engine swap do/don't?

[dan58]

I have a dilema with my rig. It's strictly a rockcrawler, FYI. It runs on propane. It will also be getting a fresh TJ999 to replace the current one.

I have a tired 360 with an Edelbrock intake and cam. It has good low end grunt, and I can't complain. The problem is the heads are worthless, as well as the exhaust manifolds. Someone welded the exhaust directly to the manifolds. 111!!!

The engine burns a ton of oil due to bad valve seals. It's 1973 vintage.

I have an 86 360 in my posession. It ran like a top when it was still in the Waggy. I had oringinally planned to swap the heads and exhaust manifolds, but that is going to be a lot of work. I plan to remove all the emissions garbage and stick with my propane and Edelbrock intake. How much low end am I going to realistically miss with that cam? It will save me a ton of time, $, and headaches to just swap the engine/tranny at the same time.

I also plan to put a 4:1 in the t-case, so I should be helping the motor a bit there as well.

[jeepsr4ever]

hmmm I may be so inclined as to replace the heads and exhaust with the parts form the donor.

[dan58]

hmmm I may be so inclined as to replace the heads and exhaust with the parts form the donor.

Reason being? :oops:

[jeepsr4ever]

Well if its only valve seals that are leaking..

[dan58]

Well if its only valve seals that are leaking..

And the exhaust manifolds are junk. We're talking piles of booger welds holding on the pipe to the manifold. The other thing was trying to actually remove those manifolds. Seems like it would be a lot of broken studs as part of the process.

[Goose]

I wouldn't think it would be a drastic amount of bottom end loss, (Realistically they claim a 20% gain in torque) which I would think would be offset by a slightly fresher engine..

[dan58]

Well if its only valve seals that are leaking..

And the exhaust manifolds are junk. We're talking piles of booger welds holding on the pipe to the manifold. The other thing was trying to actually remove those manifolds. Seems like it would be a lot of broken studs as part of the process.

bump

[AMX69PHATTY]

No expert, but would think the samller stock cam in the all original 360 would give better low end torque than the larger Edelbrock Performer cam in the old motor. The '73 motor might have the screw in rocker stud heads that allows for adjustable valvetrain, whereas the '86 motor should have the bridged rocker setup which is non-adjustable.

[AMX69PHATTY]

oops :oops:

[tufcj]

The big DON'T - put a Chevy engine in it. :?: :shock:


I don't think the Edelbrock cam's lift and duration are that far off stock, so performance shouldn't suffer too badly.

One thing I would do is install a new roller timing set, and make sure the cam is set to "0". Some of the later motors had the cam retarded a bit for emissions.

The exhaust pipes will probably need to be redone anyway, as there should be a loose flange around the pipe and a bell on the end. AMC used a donut gasket to allow for flex.

On the exhaust manifold bolts, give each one a good whack with a hammer before trying to remove them, the vibration will help break any rust free so the bolts won't twist off.

Bob
tufcj

[dan58]

The more I think about it, the more I will just swap the whole mess. I am putting a new transmission it it anyway, so this could be a good thing overall.