Roller cam/lifter problem

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Richie

Richie

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Hi everybody:

I just stumbled across this video and since I was going to get a roller cam for my 340 I was wondering if any of you have run into this problem and would it be better just to stick with a ordinary hydraulic lifter cam

 
The solution to this persons problem would be to tube the lifter bores (~ $300). When I ran a solid roller in my stroker I had solid bodied lifters (comp 828-16's if I recall correctly)...they don't have this issue because they don't have an oil band like those.

Not sure of this person's situation, but if it was a big cam (lots of lobe lift) it can cause this. Another solution to this would be get a cam with a smaller base circle.

Idk, I never ran a hydro roller, only solid roller. Only way to find out would be to test fit the parts and see if you have an issue.
 
My block had 3 lifter bores that were counterbored at the factory when the block was cast. All the others were not. Not exactly sure why they did it, but I've seen other blocks with this same issue and some with no counterboring at all. The ones on my block were all drilled at different depths too so it must have something to do with how the block came out of the molds as to whether or not this added step needed to be done. I was on the edge of having one of my lifters oil band exposed but just the one. Others here might have a better understanding as to why the factory did this. I believe Hughes Engines did a tech article on this?
 
I thought hughes roller lifters were made just for this specific problem?

From their website
Made in U.S.A. by true craftsmen.
These are oil thru lifters and will oil through the pushrods if you need them to.
The oil band has been lowered so that the small blocks with the chamfered lifter bores no longer have to be sleeved.

* The lifter bores do not need to be bushed to run these lifters.
* DO NOT use these lifters with a flat tappet cam!
 
All depends on the block and lifter combination you're using. I don't run hydraulic rollers unless I'm ordered to as flat tappets will be cheaper and make more power. If you need a roller, go solid roller and bush the lifter bores.
 
moper said:
All depends on the block and lifter combination you're using. I don't run hydraulic rollers unless I'm ordered to as flat tappets will be cheaper and make more power. If you need a roller, go solid roller and bush the lifter bores.
Click to expand...

Definitely cheaper, but make more power? You will need to help me understand how.
 
The lifters profile, rate of lift on the ramp, can be more aggressive than a Hyd. roller. This produces more area under the curve. That equals power.
Not all solid lifter cams are made this way.
AKA, very aggressive.

A Hyd. Litter can only take so much of an aggressive ramp rate before collapse. The solid lifter does not have this problem.
 
Not going for too much power maybe about 400 hp. What I'm most concerned about is durability. I'd be glad to go with conventional lifters as long as they would last with good oil and maybe a zink adative, I'm sure the place that's doing it will know. They're probably the best engine builder in town and also very honest.
 
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400 hp is an easy task. Any style cam will work. Good oil is a must with flat tapper cams. Wise with rollers. Longevity should never be an issue with 400 hp. Never!
 
stumblinhorse said:
I thought hughes roller lifters were made just for this specific problem?

They do and they work. My 408 was built with Crane retro rollers and#5 exhaust came up (.571"lift) just high enough to bleed off and tap (hot). I bought the Hughes lifters, another set of pushrods (different lifter length) and with the intake off and a priming drill set up , after setting preload, rotated the engine by hand with 70 psi on the gauge ,rechecked for bleed off. All was and is good.
Click to expand...
 
Inverse flank HR helps on the acceleration/ collapse phenomenon
all conversion HR are made by Johnson AFIK
IDK how Huges sources
Mopar has about the base circle of a BBC and most HR grinds are for a SBC base circle so no problem going to SBC base circle (longer pushrods but you are going to do the geometry drill anyway- right?
Unless you have a roller that was ground for a BBC/ Mopar
Mopar roller can use a bigger wheel (good- less side thrust) but no HR's come that way that I know of (wonder what size my magnum has)
 
stumblinhorse said:
Definitely cheaper, but make more power? You will need to help me understand how.
Click to expand...

What Rumble said. Hydraulic anything can't be moved as fast as solid anything because the lifter collapses. Add the weight of the roller lifter assembly and the geometry with a shorter pushrod and its lose lose lose as far as I'm concerned. Now once you start looking at higher power levels then the picture changes, but again I'll bush the bores and run a solid roller cam long before I choose a hydraulic roller. BTW it's not like 50% more. It's small differences. But cheaper overall and more power IS the result right up until you need a solid roller.

In the OPs case, 400hp is really a stock rebuild with a cam - and a hydraulic cam would do it fine. You just need to make sure the lifters rotate, use a good break in paste on the lobes and faces, the engine starts immediately for the first time, and can be run for the entire break in period without having to shut it down.
 
So I am confused. What was said is that Flat Tappet makes more power? Then what was said is that more aggressive ramps are the reason.

First I assumed you meant Hyd flat tappet. So I guess @moper you were talking solids? But I thought even solid FT lifters could only go so fast on ramps without the edge digging into the cam. That rollers, solid or Hyd, could have more aggressive ramps than FT. So I am wrong? and a solid FT cam can be more aggressive ramps than a Roller?
 
FWIW I got at least 25,000 miles out of a Lunati Voodoo hydraulic FT cam and lifters; when my 360 took a dump I pulled that cam out and aside from fairly normal-looking wear there was no damage to any of the lifters or cam lobes. Initially I ran typical off-the-shelf Valvoline full synthetic with Lucas Break-In zinc additive, then switched to the Valvoline VR-1 with zinc in it (intended for FT cams), then switched to Brad Penn. As long as the oil you're running has some zinc in it the cam and lifters will last a very long time.

With that said I'm building up a junkyard Magnum short block and intend to get a Racer Brown custom-grind long-snout hyd. roller cam mainly because the block is already set up for it and I got all the original roller lifters and "spider" retainer with the short block when I bought it from the junkyard (quite a bit of money to buy 16 roller lifters new). I'm not thinking it will give a huge power increase vs. a custom-grind hyd. flat tappet but the peace of mind of not having to worry about zinc along with the reduced internal friction at lower engine speeds will be nice. When I pulled the factory roller cam out of that Magnum block it looked great and that engine had at least 150k miles (didn't know the actual miles since the dash was gone from the donor truck I got it from).
 
stumblinhorse said:
So I am confused. What was said is that Flat Tappet makes more power? Then what was said is that more aggressive ramps are the reason.

First I assumed you meant Hyd flat tappet. So I guess @moper you were talking solids? But I thought even solid FT lifters could only go so fast on ramps without the edge digging into the cam. That rollers, solid or Hyd, could have more aggressive ramps than FT. So I am wrong? and a solid FT cam can be more aggressive ramps than a Roller?
Click to expand...

The initial opening of the valves with a FT is usually quicker but the overall opening rate with a roller can be a bit higher, at least that's my understanding. I think where @moper is going is that the potential overall quicker ramp rates of a roller cam are negated by the increased weight and hydraulic lifter plunger collapsing at higher RPMs with a hydraulic setup; to really get the benefits of a roller cam design you need to run solid lifters... I think? lol
 
MOPEkidD-3 said:
The initial opening of the valves with a FT is usually quicker but the overall opening rate with a roller can be a bit higher, at least that's my understanding. I think where @moper is going is that the potential overall quicker ramp rates of a roller cam are negated by the increased weight and hydraulic lifter plunger collapsing at higher RPMs with a hydraulic setup; to really get the benefits of a roller cam design you need to run solid lifters... I think? lol
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Correct! The best bennifit to the Hyd. roller cams is the overall curve. The way I see the Hyd. roller cams best use is in mild to moderate street engines because of there limitations in high rpm ranges and lifter issues in high rpm ranges. This is not to say they can not perform really well and make good power.

But it does make sense to switch to a solid roller at some point for higher rpm capability, reliability and stability. This would also be the same for Hyd. Flat tappet cams.



stumblinhorse said:
So I am confused. What was said is that Flat Tappet makes more power? Then what was said is that more aggressive ramps are the reason.
Click to expand...
FT cams can, if, the cam lobes are designed to do so.

But I thought even solid FT lifters could only go so fast on ramps without the edge digging into the cam.
Click to expand...
Correct. And at that point, your looking at a wickedly aggressive camshaft.

That rollers, solid or Hyd, could have more aggressive ramps than FT. So I am wrong?
Click to expand...
Only to a degree. It depends on what the cam is ground for. You can grind in many different profiles from a gas sipping mileage master to a full blown take no chit race cam.

and a solid FT cam can be more aggressive ramps than a Roller?
Click to expand...
Well, yes and no. Again, it depends on what the cam is ground for. What your mentioning here is a dividing point in aggressive cam lobe action.

The initial opening rate of a racing solid cam can be super aggressive. More so than a roller. However, the roller can be created to have more overall curve than a solid. To find and approach these levels, you must be in the most aggressive race engine territory. Not a mundane and 400 hp engine. You can create 400 hp with a very mild cam!

To break it down for a mental visual...

To cars at the starting line for a 1/4 mike drag race. In the left lane a small block, (solid lifter cam) in the right lane, a big block, (solid roller cam) both full blown race engines.

The small block takes off faster than the big block. It jumps out for a sizable leed in the first 400-500 feet. But what you notice is that big block is rolling up on the small block really quick and it’s getting faster and faster until it just not over takes the small block but buried it deep by the finish line.

Did that help? LOL!
 
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mope and rumble make some goodpoints
to match a FT profile with a roller you have to go inverse on the flank- grind with a small grinding wheel which the big production grinders with their CNC grinders do not want to do-- rough in on the Landis and finish on a small wheel
berco
Some claim inverse but it's inverse slightly with a big wheel
you can't go too aggressive off the seat with any roller due to the side thrust- you can go more aggressive with an inverse flank roller than a flat or almost flat flank roller
once you get up to say 100 thou you can get with the lift curve with the roller
A .904 Mopar profile looks very good against a HR or Street roller until the duration gets up there
remember that area under the curve and that duration at 200 and 300 are important as is the seat timing- which can be shorter with a .904 FT than with a comparable flat flank roller maybe 4 degrees on the opening and 4 degrees on the closing
not just race stuff
important to a low compression motor where you want to get the intake closed earlier and exhaust opened later
and especially important in a long rod engine where piston motion happens faster than in a short rod engine like those chevy cams are designed for.
 
True, race cams aren’t the only ones with hairy ramps but it was just easier to point to that then a long drawn out explanation.

For 400hp, a 4bbl. carb, intake, headers and a mild upgraded cam is all it takes.
 
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