Achieving desired SS valve lift.....

ss wannabee · 07-10-2013, 10:05 PM

I know I asked this before...but am getting old and forgot.....

WHICH is better way?

Smaller lobe lift and LOTS of rocker arm ratio....

Larger lobe lift and lesser ratio....

Pros/cons of each way....

Which is more common today?

Would running stud-mounted rockers dictate pretty much what could be done?
(ie...ratios above 1.65 not available for stud mounts...)

Combo is 283 Chevy....on a budget...with the stud-mounted rockers....

Jim Hanig · 07-12-2013, 09:48 AM

The trend has been bigger cam or lobe lift and less rocker ratio. JimHanig

Jeff Lee · 07-12-2013, 12:16 PM

budget a shaft rocker system in!

Alan Roehrich · 07-12-2013, 05:42 PM

Get the lift at the lobe not at the rocker. Run shaft rockers. And all the pushrod that will fit.

To let you know how much I believe in what Tim and Billy told me about getting the lift at the lobe, I'm buying a half set of T&D rockers, because I bought 1.75:1 rockers for the intake last time, and I'm going back to 1.7:1. I can tell you that a 1/2 set of T&D rockers are more than 1/2 the cost of a new set. And not by a small amount. If I didn't think lift at the lobe instead of the rocker was important, I'd save myself a ton of cash.

Kevin Panzino · 07-12-2013, 07:54 PM

And why exactly is this all of a sudden in fashion??

With lower lobe lift, and higher rocker ratio's, a larger portion of the valvetrain mass undergoes lower acceleration. And that is nothing but good.

If you can move the lifter, the pushrod and half of the rocker mass less distance and less quickly for a given valve lift and rate, then how can that be bad??

high rocker ratios allow more 'area under the curve' of the valve for a given duration and given cam ramp..

It blows my mind, how all of a sudden high ratio rockers are now out of fashion, and the old ratios are back in....

Perhaps Im missing something, but there is nothing at all technically negative about high ratio rockers other than increased load on the lifter, cam bearings, pushrod, and thus potential pushrod flex,.. And roller cam bearings, large diameter roller lifters, and pushrod quality and design have taken care of that problem....

Tell, you what, its all fine with me, because all I have right now is a set of 1.7's, on the intakes and 1.6's on the exhaust, and I'd like to get some 1.8's, and 1.7's, so this means I should be able to trade someone and even make a few bucks, eh ??

So there you go, all you guys with the 1.8's Intakes and 1.7 exahusts on a SBC jesel shaft, thats OLD SCHOOL.. You are sooooooo lame.....

I have what you need right here... some 1.7's and 1.6's.. PM me asap, so you can trade with me, and you can go faster....

Ed Wright · 07-12-2013, 08:03 PM

I'm doing it all wrong. LOL

ss wannabee · 07-13-2013, 06:47 PM

Well...my engine program's not so stable anyhow...so I should be just fine...w/o the
shaft-mounts...

Just hoping that the car gets down the track....period!

Alan Roehrich · 07-13-2013, 07:01 PM

Quote:

Originally Posted by Kevin Panzino

And why exactly is this all of a sudden in fashion??

With lower lobe lift, and higher rocker ratio's, a larger portion of the valvetrain mass undergoes lower acceleration. And that is nothing but good.

If you can move the lifter, the pushrod and half of the rocker mass less distance and less quickly for a given valve lift and rate, then how can that be bad??

high rocker ratios allow more 'area under the curve' of the valve for a given duration and given cam ramp..

It blows my mind, how all of a sudden high ratio rockers are now out of fashion, and the old ratios are back in....

Perhaps Im missing something, but there is nothing at all technically negative about high ratio rockers other than increased load on the lifter, cam bearings, pushrod, and thus potential pushrod flex,.. And roller cam bearings, large diameter roller lifters, and pushrod quality and design have taken care of that problem....

Tell, you what, its all fine with me, because all I have right now is a set of 1.7's, on the intakes and 1.6's on the exhaust, and I'd like to get some 1.8's, and 1.7's, so this means I should be able to trade someone and even make a few bucks, eh ??

So there you go, all you guys with the 1.8's Intakes and 1.7 exahusts on a SBC jesel shaft, thats OLD SCHOOL.. You are sooooooo lame.....

I have what you need right here... some 1.7's and 1.6's.. PM me asap, so you can trade with me, and you can go faster....

Well, good luck to you.

I'll stick with what I'm getting from the guys who developed the SpinTron and the guys who use it to refine my valvetrain components. All of whom say that weight/mass on the cam side of the rocker fulcrum is nearly irelevant compared to weight on the valve side.

Kevin Panzino · 07-13-2013, 07:02 PM

While Im a budget racer as well, I have to agree with what others have said.... Do not waste any time at all with stud mount rockers... You really need to figure in a shaft system... Particuarly with the engine size you have chosen... You are going to need to turn some good RPM.

We can argue on the ratios... But Im sure we can all agree, you need to have a shaft system and forget about stud mounted rockers....

By the time you get done with roller rockers, locks, stud girdles, you are going to be approaching 60% of the cost of a nice used Jesel setup. And that additional 40% is money well spent.

ss wannabee · 07-14-2013, 06:59 AM

Guys, ALL solid advice by everyone....

Kevin...I realize this combo works with high rpm...and that the Jesel has been the norm
for many years....

Already have my roller rockers in ALL the popular sizes....some full sets...including
some rare 1.7 ratio that were made by Crane years ago...

There are some other aspects of my "build" that might seem a bit "old" to people....
don't want to get into them....but when I say "budget" I mean it in the truest sense...

I'm down on bucks...who isn't these days?. Stock Eliminator is NOT an option for
me...Tried that back in the OEM piston and camshaft spec days...didn't go too fast...
but learned a lot....

Don't agree with TODAYS Stock rules.....

The main reason I asked the question...is that some time ago...maybe just after the
SS cyl head porting rules change...there was an ad in Dragster by a major camshaft
company indicating some "new" SBC SS roller grinds....

The cams seemed "small"...with lobe lifts just over .400"....but the ad suggested to
run them with 1.7/1.8 ratios....hence the Jesel...which I don't have anyway...

Realize that ad is probably about 20 years old now...maybe not relevant information
today? Heads being done differently, etc?

I have some older cams...in that neighborhood...probably obsolete today...but thought I
had a chance to make use of them....I'm run them anyway...with the lower ratios and see
what happens....

Just was wondering if racers favored getting the valve lift THAT way...for whatever
reason...I guess physics comes into play here....

Bottom line is it's taking too long to complete this car....many obstacles along the way...

Enough of this sob story...as they've said in the Army..."BETTER to do something NOW
and TALK about it LATER!!"

Onward!!!!

07-10-2013, 10:05 PM	#1
ss wannabee Senior Member Join Date: Jun 2005 Posts: 663 Likes: 0 Liked 7 Times in 7 Posts	Achieving desired SS valve lift..... I know I asked this before...but am getting old and forgot..... WHICH is better way? Smaller lobe lift and LOTS of rocker arm ratio.... Larger lobe lift and lesser ratio.... Pros/cons of each way.... Which is more common today? Would running stud-mounted rockers dictate pretty much what could be done? (ie...ratios above 1.65 not available for stud mounts...) Combo is 283 Chevy....on a budget...with the stud-mounted rockers....

07-12-2013, 09:48 AM	#2
Jim Hanig Senior Member Join Date: Aug 2006 Location: Pukwana SD Posts: 860 Likes: 554 Liked 99 Times in 49 Posts	Re: Achieving desired SS valve lift..... The trend has been bigger cam or lobe lift and less rocker ratio. JimHanig

07-12-2013, 12:16 PM	#3
Jeff Lee VIP Member Join Date: Jul 2007 Location: Anthem, Arizona Posts: 2,766 Likes: 0 Liked 3 Times in 3 Posts	Re: Achieving desired SS valve lift..... budget a shaft rocker system in! __________________ Jeff Lee 7494 D/S '70 AMX

07-12-2013, 05:42 PM	#4
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,111 Likes: 1,570 Liked 1,812 Times in 413 Posts	Re: Achieving desired SS valve lift..... Get the lift at the lobe not at the rocker. Run shaft rockers. And all the pushrod that will fit. To let you know how much I believe in what Tim and Billy told me about getting the lift at the lobe, I'm buying a half set of T&D rockers, because I bought 1.75:1 rockers for the intake last time, and I'm going back to 1.7:1. I can tell you that a 1/2 set of T&D rockers are more than 1/2 the cost of a new set. And not by a small amount. If I didn't think lift at the lobe instead of the rocker was important, I'd save myself a ton of cash. __________________ Alan Roehrich 212A G/S Last edited by Alan Roehrich; 07-12-2013 at 05:44 PM.

07-12-2013, 07:54 PM	#5
Kevin Panzino Senior Member Join Date: Oct 2002 Location: Pittsburgh Posts: 575 Likes: 298 Liked 747 Times in 136 Posts	Re: Achieving desired SS valve lift..... And why exactly is this all of a sudden in fashion?? With lower lobe lift, and higher rocker ratio's, a larger portion of the valvetrain mass undergoes lower acceleration. And that is nothing but good. If you can move the lifter, the pushrod and half of the rocker mass less distance and less quickly for a given valve lift and rate, then how can that be bad?? high rocker ratios allow more 'area under the curve' of the valve for a given duration and given cam ramp.. It blows my mind, how all of a sudden high ratio rockers are now out of fashion, and the old ratios are back in.... Perhaps Im missing something, but there is nothing at all technically negative about high ratio rockers other than increased load on the lifter, cam bearings, pushrod, and thus potential pushrod flex,.. And roller cam bearings, large diameter roller lifters, and pushrod quality and design have taken care of that problem.... Tell, you what, its all fine with me, because all I have right now is a set of 1.7's, on the intakes and 1.6's on the exhaust, and I'd like to get some 1.8's, and 1.7's, so this means I should be able to trade someone and even make a few bucks, eh ?? So there you go, all you guys with the 1.8's Intakes and 1.7 exahusts on a SBC jesel shaft, thats OLD SCHOOL.. You are sooooooo lame..... I have what you need right here... some 1.7's and 1.6's.. PM me asap, so you can trade with me, and you can go faster....

07-12-2013, 08:03 PM	#6
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: Achieving desired SS valve lift..... I'm doing it all wrong. LOL __________________ Ed Wright 4156 SS/JA

07-13-2013, 06:47 PM	#7
ss wannabee Senior Member Join Date: Jun 2005 Posts: 663 Likes: 0 Liked 7 Times in 7 Posts	Re: Achieving desired SS valve lift..... Well...my engine program's not so stable anyhow...so I should be just fine...w/o the shaft-mounts... Just hoping that the car gets down the track....period!

07-13-2013, 07:02 PM	#9
Kevin Panzino Senior Member Join Date: Oct 2002 Location: Pittsburgh Posts: 575 Likes: 298 Liked 747 Times in 136 Posts	Re: Achieving desired SS valve lift..... While Im a budget racer as well, I have to agree with what others have said.... Do not waste any time at all with stud mount rockers... You really need to figure in a shaft system... Particuarly with the engine size you have chosen... You are going to need to turn some good RPM. We can argue on the ratios... But Im sure we can all agree, you need to have a shaft system and forget about stud mounted rockers.... By the time you get done with roller rockers, locks, stud girdles, you are going to be approaching 60% of the cost of a nice used Jesel setup. And that additional 40% is money well spent.

07-14-2013, 06:59 AM	#10
ss wannabee Senior Member Join Date: Jun 2005 Posts: 663 Likes: 0 Liked 7 Times in 7 Posts	Re: Achieving desired SS valve lift..... Guys, ALL solid advice by everyone.... Kevin...I realize this combo works with high rpm...and that the Jesel has been the norm for many years.... Already have my roller rockers in ALL the popular sizes....some full sets...including some rare 1.7 ratio that were made by Crane years ago... There are some other aspects of my "build" that might seem a bit "old" to people.... don't want to get into them....but when I say "budget" I mean it in the truest sense... I'm down on bucks...who isn't these days?. Stock Eliminator is NOT an option for me...Tried that back in the OEM piston and camshaft spec days...didn't go too fast... but learned a lot.... Don't agree with TODAYS Stock rules..... The main reason I asked the question...is that some time ago...maybe just after the SS cyl head porting rules change...there was an ad in Dragster by a major camshaft company indicating some "new" SBC SS roller grinds.... The cams seemed "small"...with lobe lifts just over .400"....but the ad suggested to run them with 1.7/1.8 ratios....hence the Jesel...which I don't have anyway... Realize that ad is probably about 20 years old now...maybe not relevant information today? Heads being done differently, etc? I have some older cams...in that neighborhood...probably obsolete today...but thought I had a chance to make use of them....I'm run them anyway...with the lower ratios and see what happens.... Just was wondering if racers favored getting the valve lift THAT way...for whatever reason...I guess physics comes into play here.... Bottom line is it's taking too long to complete this car....many obstacles along the way... Enough of this sob story...as they've said in the Army..."BETTER to do something NOW and TALK about it LATER!!" Onward!!!!