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  #31 (permalink)  
Old 11-02-2012, 04:14 PM
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Quote:
Originally Posted by rube'68'03 View Post
Ok, so i found a set of 416's for 25$. Couldnt help myself. Im going to take it in for testing and cleaning and thought of getting all new valves. What is the suggested valvles, and with what cam/lifters. Im planning on getting steel tip roller rockers and replacing the lifters.
Roller tips without roller trunnions are a joke. Save your money for some real parts. Have the heads magnafluxed for cracks. If they're cracked, smash 'em with a sledgehammer so that nobody else will get screwed on purchasing them. Competition Products has a "kit" of valves, springs, retainers, keepers and seals to fill a cylinder head. Call 'em up and talk to 'em. You'll need to know the static compression ratio of the motor before you can purchase a cam. You'll need to know what cam you're going to use before you can buy springs.
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  #32 (permalink)  
Old 11-02-2012, 04:20 PM
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If you are going to upgrade the valves and port your heads to increase performance,

get some 1.94x 1.50 valves. These heads work well when fully home ported.
here is an example of a 305 build up using the those heads. it makes 343HP.
http://www.hioutput.com/tech/343hp/343hp.html

This lil motor with the Lunati 224deg Hyd cam likes to rev.
Yours will too, if you build it similar and want performance.

Pick a converter stall and gears accordingly : this motor wants a 3000++ stall and gears 4.10+ to run.
Advertized stall will get you about 500 less stall behind a 305- 307 .
a 10" "3500 stall gets you about a 3000 real stall..
If you are going to install on a stock 307 short block use a thin felrpo 1094 head gasket to max the compression ratio, for the cam choice. ya it matters. 10:1 is where you want to be for a motor like this (92 octane).

Last edited by F-BIRD'88; 11-02-2012 at 04:28 PM.
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  #33 (permalink)  
Old 11-02-2012, 04:26 PM
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A 307 makes for a really good little motor to supercharge with a 142 weiand blower.
You can use open chamber 76cc heads on it to get the desired low compression ratio

EG 441. 920 chevy smog era castings w 1.94 x 1.50 valves, these like home porting too. (it is the same job as port 305 heads)
to alllow lots of blower boost on pump gas. These motors make impressive power when supercharged.
Use a cam with a wide LSA 112 114deg.
A eg: for a blower cam would be a Lunati 401A3LUN (solid) or a Crane H-278-2 (hyd)
You will slay your fair share of 383's with a 142 blown 307.

you want a blower friendly compression of 7.5 to 8.5:1 low cr allows lots of boost.

Again don;t be shy with the gears and converter.. these lil motors like to rev, when hotrodded. Just like a 283 or 302.

drill and roll pin the rocker studs on your heads.

Last edited by F-BIRD'88; 11-02-2012 at 04:37 PM.
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  #34 (permalink)  
Old 11-02-2012, 04:39 PM
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F-Bird: As muh as i would like to get the old thing supercharged, its currently not in my budget. I will be taking your advice and getting the heads porter and the 1.94x 1.50 valves. The cam though, what kind of lifters/rockers should i look into?
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  #35 (permalink)  
Old 11-02-2012, 04:59 PM
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Quote:
Originally Posted by rube'68'03 View Post
F-Bird: As muh as i would like to get the old thing supercharged, its currently not in my budget. I will be taking your advice and getting the heads porter and the 1.94x 1.50 valves. The cam though, what kind of lifters/rockers should i look into?
if you have to pay someone to port these heads, its not really worth it.
Its a DIY thing on these and most stock factory SBC heads.
Porting labour costs money. it's labour-time intensive.
Port them yourself, first, then get and pay for the machining done. (new valve job etc) Don;t be shy with the porting. They need a good work over.

Use stock type long slot rockers. A hyd flat tappet cam and lifters is fine. stock diameter springs are fine EG lunati 73943.
When the machinist machines for aftermaket valve seals, get him to shorten the guide boss for high lift and the seals.
shorten the boss by .200" with the .530" -.550" aftermarket valve seal cutter.
Keep the cam under .500`lift. .440" to .480" lift is fine. Shim the springs to equal height 1.70" to 1.73"

Pick the cam duration based on intended engine rpm range. When you cam these motors up, they want to rev.

The whole point of using the 305 heads is to keep the total cost down. Don;t spnd /pay for stuff that you don;t need.
( professional head porting,screwin studs,,,, roller cams,r roller rockers etc etc. KISS
pay attention to the finished size of the chambers and the engine compression ratio.
Ya it matters. Whne you get the heads off your 307 measure the deck height at TDC. (dished piston.... flat top??)

the 416's can be flat milled to 51cc if nessessary.
here is a nice moderate cam for your 307 w ported 305 heads, RPM intake, headers and 650-750carb.
Comp cams Dual energy 265DEH 12-208-2 9.5 to 10:1 cr.
needs a stall and gears for best. perf. in a 307. Anything with similar duration will work well.
cam selection is very criticial on small CID motors. this one will buzz well past 5500 rpm in a 307 w ported heads.
A "3500 stall" 10" and 4.10's is not too much.

Last edited by F-BIRD'88; 11-02-2012 at 05:21 PM.
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  #36 (permalink)  
Old 11-02-2012, 05:22 PM
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The pistons are flat top. How do i measure the deck height? I wrote down what you said about telling the mechanist and will repeat verbatim. I apologize with for the questions, but this is my first rebuild an im having a hard time grasping how all of these parts are working in conjunction with eachother and what the ******* does lift mean? And how do you measure it.

Last edited by rube'68'03; 11-02-2012 at 05:36 PM.
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  #37 (permalink)  
Old 11-02-2012, 05:50 PM
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a cam opens and closes the valves in the heads,via lifter,push rod,rocker. How far the valve opens is called valve lift. (how far the valve is lifted off the valve seat) duration is how long the valve is lifted from the seat(time wise) counted in degrees of crankshaft rotation. A long duration cam keeps the valves open for a longer time to allow for more air flow,higher lift cams make the opening bigger,to also allow more air flow.
you need a cam that allows the exact correct amount for your engine and application
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  #38 (permalink)  
Old 11-02-2012, 05:59 PM
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Quote:
Originally Posted by vinniekq2 View Post
a cam opens and closes the valves in the heads,via lifter,push rod,rocker. How far the valve opens is called valve lift. (how far the valve is lifted off the valve seat) duration is how long the valve is lifted from the seat(time wise) counted in degrees of crankshaft rotation. A long duration cam keeps the valves open for a longer time to allow for more air flow,higher lift cams make the opening bigger,to also allow more air flow.
you need a cam that allows the exact correct amount for your engine and application
Is there a reference for this somewhere so i know which cam to choose?
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  #39 (permalink)  
Old 11-02-2012, 06:04 PM
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Quote:
Originally Posted by F-BIRD'88 View Post
if you have to pay someone to port these heads, its not really worth it.
Its a DIY thing on these and most stock factory SBC heads.
Porting labour costs money. it's labour-time intensive.
Port them yourself, first, then get and pay for the machining done. (new valve job etc) Don;t be shy with the porting. They need a good work over.
You're not talking about porting the bowels are you?
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  #40 (permalink)  
Old 11-02-2012, 06:18 PM
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there are dozens of cam grinders/sellers with thousands of choices and 4 kinds of lifters or 2 styles.
decide what you want first and what engine you will use,,,then a combination can be applied.
be specific,how is the engine going to be used,where is it,what you expect from it
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  #41 (permalink)  
Old 11-03-2012, 09:34 AM
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Quote:
Originally Posted by rube'68'03 View Post
You're not talking about porting the bowels are you?
I am talking about porting the whole intake and exhaust ports including the bowls.
Bowl hogging is just one step in the process. These heads need more than just a "stage 1" "pocket port"
"bowl port" job. The meat and potatoes flow gains are deep in the port. And it gets time/labour intenstive.
(when you are paying for the time...)

If you want a powerfull 307 you want to fully port the 416 heads as well as get the larger 1.94" intake valve so the heads flow more air than stock.

Cam choice depends on the desired rpm range, and power/torque curve desired.
Choice must be tempered to driving style, idle quality, gear ratio,vehicle weight,
purpose, trans torque converter stall speed. A cam cannot be a big race cam and a small mild cam at the same time.

Eg if you don;t want a race motor, don't use a huge racey cam.
283's 302's 305's and 307's are easy to over cam.

deck height: bring the piston to TDC and measure how far below the deck the top of the piston is, Uisng feeler gauges, a depth mic, etc. You are looking for .025" or less. Ya it matters. (to calc the compression ratio)

If you take care of the details this 307 will turn out very well.

Google search for camshaft selection and technical camshaft terms like lobe lift, duration @.050" lobe separation, valve lift, rocker arm ratio etc etc etc. many of the camshaft manufactureres have a tech section on their sites.
Crane, Isky <Comp, Lunati, Howards,, etc etc

More SBC high performance build knowledge including head porting Search for books by David Vizard on Amazon,,, local library etc.
google search for ported 305 head,, ported 416 head etc


Last edited by F-BIRD'88; 11-03-2012 at 09:49 AM.
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  #42 (permalink)  
Old 11-03-2012, 09:54 AM
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Cam choice: What kind of engine and performance are you looking to end up with.
What is the gear ratio, car weight, tire size, and transmission converter stall speed.
And are you willing to change the gears and converter to match the camshaft/engine power curve?

rough racey street brat idle or ......?
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  #43 (permalink)  
Old 11-26-2012, 08:45 PM
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Found an article on a 307 build. Not superhero power, but I'll bet you could actually afford to drive the thing how fuel prices are (grrrr!).

307 Chevy Dyno Test - Super Chevy Magazine
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  #44 (permalink)  
Old 11-26-2012, 09:20 PM
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If you haven't done a couple dozen sets of heads before, then I would advise you not to go grinding on the heads. You might accidentally cut in the right places and add a little flow, but you might just as easily cut in the wrong places and turn them into junk.

I'm gonna tell a story on myself. When my youngest son was in high school, we built a '72 Chevy Luv pickup with a California Stepside conversion. We shoehorned a bone-stock 455 Olds into it, with a TH400 and narrowed 10 1/4" Olds rear diff ('57-'64 Olds/Pontiac). Took it to the dragstrip and turned 101 mph on slicks. Pulled the heads off the motor, spent the next 26 hours sittin' at the bench with a Dumore and carbide burrs, then sanding discs. Bolted the heads back on the motor, went to the dragstrip and turned 103 mph. Picked up a crummy 2 miles per hour in return for 26 hours of labor. Now, someone who knew what they were doing may have been able to pick up some real power with those heads, but I was not that somebody and it is doubtful that you are that somebody either.
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  #45 (permalink)  
Old 11-26-2012, 09:24 PM
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If you haven't done a couple dozen sets of heads before, then I would advise you not to go grinding on the heads. You might accidentally cut in the right places and add a little flow, but you might just as easily cut in the wrong places and turn them into junk.

I'm gonna tell a story on myself. When my youngest son was in high school, we built a '72 Chevy Luv pickup with a California Stepside conversion. We shoehorned a bone-stock 455 Olds into it, with a TH400 and 10 1/4" Olds rear diff. Took it to the dragstrip and turned 101 mph. Pulled the heads off the motor, spent the next 26 hours sittin' at the bench with a Dumore and carbide burrs, then sanding rolls. Bolted the heads back on the motor, went to the dragstrip and turned 103 mph. Picked up a crummy 2 miles per hour in return for 26 hours of labor. Now, someone who knew what they were doing may have been able to pick up some real power with those heads, but I was not that somebody and it is doubtful that you are that somebody either.
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