304 Cam

[AlexHale]

I've read that 304's are not the best to run in stock 2.5s. But with injections modifications, intake modifications an full exhaust, would it run or will it force the valves into the pistons? Does anyone know if it comes on around 4k or 5k? Are Schrick updated springs nessicary? Any info would be appreciated.

[digger]

kaboom without mods piston and valve clearance.... needs uprated springs and by all reports the schricks recommendations dont work anyway. id contact VAC and ask them if their high performance springs would work (they are made by eibach and are very good springs i use them now just dont remember the coil bind on them).

unless you are running, 11.5:1 CR, heavily ported head, RHD ITB setup, proper tuned exhaust you wont really come close to realizing the benefits of this much duration and something smaller will likely make for a much better engine. not to mention that on a 2.5L power is going to peak at much higher rpm so you want a good set of rockers the OEM jobs will go up in a puff of smoke

if you want to run something this big and have the engine that can use it then there is a RHD roller rocker system or if you want the traditional rocker systel then the ENEM Z58 cam is a much more modern grind than the schrick and makes more power (according to the swedes who sell them).

[AlexHale]

Thanks digger, your post are the ones I've been reading. Clarify for me, right hand drive itbs? What's the rhd in the itb's am roller rocker system? Could you elaborate on the enem cam? Would raising the compression, ported head, And the ie had rockers making a safe setup( on miller maf with 19's- don't know of that'll work or not),

[digger]

It’s not right hand drive there are ITB kits and m20 roller cam setup available here

http://www.racehead.com.au/

ENEM cams are sold by pure performance factory (PPF) run by Andreas.

ENEM Z58
296 Duration
12.25mm lift
106LSA,
ICL 104 (i.e. 2 degrees advanced)
Lift inlet at TDC 4.2 mm
ECL 108
Lift exhaust at TDC 3.4 mm

On paper it looks good for an aggressive grind.

They also have a Z45 which seems like something that would be good for something with a little less duration than a 288 Schrick but bigger than the 284/272 Schrick

ENEM Z45
280 Duration
11.0mm lift
108 LSA
ICL 106 (i.e. 2 degrees advanced)
Lift inlet at TDC 2.5 mm
ECL 110
Lift exhaust at TDC 1.8 mm

These are a lot more $$$ than the other cams from Schrick, Catcams etc. and that’s without including shipping which alone won’t appeal to many.

Can’t really comment on the HD rockers never used them and don’t know how durable they are. But a 300ish cam with a ported head, more CR, better inlet manifold and set of headers will work well for a race engine not so much a daily driver. Once you go more compression with deeper valve pockets you are usually talking forged pistons in which case you would want to consider using a bigger crank and a full on engine build ensues unwittingly.