How To Get 500+ More RPM, Without Changing Cam |
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How To Get 500+ More RPM, Without Changing Cam |
motorvated |
Jan 15 2019, 05:50 PM
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#1
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Member Group: Members Posts: 279 Joined: 13-February 13 From: Colorado Member No.: 15,519 Region Association: Rocky Mountains |
2.0 Liter Four. Doing a top end refresh and not planning on splitting the cases or changing the cam. Would stiffer valve springs and beefier pushrods get me there. I'm a little confused when looking at aftermarket springs, as the European Motorworks Single HD springs are rated at 135 psi seat pressure, and stock springs are rated at about 175 psi. Also thinking that chromoly pushrods set at zero clearance cold don't let the valves open fully when hot due to the lower expansion of the pushrod, plus they are a lot heavier than aluminum pushrods. So what can I use to get those elusive extra 500+ rpm? My old stock 1.8 floated valves up near 6,000, which wasn't bad, but I'd like a little more with the 2.0 liter. I'm racing the car in Vintage. Any suggestions.
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tejon007 |
Jan 16 2019, 11:51 AM
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#2
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Newbie Group: Members Posts: 45 Joined: 10-February 10 From: Northern California Member No.: 11,344 Region Association: None |
Take a look at the whole picture...racing takes the right combinations of systems. Obviously, the motor and transmission are two important pieces, but there are other important things to consider like suspension, brakes, wheels, tires, etc.
It really makes sense to design a motor with the right camshaft for its intended use and how it works in your car and its setup. If you're really insistent on not changing the cam (BTW are you running carbs with a stock FI cam?), how about changing the rockers - ratio rockers? Roller rockers? (More$$ than a new cam) Yes, it's a slippery slope, but if you're gonna tear the motor apart anyway, it's not that much $$$ to get the right cam, new lifters, gear, and a gasket set...right? Might plan on replacing the bearings too...full flow the oil pump, etc. A slippery slope. Best wishes for your project!! (One of my projects is a Chalon also, but don't say it too loudly as not everyone appreciates their beauty) |
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