82 heads

[red bandit]

hi all. the 80-81 heads are said to be better for perfomance than the 78-79 heads, because of larger valves. does the 82 heads have the same perfomance qualities? is it as good as the 80-81 heads?is it worth puttin on a 79, or should i just find a 80-81 head? thanks guys

red bandit

[pggg]

Red, I'm running a 80 head/valves/cams with 78 carbs and get useable power at 2000 revs unlike my previous 78 head/valves/cams with 78 carbs which wouldn't come on till 3000 revs, but I put that difference down to cams, although my 80 motor is 1196cc compared to the previous 1102cc. Whether the larger valves on the 80's give more low grunt, I don't know, but I'm guessing it's more a combination of cams and valves that give different characteristics rather than simply the 1mm larger valves alone.

[pggg]

Thinking back, I ran 78 cams in my 80 head for a while, but the low grunt at 2000 revs wasn't there, even with the larger valves and 1196cc displacement.

[andreashweiss]

I just happen to have a 1981 h motor with approx 21000 miles on it sitting in my parts pile. In case you want the complete head I am prepared to take it apart. Also have some 80/81 intake exhaust cams ,cam chain,already out of a cylinder head. andreashweiss@yahoo.com

[red bandit]

first of all. thank you for your responses. i'm really not so worried/concerned about power under 2000 as much as above 5000. mine pulls great at all rpm's. of course not like an 1196, mine is stock. its also full dressed, so its not a racer. i thought i was understanding previous posts that the 78-79 cams, 80-81 heads were the combo for performance. the reason for the post, is i know where there is a 82 head i might be able to get cheap. but if the 80-81 is a better head (performance) or the 82 wont bolt up....i dont want to mess with it. thanks again

red bandit

[TopCatGr58]

Not necessarily getting ahead with a HEAD?

Hey there Red,

TrBIG recently did what you are talking about. The 82XJ head has some extra ports for the YICS system, and they will need to be blocked off. He has a 78-79 engine that the PO put into his XJ, and put ALL of the XJ ignition parts on it. I can't remember if he had some bent valves in his 78 head, but he had a spare 82 head with good valves and such. He put it in with the 78 cams, and it seems to work well. Whether it's working better than the OEM is hard for him to say, cause when he got his XJ, it wasn't running very good to begin with!

As to how much performance boost you can get from this swap is hard to say. You've already got a good setup with the 79 cams. And the 78 with the SMALLER valves was the fastest of the series. So, unless your engine is broken, I don't think it would be worth the effort or $$ to do the swap. Having your engine properly tuned, carbs cleaned and balanced will probably contribute more to it's overall performance! YMMV!
T.C.