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Expert
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Location: Nasco , SWEDEN | Hi everyone! i have a 1959 383 rb. i want to change to "betterflow" heads. originalstuff is the only way to go for me. someone said to me that i can´t swap to any other heads because all valves will hit my cylinderwalls is it true?  |
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Expert
Posts: 3575
 
Location: Netherlands | I believe the older heads have 2.08" intake and 1.60" exhaust valves. Most if not all heads up to about '67 had these size valves so using these heads will be no problem.
The 'issue' (if there is any) is the smallisch bore-size of the 383-block (and 413) can shroud/hinder airflow into the cylinder.
The factory therefore 'notched' the cylinderbores at the top of their highperformance Max-wedge 413 blocks, which had larger valves in the heads to improve air flow.
Why do you want 'better' heads and still stay with steel heads?
I think you will see more improvement by installing headers and a larger diameter exhaust system.
How about modifying your current heads?
If they are still old and stock, most likely they need to be rebuild so now might be a good opportunity to increase the exhaust valve-size to 1.74 and install hardened seats to run unleaded gasoline without any problems.
I've done this once with a pair of '67 "915" heads. |
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Expert
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Location: Nasco , SWEDEN | I was thinking to go the "cheapway" and get unleaded heads as a bonus if i start modifying the engine. i have a 2x4 intake and two carter carbs (625cfm) do i need to change camshaft? i do have a brandnew electricignition set. 915 heads are closed chambers? how will that effect my compression ,will i be able to run 95 octane? thank´s for your advice i am very grateful! Morgan 
Edited by mogge65 2009-12-04 7:16 AM
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Expert 5K+
Posts: 6203
Location: Big pimpin' | ANY head with hardened seats will be "open" chamber and will kill your 383's compression...NONE of the closed chamber heads had hardened seats.....
You already have Closed Chamber heads on your 383...I'd swap out the cam and lifters as well, as thew pushrods might be different with the older style lifters in that 383...The heads on your engine will have Rocker Stands that bolt on the heads, the later model closed chamber heads will be 6 BOLT Valve covers instead of 4 BOLT and will NOT have the rocker stands...
I'd go with a set of plain 'ol "516" common heads and open up the exhaust to 1.740....with 2.080 Intake valves...A slight porting job will wake up the closed chamber heads when ported with Mopar Templates...
Edited by dukeboy 2009-12-04 7:50 AM
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Expert
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Location: Netherlands | Are you running 95 octance now without pinging?
If so then that's good.
I always put 98 octane in my cars because I like to have the ignition nice and 'early' so the motor is more responsive.
With the 95octane "parts-washer-liquid" the motors ping like hell otherwise.
Edited by BigBlockMopar 2009-12-04 8:07 AM
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Expert
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| mogge65 - 2009-12-04 5:58 AM
Hi everyone! i have a 1959 383 rb. i want to change to "betterflow" heads. originalstuff is the only way to go for me. someone said to me that i can´t swap to any other heads because all valves will hit my cylinderwalls is it true? :stressed:
Your heads are pretty good as closed chambers, but like Dukeboy has said they dont have hardened valve seats.... your heads have 1.94 intake and 1.6 exhaust. You could have hardened seats installed at 2.08 and 1.74 if you want.... thats what I would do. The 516 heads do not have hardened seats either, plus the valves are 2.08 and 1.6, only the open chamber heads have the hardened seats and you would drop to 9.1 to 1 compression using them, which isnt that bad if you not building a nascar stock car.
Now if you could get your hands on 915 heads then thats the both of both worlds, hardened seats and big valves but they are pricely, well over $600 a set.... |
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Expert
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Location: Netherlands | With open chamber heads you're loosing the important piston quench-height, which in turn will make your engine prone to pinging again, even more then a little more compression ratio.
Engine compression makes torque, and that's really what you want on the street.
Personally I would stick to your current heads and have them rebuilt with larger valves, hardened seats and bronze valveguides.
I would also advise to use 'new' valves and not re-use your old ones. You'll get proper valveguide fitting and the new valves won't also have the little 'rampstep' near the edges, which has proven to hinder flow aswell.
If you do re-use the old valves, make sure to machine to 'backcut' the valves so the ramp-edge is removed.
Along with the rebuilt heads I would also install a new timing chain-set. |
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Expert
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Location: Nasco , SWEDEN | I think i will try to obtain a set of 915 heads and let my originalheads rest on the shelf for awhile. what about camshaft, i want more power on lowend but don´t want to sacrifice any on top end. i have installed 2 inch dual exhaust system with cherry´s to my original cast exhaust. do i need tube headers? i do want to hit high 13´s in the quartermile! 
Edited by mogge65 2009-12-04 8:32 AM
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Expert
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Location: Netherlands | Tube headers will be a noticable difference. But not much of what's available will fit in your chassis that easily.
I've got a set of shorty headers on my 496" stroker.
I would use large case Dynomax mufflers instead of the dreadful sounding Cherrybombs. But I understood there are somewhat better flowing cherrybombs out there these days which I wonder if they sound the same as the old crappy ones.
An X-pipe in the exhaustsystem gives a bit more torque but equals out the exhaustnoise somewhat.
Remember that not all 915 heads have 1.74" exh. valves, so you still have to enlarge these if you really want to.
Still, you might want to indeed check if the valves won't hit or are too close to the cylinder-edges. If so you'll have to grind a small notch on the top of each cylinder.
I've got an article somewhere at home which shows how the factory did this in the early '60s.
But why not keep your motor stock all together, set it aside and just swap in a 413 or a newer 440 with an extended-flange crankshaft?
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| mogge65 - 2009-12-04 8:31 AM
I think i will try to obtain a set of 915 heads and let my original heads rest on the shelf for awhile. what about camshaft, i want more power on lowend but don´t want to sacrifice any on top end. i have installed 2 inch dual exhaust system with cherry´s to my original cast exhaust. do i need tube headers? i do want to hit high 13´s in the quartermile! :laugh:
For a cam I would go with, and I have in my 383 a cam with the lift of .484 and duration of .284
Duration at 050 lift is .241 (This one is good for more top end)
http://www.summitracing.com/parts/DCC-4120235/
Or here is another good cam (This one is better for low end torque)
Duration at 050 is .214 and .224 - Lift is .465 exhaust, .442 intake
http://www.summitracing.com/parts/SUM-K6400/
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Elite Veteran
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Location: STL, MO | you are asking for your car to perform like a bone stock 68 440 b-body, thats a tall order,what do they have that you dont? 57 cubes all thru bore, more flow thruout, I would install any 66-78 440 and go from there, those RB 383's are coveted by collectors,if you put a 440 in, you will be so much further ahead cost wise and results wise, however if you decide to run the 383 and run 208/174 valves Herman is telling it like it is on cylinderwall interference, knocking 3-4 seconds off your cars stock 1/4 mile times is alot, your going to need more than 350 flywheel hp in a stock FL car to do that, you can get that out of a iron headed and manifolded pumpgas 440. |
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Location: Nasco , SWEDEN | can i put my crankshaft from my 59 383 rb into any 440 engine? i don´t want to change my tranny! 
Edited by mogge65 2009-12-06 9:16 PM
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Expert 5K+
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Location: Big pimpin' | YES you can!! That's the beauty of it....you will need to re-balance the bottom end just to be on the safe side...A 440 in that car will definatly wake it up....
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Location: Nasco , SWEDEN | Thank´s Dukeboy! 
Edited by mogge65 2009-12-06 11:33 PM
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Location: Nasco , SWEDEN | Herman, thank´s for your inputs! looks like i will try to build a complete motor of a 440 and extended crank! (early) then i can try to get some good heads in aluminium or steel! changing my rear end ratio from 2.97.1 to 3.23 won´t hurt either! i have a powerseat in the car, it´s very heavy. i would love to get a non power swivel seat! anybody got one?
Edited by mogge65 2010-01-06 9:42 PM
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Location: Netherlands | Cool. Good luck with the build!
I wouldn't alter the gear-ratio by actually changing the seperate gears in your currrent rearaxle. The change in ratio is too small to be worth the work.
If you have a complete 3.23:1 gear unit lying around, then it's doable perhaps, although you won't notice 'that' much of the change as it's only 0.25 of ratio-change.
The gain in cubicinches will have more impact IMO.
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Board Moderator
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Location: The not-so-great, dirty-white North ( Michigan) | Morgan....
Here are 915s AND a 440...Mabye make a deal only for what you need?
http://leamington.kijiji.ca/c-cars-vehicles-auto-parts-tires-engine... |
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Expert
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Location: Nasco , SWEDEN | Herman, i agree with the ratio issue! i´m searching a complete third member with suregrip 3,23 or 3.55. Hank, thank´s for that great tip. we have a 57 saratoga in wyoming whom we shall shipp to sweden soon. i can dump the parts in the same container! 
Edited by mogge65 2010-01-07 8:04 PM
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bigblock head interchangeability!
