Another "Will this work in an LN3 Question"
#11
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unfortunately you can't do that. it'd be the same effect as overtorquing the rocker bolts..
also, he said upgrading to stock roller rockers, not full rollers.. so idk.
also our pushrods are pretty light to begin with.. probably not going to make a noticable difference, and no matter what, you shouldn't be revving your engine that high if you are getting valve float... LN3s don't like upper rpm runs.
also, he said upgrading to stock roller rockers, not full rollers.. so idk.
also our pushrods are pretty light to begin with.. probably not going to make a noticable difference, and no matter what, you shouldn't be revving your engine that high if you are getting valve float... LN3s don't like upper rpm runs.
#13
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These are the figures I derived when I degreed the stock cam during my engine build. I couldn't find any stock specs so I checked when I installed the stock 1990 roller cam. All figures @ .050" lobe lift. The figures should be very close, although absolute accuracy is not guaranteed.
Intake opens @ 20.5* ATDC, closes @ 27.5* ABDC, 187* duration and .250 total lobe lift.
Exhaust opens 30* BBDC, closes 26* BTDC, 184* duration and .255 total lobe lift.
I have a cam from an '88 also and I did not install it so I do not have the opening and closing points, but I did install it in a jig I made to check the lobe lift and duration. The cam appears to be square, 180* duration on both lobes and a little more lift @ .260 on both lobes.
Interesting that both engines have the same ratings and I have heard several comments that the cars feel different between the two years even with the same gearing and tire size? With the very mild specs, it is no wonder they run out of wind at about 4500 rpm.
From Smokey Yunicks engine experimenting, little is gained from lighter lifters, pushrods and even rockers to increase the rpm potential. It does seem contrary to logic, one would think all would make a difference, but the springs, keepers and valves are where lightness has the greatest gain. At the rpm'* we are working with, it should make little if any difference. We are running 1/2-2/3 the rpm'* he was working with and smaller valves as well.
Intake opens @ 20.5* ATDC, closes @ 27.5* ABDC, 187* duration and .250 total lobe lift.
Exhaust opens 30* BBDC, closes 26* BTDC, 184* duration and .255 total lobe lift.
I have a cam from an '88 also and I did not install it so I do not have the opening and closing points, but I did install it in a jig I made to check the lobe lift and duration. The cam appears to be square, 180* duration on both lobes and a little more lift @ .260 on both lobes.
Interesting that both engines have the same ratings and I have heard several comments that the cars feel different between the two years even with the same gearing and tire size? With the very mild specs, it is no wonder they run out of wind at about 4500 rpm.
From Smokey Yunicks engine experimenting, little is gained from lighter lifters, pushrods and even rockers to increase the rpm potential. It does seem contrary to logic, one would think all would make a difference, but the springs, keepers and valves are where lightness has the greatest gain. At the rpm'* we are working with, it should make little if any difference. We are running 1/2-2/3 the rpm'* he was working with and smaller valves as well.
#15
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No, it is not a typo. The figures are @ .050" lobe lift, the valve isn't actually closed, so it is likely open slightly at TDC, the valve will be open even more with the stock 1.6 rocker ratio. With essentially no overlap, the engine should be emissions friendly and a good torque producer too, but lacks top end breathing. I did not check the actual total seat to seat duration. I know it sounds wrong, but as the piston has done almost all of it'* upward travel as the crank gets nearTDC, it is primarily swinging over center at that point. We have a relatively long rod with a pretty high rod ratio, so the piston actually dwells a longer time at the bottom and top of the stroke. If I remember right it is close to what a Chebbie 350 has if 6" rods are fitted.
#16
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I am just going to do the roller rockers from the series 1 for the purpose of wear after the mileage on my solid rockers. and the rollers will help the motor run alittle nicer
Plus its fun to work on your car
Plus its fun to work on your car
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