FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: bn69stang on May 19, 2013, 08:41:33 AM
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What valve size - stem diameter is needed to make power / flow . When comparing Jayb s book and Barry s book , they had 2 different 445 inch motors but netted the same horsepower range . Im sure there is always a different approach . i want to modify my heads now for my 428 , but want to do it one time and set my self up for a future stroker motor , a 4.25 inch crank in a 28 block or probably 427 block .
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If its a 428, I would use 2.09 and 1.65 Valves. You wont be able to use a 2.19 and 1.73 on your 428. You can on your 427. But like I said... 428 wont allow it! So you need to decide on what you want to do and the direction you want to go! JMHO
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yeah but the 2.20 inch intake and a 1.71 exhaust will , the blue thunder heads already come that way in the medium riser , and with an 11/ 32 inch stem . The blue thunder heads will not fit with out shock tower mods and custom header s in a 67-70 mustang . Talk to me guy s ..
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What makes you think the Blue Thunder heads won't fit in a '67-70 Mustang? Mine fit, with Hooker adjustable race 2 1/8" primary headers, in my 69 Mach 1. Are you concerned about the raised exhaust port? It doesn't create the fitment problems that you would think. What I did to cheat a little bit was I had the exhaust side of the head machined .060", and the I used high temp RTV to seal the header flange to the head, rather than a gasket. My car came with the shock tower supports and I did have to trim those a little to fit the big header tubes, but other than that no problems.
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i have run blue thunder 428 m/r heads on a 4.145 bore with 2.2 and 1.65 valves work out great and i have also run the same size valves in edelbrock heads on the same bore work out fine to. those big intake valves can kill your bottom end if your not builded for them.
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yeah but the 2.20 inch intake and a 1.71 exhaust will , the blue thunder heads already come that way in the medium riser , and with an 11/ 32 inch stem . The blue thunder heads will not fit with out shock tower mods and custom header s in a 67-70 mustang . Talk to me guy s ..
Ok... You where talking Ed heads and now Blue Thunder.... So which is it then!? Ed Heads or BT???
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My Q is... What are you looking for here? What kind of HP? Bigger isnt always better. Same with flow #'s.
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valve stem diam, help flow just a little not that much, but small stem are not that heavy, lite valve train is free rpm
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I have Edelbrock heads and fpa headers already , the people at fpa told me the blue thunder heads would nt fit without trimming shock tower s and re-doing header s . So i was going off what they said , so with what i have what would be my best option guy s ? .
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ford428 is right bigger is not always better
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if you have it use it
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The biggest issue with Edel's out of the box is the 30* intake seat.
If you machine it for a 45* seat with a nice cut above and below you can really pick up the flow.
Why Ed does not put a 45 at the factory?
A good home port job will net you even more.
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Do some bowl clean up! Those ED heads should be good for 550HP or so. I watched a 416CI FE make close to 500HP with nothing done to the heads. It will be worth while and you can do it yourself. JMHO
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I just want to do this once for my best all all around power with what i have already , this is my first fe . thanks for the input ..I think that if the 485 to 510 hp range is possible then thats where i would like to be . I have not bought a cam yet , or touched the heads .
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After reading jayb s book and even Barry s book , I dont want 425 hp which is where im at with what i picked out . I dont see why 1.5 hp per cubic is out of the park .
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just give barry a call he has build a lot of 445 in that hp. look on his site
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or call blair he has build a lot of 428 in that range. He is one of the best with a 428 if not the best
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thanks guy s for the input , all is appreciated and noted . SO port and bowl work and keep 2.09 and 1.66 and just use what i have already . : 0
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Nothing against anyone here but you don't need big name guys to get ya 500~550HP. There are plenty of people with knowlage to help you out. There is a ton of info and free help to get you there. Trust me!
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THANKS jayb , ford428cj , chris-r , scotiaFE ..
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silicone sealent and clearencing the the shock-tower reinforcement is near priceless. I recall reading car magazines when FE Mustangs were introduced saying you either trade the car in or pull the motor to change plugs. Boy would that writter be in for a shock.
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Couple things...
You will need to or want to tweak the Edelbrocks to get to the 500HP level in a really streetable combination (I gues that depends on your definition of streetable though).
Intake valve size is not a problem beyond checking for piston to valve clearance. You could put a dinner plate in there. The exhaust is what gets close to the bore. A 2.19 or 2.200 valve is not going to "kill" the bottom end unless you go stupid big on the port. We're not building Boss 302s - where that story got started - with a huge port, a big valve, and a small displacement. Ford used the 2.09 valve 45 years ago in 428 engines that had warrantees, stock converter automatics and highway gears...
You can absolutely get a damn good running package with well worked 2.09, 3/8 stem, 30 degree seat stuff. But even Ford went to an 11/32 stem 45 degree valve in the "new" 1968 429. It's not like we're getting into risky territory here. ;) Any decent local shop can get you a nice gain by using the extra diameter to form a straightforward multi-angle 45 degree based valve job and bowl blend. A lighter valve with better flow, coupled with no real change in port cross section will get you an easily done strong package with no real downside.
The exhaust valve size can stay "as-is", but we normally go to the smaller guide there since people would think I'd gone insane with two stem diameters in the same head. A good valve job & bowl is all you need at that side for what you're doing.
You can fit a BT head in there - you'll be cursing but it'll go. I've had them on my car. But if you're worried about low end the current generation BT MR heads have a really large port and would be more suited to a big cube package.
Wes - that 416 had to be a pretty snappy bundle of parts to go 500HP with unmodified Edelbrock heads. Any info on that combo?
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Hey Barry, I'll get you the specs. They did do a valve job on the heads. Hyd Roller cam and some other goods. Nothing really special at all. Ill try and get you the info on it. I know it was close to 500Hp.... Awesome little set up!
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Thanks Barry for the info , thanks for the phone call and all the other info as well.. have a good evening