Roller Cam, old block struggles

[JP86SS]

Like the title says I am putting a Non-retro hydraulic roller cam (XR-276HR-12) into my 817 406.
The parts arn't going together as expected and I'm looking for some guidance/experience.

The timing chain I bought is for a flat tappet (for early years) and the roller cam has a smaller bolt pattern.
Looking at a lightly used cam gear I had, I was able to install it using the new chain and crank gear.
Tooth profile lined up and looked virtually the same albiet a little bit of wear.

I purchased a torrington bearing and a roller button to use on this as I know the cam will want to push forward.
The torrington makes up the space behind the gear to keep the chain straight and the lobes appear to be centered over the lifter bores.
Q1: What keeps the torrington straight to the center of the cam behind the gear?
(both gears do not have a way to keep it centered and I am bothered by this)

The button that I have "seems" to fit with the larger end fitting into the "flat tappet" gear with the small side out to the cover.
Seeing how the roller cam has a smaller center, the button will not work with the roller gear.
Q2: Is there a different button just for rollers in old blocks?
I must be missing something here, If someone has some insight it would be greatly appreciated.
TIA

 

[79 surfwagon]

I know this can be done:
newer style OE roller camshaft in pre-rolller camshaft block casting.

bump for solution.

one of the magazines did a swap a couple or more years ago where they used vortec heads and the gm hotcam in a pre-roller block. They made it work by using retrofit rollers with oe roller cam in an old block... wish i could find that article...

on a separate note, I've seen pictures of some guys stuff on ebay where he uses the late cams in the early blocks by using v6 lifters and machining the valley with a die grinder... he must have found a solution for the late timing chain using a roller button to prevent cam walk as necessary in an early block.

 

[JP86SS]

It appears it can not be done (without some real appalachian antics anyway)

Issues:
The bolt circle pattern on the roller cam is smaller, no way to use a cam retainer plate (std 3 bolt plate does not fit)
There is no way to use the 87' up cam retainer because there are no provisions to bolt it to the block.

A thrust bearing or washer should be used behind the cam gear.
The retro-fit timing sets are available with this, the cam gear must already be machined to fit the bearing.
You can't just put a bearing on a std gear.

A cam button should be used in front of the gear.
The cam buttons I have bought for the std cam are larger diameter and are x.***" long (don't remember)
The cam button on the 87' ups are smaller diameter to fit the cam gear. Not sure on the length.

My current problem is that I have purchased a retro Howards cam and lifter set.
I repurchased another timing set with bearing behind the cam gear. (not here yet)
Using the cast aluminum timing cover, the old style cam button now hits the cover and is too long.
(This is using a sloid roller retro-fit cam as fitment until the Howards arrives)
Looks to be about 1/8" longer than needed so I have Play-Doh out there drying in place now for measurement tomorrow.

Even when you use the retro-fit parts, you still need to confirm fitment due to all the small variances in the way each company does the setups.

 

[SSedan64]

I use the OEM Cam retainer Plate with the mounting ears cut off and 4 slots about 1/16" deep for oiling behind the Gear.
The Solid or Roller Cam button needs to be turned down in a Lathe to fit the smaller hole in the OEM Roller Cam Gear. It's easiest to use a Solid Button, grind/file/sand for clearance between Cover & Button.

 

[JP86SS]

OK, I wimped out on rigging it up and went with a Howards retro fit cam setup.
110255-12 hydraulic roller. (232/236 on 112)
Now I have a couple more Q's to deal with.
the cam card states to use springs #98212 (This must be wrong! even though it states 441 rate)
There are for flat tappet cam and do not resemble the seat pressure needed for a roller to me.
I currently have Comp 986's on my heads and think they are close to the rating needed.
After researching springs for a bit I find that I could easily change to a Comp 995 for increased tension on open.

Problem is the seat pressure on 995 is only 115 lbs with a spec 402 rate for an open pressure of 325 @ 0.533"
My 986's have 132 lb seat with a 322 rate with an open pressure of 303.
Howards spring indicate about 340 open, 117 lbs seated.
My question is, Is it more important to have the following pressure higher or to have the seat pressure to reduce bounce?

I really like the look of the 995's from Comp to give me 325 lbs open but having only 115 on the seat bothers me.
Does this couple of lbs really matter ????
Thinking to just leave the 986s with 0.068" left before bind and run the crap out of it
What do you think...

 

[SSedan64]

John,
Many Hyd. Flat's & Hyd. Roller's do use the same Springs & Seat Pr.
Some larger Hyd. Roller Springs do use higher Rate & Open Pr.

The 986's are a little weak on Rate & Open Pr. for the Roller Cam.
This shows 115# Seat, 340#Open & 425# Rate for the 98212's. http://www.competitionproducts.com/ search by Item# 98212 @ top/right of Pg.

CarCraft has a great article on Hyd. Roller Lifters & Springs in their September 2011 issue
Article is called "Limited -Travel Roller Lifters" in the Index section and "Solid Roller Power from Hydraulic Lifters" on Pg.16 of Mag. Definetly worth reading.

Basically they're running newly designed Hyd. Roller Lifters with short travel Pistons and setting the preload @Max setting limiting piston travel even more to a minimum. Then running Springs with much higher Seat Pr. but about normal Open Pr. They're able to get upper rpm Solid Roller power from a Hyd. Roller Cam with no Valve float or Lifter pump up.
If you were using a higher rpm Cam it would be worth a try.
The Max Preload & higher Seat Pr. practice can still be applied to normal travel Hyd. Rlr. Lifters tho' for more top end power.

Todd

 

[ScotSea]

Like the title says I am putting a Non-retro hydraulic roller cam (XR-276HR-12) into my 817 406.
The parts arn't going together as expected and I'm looking for some guidance/experience.
TIA

I know I am really late on this, but over at Lingenfelter PE:

http://www.lingenfelter.com/ Search for L200105000

LPE Hydraulic Roller Retro Fit Cam Button Wear Plate Kit L98 SBC
Quantity in Basket: none
Part Number: L200105000
List Price: $36.61
Your Price: $32.95
Quantity in stock: 2
Shipping Weight: 1.00 pounds

This special LPE cam button kit is required for applications using a hydraulic roller camshaft in an early non roller block. The kit includes a special fiber button, wear plate and bolts. This item not legal for sale or use on California pollution controlled motor vehicles