FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: Heo on January 30, 2014, 11:08:49 PM
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The edelbrock and stock C.J intake valves is 30.deg
427 also i Think. Ford had some reason to use 30 deg
valve on hp Engines. Mercedes use 30 also
Old hopup tricks for the flathead recomend 30 deg
but i saw here the delbrock heads gain much from
changing over to 45 deg? wich valves is used for that
I have only found 30 deg cobrajet sized valves
Im about to get some C4-G heads ported witch deg
to use 30 or 45
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When we did some porting on our fe heads, the 30° had much better low lift flow than the 45°. After about 400 lift the 45° took over. At 600 lift there was a 45 cfm gain by using 45°. I would assume that ford and ebock use the 30° for better street performance. I'm sure Joe d craine or many others can give you a much better answer.
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Thank you FB 427.
Anyone else that have something to ad?
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I have done 390/C6AE-R valve jobs in angles from 25/30/35/40/45/50/55* on both the intake and exhaust valves. The shallower the angle, the better the flow at low lifts/ the steeper the angle the better the flow at higher lifts---to a point. The combustion chamber shape will determine how well this works, as well as the shape of the valve in the tulip area. Think this way---the less difference in turns into the chamber, and the less turns the airflow makes over the valve, the more flow will increase. If the short turn is shaped wrong(FE), all this goes out the window because the airflow will shear and cling to the short turn and the port will go turbulent no matter what the angle of the valve job. Joe-JDC.
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Well then i see why. Since few flatheadcams reached .400 in lift
And CJ,481 and most 427 cams at 500 they probably had best
"total"flow with 30 deg seat....
If we take for example compcams 282S/294S with 571/605 lift
whats your opinion are they better of with 30 or 45 deg.
And are there any fitting valves around 2.10 dia or do i take
2.19 427 valves and grind down?
And Another thing i was examing the heads around the exhaust
seats thinking about fitting hardened valveseats. But there is
not much material left for suport if you mill for a new seat.
Any one here that have mounted seats in C4-G heads with
sucsess??
Yess i know im better of buying new alu heads
But i traded a Volvo Amazon that i had sitting and rotting
for all the headwork
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Well then i see why. Since few flatheadcams reached .400 in lift
And CJ,481 and most 427 cams at 500 they probably had best
"total"flow with 30 deg seat....
If we take for example compcams 282S/294S with 571/605 lift
whats your opinion are they better of with 30 or 45 deg.
And are there any fitting valves around 2.10 dia or do i take
2.19 427 valves and grind down?
And Another thing i was examing the heads around the exhaust
seats thinking about fitting hardened valveseats. But there is
not much material left for suport if you mill for a new seat.
Any one here that have mounted seats in C4-G heads with
sucsess??
Yess i know im better of buying new alu heads
But i traded a Volvo Amazon that i had sitting and rotting
for all the headwork
If your running a 282 or the 292, I do believe the 45's would be the better choice at that lift. Otherwise if you had a 30 with .600, the air would dirty up. I may be wrong and Joe would correct me if I am.
As for the Valves... We took 427 size valves from 2.19 to 2.15 & 1.75 to 1.73 (C4AE-G heads) for the Poor Mans. Seam to work well for our build. But if your talking about 2.10... Why not buy a set of CJ valves (2.09, 1.65) for your C4AE-G heads? There would be plenty materiel in the head to support that size! But if you did what we did (2.15 & 1.73) was tight and not much room for the exhaust side of the house.
Whats the bore size of the engine? That has a effect on valve size as well.... JMHO
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I have bought a set of 2.09 CJ valves but the intake is 30 deg and
if i grind them to 45 then they are back to stock size
and i have not found any CJ valves with 45 deg intake
the bore is 4.11 and i have not tried how big valve i can
use with out the cyl. scrouding the valve
maby i can go bigger than 2.09
Only thing i know is back in the dark ages (the 80s) :D
I built a couple of +.030, 390s with CJ valves in C4-G heads
it was said then to not go bigger valves in a street 390
But today there is different cams availibel and better
know how about airflow and headporting
So im open for all sugestions i can get
What im trying to build is a strong street Engine for a Galaxie
with somewhat decent low rpm behavior
Im not aiming for fame and glory with this engine ;D
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I have been told by gentleman here in Albuquerque that he can improve my stock edelbrocks by about 12% - 15% with stock valves and 30 degree seats for around 500.00 , I am looking forward to having the heads done and swapping to a hyd roller cam . He s been doing heads for 30 -35 years . So i think you can use the 30 degree seats and improve flow and still have low end tq and hp .. Bud
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I know that a Nail Head Valve on the intake side will help flow. Like the stock FoMoCo intake valve
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I have been told by gentleman here in Albuquerque that he can improve my stock edelbrocks by about 12% - 15% with stock valves and 30 degree seats for around 500.00 , I am looking forward to having the heads done and swapping to a hyd roller cam . He s been doing heads for 30 -35 years . So i think you can use the 30 degree seats and improve flow and still have low end tq and hp .. Bud
You could do the same for about 30 bucks and a good day at the bench if you have a die grinder at your disposal.
He would be doing nothing more than a home bench port job. just saying.
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Here's what my ported Eboks flowed, going from a 30 degree seat to a 45 degree seat:
Lift-----30-degree-----45-degree
0.050-----36.0-----------26.9
0.100-----72.1-----------61.7
0.200----141.9----------129.3
0.300----193.0----------190.4
0.400----222.7----------236.1
0.500----259.6----------267.3
0.550----no-data------- 281.3
0.600----278.6----------293.4
0.650----279.8----------302.8
You can see that the 45 degree seat starts flowing better somewhere after .300" lift. Just FYI.
paulie
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I think 12% for 500 with a fresh valve job is pretty cheap
If a stock Edelbrock flows 248 intake / 214 exhaust at .600 (sort of a WAG number) then 112% of that would be 277 intake / 240 exhaust.
That second head could potentially support 50 more horsepower with the right combo. pretty cheap!
Paulie's numbers back that up too
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I get what you are saying Howie but with out a flow bench how would i know just what or how much improving im doing , or hurting ? l have never ground on any heads , im sure if i watched it then i would have a better idea . which is what i plan on doing and i know its not difficult , i guess i need a practice head lol Bud
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Stock Edelbrock heads will not flow 200cfm at any lift on the exhaust. Most only flow in the low 180cfm, and occasionally 190-191cfm @ .750" or higher. (CJ style with 1.665 exhaust valve) It is actually not easy to get 220cfm, much less 240 without going to 1.710 or larger valves. Joe-JDC.
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Stock Edelbrock heads will not flow 200cfm at any lift on the exhaust. Most only flow in the low 180cfm, and occasionally 190-191cfm @ .750" or higher. (CJ style with 1.665 exhaust valve) It is actually not easy to get 220cfm, much less 240 without going to 1.710 or larger valves. Joe-JDC.
That number just came off of Stan's site, that's why I mentioned it was a WAG.
My point was 12% of flow is a huge amount for the cost of a good valve job, and I doubt a little rubbing by a novice home porter will keep up with that
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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
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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
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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.
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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?
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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.
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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
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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 :)
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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
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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.
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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
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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
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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
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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
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I would say 280-300 cfm on the intake, with the 45 degree seats, at around .700" lift, if the porting is done right.
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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
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Well lets see what results my buddy get
out of my heads
Thank you all for your answers
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yeah it s time for 45 degree seats , and some port work as well , good luck Heo soon we can share our info on our heads .. Bud