351W camshaft. Hyd roller v hyd flat tappet

[AZ Cobra Mike]

Having heads redone with new beehive style springs.

Heads are AFR 1420 with stainless valves. Pistons are 4.030 forged dish type.

Carb is a edelbrock 750.

Question is this: trying to decide between comp cams

A) magnum 304 hyd roller kit CL35-462-8 or

B) magnum 292h hyd flat tappet CL35-330-3

What is the major advantage of the roller lifters?

Mike

[66AC]

You may want to read this article on Roller vs Flat Tappet Cams and Lifters.

Flat Tappet Cams vs. Roller Cams - Lunati Power

When I recently had my FE 428 refreshed, I went with Roller cam and lifters and rockers. The quick responsiveness of the engine is clearly noticeable. It just seem to have an eagerness to gain RPM. Perhaps this is the less resistance, but I really do not know.

[Ron61]

I use a roller cam and lifters in my 351 which is stroked to 408 and the response is vary quick compared to the flat tappet cam in my big block. Also roller cams let you have steeper lobe lift as the friction is less.

Ron

[AZ Cobra Mike]

Originally Posted by 66AC

You may want to read this article on Roller vs Flat Tappet Cams and Lifters.

Flat Tappet Cams vs. Roller Cams - Lunati Power

When I recently had my FE 428 refreshed, I went with Roller cam and lifters and rockers. The quick responsiveness of the engine is clearly noticeable. It just seem to have an eagerness to gain RPM. Perhaps this is the less resistance, but I really do not know.

Thanks for the link to the article. Very straight forward and makes sense.

[spdbrake]

On my wish list to change to the Hyd roller setup from my current Solid flat tappet.

https://www.youtube.com/watch?v=8VjFZMKvEwY

https://www.youtube.com/watch?v=9LTDHiUftlU

[cycleguy55]

Originally Posted by spdbrake

On my wish list to change to the Hyd roller setup from my current Solid flat tappet.

https://www.youtube.com/watch?v=8VjFZMKvEwY

https://www.youtube.com/watch?v=9LTDHiUftlU

The video at the first link above is on a 400 CID SBC. The cams used (hydraulic flat tappet vs hydraulic roller) had the same specs, though the roller lifter had 0.053 more lift - very similar to the differences between the two cams mentioned by the OP. The results were pretty much the same up to 4,500 RPM, with the roller showing more torque and HP beyond that. The roller peaked at 6.4 lb-ft higher and 21.4 HP higher plus, of course, you have FAR less worry about wiping out lobes and you can run pretty much any oil you want.

If it was me I'd go roller. The only reason I haven't already swapped out my hydraulic flat tappet cam so far is I haven't had the need (or desire) yet to open things up and make a change. When I do it won't be just for a cam and lifter change, it will almost certainly include heads and pistons as well, and perhaps an intake manifold - necessitating a larger / taller hood scoop as well.

[spdbrake]

The engine being a SBC is really not a factor.
More an Apples to Apples comparison.
I'm not real fond of the Solid tappet setup I currently have. Not that I have to adjust them (I don't drive it that much to need readjusts anyways).
The HP is not the selling point either since I don't track or cruise around above the 4500 range.

Its the piece of mind. Plus I really bought the car to tinker with since I don't turn wrenches for a living anymore.

[cycleguy55]

Originally Posted by spdbrake

The engine being a SBC is really not a factor.

Agreed, I didn't mention it as a 'factor', merely to set context.

[Karl Bebout]

AZ Mike, You also might talk to Howard's and Lunati about your cam choice. Both have been in business, pretty much since dirt was invented. I put a Howard's hyd roller in my old BBC and went with Lunati hyd. roller for my teeny Ford, mainly because the tech I talked to was familiar with Webers and knew which way to point me. since you're doing springs too, I'd recommend going with a full kit which will have the springs matched to the cam set up you're going with. My 2 1/2¢ worth.

[AZ Cobra Mike]

My head has tall valves according to the machinist. I'm waiting on his call so we can talk numbers and he can tell me the exact springs i need and then I will order the whole thing as a set. Springs,lifters, caps, pushrods, cam... oh yeah and gaskets and spark plugs and on and on...

[moore_rb]

Hey Mike-

The choice between hyd roller, versus flat tappet should be weighed against how much life you think that engine has left after your broken valve spring mishap... As a matter of preference, I definitely would go with a roller over a flat lifter cam. There are just too many benefits that absolutely justify the extra cost.

AFR 185 heads do quite nicely with tight LSA's and single pattern cams, so the Comp Cams Magnum grinds are great "off the shelf" candidates.

However (Only a personal opinion here) - The 304 Magnum is an awfully big cam for your engine. The 292 Magnum is a better choice (JMHO).

You mentioned the 292 flat tappet, but they do offer a 292 hydraulic roller that is the best of both worlds

The 304 is designed to make power up until 6500rpm. That number does not denote the recommended engine redline. An engine with the 304 cam in it should be designed to safely run past 7 grand.

When you are cruising down below 3000rpm in 5th gear, that 304 cam is going to make your car feel like it's towing a boat.

the 292 roller has a nice 5800-6000rpm power peak, and with 110 LSA, it will still power through the midrange nicely, and the idle will still sound pure evil.

Just 2 more pennies, thrown into the well of public opinion....

[Karl Bebout]

Glad you're doing your part to keep da Donald's economy cranking along.

[blykins]

Hydraulic roller.

Do yourself a favor and get a custom grind from an engine builder. Off the shelf cams are universal and are in no way optimized for a specific engine.

[Gaz64]

The roller lifter cam will make more everywhere when compared to equivalent flat tappet cams.

Choose a high quality bushed roller for a street car, not needle rollers.

[snapier]

Check out Engine Masters on U-tube. Roller vs flat tappet.

[Dwight]

snappier can you post a link to You Tube?

When I search Engine Masters it show everything but roller vs flat tappet.

Dwight

[Three Peaks]

I'm running a flat tappet Comp 292 cam in my 393 with Vic Jr. heads and an Air Gap clone manifold. My engine was a budget build and it is built on a 72 block, which isn't set up for roller lifters. Even though I drilled and tapped the valley for the spider to handle the rollers, I came upon a killer deal on the cam and decided to give it a try.
The 292 is plenty of cam in one of these cars, but for a street cruiser I would consider dropping down one cam size. Street manners are fine when I can keep it above 1600 RPM but it really isn't going to respond until you get it up in the 2500 range. A bigger cam is going to be even worse for street cruising as the power range as a rule of thumb will move up the RPM range all other things being equal. Right now I'm running around 515 hp at the crank. Not bad for a $3500 build.

However, when I do get out where I can cruise I get plenty of response with this set up and I'm quite happy with the horsepower and throttle response. The sound of the lumpy idle is incredible also. Many onlookers swear I'm running a big block but I believe that is due partly to my side pipes which have a deep, throaty sound even though I blew out the packing many miles ago.

Just keep in mind to add Zinc additive when you change oil and everything should be okay.

[Three Peaks]

Originally Posted by Dwight

snappier can you post a link to You Tube?

When I search Engine Masters it show everything but roller vs flat tappet.

Dwight

https://www.youtube.com/watch?v=8VjFZMKvEwY

[xb-60]

Originally Posted by Three Peaks

....The sound is incredible also.....

These are Cobra replicas we're talking about, so surely the sound of the flat tappets over-rides any of the plusses of the hydraulic roller ?

Cheers,
Glen

[Three Peaks]

Originally Posted by xb-60

These are Cobra replicas we're talking about, so surely the sound of the flat tappets over-rides any of the plusses of the hydraulic roller ?

Cheers,
Glen

Maybe I should go back and alter my post to say exhaust note? I guess I assumed most people would have assumed that was my intent?

Bob