2.4l cam choice

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notoriousbij
Posts: 5
Joined: Thu Apr 17, 2014 4:12 pm

2.4l cam choice

Post by notoriousbij »

Hey all,
I am building a 2.4l waterboxer to go in my syncro westy, but can't decide on a cam. My setup is:
-82mm demello crank
-96.5 SRP go westy p&ls
-5.5" scat rods
-44x38 valves in amc heads, not ported but polished, stock amc springs
-9.5:1 static compression

I am planning on going to solid type one lifters with Rocky's sleeves, Go Westy stainless exhaust, and would like to keep the stock intake. I am also ditching the digifant injection for megasquirt. I am looking for power between 2000-5000 and am torn between an engle 120 and one of the split duration webcams, like a 218/119 or a 110/119. Any input on this setup in a heavy van would be greatly appreciated. I have been researching this for a couple months now and haven't found any info on a torque motor with big valves.

Cheers
buildabiggerboxer
Posts: 621
Joined: Wed Mar 25, 2009 12:50 pm

Re: 2.4l cam choice

Post by buildabiggerboxer »

Your spac is for a race motor in a lightweight Beetle, for Bus use, Keep the stock valve sizes, these are plenty and can support 170 hp, 44s are not needed for your agenda where you need good intake gas speed for low end performance, big valves weaken the head and will crack them in short order, I hold the same view on lifters, remember it's not a race motor and you won't want to be constantly adjusting valve gaps, I would stay hydraulic because you just don't need to change the Rev range too much,
A CB hydraulic cam would be the ticket, build it for torque.
notoriousbij
Posts: 5
Joined: Thu Apr 17, 2014 4:12 pm

Re: 2.4l cam choice

Post by notoriousbij »

Thanks for the advice. I was debating going back to stock heads but was curious if anyone had tried a torque cam with big valves. I can save these heads for a later build. I still want to go with solid lifters though. The van can sit for weeks at a time, so lifter bleed down has been an on and off problem. Also it seems that better rocker oiling can be achieved with type 1 lifters once modded. Maybe one of these cams will produce a result?
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Stripped66
Posts: 1904
Joined: Tue Sep 18, 2001 12:01 am

Re: 2.4l cam choice

Post by Stripped66 »

If you're set on Type 1 lifters, consider the FK65 or K7.
notoriousbij
Posts: 5
Joined: Thu Apr 17, 2014 4:12 pm

Re: 2.4l cam choice

Post by notoriousbij »

Those might work well, .500 lift with 1.4 rockers seems like a lot, especially with stock springs. Will these cams work with 1.25 rockers ok? I have used engle 100 and 110s in the past, but not fk cams.
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Stripped66
Posts: 1904
Joined: Tue Sep 18, 2001 12:01 am

Re: 2.4l cam choice

Post by Stripped66 »

Stock springs? Stock springs are not going to control your larger valves, regardless of the cam you choose.

Yes, both cams will work with 1.25:1 rockers. Lift and duration at 0.050" will be reduced as a result.
notoriousbij
Posts: 5
Joined: Thu Apr 17, 2014 4:12 pm

Re: 2.4l cam choice

Post by notoriousbij »

Sorry, I should have put in my original post that I ran the big valve heads for about 10,000 miles without an issue in the above mentioned setup. I ran the them in a westy with an Elgin cam and megasquirt injection. I don't know much about the cam, as I haven't mapped it yet, but it ran ok, especially strong over 3000rpm and had good vacuum at idle. The problem was below 3000, not much hill pulling power, about like a 1.9l. I know this cam was designed to work with stock size valves and stock injection, so I should be able to do better with a different cam, either with stock heads or these big valve ones. I was just curious if anyone on the forum has tried big valve heads with a "torque" cam in a stroked waterboxer. The cams stripped66 mentioned sound good. I could build it to handle 1.4s, start with 1.25 rockers, see how it works, and go from there.
buildabiggerboxer
Posts: 621
Joined: Wed Mar 25, 2009 12:50 pm

Re: 2.4l cam choice

Post by buildabiggerboxer »

Be careful, You will be into valve clash territory with 5.5 rods with almost any ratio cam, even 1.25s need considerable valve pocket depth in the Pistons with fairly modest cams, unless the go westy Pistons were designed for 5.5 rods of course.
notoriousbij
Posts: 5
Joined: Thu Apr 17, 2014 4:12 pm

Re: 2.4l cam choice

Post by notoriousbij »

The pistons are made for 5.5 rods. The pin is higher and 22mm, putting the deck at 0. I could mock it up with the cam I have and see where it lands with 1.25 rockers and solid type 4 lifters. With .500" valve lift, piston clearance is also an important consideration for sure.
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