Which camshaft for an 1835 with Mexican EFi and Megasquirt?

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paullanzarotti
Posts: 41
Joined: Sat Dec 13, 2014 4:01 pm

Which camshaft for an 1835 with Mexican EFi and Megasquirt?

Post by paullanzarotti » Thu Mar 29, 2018 9:00 am

I'm looking to build an engine as a daily driver so I'm sticking to stock heads (with a bit of porting) so I can use stock heat exchangers. I am also using Mexican Fuel injection with Megasquirt and wasted spark which means my tuning options are pretty broad.

With that in mind, I'm trying to figure out what camshaft to use. I'm hoping to get 100BHP and 5500 RPM limit out of this and would prefer the power to be evenly spread rather than low end (Engle 100) or higher up (Engle 110)

I need help choosing a camshaft...as I'm using a programmable ECU I'm wondering if that means I can iron out lumpy idles etc. I looked at the 2280 Cheater cam but that's really for people using a stock carb or stock FI - neither apply here.

The rest of the spec is as follows:

1835
32/35 Heads - mildly ported
Newold stock AS21 case
Mexican Fuel Injection with Wasted Spark ignition
94mm Thick Walled
Standard heads mildly ported with HD springs, Aluminum pushrods
Solid rocker conversion 1:1:1
DPR crank balanced with flywheel etc
Camshaft???

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turbobaja
Posts: 2805
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Location: The Evergreen State

Re: Which camshaft for an 1835 with Mexican EFi and Megasquirt?

Post by turbobaja » Wed Apr 04, 2018 1:48 pm

Your heads and exhaust will probably be the limiting factors on your power potential. There's no magic cam that will lend you smooth idle, good off-idle response, solid mid range pull, plus make power (worth revving to 5,500rpm) in the upper rpms, especially with relatively small displacement. Assuming you've got thick wall 92mm bore piston/cylinders, not 94mm. For a daily driver the W100 would be fine, and be easy to tune. Overcoming a lumpy idle with EFI is not always possible. If the engine doesn't pump air efficiently due to cam/compression at a given rpm range, EFI cannot magically make it happen. Longer duration cam profiles will always trade off low rpm quality for upper rpm power. For a daily, torque is a better goal than horsepower in my opinion.
Karl

DON'T QUIT

paullanzarotti
Posts: 41
Joined: Sat Dec 13, 2014 4:01 pm

Re: Which camshaft for an 1835 with Mexican EFi and Megasquirt?

Post by paullanzarotti » Fri May 25, 2018 7:21 am

That's super helpful, thank you. Do you think I'll be wrestling with a lumpy idle if I go with a 110?

If I go mild then it's probably either the 100 or the CB 2280 Cheater cam. Do you have any thoughts on one or the other?

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