cast iron. Rollers on a cast cam will trash the cam in minutes.

The other idea of drilling your oil gallies for the factory dog bones. Is not a soultion. Looks good on the net but when the blocks are setting next to each other it does not look likes its going to work. I would not worry about the rpm limits thats mostly BS anyway to help sell lifters you dont need to buy. I have recently had the blocks setting next to each other and it was for my car figured why not go roller. But i was not going to drill the oil galley and loose a bolt into the rods and loose oil pressure at the same time if it fell out. Which it surely will if you run the engine for any length of time. Since its only going to be a few threads holding it in place. i thought about welding a threaded stand off to the lifter valley. But welding cast iron that has been soaking in oil for 20 years is not that simple either. So gave up and went flat tappet. I have a roller block I am building for a big roller cam. Also have not seen solid lifters for factory style dogbones. So it will probably get tie bar retrofit lifters anyway.

Okay, there's a couple slight miss truths that need clarifying:

Roller cams are the big power cams, not flat tappet

Some roller cams are ground on cast cores, and some flat tappet cams are ground on billet cores, there are multiple different cores that you can grind any lobe profile on.

There is more to be gained than just peak lift with a roller cam

There is absolutely NO BS that your lifters will limit your RPM in a hydraulic application, even GM knows this and uses special hyd roller lifters in its high end engines.



I just had to clarify that- nothing aggravates me more than people spreading lies like they're truths.

[hcompton]

Originally Posted by ap72

Okay, there's a couple slight miss truths that need clarifying:

Roller cams are the big power cams, not flat tappet

Some roller cams are ground on cast cores, and some flat tappet cams are ground on billet cores, there are multiple different cores that you can grind any lobe profile on.

There is more to be gained than just peak lift with a roller cam

There is absolutely NO BS that your lifters will limit your RPM in a hydraulic application, even GM knows this and uses special hyd roller lifters in its high end engines.



I just had to clarify that- nothing aggravates me more than people spreading lies like they're truths.

Lies?

Billet cams are made with steel cores. Cast roller cams are cast hardened steel not iron!! like hyd.

Roller cams make big power but they are not the cams making the most power. You do not need roller to put big numbers on the dyno. As a matter of fact around 7K rpm rollers start to loose the ability to keep up with flat tappet. The roller lifter are very heavy compared to solid flats.

Stock factory style roller lifters are good for most applications. No need to buy aftermarket ones. Just move to solid lifters with tie bars for high rpm running. Stocks are good for most applications. No need to buy lifters when you have factory block with lifters already in them.

Funny ls7 has same lifters as 87 and up vettes. Try doing a search of this forum before posting nosense. @AP27

[ap72]

Originally Posted by hcompton

Lies?

Billet cams are made with steel cores. Cast roller cams are cast hardened steel not iron!! like hyd.

Roller cams make big power but they are not the cams making the most power. You do not need roller to put big numbers on the dyno. As a matter of fact around 7K rpm rollers start to loose the ability to keep up with flat tappet. The roller lifter are very heavy compared to solid flats.

Stock factory style roller lifters are good for most applications. No need to buy aftermarket ones. Just move to solid lifters with tie bars for high rpm running. Stocks are good for most applications. No need to buy lifters when you have factory block with lifters already in them.

Funny ls7 has same lifters as 87 and up vettes. Try doing a search of this forum before posting nosense. @AP27

obviously you HNFC when it comes to cams and valve train. I only hope that some new guy doesn't see one of your posts and mistake it for useful information.

[oldbogie]

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.

Thanks guys

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.

[MouseFink]

Here are the basics:

All hydraulic roller lifter camshafts are austempered cast ductile iron and must be used with case hardened (melonized) distributor driven gears.

All hydraulic and solid flat tappet camshafts are induction hardened cast iron and can be used with regular production, induction hardened, distributor driven gears.

Solid roller cams can achieve valve lifts from .580" to .720" valve lifts. Those camshafts must be machined down between the lobes to achieve cam lobe base circles as small as .900" in order to achieve .720" valve lift or the camshaft would not clear the rods or fit through the 1.8692" ID cam bearings. Small cam lobe base circles and camshafts that are machined between the lobes weakens the camshaft to the degree that steel billet cores must be used. Steel billet camshafts must be used with sacrificial bronze or composite distributor driven gears. The small diameter cam lobe base circles increase the "lobe surface speed" and thus requires roller lifters. Flat tappets would generate too much heat and fail.

A flat tappet camshaft will never get to .720" valve lift no matter how small the base circle is due to the diameter of the lifters would cause "edge riding" with premature cam and lifter failures.

[cobalt327]

Originally Posted by allansmith859

block ID# 14093638.

Is this a roller block thats in my 94 c1500

Some casting number (c/n) 638 blocks used in trucks have been found to have the bosses cast for a hydraulic factory roller cam, but were not drilled and tapped for the fasteners. No huge deal- the holes can be easily drilled and tapped- but something to be aware of. The suffix code could tell you whether the block was used in a truck or car application, but actually looking will be the final word on what you have.

Most of the c/n 638 blocks have the mechanical fuel pump area machined for a mechanical fuel pump. On many factory hydraulic roller cam blocks the finish machining is not done.

[1Gary]

[QUOTE=oldbogie;1607883]First off w

Well said and written.

[MouseFink]

I feel like roller cams is the way to go for any application today. But, from 1968-1970 we raced a NHRA Jr. Fuel Dragster (C/FD) with a Enderle injected 355 CI Chevy engine. We used Engle, Isky and Crane roller tappet camshafts with rev-kits and sometimes we could barely could launch without bogging at 50 feet with miserable 8 and 9 sec. ETs. We changed the Scintilla mag, rear end gear ratio, jetting and Good Year slick tire compounds for little or no improvements. In March 1970, we merely stuck in a Howards flat tappet camshaft and achieved the best 7.57 ET and became consistent all season with mid-7 sec ETs.

We could only guess that was because the Howards flat tappet camshaft had less valve train mass.

[hcompton]

Originally Posted by MouseFink

I feel like roller cams is the way to go for any application today. But, from 1968-1970 we raced a NHRA Jr. Fuel Dragster (C/FD) with a Enderle injected 355 CI Chevy engine. We used Engle, Isky and Crane roller tappet camshafts with rev-kits and sometimes we could barely could launch without bogging at 50 feet with miserable 8 and 9 sec. ETs. We changed the Scintilla mag, rear end gear ratio, jetting and Good Year slick tire compounds for little or no improvements. In March 1970, we merely stuck in a Howards flat tappet camshaft and achieved the best 7.57 ET and became consistent all season with mid-7 sec ETs.

We could only guess that was because the Howards flat tappet camshaft had less valve train mass.

Yep sounds like it was floating/lifting. Didnt have 600 pound springs back in the 70's

[oldbogie]

Originally Posted by MouseFink

I feel like roller cams is the way to go for any application today. But, from 1968-1970 we raced a NHRA Jr. Fuel Dragster (C/FD) with a Enderle injected 355 CI Chevy engine. We used Engle, Isky and Crane roller tappet camshafts with rev-kits and sometimes we could barely could launch without bogging at 50 feet with miserable 8 and 9 sec. ETs. We changed the Scintilla mag, rear end gear ratio, jetting and Good Year slick tire compounds for little or no improvements. In March 1970, we merely stuck in a Howards flat tappet camshaft and achieved the best 7.57 ET and became consistent all season with mid-7 sec ETs.

We could only guess that was because the Howards flat tappet camshaft had less valve train mass.

Mass of the roller lifter was and is always a problem, this is why those extra rev kits between the bottom of the head and the top of the lifters were necessary evils.

For racing a flat tappet is still an option where lifts over .6 inch aren't used but where oil is going for street engines rollers are headed as the only reasonable choice.

Bogie

[MouseFink]

In july 1969, we replaced the Clutch-Flite transmission with a new Don Garlits 2-speed transmission in an attempt to get a better launch. Our Garlits 2-speed transmission broke at the 1969 Winter Nationals at Pomona Calfornia. The Garlits transmissions were outlawed by NHRA because they had welded gears. Big Daddy blew part of his foot off with one of those at Lions Dragstrip in 1970. Then entered the rear entered the dragsters.

I personally was of the opinion that our Enderle injectors were too large. Before we decided to change to a free Howards flat tappet camshaft, I wanted to switch smaller Hilborn injectors for more low end torque and a better launch but that idea was vetoed by the car owner/driver. He loved the top end charge the Enderle injectors provided, but the bog of the line was the cause of the poor ET.

"A drag race can be won in the first 200 feet."

[allansmith859]

On my 638 block it is machined so a mechanical fuel pump can be used. I just wonder if the holes are drilled and tapped in the lifter valley. Never thought to look when I had it apart last time.

[ap72]

Originally Posted by MouseFink

Here are the basics:

All hydraulic roller lifter camshafts are austempered cast ductile iron and must be used with case hardened (melonized) distributor driven gears.

All hydraulic and solid flat tappet camshafts are induction hardened cast iron and can be used with regular production, induction hardened, distributor driven gears.

Are you sure about that? Any cam manufacturer will say you're wrong.

As for the lift its interesting you give max valve lift while never designating a rocker ratio.

[hcompton]

Originally Posted by MouseFink

"A drag race can be won in the first 200 feet."

Agreed if you dont get off the line you will never build the mph to make your time down track.

yeah garlits did some crazy stuff. I love to look at the head work on those old engines. Seen one of his heads you could toss a golf ball down the intake port without touching the walls of the port it was slick. Intake runner was short almost none at all. Amazing custom work. That type of skill is lost. I havent seen a head with cut out and plated up ports in years. Everybody is FI these days.

Nascar uses flat tappet cams with .95 lifters give's them the 700 lift with flat cam. Works better than roller. But is short lived of course. Anything turning that fast will be.