Solid Lifter vs Hyd Lifter

[Instrument 41]

Watching Mecum auction this afternoon. Feel stupid for asking this but what is the difference between solid and hydraulic lifters? What is the advantage of one over the other? Also Big block 350 and small block 350..What's the difference??

[Nostril Cheese]

Lifters are the mechanical link between the pushrods and the camshaft. When a engine is cold, there is a gap in the valve clearance. As the motor warms up, the metal expands and the gap shrinks. Solid lifters require a adjustment from time to time to keep the gap within spec. Hydraulic ones negate the need for adjustment, however they sap a bit of power from the engine.

Small/big blocks usually refers to two GM engine families that use a basic block architecture.

The small block uses the same block from displacements from 262 to 400 cubic inches.

The big block uses a larger block from 396 to 572 cubic inches.

A big block 350 may be referring to the 348 engine in the late 50's. Other than that, im not sure what they are referring to.

[masraum]

In the Chevrolet world, the only 350 is a small block unless some of the new one's are considered big blocks, but I don't believe so. The "big" or "small" refers, I believe, to the outer dimensions of the block, not the cubic inches. I think Pontiac has what is considered a big block 350.

Hydraulic lifters have a small piston inside the lifter with a spring and fluid behind it. If the forces get too large or too fast, then the fluid can bleed out and the spring compress which causes the lifter to essentially shorten meaning you aren't getting the lift and duration that the cam is ground for. Hydraulic lifters are not normally acceptible for use with cams with very aggressive grinds, at least, not back in the day. Hydraulic lifters when run at high rpm with aggressive grinds can cause valve float because the non-rigid nature of the lifter allows the valve to not open/close completely.
Solid lifters do not have springs and hydraulic action, they are rigid and always the same length. They were usually used on the highest performance engines because they could be used at higher rpms and with more aggressive cam grinds.

[masraum]

Originally Posted by Nostril Cheese

Small/big blocks usually refers to two GM engine families that use a basic block architecture.

The small block uses the same block from displacements from 262 to 400 cubic inches.

The big block uses a larger block from 396 to 572 cubic inches.

A big block 350 may be referring to the 348 engine in the late 50's. Other than that, im not sure what they are referring to.

I believe the 348 and 409 were considered big blocks (but not directly related to the 396, 427, 454, etc...), and I think there may have been a 366 big block used in trucks as well.

I think Chevy may have come out with a new small block that's actually a 427, that they used in some of the newer corvettes.

Big and Small do seem to be mostly used when refering to Chevy engines, but I believe other manufacturers also had big and small blocks as well.

IIRC, the old school Chevy motors were

small block 262, 265, 267, 283, 302, 305, 307, 327, 350, 400

Big block (348 and 409) 366. 396 (402), 427, 454. I believe there was also a special 427 made in low numbers, and the 502 was never put in any car from the factory, but I think was out as a crate motor in the 80s/90s. I actually think that there were some other big blocks, but I think they were mostly used in buses, large trucks, etc...

[masraum]

According to Wikipedia, the LTx and LSx engines are the Gen II, III and IV small blocks.

[RANDY P]

The old Mark IV big block (65-74) 396, 402, 427, 454, who uses that these days? (not counting aftermarket blocks) You can build a nasty small block without the weight and space penalty.

I love solid lift cams. You can build a peppy small block with one- just gotta stay up on the valve lash. Not a problem once you figure out the cold lash settings (typically adjusted hot). For a cheap, powerful build you can't go wrong with a nice solid grind.

The new age however is ROLLER. Roller is where it's at.

[masraum]

Originally Posted by RANDY P

The new age however is ROLLER. Roller is where it's at.

^ Yep

[Oh Haha]

I built a solid lifter 400 small block for my old Camaro back in the day. I remember the lift, 520 intake, 540 exhaust. I still have the taped up feeler gauge that I used to set the lash. I couldn't afford a roller setup.

The valves were much easier to adjust than the 911's though.

[VINMAN]

502s are primarily used in HP marine applications The motors I built for my race boat used hydraulic roller lifters .