stevieturbo

Ive also asked this in the internals section, but was hoping for thoughts here too.

Current heads are West Coast Racing CNC'd Edelbrock 215's with dual springs ( ive emailed them too for input about valvesprings etc, but I think they are good for 0.650" )
Cam is a comp cams 3722R/3725R 224/230 on 115+4 0.581"/0.591"

Im using 1.7YT's with no problems really. But, as a good few in here seem to think they are crap, and I would like to try a little more lift, Im considering rocker options.
PTV shouldnt be an issue, as I have good cutouts in my pistons.
Im using 7.4" Trickflow pushrods, and stock lifters.

I dont think the Crane quick lifts are for me, over conventional high lifts.

A set of 1.8's will see exhaust lift hit 0.624" in theory, 1.75's around 0.603" lift.
Current max rpm is 7000rpm, although with a taller diff, Im hoping not to have to spin that hard in future, as power seems to peak around 63-6500 anyway

Finally...I dont mind grinding my valve covers, but spacers or anything that would increase their height, isnt an option.

So, there are the Harland Sharps, Comp cams pro magnums.... any others ??

Is 0.624" lift a lot to be asking ?

Will the 1.8's affect overlap to any great degree over the current 1.7's

Thanks, Stevie.

DeltaT

iTrader: (5)

Stevie,

So, there are the Harland Sharps, Comp cams pro magnums.... any others ??
The CC Pro Magnums are perfect for the job and offer a 1.85:1 setup for LSx.
Here: http://www.compcams.com/technical/Ca...106-07/269.pdf

Is 0.624" lift a lot to be asking ? Not if your springs and head setup (guide seal to spring retainer clearance, piston to valve clearance, pushrod to wall clearance) can handle it.

Will the 1.8's affect overlap to any great degree over the current 1.7's? No, the overlap is ground into the cam and does not change with rocker ratios. What does change is valve duration and you would get a very modest (~2 degrees est.) of effective overlap increase. Overall this mod should be an asset to your YSi-blown motor and help you get the best out of it.

I am bumping up my 1.6 ratio CC Hi-Tech Stainless rockers to 1.7 on the intake (for a net lift of .611") and 1.65 on the exhaust (net of .602") for the same reasons as you. I really can't go any higher without cutting the heads for larger diameter springs to deal with this solid roller.

Cool car, btw!

Jim

My Site: http://home.mindspring.com/~jim_fisk/id1.html

stevieturbo

1.85's would take that exhaust lift to 0.640 territory......Thats a lot more than I'd like to risk.

I dont think CC offer a straight 1.8 do they ?

DeltaT

iTrader: (5)

A little filling, a little filing...

No they just have the 1.75:1.

.640" doesn't seem crazy on the LSx heads. Isn't that lift reasonably common?

Jim

stevieturbo

1.8's would be more than enough I think....dont forget Im also usign stock lifters.

chriswtx

iTrader: (5)

I'm using the CC 1.75 rockers. Very nice quality.