Im building my first motor and I need help choosing a good head for my application.
sbc 350 4 bolt
stock bottom
using a Doug Herbert hydraulic flat tippet cam kit (cam & lifters)
RPM Range: 2800-6200
Advertised Duration: 285/290
Duration @ .050: 230/235
Lift: .480/.494
Lobe Center: 106c
edelbrock performance intake
4 barrel carb around 700cfm
double roller timing chain
around 9:1 compression pump gas of course
car wont be on the race track just driven during the summer as a street car. looking for around 4-450 hp
appreciate the help and comments.

 

Any aftermarket head between 180-200cc runners 64cc chambers. Edelbrock, trickflow, dart, etc.

 

Budget? Hard to beat dart shp 200's or jegs/pro-filer 195's

 

Budget is about $5-800.

 

You may need to find some good used heads then. Just dont go over 200cc runner. On a mild 350 I like the 180cc.

 

Expand that to 465$ each head and you can get the shp heads. Bout as cheap as you can get and still get a 450 hp head. Else get vortecs and settle for 400 hp or so

 

That's a very aggressive cam. Unless you're running open headers you wont benefit from lobe centers that tight.

 

its not a strip car so no open headers, hedman headers through dual exhaust

 

Then that cam is right for your application.

 

OOPS! ISN'T....

 

shps I found were a bit out of my budget, around 1000 used. what about iron eagle, sportsman II, s/r torquer, etc

 

which head would you prefer with that cam?, my dad is pushing me towards the iron eagles. He chose the cam for future reference of me rebuilding the bottom end.

 

I like the dart 200 in iron or aluminum but that cam does not like any kind of exhaust backpressure. I would look into a lobe center of 110+.

 

That cam just isnt gonna be happy in a stock head. If you cant get decent 200cc heads, you need to step down to stock heads (vortec or something) and get a milder cam. Maybe an XR276 unless you're hellbent on flat tappet.

 

SHP are 930 brand new? If you found them for 1000 used then they either have been modded with high quality parts or its a rip off scammer.

 

Any way to ease that back pressure? like large headers and exhaust 2.5 to 3 inches. I know excess back pressure increases wear on the motor and can damage cam etc

 

That tight lsa is going to give a rough idle. You wont have much vacuum for power brakes. Will want a canister for backup. But with dual 2.5 exhaust it will be fine. Just not optimal. A good set of heads doesnt really need that tight lsa and with duration that high it should also have smaller chambers for more compression.

 

I can live with a rough idle as long as the motor isnt damaged, I would hate to return the cam and shell out more money on a hyd roller when I don't necessarily have to.

 

This is generally a VERY bad idea. Don't do this when it comes to putting a motor together or you'll be kicking yourself in the *** AND wasting money doing it. Build everything as a unit to work together, or just don't do it at all. Putting things together "for later" will just create a sloppy, mismatched engine.

 

A 180cc intake port is about optimal for most carbureted street applications.

Keep in mind that the better the head flows, the less cam you will need to get the cylinders filled.

 

You need to take a step back from your parts list and re-evaluate what you want and what parts it will take to get there and do a little more research on how to make this stuff happen.

backpressure will not "damage a cam". I presume there's probably some bizarre scenario that could somehow result in that if you come up with something convoluted enough, but theres no direct relationship.

You are probably thinking about valve spring pressure that will damage a cam. More aggressive cams need stronger valve springs to control them, but springs that are too aggressive can damage a cam and lifters.

Anyway, minimizing back pressure is all about performance and maybe gas mileage, but on the whole backpressure is irrelevant. You want a balance between exhaust velocity and flow. Too small of pipes will give you high velocity but choke power, too large of pipes will slow down the exhaust a lot. You have to tune an exhaust to your particular engine. In most cases doing that perfectly requires years of research and very, very specific implementations that just arent practical in the real world for a street car with limited ground clearance. Most people just stick to general rules of thumb when it comes to exhaust. A single 3 inch pipe can support something like 400p if I remember right.

Like I said, you need to evaluate your budget and your power goals and then rebalance them. A cam that large in a street car with factory castings is going to make for a terrible performer. It might be quick, but your RPM range will be very, very limited where it works. The thing is that cam is more than doable with some quality aftermarket heads. Would make a great car, but factory castings just arent going to work at high RPMs the way that cam will. Factory castings, by their nature, tend to be designed to work well at lower RPM ranges. I'd go with an xe268 if you're stuck using factory 350 castings. Anything that ISNT 113, 083, 906, or 062 is going to be pretty crap with a few rare exceptions unless you have an EXTREMELY qualified PROFESSIONAL porting them for you, which will probably end up costing more than the aftermarket heads to begin with. Also, those heads are only good compared to other factory heads.

 

my put that cam on the shelf till the mentioned future rebuild and call about this
https://www.thirdgen.org/forums/engi...oller-cam.html