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Roller Cam Install - Cam Button & Timing Cover Help

19K views 25 replies 9 participants last post by  Wolfplace 
#1 ·
ok, so it looks like I'm going "roller" on my BBC 468 this winter. Long Story.............

I know that with the roller cams you have to control camshaft endplay so it doesnt "walk" back and forth. Unlike flat tappet cams with tapered lobes, roller cams have flat lobes and therefore need some "positioning" device to keep the cam walk within tight limits for multiple reasons.

I've seen cam buttons, and timing covers made so as to allow for adjustable cam buttons. I need more information please. Do I have to buy a "special" timing chain cover? Do I buy the cover and button together? I dont get it. What about a "thrust plate"? heard of that too. what does that do? Where does it get installed?

I need somebody who has recently done this to respond with a step by step installation instructions for me please.

thanks

Lee
 
#2 ·
Check this out. http://www.cloyes.com/HighPerformance/PerformanceHome/tabid/244/Default.aspx

I used the Cloyes rigid two piece (port hole) type cover along with a hex-a-just gear that uses the encapsulated roller gear behind the timing gear. This roller bearing is recessed in the gear and when properly loaded with against the cam roller button, it will not come out. I have used it on two motors now with many hiway cruising miles.
Cover http://www.cloyes.com/HighPerforman...ngCover/tabid/182/language/en-US/Default.aspx

Gear set
http://www.cloyes.com/HighPerforman...lerSets/tabid/180/language/en-US/Default.aspx
 
#3 ·
What Don said. You want to run a solid timing cover with externally adjustable thrust button. The Hex-adjust deal is entirely optional on a street car.

Or you could easily order a cam with the nose cut for a thrust plate that bolts to the front of the block. The BB block is usually drilled and tapped for this. Quality cam grinders are familiar with this and can supply the parts.

You should seriously consider running the expensive timing gear setup with the built-in roller thrust bearing if you're using HV/HP oil pump. Otherwise you don't need it either. The HV/HP pump is unneeded if your engine is built with normal oil clearances.
 
#4 ·
Lee,
If you are switching to a roller cam, what I have been doing lately is getting the cam ground on the late model "step nose" cores, then using a cam retainer plate and late model timing set. Just about every Big Block made has the two holes in the front for the retaining plate and now almost all the cam manufacturers have the new style cores. This does away with all the hassle of a cam button and trying to get the end play exactly right. Just bolt it together and dont worry about it. That way you can use any cover you want

Sorry Tom, didn't even finish reading your post, didnt mean to repeat it.
 
#5 ·
I dont get it. Need pictures please. Post them here or email them to me at lwallace@pcsoc.com.

When I pull my motor (in next couple weeks) I'll remove the timing chain and gears and take a look at what's there. Seems like there are to many options going on here. some guys say "just pound the timing cover" with a hammer until the end play is just right, other guys use cam buttons, and now I'm hearing about grind the cam nose and using a retainer plate. Once I pull my gears and chain I will post some pics of it and go from there.
 
#6 ·
Lee,
Dont have any pics handy, but all of the late model BigBlocks that come with factory roller cams use a camshaft retaining plate that bolts to the front of the block between the cam and the timing chain sprocket. It keeps the cam from moving forward or back. Same with newer small blocks. It is identical to what Ford has used for years if you know what they look like. The Rat blocks have always had the 2 holes for the plate because they were used in early trucks and marine engines with gear driven cams. So all you need to do is get a late model roller cam and timing chain set, and the plate and 2 screws to hold it to the block.
 
#8 ·
wow - cool. So I can get a Gen VI roller cam setup (cam, lifters, springs, etc) and install in my Gen IV block? And there will be 2 threaded holes in the block behind the cam gear for the retainer plate?

Ok, I got it, but..............How do you adjust Cam Endplay with that setup?
 
#10 ·
this whole thing seems fishy to me. has me concerned a bit, using a Gen VI cam setup in my Gen IV block............I just went to Isky website and searched their catalog - seems like there are very few cam setup for the Gen VI blocks - not as popular - not as many to choose from. Also saw some footnote about having to convert to adjustable rocker arms? I'll learn more about it but I don't know if that's the route I want to go.
 
#12 ·
this whole thing seems fishy to me. has me concerned a bit, using a Gen VI cam setup in my Gen IV block............I just went to Isky website and searched their catalog - seems like there are very few cam setup for the Gen VI blocks - not as popular - not as many to choose from. Also saw some footnote about having to convert to adjustable rocker arms? I'll learn more about it but I don't know if that's the route I want to go.
=
There is nothing wrong with using a thrust button & the "old method" almost all engines I do are this way but,,,,
It is very simple if you wish to use the late cam retainer:
Everything is the same as what you were originally going to do, the lifters, rockers, springs, pushrods etc are all exactly the same
The only thing that would change is the cam core, the way the cam is retained & the timing set

You are making this way too complicated trying to read into it the things you have to do to the later non adjustable rockers etc. ;)
This has nothing to do with the early heads or any aftermarket head, they have the standard studs, guideplates & use adjustable rockers so all this stuff stays the same.

As for cams, you are not limited to what you see in a catalog
I rarely use a shelf roller cam. A custom is only a few dollars more from most any cam company
You can specify the core you want it ground on, the intake & exhaust lobes you want, the LSA, even a firing order swap if you so desire.

As for timing sets, you certainly do not need the adjustable ones they just make life easier for the installer to dial in the cam.
Sometimes I use them sometimes not but there is nothing wrong with them at least I have never had an issue with them
The majority of issues with them are self inflicted by installers that do not care to use some common sense.

Personally I would never consider a plastic timing set, I have seen way too many of them in the oil pan & this is with stock cams & spring loads,,,,,
But to each his own :)
 
#13 ·
With the Gen VI retainer setup, is there a bearing or shim between the cam sprocket and the block thrust plate?

Or is it just cam sprocket face to block separated by an oil film?
 
#14 ·
Let me give 2 recent scenarios why I would most definitely NOT get involved in the "retainer-plate" deal. Again, this is drawing on all my own experiences.

First, I have a "roller" Pontiac on the stand scheduled for the dyno next week. For those not familiar with the Pontiac's, this is all they've ever used, the identical setup as the Mk-VI deal. Upon initial pre-assembly I had "zero" end play on the cam.

It turned out to be somewhat of a time-consuming issue for 2 reasons, one the cam had to be repositioned in the block fore and aft for proper lobe "centering", and THEN the 2nd reason to correct the needed end-play. It was a "chore" to say the least and cost the customer more a bit more than he expected!

Now that raises the second point, you're going to have much extra time if you need to reposition the cam, front to rear, with the plate setup in the BB in order to "center" the lobe for the roller setup. I realize ALL this can be accomplished, but it sure as hell is much easier with a full-complement of equipment at your disposal. Kinda tough to do it in your garage!! Remember, the Mk-VI was NOT designed with the "small" cam snout in the program!! I do realize it's extra work either way, but I also suspect it's somewhat easier without the plate!

Let me raise one more point while I'm here, in the last 5 years or so we've had 3 pins actually work their way out of the cam snouts. For many here it is not an everyday occurence, but we've seen it too many time so far. What we've come to realize/learn from the very first one, is to use the cam-lock-plate as a dual-purpose piece. It's main design is to keep the bolts from backing out when in service, BUT, it can be used also to keep the cam pin from walking out by "covering" the pin instead of using the 4th hole in the plate as a "clearance" hole.

(Add) I'm not certain there's a plate available for the "small" bolt patterns on the late cams!

Thanks, Gary in N.Y.

P.S. Couple "shots" of cam pin damage we've encountered and how we install the plate!

 
#15 ·
This is getting to involved for something that is very simple. GM used a bolt on retainer for years on trucks and reverse rotation marine (aka - GenVI design). It is simple deal. GenVI all went to rollers. THe cam has a stepped nose and uses a hardened machined retainer that will bolt right up to a MrkIV block. For this setup, use a GenVI timing set, that's all that's to it. I use a GenVI cam in my '87 MRKIV block now with a stock timing set from the ZZ502 motors (about 50.00 for the set from GM, includes the retaining plate). I run a high volume oil pump, have ran it hard this past season with no signs of any wear on the retaining plate (not visually inspected yet, but the first indication woud be a change in ignition timing. The reference to changing from non-adjustable rockers applies to the GenVI truck motor and 454HO & 502HO (basically any iron head motor made after 1996).

PS - you don't have to position anything using a GenVI style cam and timing set, that's the beauty of it. For the individual that is not sure what/how to set up cam thrust clearances, it is foolproof.
 
#16 ·
This is getting to involved for something that is very simple. GM used a bolt on retainer for years on trucks and reverse rotation marine (aka - GenVI design). It is simple deal. GenVI all went to rollers. THe cam has a stepped nose and uses a hardened machined retainer that will bolt right up to a MrkIV block. For this setup, use a GenVI timing set, that's all that's to it. I use a GenVI cam in my '87 MRKIV block now with a stock timing set from the ZZ502 motors (about 50.00 for the set from GM, includes the retaining plate). I run a high volume oil pump, have ran it hard this past season with no signs of any wear on the retaining plate (not visually inspected yet, but the first indication woud be a change in ignition timing. The reference to changing from non-adjustable rockers applies to the GenVI truck motor and 454HO & 502HO (basically any iron head motor made after 1996).

PS - you don't have to position anything using a GenVI style cam and timing set, that's the beauty of it. For the individual that is not sure what/how to set up cam thrust clearances, it is foolproof.
=
Exactly my point, it is simple, it has nothing to do with Pontiacs (or Fords)
It works very well.
ALL YOU CHANGE IS THE CAM CORE & THE TIMING SET ALONG WITH THE VERY SIMPLE RETAINING PLATE
 
#20 ·
Lee,
There is no "stupid picture". The cam buttons have to be either ground to the correct length while you keep checking the end play of the cam, or you can "bend" the timing cover till you get it right. You also need to somtimes weld a stiffening plate in the cover to keep it from moving. That is why for a beginner like yourself, the late model setup with the retainer plate is the way to go. There is nothing to be done other than bolt it in place. Nothing to check or adjust. Why would you want to go any other way ?????????
 
#21 ·
but with the "late model" setup like you're talking about, are you saying the cam also? or just the timing cover and stuff underneath? As far as machining the cam button for end play, I can do that myself right - just using a grinder or something - maybe a file? Do I What holds the cam button in place?
 
#22 ·
Lee, this is a Cloyes set up with the adjustable roller button in the cover.
http://www.cloyes.com/HighPerforman...ngCover/tabid/182/language/en-US/Default.aspx

This picture is the other universal cam buttom Bill could be talking about. Its been around for some 40 years and sometime require tack welding a wear plate on the inside of the stock timing cover to take the wear and load as most old stock covers were thin.
http://www.mr-gasket.com/ProductDetails.aspx?brandID=1&productID=10083048&txtSearch=cam button
Some of these have been made of differant materials but all serve the same purpose, preventing cam walk even in flat tappet cams. Other engines have the thrust plate type like bbc motors and the newer LT motors . Hope this helps. You might pick up a book " Hotroding SBC & BBc motor" and it should fill you in on all what has happened in the last 50 years.
 
#25 ·
Was doing a bit of searching and came across this excellent thread regarding the use of the Gen VI retainer plate, timing set and cam.

How does the cam gear get any oiling when there is a retainer plate?

Or is there still enough seepage from the end of the cam and between the retainer plate to keep the retainer plate thrust area lubricated?

I like this solution. Will save the block thrust, no need for torrington bearing and a positive way to control cam movement. No more messing with the timing cover buttons and trial and error fittment.

Too bad I was not aware of this slick solution last summer when I had a new motor assembled! I need a smaller cam anyway.
 
#26 ·
Was doing a bit of searching and came across this excellent thread regarding the use of the Gen VI retainer plate, timing set and cam.

How does the cam gear get any oiling when there is a retainer plate?

Or is there still enough seepage from the end of the cam and between the retainer plate to keep the retainer plate thrust area lubricated?

I like this solution. Will save the block thrust, no need for torrington bearing and a positive way to control cam movement. No more messing with the timing cover buttons and trial and error fittment.

Too bad I was not aware of this slick solution last summer when I had a new motor assembled! I need a smaller cam anyway.
=
Correct, it gets plenty of oil from "leakage" off the front cam bearing ;)
 
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