Just got my heads back from the shop and here are the results
These heads now have 2.00" intake and 1.56" exhaust Manly valves.
W/comp beehive springs 915 with stock retainers.
Scorpion self aligning 1.6 rockers with arp 3/8" rocker studs
The cam I will be using is the comp cams 268xfi 07-466-8
cam specs are:
Operating Range: 1800-5800 RPM
Duration Advertised: 268° Intake / 276° Exhaust
Duration @ .050'' Lift: 218° Intake / 224° Exhaust
Valve Lift w/1.6 Rockers: .570'' Intake / .565'' Exhaust
Lobe Separation Angle: 113°

INTAKE LIFT.....FLOW RANGE.......%FLOW.....CFM@28"
.100.....................123...................63. 1......62.8
.200.....................1234.................75.5 ......133.7
.300.....................1235.................78.4 ......185.3
.400.....................12345................71.6 ......220.1
.500.....................12345................71.0 ......251.6
.600.....................12345................73.5 ......257.4

EXHAUST LIFT.....FLOW RANGE.......%FLOW.....CFM@28"
.100........................13..................72 .5........49.2
.200........................134.................73 ..........101.43
.300........................1234...............79. 5........139.1
.400........................1235...............70. 7........163.04
.500........................1235...............74. 5........174.7
.600........................1235...............77. 5........182.3

Let me know what you think positive or negative.
I am doing a 350 unfortunately not a 383.

 

That is a lot of lift to be running with self-aligning rockers. Might want some NSA's. Most say over .550 u should run NSA's

 

I have my doubts about those springs with that cam.

 

thats what comp recommends

 

not sure if i am going to use those i have them on my other motor that broke

 

why can't you run sa rocker over .550 lift?
what happens?

 

Congratulations Sam!

Very nice looking flow numbers, should be awesome with the cam you/I are running. I asked about the 915 springs with that cam on here and replies said to go with the 918's. I was surprised when the cam card said to use the 915 springs, already had the 918's when the cam cam in but no biggy. I went with the special locators for the beehives and the + .050" 10 degree locks to get reasonable installed height. The stock locators are supposed to work with these springs according to Comp Cams but they fit like crap, they won't seat fully and the spring is angled only touching at one side. Some people radius the inside edge of the bottom spring coil from what I here to use the stock locators. What setup are you running on locators, locks, etc?

Give us any details you can on your ports. Do you have port volumes, how large were the throats opened up for the larger valves, who did them? Details about differences you can see in port form compared to the stock ports would be interesting too.

Good luck with your build,

Michael

 

I wouldn't use the stock retainers as the WILL break. Ask me how I know. I used them with LT4 springs with stock cam and one broke and cost a complete engine. Only thing left good was the intake and crank.The crank would have to have been straightened.

Who did your heads?

Crower has one of my cams they put in their line up that is close to these spects. Call them and talk to Dave as this thing pulls strong in a built right 355.

 

My heads were done by HPS Cylinder heads in Tarpon Springs, Fl
http://www.hpscylinderheads.com/
He was great to work with!!
I got a stage III 1/2 package.
The reason for the 1/2 is because I wanted a bit more done than was listed.
He raised the roof on the intake and port matched the intake and gaskets to the same size. Intake ports were enlarged to 195cc's
The throats were machined to its max opening to fit the valves, he also back cut the valves and gave it a 3 angle valve job. The valves are stainless steel
Manley street/master hd valves 10764-8 int and 10747-8 ex. 11/32" stem so i could use sa rockers. Retainers were for the beehive and 7deg. locks. The spring pockets had to be cut to achieve the installed height needed.
Chambers were cc'd.
I wish I could give you pics but my cam phone sucks ***.

NOW CAN SOMBODY EXPLAIN TO ME WHY I CAN'T RUN SA ROCKERS ABOVE .550"?

 

3.5 Gotta love it.

Put it together,make two of your lifters solid and roll it over and see if the side skirts get away from the valve tip. If they do the rockers will come off the stem and possibly unhinge a valve=severely blown engine. Don't know cause I don't use them in any of my builds.

 

THANK YOU!!! That makes sense.

 

Do you know how to make your lifters solid? If not I have written in several threads how to do it. If ya can't find it I will rewright it for ya.

 

If you could repost it, that would be great thanks.

 

Take the lock out,remove the guts,may take a little doing 'cause of oil lock.
Cut a 3/8" bolt off and grind it till the top cap and lock will just fit. Waaalllla-- solid lifter.

When ya go back together make sure everything is super CLEAN. Put the lifter in a flat bottom pan covered with oil and take a large Phillips screw driver and pump some oil into them standing on the bottom of the pan. They may not pump all the way up but that's OK as they will in the engine.
When ya set the valves do it BEFORE ya install the intake as ya can feel the load when twisting the PR and ya can see the cap on the lifter when it moves so as to find correct "0". "0" is right when the cap moves.Just when it moves back off some and then tighten till it JUST bareleeeeeey moves and that's "0". Then turn them down your 1/8,1/4 or whatever ya use. I generally use 1/4 turn.Make sure ya got each piston/cyl on TDC firing rotating correctly and in the right firing order and both valves would be closed.
Don't be excited if the clack when ya first start it up as it may take a few minutes to get pumped up . After 5 minutes they should be quiet,but if they are still clacking loudly ya may have something wrong.
Remember to tighten the poly locks tighter than s***.
Tighten the center lock screw and then the wrench with a few bumps of your palm in the clockwise direction. After a couple ya can tell when they are tight. But bump the pretty good with your open hand.