what are the benifits of useing 1.5 RR's on the intake side and 1.6 RR's on the exhaust side?the heads i'm useing are WORLD PRODUCTS S/R 305 heads.the intake side flows better than the aluminuim vette heads but not as good on the exhaust side.58cc 171cc runners 1.94 intake 1.54 exhaust.i will be useing an LT1 cam with a 5.7 TPI

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1991 banditt2 #130 of 600
Project 350 TPI Banditt II
http://www.street-dawg-racing.cityslide.com
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1.6 on the exhaust side gives more valve lift, to allow for more flow. it gets a little complicated with dual pattern cams, most all have less lift on the intake side. i've never mixed rockers, but a lot of people do.

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ICON Motorsports

1st & 3rd
MM Black Diamond 538 F&AM

 

You never mix rockers unless you have a reason to. Reasons include:

1) The need to increase lift in order to allow more flow IF AND ONLY IF the heads flow better at that lift.
2) The need to decrease lift in order to

• decrease piston to valve clearance
• decrease flow
• obtain better idle quality

A good example is my new cam that yields 0.510" intake and 0.540" exhaust lift. My heads flow incredibly well up to 0.600" lift. I pumped up the intake lift by adding 1.6 rockers to the intake. I did not add 1.6 rockers to the exhaust because the lift would be so big that piston-to-valve clearance could be compromised. Furthermore, the cam is already a split duration cam with significantly more exhaust duration so there is no need for me to bump the exhaust up anymore.

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
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