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I know enough about cars to get by and to help my friends with theirs, but I just thought of a question that makes me feel kinda stupid. I have a dodge neon as my daily driver. It has a 2.0 SOHC motor in it. The neons also came with a 2.0 DOHC motor which has a factory rating of 150hp compared to my rating of 132. Both motors have 4 valves/cylinder, the same blocks and most of the same "hardware." The DOHC does have a little higher compression pistons and a better manifold. What I am asking is this: how can having two cams be better than one? I would understand it if the DOHC had more valves, but it doesn't. Does anyone have any thoughts? The only power difference is probably because of the pistons and the better flowing exhaust, right?

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No LUV anymore, but still in the GM truck family. Running a lifted 2002 Silverado Z-71!

most likely the SOHC has 2 valves per cylinder and the DOHC has 4 per. That would be the advantage... more valves and thus more air flow in and out of the cylinders. with DOHC you get more popwer, with smaller cam lifts which gives you better valve train geometry and ultimately more longevity and reliablity.

i have a 98 neon my girls actually. man that thing is slow but when when you get it up to speed the damn thing cruises. i found a dohc and might just swap the single out. i hear there pretty quick

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1980 luv sport 4x4 Just a memory now
Frame rusted from the inside. Truck stripped and now looking for a new donor in southern ohio

I rented a Neon once.... put a 100 shot on it and tore up the streets for a weekend. It beat EVERY single ricer that I raced. The thing probably put down a 14 sec ET all stock with automatic and nitrous. The jug really wakes things up.

That would make sense if the DOHC had more valves than the single, but they both still have 4 per cylinder. Hey bcg187 if you put pistons from a DOHC in a SOHC, it puts you at about 10.2:1 compression and you will rape a DOHC. The blocks are identical between the motors and the bore is identical, just the compression ratios are different. It would be much cheaper ($50-$100) to do that than a motor swap ($700+). But, if you do a motor swap, remember to change the ECU and Wiring harness also because the firing order and fuel curves are different. Plus the SOHC has a speed limiter of 120 mph, where the DOHC has one of about 140.

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No LUV anymore, but still in the GM truck family. Running a lifted 2002 Silverado Z-71!

Hmmm i dunno then... to me a DOHC with 4 valves per vs. a SOHC with 4 valves per is a disadvantage.. the extra cam with the extra spring pressures from 8 valve springs causes extra friction in the motor and some parasitic HP loss.

Thats probably why it has higher compression pistons and better flowing manifolds. It also has more aggresive timing curves and a higher rev limiter. I guess that is why my SOHC with a cold air intake walks all over my friends stock DOHC. He also has 17's compared to my 14's, that tends to kill extra 15 hp that he has over me. I'm a little better driver too. I have worked on both motors though, and they do have the same number of valves. Kinda silly

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No LUV anymore, but still in the GM truck family. Running a lifted 2002 Silverado Z-71!