cam choices

[60ratrod]

so here i am wondering which cam will suit my 307 the best. i know that the 1st question that you guys are gonna ask is what do i want?? well here's my answer to that. what i am looking for in a cam is great gas milage, but not stock. just a little bump up in power is all i am looking for. another question that i have is how hard is it to convert my cam and lifters to roller cam and lifters?? what all do i need to do to it?? any machining involved, or can i just throw and go??

[manimal]

if you convert your cam to hydraulic roller, the lifters alone will cost over $400. I would say for your 307 go with a CompCams Xtreme 4x4 cam,a small one. They have the bottom end needed for these trucks. Put an aluminum dual plane intake and 500 cfm 4bbl carb on and you'll be happy.JMO
-Lance

[70cst]

If you are doing this just for better milage it may not be a good return on your $$$ unless you drive a lot. You look at what your present mpg verses what improvement will be gained...then look at total cost to make the engine mods. I will be spending $$$ to have my 402 rebuilt this winter plus I will likely install a Gear Vendor unit. I realize I will never see a positive return on my expenses but I am doing it so I can have fun when I do go out for a drive. I am not sure any of our V8's get really good mpg? I might be wrong. Sounds like you have a nice project and your truck will be fun (more fun) to drive once you get your upgrades completed. Good Luck.

[geoman]

Try the crane energizer series. They come with lifters, make good power, quality, and inexpensive.

It is not worth converting over the 307. I would start with a 87 and up 350 roller block, plus as mentioned above, the costs are much more.

The 307 is a good engine. Great torque which is what is needed for these trucks, just not a powerhouse. Keep and play with the 307 until the time comes if/when you are ready to step up to a different engine.

Good luck!

[Billla]

What do you have for carb, intake manifold, exhaust and gears? Better recommendation can come from more information

The stock cam is the the very common GM "390" or "929" cam, known by those numbers either by the intake lift (.390) or the GM P/N 3896929. This cam was pretty much the common base engine cam for the SBC from 1965-1972, and is still available today under CompCams P/N 12-105-3

As a low-end torque cam, it's pretty good - and for a 307 w/9:1 CR, moving to a significantly larger cam is likely to hurt low-end torque to provide top-end power...probably not what you're looking. I agree completely with manimal - the CompCams Xtreme 4x4 XE250H (P/N 12-231-2) is about as far as I would go...and there only if you've already installed headers. I'd probably skip the intake and carb (although the carb size of 500 CFM is right on) unless you're turning above 5500 RPM.

[Slammed70]

If I were you, I would run into an Autozone or your local O'Reilly and pick up the "performance" cam that they usually have in stock. Its either a Comp or a Crane depending on where you go. Its a modest cam at around .454 lift, I forget the duration but its healthy. And its small enough to fit the stockest of engines....it can even be ran on Vortec heads with out a problem.

Its around $130 last time I checked, it comes with the cam(obviously), new lifters, assembly lube, and cool stickers to 'purty up your tool box with afterwards.

[Billla]

One note on general performance cams vs. "RV" or 4x4 cams is that typically the general performance cams will focus more on mid- and top-end power vs. low-end torque (overlap/ground-in advance)...and torque is where the money's at for our trucks.

As a generalization, this isn't always true - but it's worth taking a look at.

.450 lift or so is definitely as far as you want to go on stock springs for lift...

[Slammed70]

Originally Posted by Billla

.450 lift or so is definitely as far as you want to go on stock springs for lift...

For a Vortec maybe, Ive ran .490-.500 with out coil bind on stock SBC heads.

[60ratrod]

ok so you guys are wanting to know that i have done so far so here it is. i have an edelbrock 1405 carb that i "borrowed" from my 60(aka problem child), an edelbrock 2101 performer intake that i got from the junkyard at a grand total of $30, an hei distributor, internally regulated alternator, and flowtech headers cause they were cheeper than buying one replacement manifold. and yes this truck is pretty much my DD(daily driver). i'm just looking for opinions. i actually used the crane energizer 272H grind cam in my 60's 350 so i am no stranger to the crane line of cams. but i would like to know what it would take to get a roller cam to fit into one of these blocks. just one of those curiosity things you know

[manimal]

A roller cam will fit. BUT the rest of the set-up will cost BIG $$$$! If you go hydraulic roller, you can expect topay from 350-425 for just the lifters. Cams are from 150-400, then you'll have to get new pushrods. And while you're at it you're gonna have to change over the springs. So while you have the heads torn down,you might as well install screw in studs and guide plates. Then to get the maximum benefit of the roller set up might as well install full roller rockers. It just starts to snow ball as soon as you start messin with this stuff. You DON'T have to put all those things in,but to take advantage of it you might as well.
Just stick with a flat tappet unless you are building one hell of a motor or late model block.JMO
And sorry for the long post.
-Lance

[Billla]

Originally Posted by Slammed70

For a Vortec maybe, Ive ran .490-.500 with out coil bind on stock SBC heads.

Then you've been lucky, or the heads have aftermarket springs and PC seals. I've seen enough broken springs, etc. from coil bind to stand by that recommendation.

Not disagreeing with you - we've just had different experiences.

[pocoloco71]

thhttp://www.superchevy.com/technical/engines_drivetrain/cams_heads_valvetrain/sucp_0604_chevy_engine_performance/index.htmlis may or may not help, but it is and interesting article about 307 build

[geoman]

Originally Posted by pocoloco71

thhttp://www.superchevy.com/technical/engines_drivetrain/cams_heads_valvetrain/sucp_0604_chevy_engine_performance/index.htmlis may or may not help, but it is and interesting article about 307 build

I read that same article and it was a good one. I would suggest rerading it as well. To convert to a haudraulic roller, you are going to pay ALOT of money. Lifters, cam, rockers, pushrods, etc. are not cheap compared to stocker type stuff.

[airdale94]

I always like to go with the the lowest RPM band. With good flowing exhaust, carb., and compression. I think they make the best power for street. Especially with a big block. The big cams are fun. But to get into the power band the only place thats really good is the track.

[streetstar]

any one of the "RV" type cams will work good - and manimals suggestions are excellent. The problem with putting regular performance cams into a truck with a 307 (if the bottom end is stock) is the low compression these motors had - the low compression almost fights against the capabilities of the big cam and makes the engine feel doggy until it gets to maybe a 500 5pm spread at 4 - 4500 rpm -- after that the size of the valves cant keep up with what the cam wants to do and the motor falls flat.

The motor will do anything any other small block will with the right heads and pistons , but high performance pistons for the 307 are not very cost effective and most people just say "heck with it" , and build a 350 or 350 based stroker.
But as i said in another post, the 307 is one of those underrated engines that works great on the street if properly tuned, but poor on the dyno

[60ratrod]

hey the 307 build link didn't work. i was just curious as to what it would take is all as far as machine work.

[lpaine]

I think it's a myth that converting to a roller cam/lifter setup is expensive; there is a guy selling the info on how to do this on ebay,and apparently you can use stock used parts readily availble on ebay. Lifters, spider, retainers, and sometimes cams can be bought as a package-something to consider in this age of low zinc oils which can wreak havoc on hydraulic lifters. I'm guessing it might cost around $300 for the parts, more if you have to upgrade the valve springs.

[Billla]

Factory SBC rollers require cast bosses in the cam valley to mount the spider and provisions on the front of the block for a cam retainer; these are in place for '87 up factory blocks or new GMPP blocks. This is definitely the cheapest way to go - but if the block isn't machined for it then a retrofit kit is required. Note that the stock hydraulic rollers are lift-limited to around .525.

Primary cost when retrofitting are the lifters which require a connector bar to keep them from rotating. Valve spring upgrades are absolutely required with a hydraulic roller; seat pressure and open pressure are significantly higher - typically seat pressure over about 100# requires screw-in studs - and just about every roller spring will be 120# or better seat pressure and 400# open pressure.

Bottom line is that - as everyone who has done one will attest to - this is a fairly expensive upgrade by the time all components are in place.

[1bad chevy]

put a set of 882 heads with a 1.94 / 1.5 valves and one of these cam's http://store.summitracing.com/partde...3&autoview=sku or this is what i would use put it a 355 and man did it run good all kind's of power for your truck http://store.summitracing.com/partde...3&autoview=sku

[Billla]

I think what we're struggling with here is a) spending money on an engine with 43 less CID means you're spending the same amount you'd spend on a 350 (or 383) to make less power and b) rollers, heads, etc. are all about getting more air into the engine...and with 307 CID and 9:0 CR your engine can't use it. A mild cam swap is about the only route that makes sense IMHO.

[60ratrod]

hey i wasn't considdering the roller swap as one of my options. just wondering what i took. but the 307 should be running a 9:1 ratio?? i have a set of 882's on my other truck that has a 350 and they are leaving me with a little to be desired. eventually with the 350 in my project truck i'm gonna upgrade it with 64cc heads since the 882's are 76cc heads. but thanks for your guys imput. i think when i get around to it i am going to put in a mild rv cam.

[ChevLoRay]

Anybody running one of the Thump'r cams from Cam Dynamics? I'd sure be interested in how they like it....like in a 350?