About Heads

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injected360

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OK need help on heads .........I have a pair of 70s 360 heads and I want to know what would be the max the could be ported, and whats the largest valves? When talking about porting I mean professional to port, but before I get all ready to ship heads I thought I would at the Mopar guys who know about the heads first hand.....I dont even know what they flow stock? thanks guys........
 
you should be able to get a lot of good replies on here about this....i dont know much about the heads from different years, but i think the biggest is a 2.02 intake and 1.60 or 1.80 exhaust valve at most...not sure though
 
You can get 260-280cfm on average full ported.

2.05/1.60-2.02/1.65 I think 2.08 fits, really whatever the machinist can fit comfortably without shrouding issues.
 
Yea, what he said. Unless your going to do some type of class racing and head must be stock but OK for mods, over 300 cfm is possible, but that requires some of the most absoulte nutty-est mods going. And of course, crazy money spent on it.

Anyway, the stock heads flow around 190 - 200 cfm on the intake give or take a few cfm on ethier side. The better old tyme X head will flow 10 above the others.
 
Thanks guys I would really like to run the heads I have, and have them ported to the max with a 202 valve, I. like iron heads for the nostalgic look. I've got a 1970 never used Hilborn mechanical injection set up and a out of production n.o.s. Milodon oil pan, just want to keep it vintage late 60s early 70s, thanks again for the input.........
 
injected360 said:
OK need help on heads .........I have a pair of 70s 360 heads and I want to know what would be the max the could be ported, and whats the largest valves? When talking about porting I mean professional to port, but before I get all ready to ship heads I thought I would at the Mopar guys who know about the heads first hand.....I dont even know what they flow stock? thanks guys........
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I use a 2.02 valve cut down to 2.00 for stock type heads. Fully ported with no welding or epoxy I will get 270cfm at .500, 278cfm at .550 and then the port will quit flowing air.
Bigger valves will flow more air, but even though the flow bench says the port flows more with the larger valve, I have not seen any HP increase on the dyno or track. So I stick to the 2" valve.

I do quite a bit of chamber work too, so often my customers will start with a dome piston just to keep the compression good. Chambers ofter finish in the 74cc range with no milling. So to keep from milling the heads alot, we just use a dome piston (or flattop if using a 4" crank).
 
thanks for the help I will bookmark the page so I can come back to it at a later time...so with a dome piston and a 408 displacement with a .550 lift it would be possible to make 525 hp if the heads are ported correctly?
 
flat tops with 4" crank...
domes with stock crank.
 
Problem with trying to make over 400-450 HP with a small block is longevity. Many engine builders will state that they have small blocks making over 500 HP easy but they fail to say how many will with stand that level of over a t period of time. A friend of mine was running a 340 with 550 HP for about nine months before the engine was destyroyed beyond repair. Iron heads are my preferance for street duty, I have the eddy aluminum stuff with
TTI exhaust system on a 360 Duster, living in the high desert the car will shut down when parked and will not start until the engine cools to ambient temperature. The 340 duster with iron heads and 340 exhaust never experiences the same problems. Good luck with your build .
 
I figure the engine want be built for the long haul but the car want be drove every day I just want it to push the envelope but not rip it in half the first time I run it, I also know I want to get the max out of the small block but I would the right parts to do so if I needed to , would be a aftermarket crank, Milodon 4 bolt mains, ARP main studs, aftermarket rods, ARP rod bolts, forged high comp pistons, ARP head studs, port the crap out of the stock heads, stainless valves, aftermarket rocker assy. and my Hilborn mech. injection with a Hunt mag. the car will be a throw back of the late 60s early 70s drag car. nothing fancy no heat no radio just two seats the minimum on the interior. to drive once and awhile and have fun when I do. you guys have gave alot of info and thanks for it just keep it coming I'm bookmarking all of it...........
 
injected360 said:
a 408 displacement with a .550 lift it would be possible to make 525 hp if the heads are ported correctly?
Click to expand...

I don't see why not. All the part working togther, decent duration on the cam, etc....
 
G. G. LEVERETTE said:
Problem with trying to make over 400-450 HP with a small block is longevity. Many engine builders will state that they have small blocks making over 500 HP easy but they fail to say how many will with stand that level of over a t period of time. A friend of mine was running a 340 with 550 HP for about nine months before the engine was destyroyed beyond repair. Iron heads are my preferance for street duty, I have the eddy aluminum stuff with
TTI exhaust system on a 360 Duster, living in the high desert the car will shut down when parked and will not start until the engine cools to ambient temperature. The 340 duster with iron heads and 340 exhaust never experiences the same problems. Good luck with your build .
Click to expand...

What exactly failed in your friend's 340? I raced my 360 for 4 years, which was roughly 170 runs or so before I tore into it to freshen (I was bored and looking to see if I could extract a few more HP)only to find it needed nothing! Ring gap was still exactly how I set it up, bearings were great and pistons looked almost unrun...LOL!

So I changed the cam, carb and a tad more chamber work and netted 30HP more for 560. Put it back in the car, and it picked up about .2 initially then played with launch rpm and now have .3 better than it had run previously.
Recently sold the heads and now need to sell the shortblock cause I'm building a new R1 block 360.
Just curious about your friend's 340 and what failed. I've run my stock rods (sized stock eliminator style)stock crank 360 over 200 passes with no problems.
I'm not the only one either...
 
Hey ou812 question for you how much does the hot rod weight and whats your best ET? thanks.........
 
injected360 said:
Hey ou812 question for you how much does the hot rod weight and whats your best ET? thanks.........
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With me it weigh's 3350 with a full tank in the back. Best E.T. is 10.52 @.127mph with a 1.37 60ft.
That's with a FT cam. 904 low gear trans, Dana 60 w/4.56 gear and M/T 28x11.5 slicks. It's a ladder bar/coil over rear and stock front w/RME upper A arms, RME front struts, and Koni adj. shock.
I run a ProTrans brake and an A1 5600 8" converter. It's also 100% street legal if I want to drive it (I have a short exhaust system for it).
Full interior with back seat and all. 6pt. bar.

engine in car 002.jpg


engine in car 001.jpg
 
injected360 said:
WOW that way COOL!!!!! I really like the hot rod!!!!!!!!!!!
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OU812 isn't one to brag on himself...his profile has a link to his web site, there is more info about the orange Duster. Impressive.
 
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