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stugray |
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Advanced Member ![]() ![]() ![]() ![]() Group: Members Posts: 3,825 Joined: 17-September 09 From: Longmont, CO Member No.: 10,819 Region Association: None ![]() |
I am adjusting the valve geometry while putting in a Raby 9700 cam and I am seeing .38 on the exhaust cam lift and .496 at the valve (an exh rocker ratio of 1.3) and I have a .39 on the intake with a .546 at the valve ( an int rocker ratio of 1.4) is this what everyone else gets for rocker ratios:
Intake rocker ratio = 1.4 Exhaust rocker ratio = 1.3 These are the 1.7 (1.8?) rockers that accept the 911 swivel feet. I am using the swivel feet, have modified the rocker faces, adjustable push rod, and zero lash to do the meaurements. Do those rocker ratios look like stock? I want to take 50 thousandths off the Combustion chambers to increase the CR, but my measurements say I wont have enough clearance on the Intake valve once I shave off 50 thousandths. I only have ~0.075 clearance now from the piston to the Int valve as it is with a deck of 0.030 and everything else (crank & rods) stock - flat top 96mm pistons. That Intake valve travel of ~0.55 looks huge to me. Anyone else care to comment? Stu |
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stugray |
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Advanced Member ![]() ![]() ![]() ![]() Group: Members Posts: 3,825 Joined: 17-September 09 From: Longmont, CO Member No.: 10,819 Region Association: None ![]() |
So I had the engine case "decked", the rods re-bushed and measured, and the heads cut by .020 and I repeat the valve travel measurements and I get:
Intake Valve travel is STILL .525 with the "old" Intake rockers. Intake Valve travel is .519 with a set of new rockers' (completely different FI 1.8L car) WHICH Means that MOST of these cars have 1.4 Intake Rockers so I cannot reach the desired intake valve travel with the current cam without getting special rocker arms. So does anyone have Intake rockers that are GUARANTEED to be what "Some" assume to be 1.3, or do I need to machine my cam to accept the fact that Type-IV Intake rockers are 1.4 instead of 1.3? Stu |
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