30 vs 45 degre valves?

[plovett]

Here's what my stock unported Edelbrocks flowed, with the 30 degree intake seat.  Not saying anybody is wrong or right.  Just saying what the flow bench said.  2.09/1.655" Ferrea valves. Superflow SF600. 28" vacuum.  4.18" bore tube. Altitude around 1000 ft.  Clay radius on intake ports.  No pipe on the exhaust.

Lift-----Intake---Exhaust
0.050----34.8-----20.8
0.100----69.9-----47.3
0.200---143.4-----91.2
0.300---193.3----123.8
0.400---230.4----153.6
0.500---252.5----182.2
0.600---249.5----197.8
0.650---252.5----------
0.700--------------205.1
0.800--------------208.9

Mildly ported exhaust with same valves:

Lift-----Exhaust
0.050----25.6
0.100----53.6
0.200----97.0
0.300---131.5
0.400---162.7
0.500---191.4
0.600---205.8
0.700---213.1
0.800---217.6

Again, just FYI.

paulie

[bn69stang]

Doe s anyone have info on a set edelbrocks that have been re worked with say a 2.12 or a 2.15 intake and a 1.67 or 1.71 exhaust , thanks for input Paulie .. Im sure bigger valves , 11/ 32 stems and 45 degree seats would the way to go , but decent power can be made with 2.09 and 1.66 im sure .if i have to buy valves i may as well go that way .. Bud

[jayb]

If you happen to have my book you can look in the dyno mule chapter.  The heads on the 427 sideoiler and 427 stroker engines are reworked with bigger valves, and the flow numbers are shown in the chapter.  Peak flow for the street/strip ported heads used on the 427 sideoiler was 304 at .700" lift on the intake, and 244 at .700" on the exhaust.  Valves were 2.19/1.71 with 11/32 stems.  Peak flow for the more radically ported heads on the 427 stroker was 343 at .700" on the intake and 261 at .700" on the exhaust, with 2.25/1/75 valves and 11/32 stems.

[Heo]

Thanks for all  answers. So if i aimed for 600 hp 45 deg is a must
But my modest goal is around 400 hp and somewhat decent fuel
consumption and low rpm behavior out of 405 cuin at sea level
with 98 oktan and EFI
If i understand things right. So im better of with 45 deg intake valve?

 

[Joe-jdc]

Stock Edelbrock RPM heads will give you 400hp if the camshaft is in the 230-236* range and .500"lift or more.  Don't worry about the valve angles at that hp level.  Waste of money and time.  Joe-JDC.

[Heo]

Yes but I have a set of Ford C4-G heads that i was thinking of instal
CJ Valves Like we did in Sweden in the 80s. Beacuse that was
The best alternativ we had if not the only one.
And a buddy that do a lot of headwork wanted to buy a
Volvo Amazon i had. So i traded for a port and valve job.
I know im probably better of buying a new set of alu heads
but i like to try this set first since it wont cost me anything

So since he have to grind bigger seats in the head i can go 30
or 45 ( wich one thats better for my use) and find fitting valves.

Sorry if my English and Spelling is bad. But i had two strokes that
tock most of my English away

[bluef100fe]

If your going with a comp 282s or smaller cam I would stick with the 30 degree intake seat.... If your planning for a comp 294s cam or bigger... I'd buy the valves with 45 degree cut on them... SI valves makes the 2.09 intake valve in both the 30 and 45 degree seat angles for the FE... Hope this helps

[bn69stang]

Thanks Jay , looking at your book now and doing homework on all this , if im going to re-do my heads now i may as well over do them for my 434 inch motor so that when i do a 465 or 482 they re ready or ?  ?  .. Bud

[jayb]

More cubic inches means you'll need more flow, so if you are planning a larger motor in the future it wouldn't hurt to do the heads now.  There is a tradeoff here, of course, because as you increase the size of the head ports and the valves, the same volume of air will move more slowly, and that can hurt cylinder filling.  Flow and velocity will factor into the horsepower equation, not just flow.  In any case, though, if you went up to something like a 2.15/1.71 valve combination, that would work really well on a 434" engine or a 482" engine, so you probably can't go wrong with that approach.

[bn69stang]

Thanks again Jay , yeah i think that would be a good idea to go that way , most likely i ll just build the other 428 block into a stroker 465 and that valve size would be fine , along with the rest of the parts i have to use .. Bud

[Heo]

Thanks Blue F100 thats the kind of answer im after.
And now i know were to get the valves with 45 deg.
if i go with that

[Ford428CJ]

If i understand things right. So im better of with 45 deg intake valve?

 I do believe you are better off with the 45 degree seat. Your lift is well over 500 and close to 600. Even in the Autolite Hi-Per book, they talk about using a 45 degree seat.... I'm sure you can benefit from it! JMHO 

[Heo]

Yes i Think i order a set of 45 deg int.valves then

About how much will a good "street" ported C4-G head with CJ valves
flow? on a 4.11bore

[jayb]

I would say 280-300 cfm on the intake, with the 45 degree seats, at around .700" lift, if the porting is done right.

[bluef100fe]

270-280 by 0.700 lift with a 2.09 valve is getting after it pretty well... To get to 300 with a 2.09 in a early low riser port is really pushing it in my opinion... Average 290 in/200 out on all 8 ports is a stout set of low riser FE heads... There's also more to cylinder heads than just airflow... Have fun