solid flat tappet VS hydraulic roller

[ap72]

I'm having a dilemna that I just can seem to sort out. Lets say a guy is wanting to build a plain jane sbc 350 that can rev to 7,000-7,500 and make about 550hp.

Around the usual street specs, 10:1 compression, RPM AirGap or Super vic intake, 195-220cc heads, 950cfm carb, a well sorted out HEI type ignition.

Cylinder heads are running stainless valves and good but not really expensive valve springs (say any that sell for less than $150 a set).

roller rockers, thickwalled 5/16" pushrods or 3/8" pushrods, no rev kit.


And here's the question-

Would you prefer to run a solid flat tappet cam with face oiling lifters or a hydraulic roller cam with stock lifters (cost is about the same for either scenario), we'll even say you can shim the lifter internals to limit travel to .015" but you have to use the stock dogbone/spider setup. Oh, and stock cam core size stock lifter diameter.

I'm thinking the solid flat tappet would have an advantage here because of the weight, but perhaps I am wrong?

[CamKing]

Solid flat tappet.

To get a hydraulic roller to turn 7,500, you'd need to spend a lot more money(aftermarket lifters, beehive springs, ect)

[ap72]

That's what I was thinking. What about 6500 RPM? Where would you put the APPROXIMATE cutoff? I realize the ramps can components can make it vary some but just a rule of thumb.

[dfree383]

6500 is doable with HR stuff with nothing exotic.

[jeff swisher]

I would like to see the cam that would make those numbers,,
350 cubes..10:1 compression 550hp....some really good heads will be needed

I like my solids with the flat lifters...I spank a bunch of people (friends ) with hy rollers and solid rollers with my flat lifters

But i think it boils down to combo of parts...
I still think that would be a big duration cam and i would bet closer to 8000-8500 rpm shifts and i would tunnel ram it
just saying

[F-BIRD'88]

A good solid flat tappet racing cam will get it done.

You need to get the cr up above 10:1 but just under 11:1, if you want pump gas. (more {is better} if on race fuel) don;t be shy with the cr.
Try a Crane Saturday night special F268/3814-2S-6 VTP clearance will need to be checked.
give Crane Cams a call.

clean up the heads a bit.


A street tunnel ram makes it easy. rev it up to go fast.

[CamKing]

6500 is doable with HR stuff with nothing exotic.

With stock lifters, that seems to be the RPM to not go above.

[CREngines]

Most generally I favor flat tappets, but its hard to ignore this. GM Part # 88958689 Cadillac Developed Racing LS series Hyd roller lifters. Compatable with factory dogbone early small blocks. Tested to 8000 rpm, around 300 bucks from your local friendly Gm dealer.