Camshaft regrinding /6

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superdart426

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Need to get a cam reground anyone know of a good company to do it??? I thought oregon cams but can't find any cam profiles on their site unless i'm looking at the wrong site,,,any help appreciated..sd426
 
street motor,, the pistons are turbo's so they are dished prob 9.5 comp not sure rustyratrod,,rob showed me a chart and there was a grind on it that was great for my build,,but I can't find the chart,,
 
superdart426 said:
street motor,, the pistons are turbo's so they are dished prob 9.5 comp not sure rustyratrod,,rob showed me a chart and there was a grind on it that was great for my build,,but I can't find the chart,,
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i would be around 220- 230 * .050, 110 or 108 LSA with as much lift as they can give you!
 
280 is not a good choice for a slant 6 cam. Because of the small valves and long stroke the engine likes a narrow LSA (around 106). The 280 cam has a really wide LSA and slow ramps (low lift with lots of duration). Honestly it doesn't look much better than a stock cam. What springs/valves are your running? Stock?

#791 would make a good choice, if tightened up to 106 LSA. If you can use that much lift, of course.

#346 is one used by many people.

I am having a custom grind done by Delta cams with a bit more lift and timing on the intake but with the same exhaust lobes as the Oregon 791 cam.
 
Try Crower Cams. Dave Crower made a nice cam for my ex's 64 Dart.
 
Schneider Cams. They are not technically listed (as far as specific grinds) anymore but I contacted less than a month ago. They told me $200 plus shipping.
 
To say "slants like a narrow LSA" as a blanket statement is simply not true. They are a piston driven, 2 valve per cylinder engine, just like the rest, and respond to cam changes in the same way. There's nothing special and there's no voodoo black magic that makes a slant react differently to camshafts than other engines. It's simply not true.

The reason people say that...and it IS true in this instance, is because the slant has dismal compression in stock form. So, it needs every bit of help it can get to get cylinder pressure up and a narrow LSA is a good way to do it.

No one has asked the OP what he's running, what it's going in, what transmission he's going to use or gears. So, any recommendations at this point are worthless.

All of this is going in an early A. 225, 4 speed OD with 3.55 gears. "I" recommended grind number 280 BECAUSE of the wider LSA. It will increase bottom end torque and flatten the torque curve....at the VERY small expense of high RPM torque, which he is not concerned about anyway. It will also have much better idle characteristics and pull a nice vacuum signal in case he wants to run power brakes. This is after all, a street car 100%.

Since he does not have an automatic, there is no torque multiplier. A narrow LSA will drop bottom end torque off some and IMO he will be better off with the wider LSA since he is running a 4 speed with 3.55 gears. The 112 LSA will respond off the line better with a manual transmission and 3.55 gears. Were he to run a 4.10 gear, it might not be too critical, but again, this is a street car, 100%.

He's already got a modified head and will be milling it to get the compression up, so cylinder pressure will not be an issue. With the 112 LSA, he will have good street manners and it will pull better in high gear since he is planning on running a 4 speed OD.

Bob, we've talked about this and I have built this engine theoretically for you probably 50 or more times. Run what you want. It's your car. But very narrow lobe centers are geared more towards race engines and will not provide the good vacuum signal, street manners or the good pull in OD that a wider LSA will. It just won't happen.

While it is true, all things equal, a narrow LSA will have a higher peak torque and horse power number than the wider one, the wider one will have more bottom end torque and a MUCH flatter torque curve at the expense of losing a little top end power. That's a great trade off in my book for a good street engine. Ok, yall carry on. I am out.
 
Thanks. Maybe so, but I'm sure there'll be some argument. lol
 
Thanks rob,,i'm ready to get it ground and really wanted to hear from you as you really know my build,,,thanks for the response,,,and thanks to 805moparkid for help in finding the chart that i couldn't find,,and also to the others for their input...sd426
 
Just to clear up the misinformation - a tighter LSA LOWERS (low-rpm) cylinder pressure because the intake closing point is later (advanced) compared to a wider LSA.

I.E. if you have two cams with identical intake lobes and one has an intake cl of 106 and the other is 104, the one with the 104 cl will close the valve 2 degrees later, which reduces the effective stroke on the compression cycle. Same thing happens when you advance the cam. (except with a tigher LSA you also increase overlap)

In theory it will increase high-rpm cylinder pressure due to the extra scavenging from the increased overlap but a slant won't rev high enough for that to happen.

One reason people use narrow LSAs in slant six engines is because they can then use a higher-than-normal compression ratio to boost low and midrange power.

Most guys running tight LSA cams are also running them quite advanced, to accentuate that aspect.

You need to work backwards from your compression ratio to arrive at a good intake closing point for the right dynamic compression ratio.

Ideal LSA can be estimated by the ratio of intake valve diameter to cylinder displacement.

Pick duration based on your rpm range (or based on the amount of overlap you want/can tolerate)

Get as much lift as you can within that duration.

Check this out:
http://www.popularhotrodding.com/tech/0607phr_camshaft_basics/


I have played with a lot of engines over the years, and the things that people are doing with the slant are very strange to me too. But the slant's very undersquare bore/stroke ratio and poor breathing potential require a unique approach.
 
robertob said:
I have played with a lot of engines over the years, and the things that people are doing with the slant are very strange to me too. But the slant's very undersquare bore/stroke ratio and poor breathing potential require a unique approach.
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I go along with that, but it don't require an approach that's SLAM backwards from other engines. And that's what people seem to be doing......or talking about at least. Oh, and don't tell Mark Etheridge a slant won't rev! lol
 
You can, but for what you're doin you'll never know the difference.
 
What kind of fuel do you want to run? (I recommend 91+ octane, since the price difference isn't much at the pum)

What pistons are you using? (i.e. how much CR can you get with them)

What valvesprings/valves/head? (i.e. how much valve lift & flow can you use)

What intake/exhaust will the motor have?

Do you care about idle quality? Are you using a stock converter?

If we know those things we can recommend a cam.

We already know it's going in an early a-body, so light car.
 
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