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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motorvated |
Jan 16 2019, 12:24 PM
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#2
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Member Group: Members Posts: 279 Joined: 13-February 13 From: Colorado Member No.: 15,519 Region Association: Rocky Mountains |
I'm running 235 50 15's Toyo Proxes on the rear with Chalon flares and I have upgraded to 911 suspension and brakes, so the car is set up nicely for the track. The 1.8 in it now is just underpowered. I picked up this 2.0 liter four and just now pulling it apart to see what it looks like inside. Don't know what cam or lifters are in it now, and it came with a set of 40IDFs not mounted on the motor. So I don't know if the motor had last been running carbs or FI. Not yet sure where I'm going with this motor, as I also have a Buick 215 V-8 conversion package that I might install if I choose to ditch Vintage and race with my regional SCCA. So I'll race this season with the 2.0 liter in Vintage and one or two SCCA events and see where I want to go after that.
So a couple of quick questions about the 2.0 liter. Can I remove the lifters from the top without splitting the cases, maybe by rotating the engine on the stand to get them to drop out or by somehow pulling them upwards and out? I need to determine if they are solid or hydraulic. And how much more difficult is it to split the cases once the P&Cs etc have been removed. Then can I replace the cam without disturbing the crank bearings. |
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