What the difference in 1.6 or 1.7 RR?

October 18th, 2007, 11:15 PM	#1
JONJON Regular 1988 Ford Mustang GT 8.372@82.8 1/8mile w/1.825 60' Join Date: Sep 2007 Location: Miami,FL Posts: 357	What the difference in 1.6 or 1.7 RR? What are the bennefits and disadvantages of 1.6 to 1.7.Thank for your help,this site is the best I dont even post on the others anymore.

October 18th, 2007, 11:20 PM	#2
Darrell Feb 08 ROTM 1990 Mustang LX 9.36@143 mph Join Date: Jan 2006 Location: Fond du Lac, Wisconsin Posts: 7,287	Valve lift is the only difference. Rocker ratio is a lift multiplier. A 1.7 rocker arm will add more lift at the valve. To determine how much divide the cam lift by 1.6 and multiply times 1.7. Example .542 divided by 1.6 = .33875 x 1.7 = .575875 __________________ Racing in memory of Dave Bandt 11/19/69 - 3/23/08 "he's traded his wheels for wings" Professor of Natural Aspiration Thanks to: Artie at Trick Flow, Dave at Team Z Motorsports, Brian at Total Engine Airflow and Harold at Furo Racecraft

October 18th, 2007, 11:27 PM	#3
JONJON Regular 1988 Ford Mustang GT 8.372@82.8 1/8mile w/1.825 60' Join Date: Sep 2007 Location: Miami,FL Posts: 357	I really dont understand I want to know to see what I should buy.Why would you use 1.7?or y use 1.6?Thanks

October 18th, 2007, 11:30 PM	#4
JONJON Regular 1988 Ford Mustang GT 8.372@82.8 1/8mile w/1.825 60' Join Date: Sep 2007 Location: Miami,FL Posts: 357	nevermind I get it.Thanks

October 18th, 2007, 11:33 PM

Speedstang302

MM Fanatic

1989 Mustang LX 5.0

12.86@ 111mph

Join Date: Apr 2007

Location: Massachusetss

Posts: 4,533

Originally Posted by Darrell

Valve lift is the only difference. Rocker ratio is a lift multiplier. A 1.7 rocker arm will add more lift at the valve. To determine how much divide the cam lift by 1.6 and multiply times 1.7. Example .542 divided by 1.6 = .33875 x 1.7 = .575875

OK well that tells me that w/ my f303 cam i'd be at .544 w/ 1.7's..than is .512 the lift for the f303 w/ 1.6's..cuz that equation in that case X's out the 1.6 and just makes lift the same??

__________________

1989 Mustang LX 5.0
Stock w/ F303 cam and 1.6 Roller Rockers
BBK Shortys, BBK o/r H, Flowmaster Super 44s

"The LS1 was subject to a paternity test!!! The results are back....03 cobra you are the Father!!!!"

October 18th, 2007, 11:35 PM	#6
Speedstang302 MM Fanatic 1989 Mustang LX 5.0 12.86@ 111mph Join Date: Apr 2007 Location: Massachusetss Posts: 4,533	and also i have 1.6's and noticed a difference, but w/ 1.7's that makes my lift too big for stock springs..but im not sure if any that 1.6's to 1.7's make a dif HP wise.. i say harland sharp, crane, comp or jesel rocker arms too!!! __________________ 1989 Mustang LX 5.0 Stock w/ F303 cam and 1.6 Roller Rockers BBK Shortys, BBK o/r H, Flowmaster Super 44s "The LS1 was subject to a paternity test!!! The results are back....03 cobra you are the Father!!!!"

October 18th, 2007, 11:53 PM

Darrell

Feb 08 ROTM

1990 Mustang LX

9.36@143 mph

Join Date: Jan 2006

Location: Fond du Lac, Wisconsin

Posts: 7,287

Originally Posted by Speedstang302

OK well that tells me that w/ my f303 cam i'd be at .544 w/ 1.7's..than is .512 the lift for the f303 w/ 1.6's..cuz that equation in that case X's out the 1.6 and just makes lift the same??

1.6 is the factory rocker ratio for Ford Windsor small blocks (221-351W). All cams are based on a 1.6 rocker ratio unless otherwise noted. Going to a 1.7 ratio will increase lift. Will it gain you any horsepower? That depends. If the heads don't flow any more air with the added lift you won't gain any power.

__________________
Racing in memory of Dave Bandt 11/19/69 - 3/23/08
"he's traded his wheels for wings"

Professor of Natural Aspiration

Thanks to: Artie at Trick Flow, Dave at Team Z Motorsports, Brian at Total Engine Airflow and Harold at Furo Racecraft

October 19th, 2007, 12:21 AM	#8
ken5_0 Regular Join Date: Aug 2006 Posts: 192	Damn Darrell...! Wanna be my friend? How long you been puttin people in boxes round here?

October 19th, 2007, 10:34 AM