Cam selection

[ratkiller]

Solid Flat
Solid Roller
Hydraulic Flat
Hydraulic Roller

What are you guys using in your W motors? What's giving you the highest performance with the logest life? Has anyone experimented with Hydraulic Roller and got the performance matched up with the run life compared to the Solid Flat?

 

[tripowerguy]

While the solid lifter flat tappet cam I have now is not matched with the convertor I have it is does exactly what Crane said it would do. What I wanted to tell you though is that I have Poly Locks on the rocker arms and they are the way to go. I check valve clearance often and rarely find any rocker arms that need adjustment. With the stock ball and nut you always need to tweak the adjustment. If it were me and I had the money a solid roller cam would be the way to go. You can have a lot faster ramps with a roller. Roy

 

[models916]

What's the cost.

Rollers make the best power, but at a cost. Expensive. Solid roller is lighter and easier on the valvetrain than Hyd. If you run a mild roller like GM uses (light springs) in its current engines there is not much of a problem. If you go aftermarket HP and do a lot of driving on the street, there are issues with the durability of the roller wheels and the shafts from the high spring pressure they must endure and the poor oiling they get. Stop and go traffic with high spring pressure will kill the wheel shafts rapidly. There are some rollers out there that address the problem but are expensive and only a band-aid. If it's a week end warrior you probably won't have problems. Call Crane or Comp Cams, they are pretty good at picking cams if you give them all the info.

 

[dq409]

While the solid lifter flat tappet cam I have now is not matched with the convertor I have it is does exactly what Crane said it would do. What I wanted to tell you though is that I have Poly Locks on the rocker arms and they are the way to go. I check valve clearance often and rarely find any rocker arms that need adjustment. With the stock ball and nut you always need to tweak the adjustment. If it were me and I had the money a solid roller cam would be the way to go. You can have a lot faster ramps with a roller. Roy

I would agree to what Tripower said and add that using roller rockers is also an added plus. The price is not that bad either.
A roller rocker will add life to your valve stems, guides and has less friction.

Stock stamped rockers add side pressure to the guides, stems, and stem tips by pushing the valve in a side ways motion rather then the tip of the valve stem riding on a roller that lets the valve and stem follow the guide in a straighter up and down line which will give added life to these parts. dq

 

[ratkiller]

I would agree to what Tripower said and add that using roller rockers is also an added plus. The price is not that bad either.
A roller rocker will add life to your valve stems, guides and has less friction.

Stock stamped rockers add side pressure to the guides, stems, and stem tips by pushing the valve in a side ways motion rather then the tip of the valve stem riding on a roller that lets the valve and stem follow the guide in a straighter up and down line which will give added life to these parts. dq

Are you saying that the attack straightness of a roller cam will add life to the stems? This is contrary to over all rocker and spring life that is shortened by the high lift throws from the roller lob. That's why I asked if anyone has experimented with roller hydraulics to ease the high lift impact yet still take adavantage of the lob duration.

I'm looking for the highest performance with the longest life and least maintainence.

Am I asking too much? :

 

[Ronnie Russell]

dq makes a good point about the rockers. Enclosed is a pic. of a small-block dirt track motor a customer brought in over the weekend. He said the motor was running good, but some drivers were getting by him that he knew he could outrun. Said the motor seemed to be " down on power". Left it for a rebuild. Started teardown and look what I found. Luckily for him they just changed the rules to allow roller-rockers for this year. I would say he was down on power.

 

[skipxt4]

Ronnie: If have seen this happen many times. Some of the stamped steel rockers were really cheaply made. All the hi-po small block chevy rockers used to have an 0 stamped on them. Still could break them though. if you really pounded your engine,running a high lift cam. There's definately a big advantage using roller rockers. Skip

 

[Quickshift409]

Down on Power

Ronnie, did you tell him it's hard to win on 7 cylinders.
QS409

 

[jim_ss409]

This is only my own rule of thumb but I think that a roller cam with let's say 230 deg. @.050 will make about the same power as a flat tappet cam with about 240 deg. Hydraulic rollers with 1.75 rockers will usually start to float at about 6,200rpm or so. Lighter valvetrain and stiffer springs will bring that up a few hundred rpm but in my opinion if you intend to rev over about 6,000 a solid roller or a flat tappet cam is the way to go. I've got a hydraulic roller in my Impala (476 ci stroker) it works great because it's peak power is at 5,700 Solid rollers used to be "race only" but they now build street rollers that are truely streetable. For overall value, power and reliability it's hard to beat a modern hydraulic flat tappet cam with a set of roller rockers. If you've got a stock stroke 409 with low performance heads I think a roller cam probably wouldn't be worth the expense, but if you want to get the most out of a set of hi-po heads a roller cam looks pretty good.

 

[5509]

hyd for me

I ran crane hyd cam with rodhes style bleed down lifters.690 heads/truck block.Idled at 700rpm ran 105mph in my 55 4dr.On paper made 375hp at rear wheels.Shifted at 5200rpm,never hurt motor.I agree roller rockers are GOOD IDEA!!

 

[dq409]

Are you saying that the attack straightness of a roller cam will add life to the stems? This is contrary to over all rocker and spring life that is shortened by the high lift throws from the roller lob. That's why I asked if anyone has experimented with roller hydraulics to ease the high lift impact yet still take adavantage of the lob duration.

I'm looking for the highest performance with the longest life and least maintainence.

Am I asking too much? :

I think you missed the point here.

You don`t need a balls out high lift cam touse the added the advantages of a roller rocker.
They are stronger then a stamped rocker and offer less friction and better geometrics to the valve train. Thus longer life.

Think about the way a stamped rocker contacts the valve and the way it has to open that valve.
It has to push the valve open on a flat steel surface against another flat steel surface, the valve stem head, with only a thin oil film as lube.
This can cause valve defection in a inward outward motion.
A roller rocker has a steel wheel that is the contact point between the roller and the valve stem head that will roll back and forth as the valve opens with a linear motion that allows the vlave to open and close straighter up and down.
Less wear and tear on the valve,guides and roller,


dq

 

[Skip FIx]

Alot of guys with all types of motor are experiencing flat tappet lobes going flat after break in. Most oils now have deleted the zinc in them(EPA). Chevy solid lifters can be purchased with a small oil feed hole to help lube them. One extra advantage of solid and hydraulic rollers-no break in.
Solid rollers on the street long term can wear out the roller bearings. Several comapnies have direct lube for them also.

 

[MK IISS]

"balls out high lift"

It's a technical term.

 

[dq409]

Full Race? Half race? quarter race? I all so liked these terms !!!

 

[ratkiller]

DQ - thanks for the update on the roller rockers - but that's a mute point as this engine is a QB block 690 heads 4" stroke. Roller rockers are manditor at this point. And god forsake anyone with the trust of stock stamped rockers having even a close lift variation between them.

I'm talking "balls out lift" here -

I want to know what you guys have successfully ran. A solid roller is only good for maaaaybe 5K miles, hydraulic longer but you're loosing the lift advantage an still a shorter life of the valvetrain wear. The only advantace to a roller is you get the sleeper effect with a humming engine without the idle thump giving away whats under the hood.

I'm thinking solid tap - and lash adjustment every few thousand miles

Unless someone has found a better formula

 

[ratkiller]

This is only my own rule of thumb but I think that a roller cam with let's say 230 deg. @.050 will make about the same power as a flat tappet cam with about 240 deg. Hydraulic rollers with 1.75 rockers will usually start to float at about 6,200rpm or so. Lighter valvetrain and stiffer springs will bring that up a few hundred rpm but in my opinion if you intend to rev over about 6,000 a solid roller or a flat tappet cam is the way to go. I've got a hydraulic roller in my Impala (476 ci stroker) it works great because it's peak power is at 5,700 Solid rollers used to be "race only" but they now build street rollers that are truely streetable. For overall value, power and reliability it's hard to beat a modern hydraulic flat tappet cam with a set of roller rockers. If you've got a stock stroke 409 with low performance heads I think a roller cam probably wouldn't be worth the expense, but if you want to get the most out of a set of hi-po heads a roller cam looks pretty good.

Jim 5700 is not a bad rev limit - in my book anyhow. How much torque are you pulling with that hydro roller? Do you get enough power to make it worth while? And what do you think the life of that setup is good for? 10K? 20K?

Hows that 55 09' gasser coming btw

 

[jim_ss409]

The 55's coming along. I hope paint it this weekend.

I've never dynoed the engine but it's got lots of torque. My shift light is set a 5,700 so I'm probably shifting at about 5,800 or 5,900. My best 1/4 mile mph was 112 mph and the car weighs about 4,500 lbs with a driver and a full tank of fuel. If I remember correctly Curt Harvey said that when he used this cam on 4" stroker motors they usually made about 520 hp and about 540 ft. lbs. of torque. I think I should be in the 500hp range. My cam is an Isky hydraulic roller with 238/248 @.050 with a 110deg. lobe separation and it's installed at 108 deg. I'm using 1.7 roller rockers so the lift is .578 int. and .608 ext. I forgot to write down the specs for the valve springs but I remember thinking that they were no where near as strong as I expected. Curt said the cam should last as long as the rest of the engine but who knows? All things considered I like the cam, it has good street manners but it still has a muscle car idle. The same cam with a 112deg. lobe separation would idle smoother without giving up much power. I'm going to rob this engine out of the Impala to put in the 55 for now so of course I wish it had a bigger cam right now but it should move the light 55 just fine for now.

 

[tripowerguy]

I'm wondering something here, some are saying that the new roller lifters are short lived but Ford and Chevrolet all run roller lifters in their production engines. I think that engineering has solved the longevity problem. I have never ran a roller cam on the street so I can't speak from experience. Surely the manufacturers would put a disclaimer on the cam about running it on the street if they felt that running their roller cam on the street would shorten it's life. Roy

 

[mpris]

I think most all of the factory rollers are hydraulic rollers. These do not have the spring tension of the hard rollers nor do not have the ability to rev to the high rpms of the hard rollers. I have a Crane hyd. roller in my 409. The valves float at 6500 with a seat pressure of 120 and open preasure of 390 using triple springs. Very few of the hyd. roller cams used in production cars have the high lift and/or rapid ramp of the hard roller cams most of us would use. So I quess that's how the factories can get by with using them and getting very good results. Very, very few cars with hard rollers end up as high mileage vehicles.

Poocho

 

[dq409]

Very, very few cars with hard rollers end up as high mileage vehicles.

Poocho

You hit it on the head ! How many real miles do we put on our classics?
I don`t think it`s any where near where it would be a problem,dq