L67 camshaft choice discussion

[vHell83]

Thanks for the info.

I'm sorta leaning towards the xp hot cam from zzp and thinking to stick it with Yella Terra 1.7 rockers.

The quest to find a set now begins.

Just buy them yella terra. 1.7 will be the pro street? Series. Or you can get the ultra lites as the cam isn't huge therefore won't flog the rockers and you have the bonus reduced weight which = better valve control.

I saw that. But it's about 300 to 400 difference in price. Not worth it imo. The total valve lift will be smaller than what I currently have so surely that would have to account for something.

[vlad01]

What are you currently using?

[OZ38]

I think he said 1.98:1 which could be the MACE reworked rockers ?

You could also look at ZZP for the YT 1.7:1 Ultralites as they usually sell about $200 cheaper than you can buy them in OZ. But you will need to do an order for other stuff you need & keep it under $1000.00 as the US postage hurts a bit on single items.

[vHell83]

Total lift is. 610" at the valve.

307 on the lobe with 1.98:1 ultra high ratio rockers.

I'll suss out zzp, I know on the YT site they were over 1k. Thankfully I am local to YT If I can't succeed in getting them at a lesser price

[immortality]

YT aren't cheap unless you can find a 2nd had set somewhere

[vlad01]

no where near 1k

http://store.yellaterra.com.au/holden-b ... ef-yt6649/

The reworked factory rockers are rubbish. They are welded and re-drilled and loose there case hardening at the rod seat and the rod crews the shit out of the rocker in no time.

[immortality]

no where near 1k

http://store.yellaterra.com.au/holden-b ... ef-yt6649/

The reworked factory rockers are rubbish. They are welded and re-drilled and loose there case hardening at the rod seat and the rod crews the shit out of the rocker in no time.

I actually think it's the other way around TBH. Used push rods with re-manufactured rockers = fail unless the push rod tips are in perfect condition. Fairly much every ecotec I've seen has had some sort of wear on the push rod where it sits on the rocker and I believe this is because of the roller lifters which means the push rods don't spin. Our Calais was the same and was starting to get a slightly noisy valve train which on the ecotec has always been blamed on the lifters but I believe is in fact wear on the push rods causing the lifters to loose there pre-load. I fitted new rockers and push rods and she's quiet as now.

I have a set of worn 1.9 rockers here, push rod cup in the rocker has some wear but the push rods themselves are totally stuffed. I was going to try and clean up the rocker seats but the fuckers are still hard as fuck.

[vlad01]

no where near 1k

http://store.yellaterra.com.au/holden-b ... ef-yt6649/

The reworked factory rockers are rubbish. They are welded and re-drilled and loose there case hardening at the rod seat and the rod crews the shit out of the rocker in no time.

I actually think it's the other way around TBH. Used push rods with re-manufactured rockers = fail unless the push rod tips are in perfect condition. Fairly much every ecotec I've seen has had some sort of wear on the push rod where it sits on the rocker and I believe this is because of the roller lifters which means the push rods don't spin. Our Calais was the same and was starting to get a slightly noisy valve train which on the ecotec has always been blamed on the lifters but I believe is in fact wear on the push rods causing the lifters to loose there pre-load. I fitted new rockers and push rods and she's quiet as now.

I have a set of worn 1.9 rockers here, push rod cup in the rocker has some wear but the push rods themselves are totally stuffed. I was going to try and clean up the rocker seats but the fuckers are still hard as fuck.

No this issue occurs with brand new push rods from crow cams. all rockers were chewed out but the push rods weren't even worn in, so that means the reworked rockers are too soft and just get mooshed like play dough from the hard push rods. I was able to dig at the rocker seats with a stanley knife to try trim off the burs.

[vHell83]

My bad. It was the platinum that was near 1k.

What's the difference between the two? I know there was size differences stated?

For the record, I have a noisy valve train and have had so with my old cam and the current 108 cam too. It's like valve train chatter almost. The noise has been there for a very long time and is quite annoying.

This is the reason I'm swapping out cams, I figured well if I'm going down to lifters, two more components and the cam is exposed so why not get something nice and boost friendly (xp hot)

[vlad01]

My bad. It was the platinum that was near 1k.

What's the difference between the two? I know there was size differences stated?

For the record, I have a noisy valve train and have had so with my old cam and the current 108 cam too. It's like valve train chatter almost. The noise has been there for a very long time and is quite annoying.

This is the reason I'm swapping out cams, I figured well if I'm going down to lifters, two more components and the cam is exposed so why not get something nice and boost friendly (xp hot)

Platinum ones are really beefy, for full race cars where 600 lift and 300º duration with double springs are used, 7K+ rpm etc....

They are also fully adjustable so that you can use solid roller or solid flat tappet or rare and expensive short travel hydro. Only known ones like that are from Morel for the V6 from old 80s buick and ecotec/L67, tie bar as well. They are set to 5 thou travel.

As for noisy valve train, its likely the lifters are stuffed. Stock ones and even a lot of the off the shelf ones are pretty crap. After a good flogging they no longer pump up properly and just bleed down, sounding like a can of marballs when running. Would highly recommend genuine GM LS lifters at the min or LS race spec hydo ones from Morel using stock retainers, or the V6 buick ones or normal travel tie bar type.

With platinum you need custom tall rocker covers or large spacers.

Ultralites are a really good performance rocker and easily handle the "stage 3" and bit beyond that no problems at all. They are still in the grand scheme of things still mild cams.