My Cherokee Beavis is alive again!

[zero cool]

You can read a little about it here: http://www.grimmjeeper.com/beavis

Short story is simple:

Started the 401 conversion to TBI last spring. When doing the cam swap, half the bearing came out. Further investigation showed need for a full rebuild. Everything gone over. 10/10 on the crank, .030 over on the pistons, line honed, new bearings, balanced, the works.

Fast forward to the summer, the TBI wiring goes in and gets hooked up. Short bursts of work gets everything hooked up over time.

I started working on a dual compressor setup but that's on temporary hold.

Finally got it all back together with a few trivial pieces left.

First shot cranking, it's a little slow because the battery has been sitting forever. But within the first 5 seconds, it catches fire. First crank and it's running!

It has no exhaust so I don't run it long. The battery is low so I hook up the charger. This morning as I was taking off the charger, I notice that I forgot to cap two of the vacuum ports on the throttle body.

But it still cranked and ran with a huge vacuum leak. I capped the ports but didn't want to do a no-exhaust test fire at 7:00am and wake the neighborhood. I'll try that out when I get home from work.


But, for the record, a 401 with a TBI setup from a 454 seems to work pretty well.

[AMX69PHATTY]

If you have a new cam and lifters in the motor, when it's first started up,
it has to be ran for 30 minutes at varying rpms between 1800 and 4000
to properly break in the new cam and lifters, right ?
The cam and lifters actually lapp into one another I think.

[zero cool]

Yeah. I'm going to be doing a full break in but I can't do that until the exhaust is on or I'll burn a couple of valves and that's a "bad thing".

[zero cool]

So I start the first round of break in and it runs ok, if a little rich. But after that round, I open the hood to find the source of the hissing sound. It's half a dozen of the freshly installed freeze plugs squirting out streams of coolant, one right onto the exhaust manifold!

The machine shop said they'd fix it but it's going to be that much longer without my Cherokee...

[Goose]

Holy cow.. 6 freeze plugs misinstalled..um you dont suppose they punched em .010 ??

[runnamuck]

man that sucks. you gonna have to pull the engine again or are they gonna fix it in the truck? for your sake i hope they fix it in the truck. faster trun around that way.

[zero cool]

Each one of them is leaking from one spot each, shooting out coolant when hot as if from a pinhole leak between the plug and the block.

My bet is that when they popped the old ones out, the idiot used a cold chisel on the lip of the plug and scored the block in the process. Had they used a brass drift on the inside of the plug, it wouldn't have been a problem.

The trouble with fixing them in the truck is that one of the problem freeze plugs is on the back of the block. It's dripping out of the bellhousing with no leaks above it. I'm either going to have to pull the engine or tranny. So the engine is coming out. Again.

At least the shop appears to be willing to man up to the problem and fix it out of their pocket.

[Mudrat]

Watch close for JB weld or a similar "fix". It's OK as a trail fix, not on a fresh rebuild.

[zero cool]

So besides boring out the holes and using oversized plugs, what can one do to "fix" the leaks? Is there something one can use with standard size plugs to fill in the gap?


Though on a good note, I forgot to mention that the oil pressure went straight to around 50 psi and held there the whole time. New timing cover, oil pump gears, mid plate, etc. did wonders for the 0-20 psi I was seeing when I tore the engine apart.

[Mudrat]

Couple options ... see if you can spot the common thread

First, a BRASS plug may well seal the leak by it's self. Use a light coat of sealant around the plug befor SQUARELY seating the new BRASS plug. A proper sized driver will help, either a plug seat or a socket the same size as the ID of the convex part of the brass plug.

Second, If the dweeb used a punch or chisel to ding in the sides of the plug (rather than punch one side and set it sideways before removing) and scored the side of the plug opening (dumb rookie error by the way) you may need some weld repair if it's bad enough. The weld will need to be ground down and made ROUND, and more sealant used around the plug - before using the correct size punch or socket to replace it. In this case JB weld properly mixed and cured shouldn't be a major concern, as long as the hole is made round again.

There are some who say these really aren't "Freeze Plusgs" but openings in the block to clear casting sand and water jacket flash after casting. I've never had one pop out when frozen - but then again, I've never frozen the water in the block Pistons yes, water never

But in any case, remove the old plug, inspect the walls of the hole, and don't drive the new BRASS plug in too deep or you'll block the water passage