Cams How do you choose one?

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j par said:
Good gravy I had to erase a bunch to just quote this much LOL
I'd love to hear about your getting into snowmobiles? I have a thread on the general discussion snowmobile Blues...
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Hey jpar..... I like to give readers value for their money in my posts LOL.

As for the snowmobiles, well business has been REALLY good for 3 years , but we have taken very little time off. Snowmobiles have always been fascinating, and playing in winter snow, and there was this pile of $$ lying there after a particularly big project. So I decided that part of the 2107 bonus was going to be snowmobiles for my son and myself. Then we could go and have some relaxing and healthy outdoor fun in winter, when our work is typically a bit slower. And it gets us out in the same territory of our love in car racing, which is rallying, which takes place on roads in the same types of remote areas.

Nothing spectacular.... low end Ski-Doo 4 strokes for both of us. Towed out to Togwotee pass last winter and then to the Big Horns and then Yellowstone. Learned the value of a long track in some really virgin loose powder LOL. This coming season, we are looking to head to New Brunswick.

Yeah, I have seen your snowmobile posts here and there. Very cool. I'll venture over to the General forum ad see what mischief you are creating now LOL. I read and post a very little on the Doo-Talk General forum.
 
Hi just to finish this off to much work no play till now lol, so to end this I did call Oregon and got
262/270. 218/226. .441/.449. 110/106. ICA 57 Ol 46
256/268. 212/218 .447/.455. 110/106. ICA 54. Ol 42
Then the last one lol racer brown well thanks 66fs after talking to Jim a bunch of times and questions I know a lot more now than when I started this but still a rookie and I know if I would of asked any of the cam grinders they would of helped me . Everyone that has suggested a cam has been right some a little better than others for my exact needs. But none have been to wrong , the funny thing after talking to Jim and talking about one motor with compression he came up with 9.7 scr and 8.27 dcr vp 142 with 215-220 @.050 close to AJ’s lol a little different on the cam for Jim. So I did Ordered a cam from racer brown for my current motor and a Howard cam for my 273 to rebuild (original motor for the cuda) and then when ready for the higher compression 360 I”ll go with probably another racer brown cam they are not that much more. The first post under mine by Valiant Racing almost hit it on the nose 214/ 477. Lol Thanks a lot no one gave me bad advice and I know this question has been asked 1000+ times so to those that try to help me Thanks for answering that same old question where’s the beer lol no what cam to buy. Lol on to the questions gary
 
It also helps to ask the manufacturer which engine in the family they are basing there descriptions on. Comp Cams bases their LA cam descriptions on a 360. That same cam will act MUCH differently in a 318 or 273.
 
I just like to mention that just because the cam card says to put the cam in at 106, doesn't mean that, that is absolutely the best place to install it at.
Take this cam for instance;
256/268. 212/218 .447/.455. 110/106. ICA 54. Ol 42
With headers that 106 is a reasonable number because the Effective overlap will be 40*
But with log manifolds, the overlap will not be effective so then; is there a better install?
Well the 256 to 268 split gives you a lotta freedom to move it around.
So if your cylinder pressure is low, then you can close the intake sooner and trap some extra cylinder pressure. Say you put it in at 102 for an Ica of 50*, and pick up 6psi, good deal. The downside is you lose that same 4* on the powerstroke, and so the fuel mileage may suffer.
Or say you have a lot of pressure and would like to pump up the mpgs. In this case you could install that cam at 114 for an Ica of 62*. This would move the power peak up some, kill some pressure and increase the power extraction to 8* over what it was, when installed at 106 . Maybe it works and maybe the loss of pressure makes it a draw.
The point is that a 12* split can be a good tuning tool with log manifolds.
But I wouldn't run it with headers, unless the heads really need the exhaust help, cuz it could sacrifice too much fuel economy if you advance it too far.
That cam will probably like 106 with headers; but with logs,could probably be installed pretty much anywhere between 102 and 112, depending on your cylinder pressure/compression ratio, and need for fuel-economy.
Jus saying
 
In a nut shell.....

You can move it around to experiment with how the cam acts rpm wise and with torque and hp output with varying cylinder pressure levels with the changed timing events.

This could led to more torque for a quicker off the line feel or more top end.

Have fun and experiment!!!
Get out there & tinker!!!!!!
 
This is the one single pattern he said do not want more duration on exhaust I don’t have enough compression or high enough rpms to use more ,if I did increase the exhaust it would severely hurt torque, this one he called seat of your pants power lda 108 cl 105 this is a mopar lobe so fast open and a little slower on the close and did offer one other cam 220 lift of .450 and lda 110 a will live with some drivability issues

F04DE420-A94F-4598-B4DF-3DF9F2F6FFA7.jpeg
 
from above
,if I did increase the exhaust it would severely hurt torque,
, cuz it could sacrifice too much fuel economy if you advance it too far.
The downside is you lose that same 4* on the powerstroke, and so the fuel mileage may suffer.

pitfalls to advancing the cam-
like trying to make a stock 360 cam work in a 273, or a 340 cam work in a low compression motor
more heat in the exhaust also
same with spreading the lobe centers out, decreasing overlap but closing intake later and opening exhaust earlier
that's why you have to watch both your intake and exhaust duration and your lobe centers at the same time
another reason to use a shorter duration cam is that you can have dynamic compression AND a full power stroke
remember DC and Racer Brown use .008 for advertised (DC almost) and Crane uses.004
 
Yes he did reasons are increased torque,build higher cylinder pressure which increases effective and cranking compression 108 lsa in at 105 .
 
When you just can’t make that final decision....... tear out the page in the catalog that has the cams you’re interested in and pin it to the wall.

Standing at the correct competition distance from the wall...... let the three Darts make the decision for you.

If you don’t have any darts handy....... in a pinch, I’ve used a Ouija board.
 
PRH said:
When you just can’t make that final decision....... tear out the page in the catalog that has the cams you’re interested in and pin it to the wall.

Standing at the correct competition distance from the wall...... let the three Darts make the decision for you.

If you don’t have any darts handy....... in a pinch, I’ve used a Ouija board.
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I like the custom grind approach myself... I needed a hyd. roller cam for my 5.9 Magnum build but due to the high altitude and somewhat low compression (9:1 with AL heads) I felt like choosing an off-the-shelf grind would let me down in some aspect. I called Jim at Racer Brown and he custom-ground me a cam that works fantastic. Pulls hard to 6000 RPM yet still has enough grunt to get my Duster moving with 2.94 gears (3.55s are a high priority now) and has a nice-sounding choppy idle. I will probably hit him up again for any engine builds I do in the future unless it's some low-dollar thrown-together combo from spare parts.
 
Wyrmrider said:
so what specs did Jim come up with?
what's your cranking compression
help us learn something
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Good question I haven't checked cranking compression yet. I have the cam specs in a folder of all my build stuff I'll post it up in a bit.
 
Here's the cam card. I think I'll check cranking compression sometime in the next few days or this weekend.

20190625_175022.jpg
 
Thanks R&D
for those following:
Racer specs advertised at .008 so for those who want to compare with the Xe274hl (.006) comp this s more like a 280 comp or 285 Crane
as opposed to some grinders Jim seems to give all the info you need and I'd bet he'd give the seat timing for DCR calk if you asked
another note
notice that even if the exhaust is longer the lift is less showing RB is using a different series of masters for his exhaust instead of just taking then next bigger lobe down the list
this also makes it easier to set up your springs
 
MopaR&D said:
Here's the cam card. I think I'll check cranking compression sometime in the next few days or this weekend.

View attachment 1715355169
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I looked up a few of our master here at Crower to compare to them. The intake is very fast that lobe lift is 0.356" with 222 at 0.050" so make sure the spring pressures on the seat are correct. If I were to use this master I would tell you 150# seat and 360# over the nose. The exhaust is a much slower ramp. Should make good power and might make a little tick noise when hot because of how fast the intake is. Just my two cents.
 
dart19666 said:
I looked up a few of our master here at Crower to compare to them. The intake is very fast that lobe lift is 0.356" with 222 at 0.050" so make sure the spring pressures on the seat are correct. If I were to use this master I would tell you 150# seat and 360# over the nose. The exhaust is a much slower ramp. Should make good power and might make a little tick noise when hot because of how fast the intake is. Just my two cents.
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Good advice thanks, I actually gave the cam and spring specs to the machine shop that did my heads so they purchased and installed the correct springs for the application. Not sure the exact part number of the springs but they are dual with a damper.

Regarding the noise it's actually surprisingly quiet. I read on Hughes Engines site that factory Magnum hydraulic roller lifters like .080-.095" of preload (quite a bit more than HFT's), they'll run fine with less but they'll be noisy. So I spec'd my pushrods for about .090" preload and there's basically no valvetrain noise. Certainly less than my previous 360 that had a small Lunati Voodoo HFT cam.

It does make excellent power, I really need some 3.55s in place of my current 2.94 gears because this thing pulls hard to 6000+ RPM and with my current trans/rear gears I can hit almost 70 MPH in first gear lol. No valve float or other weird stuff at the higher revs too, though again I don't get many chances to really rev it up because of the tall gearing. It has enough low-end and mid-range torque I usually shift around 4500 RPM when I'm getting on it around town and that's enough to pass anything. Normal driving it rarely goes over 2500 RPM and smooths out as soon as it gets above idle. Really quite impressive IMO considering the low air density and modest (9:1) compression. Racer Brown FTW!

Here's a video I took yesterday of it running to get an idea of the sound:
 
MopaR&D said:
Good advice thanks, I actually gave the cam and spring specs to the machine shop that did my heads so they purchased and installed the correct springs for the application. Not sure the exact part number of the springs but they are dual with a damper.

Regarding the noise it's actually surprisingly quiet. I read on Hughes Engines site that factory Magnum hydraulic roller lifters like .080-.095" of preload (quite a bit more than HFT's), they'll run fine with less but they'll be noisy. So I spec'd my pushrods for about .090" preload and there's basically no valvetrain noise. Certainly less than my previous 360 that had a small Lunati Voodoo HFT cam.

It does make excellent power, I really need some 3.55s in place of my current 2.94 gears because this thing pulls hard to 6000+ RPM and with my current trans/rear gears I can hit almost 70 MPH in first gear lol. No valve float or other weird stuff at the higher revs too, though again I don't get many chances to really rev it up because of the tall gearing. It has enough low-end and mid-range torque I usually shift around 4500 RPM when I'm getting on it around town and that's enough to pass anything. Normal driving it rarely goes over 2500 RPM and smooths out as soon as it gets above idle. Really quite impressive IMO considering the low air density and modest (9:1) compression. Racer Brown FTW!

Here's a video I took yesterday of it running to get an idea of the sound:
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Sounds great and it has good street manners. Yes you need some 3:55's (or more). That will make that car come alive.
 
HFT not HR right
DART-thanks for posting in
you guys wanting a cam put Dart and Crower on your short list
 
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