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big blocks and roller cams?

Started by max, October 31, 2007, 09:37:37 AM

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max

i'm thinking out loud on this one and was wanting to see just what needs to be done to run a roller cam in a big block.

what oiling mods need to be done to the lifter bores?

this is basically a street only engine so there isn't any need to go super crazy on the parts.

is it possible to use the 318/360 magnum roller lifters to help cut some of the cost down?

Challenger340

HYDRAULIC Roller Cam in a BB.

Control Cam Endthrust.
Adequate Valve Spring Pressure & Rate for the Cam.
Adequate Valvetrain Parts ie; Rockers/pushrods.
No Lifter Gallery Mods

Dunno 'bout the SB Lifters ?
They'll fit in the bores, but I suspect other problems like exposing the Oil gallery either on base circle or @ lift.

Sorry, can't help more.



Only wimps wear Bowties !

max

thanks Challenger340, those are very good points with the other parts needed.

i have never set an engine up for a roller cam so this is a first for me. i bought a built small block ("X" block) several years ago that has a roller in it and it has the lifter bore mods done to it and also the brass oil pump gear.

but i wasn't sure if a big block would be set up the same as that X block or not.   

Challenger340

Sounds like your SB roller was a MECHANICAL type Roller Cam setup, that will use a billet type steel cam core, and yes THAT would require the Bronze Dist. gear/bushed Lifter deal (oldschool).

I thought from your earlier post, when you mentioned using 318/360 "magnum" Roller Lifters, that we were talking about HYDRAULIC ROLLER type Cam setup.

What are you looking at doing to the BB, HYDRAULIC Roller, or MECHANICAL Roller Cam setup. Big difference in setup & parts.

Bob out.
Only wimps wear Bowties !

max

Quote from: Challenger340 on November 02, 2007, 09:40:01 AM
Sounds like your SB roller was a MECHANICAL type Roller Cam setup, that will use a billet type steel cam core, and yes THAT would require the Bronze Dist. gear/bushed Lifter deal (oldschool).

I thought from your earlier post, when you mentioned using 318/360 "magnum" Roller Lifters, that we were talking about HYDRAULIC ROLLER type Cam setup.

What are you looking at doing to the BB, HYDRAULIC Roller, or MECHANICAL Roller Cam setup. Big difference in setup & parts.

Bob out.

yes, the small block is a mechanical roller set up.

on the bb i was/am looking to go roller but that is were i'm a bit confused so thanks for correcting me on the apples and oranges.

being mostly a street only bb, a hydraulic roller would be just fine especially for the major difference in the set up cost and i assume the set up would be alot easier (less work) as well going with a hydraulic roller.   

Challenger340

I dunno how to quite put this ?

These are just my opinions, so take them as just that.

HYDRAULIC Rollers are very nice ! But they just aren't a "magic bullett" for power in all BB applications.

Hydraulic Roller setups are still a Roller setup, just instead of a straight solid MECHANICAL Lifter, the lifter has a HYDRAULIC plunger in it the same as regular Flat-Tappet Lifter.
BIG power difference between the two !
However, The same Cam endthrust factors must be controlled, (cam Button), and valve Spring Pressures/Rates adhered to, so as to maintain Lifter contact with the Cam Profile, as well as conduscive type Rocker Arms, etc.
Check the Hyd. Roller Cam Manu for shaft material, usually Bronze Dist. gear not req'd.

Generally speaking, the Hyd. Roller profiles, don't make that much more power, than a well matched Flat-Tappet solid Cam, when comparing profiles above 240*@ .050 on many BB Mopar head castings.
Especially with the Mopar .904" Lifter Dia. and profiles available for Flat-Tappets.
And actually, given the Flat-Tappets better "rev-ability" in the higher rpm ranges, the benefits of the Roller may be totally squished out depending upon "where" you want your best events.
The Hyd. Rollers are tougher to keep the Hyd. Lifter pumped up against the spring pressures @ rpm.

On the "mid" rpm stuff, up to around the 5500 rpm range, then yes, the Hyd. Roller profiles do offer superior events over the Falt-Tappet solids due to the faster Valve opening & closing rates that can be attained with the Roller down lower.
But, and here's the "kicker", the "best" application for those Rollers, is to be utilized in conjunction with Cyl. Heads that are pretty FAT  in the mid-higher lift ranges, because the "time spent" at the lower & mid-lift ranges is sometimes less than the Flat-tappets.
The term, is the Heads Flow "area under the curve" being maximized.

IMO, it all boils down to what you want, and where. I'm not trying to DIS the Hyd. Rollers, rather, I'm just attempting to point out that there are factors to justifying the added expenses incurred for the Roller over the Flat-Tappet.

One BIG plus for the Hyd. Roller expense is the lack of worry during Camshaft break-in, NONE !
Whereas the Flat-Tappet stuff with todays Oils is becoming a P.I.T.A. ! Changing out inner springs/additives, etc.

Thats the best I can do without writing a Novel,

or did I ?

Awfully Sorry 'bout that,

Bob out.
Only wimps wear Bowties !

firefighter3931

Quote from: Challenger340 on November 03, 2007, 10:14:20 AM
These are just my opinions, so take them as just that.

HYDRAULIC Rollers are very nice ! But they just aren't a "magic bullett" for power in all BB applications.


On the "mid" rpm stuff, up to around the 5500 rpm range, then yes, the Hyd. Roller profiles do offer superior events over the Falt-Tappet solids due to the faster Valve opening & closing rates that can be attained with the Roller down lower.
But, and here's the "kicker", the "best" application for those Rollers, is to be utilized in conjunction with Cyl. Heads that are pretty FAT  in the mid-higher lift ranges, because the "time spent" at the lower & mid-lift ranges is sometimes less than the Flat-tappets.
The term, is the Heads Flow "area under the curve" being maximized.





That's pretty much it...i'd have to agree with Bob. The hyd rollers are limited by spring pressures and you need a fat flow curve to make them shine. The associated costs aren't justified, inmo. If you want to go roller it's worth it to go solid (Roller) and choose an "endurance" grind that is easy on parts.

That being said ; there are some nice flat tappet profiles out there that have similar .050-.200 valve lift specs that will make pretty close to the same power as a mild roller. The EDM solid lifers with priority cam lobe oiling look like an excellent option for more agressive profiles. If i was going to run a fast rate solid these lifters would be my choice along with some good oil and the appropriate supplements loaded with Zinc/Phos for anti wear protection.

EDM lifter link :

http://www.engine-builder.com/ar/eb40644.htm


From that link :


"Flat tappet solid lifters have improved say experts, but how much? Howards Cams is one of a few suppliers that offer solid lifters with an electrical discharge machining (EDM) hole in the face for added lubrication. "The Direct Loop lifter with the EDM hole works best in two extremes: for circle track racers who use very fast or high ramp rates on the cam lobe, which requires fairly healthy spring loadings to handle the fast ramp rates and high rpm. Some additional oiling is needed because of the heavier load ratings," says Steely. "And it helps in the extreme opposite end for the street guy with the solid lifter who doesn't turn any rpm. There's not enough rpm to oil the lifters and cam because the camshaft is oiled by splash. If you're only revving at 1,500-2,000 rpm there is a good chance it's not getting enough oil in a healthy solid lifter camshaft."



Ron
68 Charger R/T "Black Pig" Street/Strip bruiser, 70 Charger R/T 440-6bbl Cruiser. Firecore ignition  authorized dealer ; contact me with your needs

max

Bob and Ron, thanks for clearing all that up and for that link.

i figured the valve spring pressure would be a major factor on the hyd roller lifters, the spring pressure would have to be really precise since the lifters need to stay planted on the lobes but yet not to much pressure to collapes the lifter springs.

i didn't think of the mid range spike that would be on the cylinder heads, which explains the reason the 5.9 magnum engines have that slugish low rpm and really don't start making power until 2200-2500 rpm range.

to be quite honest the reasoning for the post is because of the poor quality of oil these days which will only get worse with time and the possiblities of wiping cam lobes.

in the last 25-30 years that i have put mopar engines togeather i have just had my first bad expierance with a wiped lobe last year so i was thinking it was time for me to get away from the old school design of flat tappets and start looking into roller cams.

i seen those EDM solid lifter design alittle while back and thought that was a really neat idea but wondered if that help cure the problem of wiped lobes 100% or if they just help decreased the chances of it and if they would cause a drop in oil pressure because of the added oil hole in the bottom of the lifter?

so if a person was looking to go solid roller in a big block then what type of oil mods if any would need to be done to lifter bores?

am i correct if you get to much of an aggressive lift on a roller cam with out the right roller lifters that the lifter can raise high enough in the lifter bore to cause a momentary loose in oil pressure.   

firefighter3931

Quote from: max on November 04, 2007, 02:52:14 AM

i seen those EDM solid lifter design alittle while back and thought that was a really neat idea but wondered if that help cure the problem of wiped lobes 100% or if they just help decreased the chances of it and if they would cause a drop in oil pressure because of the added oil hole in the bottom of the lifter?



With a good oil package and EDM priority cam lobe oiling i don't think you'll have to worry about wiped lobes. Another member here ; 706pkrt (Ricky) is running them in his new e-headed 440 build. Mopar Engines West did the assembly and Dyno tune on Ricky's motor and had nothing but positive comments on the lifter design.  :2thumbs: Personally, i think the combination of splash lube, higher spring pressures and poor oil quality is the main reason for all the wiped cams we're seeing.  :P So far, Ricky's engine is running great .....oil pressure is 60 psi....no loss of pressure with the EDM lifters.  :icon_smile_big:


Quote from: max on November 04, 2007, 02:52:14 AM
so if a person was looking to go solid roller in a big block then what type of oil mods if any would need to be done to lifter bores?

am i correct if you get to much of an aggressive lift on a roller cam with out the right roller lifters that the lifter can raise high enough in the lifter bore to cause a momentary loose in oil pressure.


Most running solid roller cams don't do any mods to the lifter bores. It doesn't hurt to have the geometry checked and in some cases the bores need to be bushed. Member Blown68Coronet (Kevin) is running the full bodied Comp roller lifters in an unbushed block with a .630 lift "endurance" solid roller grind in his 671 supercharged 446 with no issues. The key is to make sure you use the solid body roller lifter and the oil feed hole doesn't raise above the lifter bore.  :yesnod:


Max, we all feel your pain...wiped cams just plain suck ! Roller cams are the right answer but the added costs and maintenance are hard to swallow. Not only is the roller setup expensive but so are the reast of the valvetrain parts....you need a good rocker arm (Harland Sharp/T&D/Jesel) to make it live so that adds a lot of expense to the initial build costs of going to a solid roller setup. :Twocents:



Ron
68 Charger R/T "Black Pig" Street/Strip bruiser, 70 Charger R/T 440-6bbl Cruiser. Firecore ignition  authorized dealer ; contact me with your needs

max

Ron, thanks on that information. my next engine build is alittle ways down the road so that will give me plenty of time to look into those EDM lifters more.

in all reality my engines are 99% street driven so the roller cam sounds like an over kill for anything i would build not too mention the cost of setting it all up.

one thing for certain i will look into any option that will keep me from wiping another lobe.

Mike DC

Quotein all reality my engines are 99% street driven so the roller cam sounds like an over kill for anything i would build not too mention the cost of setting it all up.

With rollers pushing the midrange up in proportion to the higher RPM areas, I think the rollers are actually a better street item than a street/track dual purpose deal.  The fast-ass ramp profiles basically mean more immediate midrange power in proportion to the given amount of unruly "lumpy cam" side effects that it gives you.   

Rollers are still expensive though.  And the big-diameter Mopar specific cam grinds we're getting lately have really taken a bite out of the roller's traditional edge even in this area.  Jump through the hoops to break the cam in effectively once, and you're probably coming out pretty well running one of those flat-tappet cams. 


max

Mike, thanks for that input.

i starting to lean towards the old flat tappets again after taking in all of this helpfull information :scratchchin:

given my record of only losing one cam lobe in a 25-30 year time period dosen't sound to bad. i just hope it's my last one for a long while, but either way it sounds like going through an engine after a cam failure would still be cheaper then converting one over to a solid roller :shruggy:

firefighter3931

For a street motor that will see lots of extended low speed operation (idleing) the flat tappet is the better option, inmo. Solid rollers don't like to be idled at low speed. The extra mantenance also has to be factored in as well. Roller lifters need rebuilding every couple thousand of miles and valvesprings have a much shorter lifespan....and have to be checked frequently.


Ron
68 Charger R/T "Black Pig" Street/Strip bruiser, 70 Charger R/T 440-6bbl Cruiser. Firecore ignition  authorized dealer ; contact me with your needs

max

Ron with that statement you just put the final nail in the coffin for my use of a roller cam.

like i mentioned above it will see 99% street use with a maximum rpm of roughly 5500, so that is alot of low rpm usage.

firefighter3931

Max, some additional testimonials on the EDM lifters : 

"For those of you with interest in this, I just pulled a set of EDM lifters out of a hemi with about 3500 hard street/strip miles on them and the lifter faces are perfect. The cam lobes look excellent as well."

From this thread :

http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=3769063&an=0&page=1#Post3769063


Sounds very promising to me  :2thumbs:



Ron
68 Charger R/T "Black Pig" Street/Strip bruiser, 70 Charger R/T 440-6bbl Cruiser. Firecore ignition  authorized dealer ; contact me with your needs

max

from reading that post, they sound very promising and the price isn't that bad either.

QuoteA precision "E.D.M." laser burns a .021" hole in the bottom of the lifter.

that's not much of a hole in the bottom of those lifters at all.

i just wonder how many back yard guys have drilled their own lifters? :icon_smile_big: