Rocker Arm Ratio - Page 2

Alan Roehrich · 07-20-2012, 09:17 AM

They can, and will, check lift at the valve, and then lift at the cam. From that they will check rocker arm ratio. If the ratio is greater than what is in the blueprint specs, they will throw you out.

Feel free to ask Travis Miller, or Dave Ley about this, they will explain it to you. There are also several threads on the subject that explain why and how about rocker ratio. I have seen people thrown out for rocker ratio.

Marine One · 07-20-2012, 11:41 PM

Rocker ratio is not constant in the swing of the arc. Check max lift at the valve and at the cam all you want and you will never catch it that way, unless you went crazy and tried to go from something like 1.6 to 1.8

RULER · 07-21-2012, 03:06 AM

If they check lobe lift and x it by the correct ratio it better be the same or damn close to what it checks at the valve, you will always loose some from spring pressure but not the difference between 1.5 and 1.6, but when was the last time they checked lobe lift ? and is that something there doing now ?

Charley Downing · 08-03-2012, 03:57 PM

As per Danny and Bruce at Chicago nationals this year any ratio is allowed.
Dalles Glens corvette had 1.55 rockers from comp cams on his lt1 corvette and 1.5 is the spec .Danny told me all NHRA cares about is that the cam checks
And that is fact.

PJ305 · 08-03-2012, 04:22 PM

Charley,

Wade O. said Travis checked all the rocker ratio's at Chicago so how could Dallas Glenn be legal with 1.55 rockers when 1.50 are in the blueprint spec.
Travis can you clear this up for the guys going to Indy.

Thanks

Alan Roehrich · 08-03-2012, 04:29 PM

Quote:

Originally Posted by PJ305

Charley,

Wade O. said Travis checked all the rocker ratio's at Chicago so how could Dallas Glenn be legal with 1.55 rockers when 1.50 are in the blueprint spec.
Travis can you clear this up for the guys going to Indy.

Thanks

Get it in writing from Glendora. Email them, and then follow up with a phone call.

PJ305 · 08-03-2012, 04:41 PM

Alan,

You can use a letter from Glendora for toilet paper. I spent $1000 for a Pontiac carb for my Chevy and have a letter that it's legal but I can't run it. I have another letter from Glendora that says angle adapters for spark plugs are legal and wasted $500 and there not legal.

Alan Roehrich · 08-03-2012, 04:51 PM

Quote:

Originally Posted by PJ305

Alan,

You can use a letter from Glendora for toilet paper. I spent $1000 for a Pontiac carb for my Chevy and have a letter that it's legal but I can't run it. I have another letter from Glendora that says angle adapters for spark plugs are legal and wasted $500 and there not legal.

It holds up a little better than their word, or second hand information.

I'm betting Travis will not post any clarification, as NHRA won't want him to. Not to mention they may over rule him on a whim. Which is one of the reasons Wesley Roberson has completely quit.

PJ305 · 08-03-2012, 05:21 PM

Thanks Alan, I will roll the dice at Indy and if I get thrown out at tear down I will be just another cheater.

Bob Pagano · 08-03-2012, 05:50 PM

And folks wonder why people just stop racing, the rules are still not the same across the board. Alan, you are right even tech directors are at a loss when Danny is around.

07-20-2012, 09:17 AM	#11
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,118 Likes: 1,578 Liked 1,837 Times in 417 Posts	Re: Rocker Arm Ratio They can, and will, check lift at the valve, and then lift at the cam. From that they will check rocker arm ratio. If the ratio is greater than what is in the blueprint specs, they will throw you out. Feel free to ask Travis Miller, or Dave Ley about this, they will explain it to you. There are also several threads on the subject that explain why and how about rocker ratio. I have seen people thrown out for rocker ratio. __________________ Alan Roehrich 212A G/S

07-20-2012, 11:41 PM	#12
Marine One Junior Member Join Date: Mar 2010 Location: Indiana Posts: 69 Likes: 2 Liked 0 Times in 0 Posts	Re: Rocker Arm Ratio Rocker ratio is not constant in the swing of the arc. Check max lift at the valve and at the cam all you want and you will never catch it that way, unless you went crazy and tried to go from something like 1.6 to 1.8 __________________ Chad Sheets \| STK 319 \| 10.69 \| 1.39 Last edited by Marine One; 07-20-2012 at 11:46 PM.

07-21-2012, 03:06 AM	#13
RULER Member Join Date: Jan 2006 Posts: 222 Likes: 15 Liked 58 Times in 18 Posts	Re: Rocker Arm Ratio If they check lobe lift and x it by the correct ratio it better be the same or damn close to what it checks at the valve, you will always loose some from spring pressure but not the difference between 1.5 and 1.6, but when was the last time they checked lobe lift ? and is that something there doing now ?

08-03-2012, 03:57 PM	#14
Charley Downing Senior Member Join Date: Sep 2007 Posts: 762 Likes: 16 Liked 641 Times in 89 Posts	Re: Rocker Arm Ratio As per Danny and Bruce at Chicago nationals this year any ratio is allowed. Dalles Glens corvette had 1.55 rockers from comp cams on his lt1 corvette and 1.5 is the spec .Danny told me all NHRA cares about is that the cam checks And that is fact. __________________ Charley Downing 3548 STK Last edited by Charley Downing; 08-03-2012 at 04:00 PM.

08-03-2012, 04:22 PM	#15
PJ305 Member Join Date: Jul 2007 Posts: 137 Likes: 0 Liked 5 Times in 4 Posts	Re: Rocker Arm Ratio Charley, Wade O. said Travis checked all the rocker ratio's at Chicago so how could Dallas Glenn be legal with 1.55 rockers when 1.50 are in the blueprint spec. Travis can you clear this up for the guys going to Indy. Thanks

08-03-2012, 04:41 PM	#17
PJ305 Member Join Date: Jul 2007 Posts: 137 Likes: 0 Liked 5 Times in 4 Posts	Re: Rocker Arm Ratio Alan, You can use a letter from Glendora for toilet paper. I spent $1000 for a Pontiac carb for my Chevy and have a letter that it's legal but I can't run it. I have another letter from Glendora that says angle adapters for spark plugs are legal and wasted $500 and there not legal.

08-03-2012, 05:21 PM	#19
PJ305 Member Join Date: Jul 2007 Posts: 137 Likes: 0 Liked 5 Times in 4 Posts	Re: Rocker Arm Ratio Thanks Alan, I will roll the dice at Indy and if I get thrown out at tear down I will be just another cheater.

08-03-2012, 05:50 PM	#20
Bob Pagano VIP Member Join Date: Jun 2002 Location: New Holland, PA Mooresville,NC Posts: 1,163 Likes: 241 Liked 16 Times in 11 Posts	Re: Rocker Arm Ratio And folks wonder why people just stop racing, the rules are still not the same across the board. Alan, you are right even tech directors are at a loss when Danny is around. __________________ Bob Pagano A/SA