how does the whole roller cam button thing work? what does it entail and how is it properly installed on a non roller block? the first ive heard of such a thing was last week.

 

Just kinda sits in the center of the cam sprocket, ideally leaving clearance of around .010" to a reinforced timing cover. Real simple.

 

so what does everyone do for lifters? link bar? not that i have a problem with them but i thought the concept of the button was to keep cost down, lifters are almost the price of a retrofit kit. or can v6 roller lifters be used with out the spider or is there something with the stock roller stuff that can be done?

 

Roller cams need some sort of button. As a cam rotates, it automatically wants to walk forward as it drives the distributor and oil pump. Flat tappet cams because of the lobe designs help to keep the cam in the block. With a roller cam, the lifters don't rotate on the cam lobe like they do on flat tappets so some sort of retainer is required to keep the cam in the block.

Roller blocks usually have some sort of retainer that's bolted to the block to hold the cam in place. Installing a roller cam in a non roller block means a button needs to be used to allow the cams forward force to push up against the timing cover.

Roller lifters do not rotate like flat tappets. Non roller blocks don't have the guide slots in the lifter bores to keep the lifters aligned. You then need some sort of roller lifter that uses link bars to keep them straight.

 

The oil pump, via the distributor, pulls the cam rearward into the block, no matter what kind of lifters are used. The rear of the cam sprocket is a thrust surface against the front of the block.

Flat tappets aren't flat. They're convex, with a radius of like 5' or something. You can see that for yourself if you put two of them together, bottoms facing: they won't sit flat against each other. Similarly, cams for flat tappets aren't flat across the lobe; they're taller in the rear than the front. The lifter is designed to have its center close to the rearward edge of the lobe, and as the lobe spins under the lifter, the outer edge of the lifter is supposed to contact near the edge of the lifter. That forces the lifter to rotate.

A roller tappet has to somehow be held securely with the axis of its roller parallel to the axis of the cam. It MUST NOT rotate. The roller lifters we had all been using for decades before the factories adopted them came with link bars for that. The factory systems all use figure 8s or the like, with flats on the sides of the lifters, to hold them in alignment.

In a roller system, without the extra holding power of the lifters on the cam lobes holding the cam in, and with the possibility of INSTANT destruction if the edge of a cam lobe contacts the lifter in front of it, a cam button is used for security. 99.999% of the time, the oil pump load on the dist gear will hold the cam in; but just in case, there's a button there; or more recently, in the factory systems, a retainer plate.

A button doesn't "replace" link bars somehow. It does something COMPLETELY different, namely hold the cam to the rear, whereas the link bars hold the lifters themselves from rotating. You need both, in a typical non-factory-roller block. In a factory-roller block, the figure-8s and "spider" keep the lifters from turning, and a retainer plate holds the cam back.

Not sure what "everyone" does; I can only speak for what I have done.

 

it has the flat area for the lifters but not the bosses or anything for roller spider or retainer plate, its an odball canada block.

im aware of the button stuff and why roller lifters are in certain things etc, was just wondering about lifters, seems thered be a better way or theres no real reason to use a roler button and just buy the entire retrofit set.

 

It doesn't matter what style of roller lifters you can use or not. You'll still need some sort of a cam button or cam retainer to keep the cam pushed back into the block.

 

correct, im not getting my question across properly, i understand the cam button needs to retain the lifters and cam from moving forward as a roller cam nor lifters have the taper to thrust the cam back. my question is as far as lifters go. can one just use vortec lifters and the dog bones without the spider retainer? maybe my literature is inccorect? the block i have has the bosses for the dogbones to keep the lifters from spinning, just has no bosses at all for the spider.

 

The cam button does NOT retain the lifters. Only the cam.

Can't use the "figure-8s" without the "spider". Gotta hold the figure-8s down somehow, otherwise they'll just go flying off into space and cease to retain the lifters, and the lifters will turn.

No idea about "literature" being "correct"; can't quite see it. Still too dark out I guess.

 

i just dont really picture them flying off. link bars it is.

 

My BBC uses link bar lifters. I prefer vertical link bars compared to the horizontal style but I guess for a street engine, it really doesn't matter. Either way, they're never going to be inexpensive. I use Crower HIPPO lifters. They're only $700 for a complete set.

 

The dog bones keep the lifters square to the cam lobe but something has to to hold the dog bones in place. They only fit around the lifters but are not attached to them mechanically. The spider holds them down.
Does your block have the bosses for the spider bolts but not drilled or tapped? It's possible to do it yourself but only if the bosses are present.
The link bars are riveted to each pair of lifters so everything operates as a unit.

 

it doesnt have any of the bosses but that pads in the valley are machined down. wierd right. its a 1 pc canadian block from what ive found, similar to the oddball 85 or 86 1 pc block it was like a 509 castig or something of the sort that had the openings in the lifter valley similar to big blocks.

 

Link bars don't "fly off".

Figure-8s, however, WOULD, without the spider.

509 is a 400 block. Kinda like this one here. (which incidentally, has link-bar roller lifters in it)



All SBCs have openings in the lifter valley on either side of the cam.

 

So does a 1991 L98 come with a cam button from the factory?

 

No.

The factory roller system uses a retainer plate with a hole that goes in a chamfer around the nose of the cam, between the sprocket and the cam.

 

It's uses a thrust plate

 

Thanks for the info. Is the thrust plate something that should be changed out when doing the timing chain and gears?

 

It's a low friction item

 

Right; it basically doesn't ever "go bad". No need to mess with it usually.

 

Thanks for the advice. Since my timing cover is coming off, I'm replacing the chain, gears, water pump, and gaskets. Is there anything I'm missing? Can anyone recommend a good aftermarket timing chain cover that won't give me issues?

 

Somebody else asked the same question in a post just today.

The answer to you would be the same:

An aftermarket timing cover (a) won't have the correct timing tab to work with your crank damper's mark, and (b) won't do anything any different than what your stock one does (keep the oil in). Total waste of money. Makes your car faster by way of weight reduction, with all weight savings concentrated at the driver's wallet.

Clean your stock one up, paint it if need be, put it back on, keep the weight inside your wallet.

 

What was your reasoning for holes in both lifter galley plugs?
You will have a flood of oil flowing under the timing cover.

The reason I ask is that I had a problem with my 334 SBC where the lifters would not pump oil to the rockers. I ended up completely troubleshooting the oiling system by using kerosene and running the oil pump with a preluber shaft and drill motor. Also to flush all the oil passages after a cam lobe started on its way to becoming circular. Here is what I learned in the pictures.

The pictures are not the best, I know. But notice the diesel oil streams shooting out from both parting lines in the front main bearing. This alone would be plenty of oil to lubricate the timing set. So the extra holes in those plugs is not needed, and I replaced my drilled plug with a solid one after witnessing this.

 

Holes in the lifter gallery plugs are for increased oiling to the timing chain. The chain is normally splashed lubed. Drilling those small holes allows pressurized oil from the lifter galleries to sprat lube the chain. Hole are very small. Usually less than 1/16".

The gallery holes also limit the amount of oil going to the lifters, pushrods and rockers. On a high rpm engine on a dragstrip, it's easy to pump so much oil through the system that the valve covers are full of oil at the top.

Those valley screens in the above picture also slow oil flow back to the pan. In my engine, I have no screens. I want the oil to get back into the pan as soon as possible. I also have drain hoses at the back of the heads which allow oil to drain straight back into the pan without having to flow through the lifter valley and down onto the crankshaft.