79 Engine in an 80 Frame

[vanimal5k]

Hello,
My 1980 is not running the greatest. I know someone who has just a 1979 engine. What would I need to do/change to get it to work with my wiring harness?

[TopCatGr58]

Nothing that I know of, the 78 thru 80's are essentially plug and play with regards to the ignition/wiring harness. It's when you try to put an 81/82 into and earlier frame or vice versa that problems ensue!

T.C.

[vanimal5k]

Re: 79 Engine

Thanks for the info. Guess I need to go talk to my friend.

[BA80]

Look at my signature.

It's a direct swap, no changes needed. I personally like the older carbs too.

That 79 engine will feel a little boggy under 3.5 - 4.5K but when it hits that power band hang on.

[D0wn5h1ft]

Look at my signature.

It's a direct swap, no changes needed. I personally like the older carbs too.

That 79 engine will feel a little boggy under 3.5 - 4.5K but when it hits that power band hang on.

What about the other engines make it better than the '79 in terms of bogging down in that RPM range?

[BA80]

The newer engines (80 -81-XJ) have a milder cam grind with larger valves. The 78- 79 engines have an aggressive long duration, high lift grind but smaller intake valves.

They also have different timing curves to accommodate the different cams.

[motoman]

The newer engines (80 -81-XJ) have a milder cam grind with larger valves. The 78- 79 engines have an aggressive long duration, high lift grind but smaller intake valves.

They also have different timing curves to accommodate the different cams.

.....and of course TCI managed mechanical advance for timing and different TCI for 81's, and again a tottally different ignition for the XJ's.

[BA80]

.....and of course TCI managed mechanical advance for timing and different TCI for 81's, and again a tottally different ignition for the XJ's.

Yes Brant, but that has nothing to do with the question he asked.