Questions regarding LS376/525hp
03-31-2016, 08:39 PM
#21
The cam in the 376/525 is known as the ASA cam, it has lower lift than a stock LS3 cam and more power can be made with a higher valve lift....problem is the LS3 crate motor comes with Pistons without valve clearance notches in the Pistons while the displacement on demand LS3 motors in auto trans equipped Camaros have valve notches. Increasing the lift and duration of a LS3 cam can quickly get you into valve to piston interference problems. You really fight the fact that the LS3 crate motor cannot be equipped with a proper cam unless you machine/replace the Pistons. The FAST intake has not been proven to make significant power increase over a LS3 intake your better spending your $$$ on porting a factory intake for 1/3 the expense of the FAST. Your 376/525 motor comes with a warranty from GM perhaps keeping it stock might be the best plan of action for a while, it should make pretty good power with a free flowing exhaust system on it. In a lightweight car it should do very well right out of the crate....maybe consider a LS7 motor if really big HP numbers are in your plans. The LS3 can make 550HP but, the LS7.....625+ is easily done.
04-01-2016, 07:03 AM
#24
Staging Lane
Valve size, angle, piston design, deck height, cam lift, ramp and duration. If you wanted to get **** stoke, rod length, piston dwell and expansion rate of all material could also play a small part! And of course they are all interrelated! Yes I have been known to over think things!
Al
Al
04-02-2016, 12:38 AM
#25
Otherwise.....I'll put all valve/piston contact on WHEN the valves open and close versus how much they open.
KW
04-02-2016, 05:02 AM
#26
When you show me a cam profile that has the valves fully opened when the pistons are at or near DTC.....AND......where .050" to .100" of an inch will make any difference what-so-ever between whether there's valve/piston contact or no contact, then and only then will you have me convinced.
Otherwise.....I'll put all valve/piston contact on WHEN the valves open and close versus how much they open.
KW
Otherwise.....I'll put all valve/piston contact on WHEN the valves open and close versus how much they open.
KW
Come on dude. Without lift the valve never leaves the seat.
04-04-2016, 08:07 AM
#29
Lobe lift is not an issue in a usable cam. I mean.....you can't account for flat out stupidity when it comes to spec'ing a cam.
I could spec a cam that would have PVC issues with .400" of lift. But I'm not (and I'm pretty sure you're not) so stupid as to say lift was the issue with that cam.
Just like a properly spec'ed cam can have .660" lift and not have any PVC issues in the same engine.
The .400" cam won't have PVC issues because of lift, it'll have those issues because of when the valves open and close. And you'd have to be beyond stupid to spec such an unusable cam.
KW
I could spec a cam that would have PVC issues with .400" of lift. But I'm not (and I'm pretty sure you're not) so stupid as to say lift was the issue with that cam.
Just like a properly spec'ed cam can have .660" lift and not have any PVC issues in the same engine.
The .400" cam won't have PVC issues because of lift, it'll have those issues because of when the valves open and close. And you'd have to be beyond stupid to spec such an unusable cam.
KW
Last edited by KW Baraka; 04-04-2016 at 08:16 AM.
04-04-2016, 09:56 AM
#30
Staging Lane
True because when a piston is beating the h-ll out of a valve it's not going to be a "usable" cam! If you think lift does not matter call Comp Cams and ask them should you check your PVC when changing to a higher ratio rocker! This will change your valve timing and duration nil, pretty much only LIFT! For a High Performance engine I can already tell you what they are going to say!
It's not the plane crash that hurts you, it's that sudden STOP!
Al
04-04-2016, 05:31 PM
#37
Staging Lane
In the "Real World" lift matters! In the real world valves don't go from 0.0" to open 0.660" in zero degrees of crankshaft movement (and piston movement)! Even with F-1 and Indy engines with pneumatic valves springs there are limits to how fast valves can open and close! With this in mind, it means the valve is open wider longer! That means more chance of PVC sometime during the valves cycle! When it happened is not going to fix the hole in your piston!
Again it IS all interrelated, part of the whole system!
Al
Again it IS all interrelated, part of the whole system!
Al
