Sick and thinking.

[Old Yeller]

I sitting at home on a friday night with the flu (yea, isn't that awesome), and I'm thinking about my upcoming engine swap.

I have a 93 Parts YJ, with a 4.0L that I'm stealing the motor and transmission for my 90 YJ (currently has 4.2L)

Some Internet searching shows me this will be a fairly straight forward swap, but I fully expect to run into something. I have never had a major job on my jeep go flawless yet.

Anyways, the 4.0L has about 260,000km on it. If I'm going through the effort of a motor swap, what should I be doing to freshen this thing up a bit? It runs great, but thats a fair number of kms.

Should I just drop it in, and drive it? Should I be doing a cylinder hone/ring job? Valves?

What would you do?

Rob D

[cherokeefan]

get a chev 350 for the transplant instead, lots around and easy to get parts. the added grunt would be sweet.

[Creepy]

Nothing you list there, that's all rebuild stuff.

Compression test.

Maybe a rear main seal. Easy if the motor is out, pain in the ass if it isn't.

The valve cover baffles get clogged too.

Other than that....drop 'er in.

[theonlybull]

timming chain, water pump, thermostat. clean and paint base/valve covers, new gaskets.. stuff i normally do when swapin' a motor.... doesn't cost much, and it's parts your not gonna be wondering about.

[90bronco]

Like jan said that's engine work .... no need but like theonlybull says ,i would put a timing chain in it and all the gaskets i:e base pan,valve pan and front gaskets . Maby a water pump ,for sure a t-stat , front and rear main seals . All easier when it's out on a stand.

[Creepy]

I've never had to replace a 4.0 timing chain, or even heard of one causing issues, and wouldn't bother with the water pump unless it was leaking/bad bearing.

T-stat - he says it runs great now, and the t-stat is very accessable in the vehicle, so maybe don't bother.

if it ain't broke.....

I mentioned the rear main seal because its much more difficult in the rig. the front of the engine stuff on a YJ is easy, just pull the grill/rad.

[theonlybull]

Aug 6, 2010 22:49:42 GMT -4 Creepy said:

I've never had to replace a 4.0 timing chain, or even heard of one causing issues.

then don't worry about it..... dunno what they cost, but about $28 for a 5.0L always figure it's cheap insurance

[90bronco]

Aug 6, 2010 22:49:42 GMT -4 Creepy said:

I've never had to replace a 4.0 timing chain, or even heard of one causing issues.

Ok that's why i try to pay attention here lol ;D i have never had a 4.0 ,i would have pulled the cover and checked it anyway and new gaskets.

[Creepy]

One of the bulletproof features of the 4.0 i guess. Its just not a problem.

Now the 360 on the other hand.....

[theonlybull]

lol. stuff's just better now i guess. used to be every ford i pulled apart needed a timing chain. the last 4-5 have been as good as new..... but i always swapped them aswell..... makes me feel all warm and fuzzy..... lets me sleep at night not having to worry about it lol

[Old Yeller]

Thanks for the thoughts guys. Working on the engine in the YJ isn't that big of a chore, and like you say, if it ain't broke, don't fix it. It works good now, so I should when I swap it over. I'll then go from there. I'll be sure to get some pics.

Rob D

[davidson]

ya if it were me i would just change the rear main seal and oilpan gaskets now just because they suck to change when in the vehicle. anything else is easier to get at later on.

[Old Yeller]

Agreed. I've actually done the rear main twice already, once in a 4.2L YJ and once in a 4.0L XJ. I noticed the waterpump leaking when I had it running, so that will be getting swapped out as well.

Good progress today, front of the jeep is stripped, including wiring, and may get the motor out tomorrow.

Rob D