kenkaru

I know this was posted a long time ago but I can't find it.
How much HP would I expect from HS 1.8 rockers with my Hotcam.
I will be putting on home ported heads this spring too.
TIA

Redneck Z

iTrader: (3)

I've seen lots of complaints about the HS and other aftermarket rockers arount here. That's why I've steered clear of them. They are heavier than stock and some have trouble with valve float. If you want more lift, just put in a new cam and get the lift where you want it.

orangeapeel

iTrader: (18)

Im with him.

kenkaru

hmm
A few years ago, I got some Yella Terras and they didn't fit under the valve covers but I thought the HS's would be ok. I didn't think about valve float though.
Redneck,
Did you feel a nice seat of pants difference with the intake?
What's this Lithium joke?

vettenuts

iTrader: (4)

Not sure about the Harlands, but the Cranes have a lower rotational mass moment of inertia than the stockers. You can't go by weight alone. Yella Terra has also introduced their new lower inertia rockers as well, haven't seen any results on them yet.

If I were considering a high ratio rocker, I would look at the Cranes, just make sure your springs are up to task.

kenkaru

would my LS6 springs be a no-go with 1.8's?

Predator

I believe, although I haven't proven it yet with my own setup (not installed yet), that if you're going to use aftermarket rockers, you need a set of springs that have some headroom and not maxed out. For example, my cam has a .563 lift which is okay with 918s, but add in 1.8 rockers and the lift goes to about .596, so I ordered my heads with PP .650 springs, hopefully preventing valve float as well as being plenty of spring to handle the lift, with room to spare (headroom).

Nasty N8

iTrader: (33)

Where do you get that the Harland Sharps are lighter than stockby several grams. The only people having valve float problems are the ones that do not have enough spring pressure and are blaming the rockers.

1.8 rocker will be perfect to add axtra lift to your cam. Just get a good set of springs for the added lift. We have seen 18+hp gains and even more TQ from 1.8 ratio rockers.

Nate

kenkaru

I'm calculating .555 lift with 1.8's so would I still be ok with the LS6 valve springs?
Here's a quote from Scoggin Dickey Performance regarding the LS6 springs...
How much "headroom" is good for valve springs?

BadAzz96Z28

iTrader: (8)

This may be one in a million but something to consider.....A guy I met here on the forum has a 01 Z06 with normal bolt-ons, stock cam and swapped to the crane 1.8's and comp 918's. I was at Dynolab with him when he dynoed the car after the swap and he lost 10 hp on the entire curve from idle to rev limiter.

vettenuts

iTrader: (4)

Have to agree. Usually any problems that occur on the dyno if aftermarket rockers are installed, it automatically falls upon the rocker as the problem. Everyone jumps on the "its too heavy" band wagon when weight is not the real issue. There is more to the valve train than the rocker. Spring harmonics, wipe pattern and valve lifters all play a role in what is going on. The pushrod can also be a major contributor to problems, but most here are running the better aftermarket thicker walled pushrods. Some springs also don't play well with some rockers and the system excitation that comes from the cam lobe can be a player as well. As soon as you get away from a stock setup, and run into issues, it is necessary to step back and figure out the problem. The higher ratio rockers on this cam have been successfully run by quite a few people from what I have read, and it should be a good setup.

I have a small problem with my setup right now, but I think I have finally figured out what needs to be done to correct it. I will take these corrective actions when I change the heads this spring.

kenkaru

Why do people even post stuff like this?
FYI there was definitely another factor that caused the loss in power.

Redneck Z

iTrader: (3)

I noticed a slight difference with the LS6 intake, but didn't dyno afterwards. Lithium has been without his car for a LONG time now lol. Check his thread out. You have the "potential" for gains with aftermarket rockers, but there have been lots of people who have started out with them and ended up going back to the stockers because they couldn't get them to work right. If the search button wasn't crippled you'd find lots of threads about the headache's they can cause. I thought about them at one point and did the rresearch. It's a headache I choose not to deal with. There are tons of fast cars with stock rockers, so I figure why hassle with them. They aren't necessary.

vettenuts

iTrader: (4)

As I remember, there was a vast temperature difference on the dyno after the rocker installation and that a later dyno (he sold the car) resulted in a gain when the weather was more like the pre installation dyno.

WhiteRhino

iTrader: (6)

I just put the 1.8 Cranes with my Hotcam.I'm getting mine retuned/dyno'd tomorrow morning.I also put on a set of ported Patriot heads as well so the numbers arent going to be just a rocker swap.But for what its worth I'll throw up the the numbers later on tomorrow.

I also think that most of the people swapping rockers just arent getting something right.When I got mine done,it fired right up and I havnt had a single issue with noise/float or any other problem some have.I think alot has to do with lash/swipe/springs.Most people I know just want to throw things together and cut corners.I like to take my time,especially with something as important as your valve train.

I have another question if someone knows?The Cranes come with smaller pushrods when you get the kit.Is it possable that some people buy just the rockers saving a few bucks and install them with the wrong length pushrods.So then this could be causing alot of their problems?Like the Hotcam has the stock base circle while aftermarket cams a different base circle.

TAF Motorsports

iTrader: (10)

LS7 Exhaust Rockers Part# 12579617 1.8 ratio about 8 bucks a piece

kenkaru

I think you hit the nail on the head.

Can anyone confirm these will work!?
I love this board!

vettenuts

iTrader: (4)

There are several threads on this, including on the truck board farther down on this forum. I haven't seen any results yet, because most who have ordered them are still waiting for parts. Initial indications are they do fit from what I have read. I think the jury is still out, but with the number of guys who have ordered them so far, there should be a lot more information in the coming month or two.

kenkaru

cool!

jbuckweiser

I have Jessel 1.8 rr's and the 2002 ls6 springs that are rated for the higher lift
ls6(405hp)vs the (385hp) ls6 that had the .525 lift. If you buy the Hotcam it
came with the .525 springs. The ls6 heads I bought came with the higher lift
ones. Hope this helps.