I'm getting a new cam soon, similar to the one I have now. 221/226 .566/.562 my new cam will have less exhaust too. Friends have recommended to me that I need a cam with more exhaust lift then intake or the same lift intake & exhaust.
I'm not breaking records with the cam I have now, but from what I've heard and seen it has done good.
The cam I have now. The exhaust opens 54.1BBDC & closes -4.7ATDC. What does this mean?
I've been told no reason to lift it more then what it can flow.
I've also been told the more exhaust lift the better it will flow.

I would like for someone too break all this down & put it in dummy terms so I can understand..

 

Overlap:
While valve duration is the amount of time a valve remains off its seat, overlap is a measurement of time that the intake and exhaust valves in the same cylinder are both open simultaneously. This overlapping of the valves is required to take advantage of an engine's maximum potential but comes with a few disadvantages. The first drawback: When a cylinder fires during its combustion stoke, both valves are closed in order to contain compression. However, to maximize exhaust potential, an engine builder may use a camshaft that opens the exhaust valve before the piston reaches bottom dead center (BDC) and closes slightly after the exhaust stroke passes TDC during the early induction cycle. The benefit here is a well-scavenged exhaust stroke but it comes at the expense of some bled-off cylinder pressure and a slightly contaminated intake charge. Along with a disturbed intake charge, the engine's vacuum signal is weakened because the piston's vacuum is not only drawing its intake charge from the induction system, it's also pulling dirty air from the open exhaust valve. This weakened air signal raises emissions and lowers idle engine vacuum, which plays a major role in the operation of engine-driven accessories. Along with the previously mentioned problems, excessive overlap also creates a weak torque curve, as the induction system is not functioning at its maximum potential when the cylinder is not being filled properly. In this case, low- and mid-speed torque are traded for peaky upper-end horsepower.
This answered my question.

Does a cam with more exhaust lift have a higher overlap?
Are can someone with a full cam spec sheet post there BBDC & ATDC..

 

Make sure difference is worth changing. If cams are similar they will give similar results.

 

Same design I should of said. New cam is 228/233 .595/.578

 

No, you get more overlap by increasing duration and tightening up the LSA (simply put)

 

What are your other mods? I'm sure someone on here has had success with a cam with mods similar to yours.

 

Lq4,243's milled .042,87mm tb,nnbs intake (hasn't been to the track with new intake & tb),obx lts,42lb inj,k&n cai,3200 stall,dual cutouts,4:30 gear,221/226 .566/.562 114+1. 4885 race weight.

 

I like those specs, who's grind is it and what's the LSA? I'd have the converter restalled to 3600-3800 as that cam will have a higher powerband than your current one...

 

It's a 113 + 4. Cam motion, Same folks as my current cam.. I got some trust in them.. Cam is spec'd for my current setup.. Not doing anything new, but you built trans & converter.

 

I lie new headers too. Maybe some p&p's heads later.. I like to compare the gains from each upgrade, but having problems with getting it back on the same dyno's..