X Head cc's

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keep in mind of the seats were cut or if the head was ever surfaced it will be more or less.
 
I'd wager it's more anyway. Closer to 74-75. The spec was 72 IIRC...
 
hi, the min chamber volume is 63.3 cc. most are usually 67 to 68 cc untouched. port volumes are int=160 cc, exh port= 75 cc. information, provided by mopar and NHRA.
 
Cap, didn't you say they were milled and ported & bpolished etc........
 
OK...X J.... I have heard two diffeent stories one says they are essentially the same depending on the casting/year the other says they are very different regardless.....any one have the straight info? I have not seen enough of either to form an opinion....also heard that J's have same big valves .....comments please info starved and currently rebuilding a 340 from the pan up....horsepower hints welcomed
 
HP hits are all over this board. Start up a new thread with some specs and what you want to do with the car.

I have been told that J heads came with 2.02's stock, but yet have to see a set of stock 2.02's in a J head. My J's also have the same casting numbers as 340 heads.
 
I believe most J heads had 1.88 int and most X heads had 2.02 int...I think...Lee
 
1qwikScamp said:
a friend of mine has a set of j's with 2.02 valves
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But are you sure there not just OE valves but the ones from the factory the head was born with?

My "J's" have OE 2.02's as well.
 
depends on your valve type. I just cc'd mine at 69 cc's w/ ferra valves , more of a nailhead, 74 cc's w/stock valves
 
hi, In 1971 mopar brought out the 360, they also brought out the J head/915 casting. it came with 1.88 for 360 and 2.02 wth the 340. I have had an original pair of 915/J heads with 2.02 valves. all X heads had 2.02 valves.
 
T/A's also used they 915 casting with offset pushrod holes, these were also 2.02 intake.


Chuck
 
rumblefish360 said:
Cap, didn't you say they were milled and ported & bpolished etc........
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Ported and polished, yes. Milled, no. CC'd....well, I'd paid for them to be cc'd, but with 67cc chambers I'd guess I was taken......... :wack:
 
My 68 340 X heads have been milled .020 and they CC'd at 70.68 cc's with O.E. valves. I'm replacing the valves with REV Ind. valves and believe Dogdart65 is right about the valve type making a difference although I haven't proved it yet. Hope to have the heads together by end of next week and I'll cc them again to see how much difference the valves make. Hopefully I'll gain a little compression with them.
 
pagilman said:
according to my book all j heads were 1.88 and x's were 2.02 from factory. :coffee2:
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I know, but I have seen dozens and pulled off dozens of 915Js thare are 2.02. I worked at Dodge back in mid to late 70s.


Most of the 71 and up and most all 360 Js were 1.88s though. except the TA
 
My J heads are 68cc. Don't know the history, but I'm glad they are what they are! 2.02 valves, mine are off a 340. They are on a 318 ELE for now but will end up on top of the 360 I am building. I saw a mark on a rod journal the other day, from a bearing, it was like the shape of the little slot where you index it dirrectionally in the saddle, I wonder if a micro polish will take it off, or if I gotta have it taken down .010/.010, I obviously ain't made it to the machine shop yet, ya know, but I decided to build a straight 360, I can't afford a stroker kit right now. I don't mind, I saw the thread about dyno'd 360's and I am sure I'll be happy. Good luck w/ your heads.
 
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