OST-075: Blue(top) Hawaii

[oldeskewltoy]

(05-06-2021 10:51 PM)Bean Wrote:  The nomenclature is very strange to begin with and the visual aid isn't helping at all with the intake going full circle.

The duration @0.05 lift and the opening closing degrees don't add up for me. The intake calcutes to 212 but the exhaust ends up at 228. If I interpret the minus sign for the exhaust wrong I can get it to 212 but then there wouldn't be any overlap (on the contrary all valves would be closed for 8°). Also the ramp seems to be very slow/wide but that might just be me as I'm comparing it to Catcams which are known for a rather aggressive ramp angle.

I haven't wrapped my brain around engine related things for years and it's very late so I might be completely off

from another forum Wrote:I'll venture an uneducated guess. A negative number for the exhaust valve closure, i.e. -8.0 BTDC. Perhaps a negative "before" degree reading equals "after"?

PS: Are you keeping the fishing line weight or returning it to the client?

In this case it is 8 degrees BTDC, otherwise as Bean mentioned we would be @ 228 if it were after TDC. A few things to remember most of the mild cams will close the exhaust valve BTDC, or close to TDC, while still at a certain lift point (either .040"/1mm, or .050"), seat to seat the valve still usually closes after top dead center - dependent on cam timing.

agreed, their timing wheel/diagram doesn't help either......

As to comparing them to Cat cams - yes, the Crower are far more mild a ramp, and offer only a minimal lift increase (7.75mm lift) over stock cams. The Cat cams I typically recommend for mild builds are 212 @ .040" (likely around [email protected]"), but with 8mm lift. So the Cat cams are a tiny bit shorter in duration @, much shorter in duration overall, and offer more lift. The Crowers will twist a few hundred more rpm.


But while all that is pertinent, that wasn't what I was after.....


This is what I was focused on..... Crower had HOT clearances... something you just don't get, and the FSM only has a reference for.... AND the reference is looser then Crower's spec - possibly making clearances too tight on the Crower cams....







more to come.......

PS - didn't keep the weight....