F 14

[Roadster90]

Phillip,,,

I know you are somewhat tied up with tranny probs at present, but what did you come up with on the performance lifters?

[Guest F14CRAZY]

Nic: it's one L <img src="http://forums.aaca.org/images/graemlins/grin.gif" alt="" />

From what I've found out, you need to have the newer style heads to use those performance rockers. I think it's 1992 until 1994-5. The heads themselves will bolt up just fine, but the job is more intensive than we first figured.

Reason is that the newer heads have roller tips. I'm still not THAT smart on valvetrain stuff but I'm learning.

Here's the Bonneville Club discussion on it

[manikmekanik]

...but will the newer style heads match-up with the "C" engine and the "L" series S/C? Roller cams/lifters sound fun!!

[Guest F14CRAZY]

yes

[2seater]

What sort of rockers are in that later model L67 you borrowed the S/C from? I purchased one late model rocker several years ago and it appeared to be a powder metal part and it had a roller fulcrum only. The tip was the standard sliding design. The geometry was wrong for the LN3 engine and it wouldn't work even though the trunnion was drilled larger to fit the stock studs. We already have a roller cam as standard equipment. I am not sure they would be of great benefit unless the ratio was larger for more lift.

[Guest F14CRAZY]

Hey Hal: I have a '95 L67. The Later Series II heads won't work (without excessive modification). I guess it's the roller tip that the '92-95 heads have. BC said that itself would be a 5 hp gain. Probably not worth swapping, but it would be if you used the 1.8 rockers with it.

[2seater]

I admit to be a little confused. The '95 donor engine has roller tip rockers? Is the pivot a roller also? In other words, is it what I would call a true roller rocker, with roller bearings in two locations? The rocker I have may or may not have been a Series II. I do not remember the application. I have often wondered why the factory did not use full roller rockers if they are truly beneficial. The cost is certainly higher and that may be the only reason, but if it would result in essentially free horsepower of any significance it would be good thing. Maybe the long term durability isn't as good? Intuitively, a roller would seem to be a good thing and would reduce friction. Oddly, I have read things like roller bearings for the camshaft have the opposite effect. The weight or inertia of the roller actually caused a greater drag than the cam rotating on a film of oil and a standard bearing.

[Guest Greg Ross]

I looked at the Series II Roller Rockers vs the '91-'94 (95) Series I heads and they do not fit. (Had the Dealer bring one Rocker in for me while my Crate Engine was still sitting in their stock room)

Nada, No Go

[Guest F14CRAZY]

I'd tell you Hal, if I knew what i was talking about