Hydraulic roller engine vs. flat tappet.

[greenmachine]

I am building a street motor. 440 .30 over eddy rpm 84cc heads. I’m debating doing a flat tappet cam vs a hydraulic roller. Looking for insight. This will be a 98% street motor and be in the 9.3-1 range with pistons im using. Probly around 480hp.

 

[68 HEMI GTS]

Sounds like a perfect combo for a HR if it’s in the budget.

 

[PRHeads]

Sounds like a perfect combo for a HR if it’s in the budget.

Yup.
No break in worries, and will make a bit more power, all else being equal....... but that doesn’t come for free.

 

[wyrmrider]

what compression, what pistons, any quench? wht's the rest of your combo
for short cams a .904 hyd can have a better lift curve than a flat flank HR
only exception is Mike Jones inverse flank HR profiles
all retro kits are made by the same vendor AFIK, all have a small roller
a .904 master solid with Iron rockers also makes good combo

 

[diesel_lv]

I went hydraulic roller in my 383 strokes to 496. Not for performance, but for long term reliability. If you are not going for the n'th degree of performance, you can keep your stock rocker arms. However, Comp Cams retro hydraulic roller lifters are taller than hydraulic flat tappet lifters. This means you will also have to buy a pushrod length checking tool then custom order new pushrods. Since I went with roller rocker arms, I had to get ball n cup pushrods. They were a little over $200 w shipping from Smith Brothers. But, hydraulic roller cam n lifters last considerably longer and don't need high zinc oils.

 

[greenmachine]

I went hydraulic roller in my 383 strokes to 496. Not for performance, but for long term reliability. If you are not going for the n'th degree of performance, you can keep your stock rocker arms. However, Comp Cams retro hydraulic roller lifters are taller than hydraulic flat tappet lifters. This means you will also have to buy a pushrod length checking tool then custom order new pushrods. Since I went with roller rocker arms, I had to get ball n cup pushrods. They were a little over $200 w shipping from Smith Brothers. But, hydraulic roller cam n lifters last considerably longer and don't need high zinc oils.

I was thinking comp cams 1621-16 ultra pro magnum and smith brothers. Thinking of Howard’s cam (723445-10) and lifters.

 

[vintage chromoly]

I went the other direction with mine. Not saying it’s right or wrong, just what I did. The other posters here have WAY more experience than I.

I used a custom grind Crower solid flat tappet with their EDM lifters.
I didn’t want to spend the extra money for the roller cam and the extra money on good roller lifters.

I bought a set of used Isky ductile iron rockers from a local friend and sourced some shafts (banana grooved) and hold down hardware from RAS. We had to put the arms in a lathe to take some width off them.

My goals were similar to yours, and I’m happy with my outcome

Here is the cam I bought and here are the flow numbers from my ported 906 heads:

 

[Ranger16]

I replaced my cam a year after I bought the car simply to tame it down. The cam the previous owner had in it was just way too wild for a 100% street machine. I did not want to get into push rods and added cost, just cam and lifters, and went with a Comp cam and flat tappet hydraulics. No problems and no regrets.

 

[Curiousyellow71]

Power goals can be reached with either cam. Since it sounds like your engine builder is doing the assembly, sounds like a good fit for a Hyd roller and you don't have to worry about valve lash and make a few more hp. If you were assembling yourself trying to save a buck where you can... solid.

 

[wyrmrider]

you builders with roller tip rockers also need to factor in a B3 kit B4 ordering pushrods
cup adjusters- good move
I also like to lube the adjusters through the pushrods