Camshaft selection

**Xenon** · 10-07-2013

There are many people that claim to be experts on camshafts, some are and some are not.

you guys all seem to be very knowledgable so I thought I'd ask you.

My 406, I've been told by mark has a somewhat aggressive cam. I'm starting to think I may have been built to be a circle track engine or something, as it lacks power until higher rpms.

Wanting to change cams, but I don't know much about them honestly. I'm thinking maybe an RV type cam? It's in a 6500lb suburban, 3.73 gears and a th400, soon to be th700r4. So looking for really good low end torque, not worried about much over 3600.

What would your suggestions be? Thanks.

**EagleMark** · 10-07-2013

Originally Posted by Xenon

What would your suggestions be? Thanks.

Keep the Turbo 400?

Most stock cams can be considered an RV cam. Power from idle up. So don't get stock on a name, RV cams are sometimes so close to stock it does not matter. That said I'm not the cam guy, I can tune any cam you put in! But I can't change... much... the cam if it starts to work at 1500 RPM. If it starts at 1500 RPM and you have an auto trans? Well you should also have a higher stall converter! Which would also solve your issue right now. But this ends up running higher RPM always and does nothing but hurt fuel milage. Works great for going fast!

One of the cam guys/engine builders will jump in. My quick recommendation is cam recommendations that state idle to ? RPM! Not 1000 or 1500 RPM up to ? RPM. What does the cam you have say?

**Xenon** · 10-07-2013

Well I don't exactly know. I bought the engine with 0 miles on the rebuild but it had changed hands a few times since it had been rebuilt. But in tuning you said that if everything was in good condition, which it is, the low vacuum would indicate a more aggressive cam. Which makes sense.

I just want good low end torque, good drivability, and good fuel economy.

Id keep he th400 if it had overdrive, that's the only reason im leaning towards a 700r4 swap.

**EagleMark** · 10-07-2013

Originally Posted by Xenon

Id keep he th400 if it had overdrive, that's the only reason im leaning towards a 700r4 swap.

Better build it to handle the BB or it will be short lived.

Originally Posted by Xenon

Well I don't exactly know. I bought the engine with 0 miles on the rebuild but it had changed hands a few times since it had been rebuilt. But in tuning you said that if everything was in good condition, which it is, the low vacuum would indicate a more aggressive cam. Which makes sense.

I just want good low end torque, good drivability, and good fuel economy.

You can have all that in a BB Suburban except the fuel economy...

So I take it your burb is kind of blah/dead until you rev it to higher RPM then it has loads of power?

**Xenon** · 10-07-2013

Pretty much. After 2500 it just flys, but its mediocre off the line. It's not a really built engine or anything, just 8.6:1 cr but it should do better than this I think.