Replacement Head Options

[DPDISXR4Ti]

Not an immediate requirement, but I know the stock "86TM" heads are prone to cracking. World Products used to make an upgraded head with a thicker deck, but they no longer sell it. It would appear however that most of the new replacement heads available today from places like Promaxx & King Cylinder Heads use the improved casting. Is this correct? Is there a way to easily (i.e. externally) identify these in the field (junkyard)?

What about the later "89TM" heads that were used on the Ranger 2.9 starting in late '88? Are these essentially equivalent to the World Products heads and plug-n-play swap-able? Here's a pic showing how to identify those...

[Merkurfast]

I dont know the answer to your question, but I purchased 2.9 89 heads from Pep Boys with a coupon.. They are ATK brand. I imagine they are the same as Ranger heads. They are the improved type. I researched the ATK brand and they are pretty good.

[brokencase]

The newly made ITM heads appear to have square pedestals.

[DPDISXR4Ti]

The newly made ITM heads appear to have square pedestals.

Like the ones shown above, on the right? Or an entirely different casting?

[Merkurfast]

The heads i purchased looked like the ones on the right.

[brokencase]

The newly made ITM heads appear to have square pedestals.

Like the ones shown above, on the right? Or an entirely different casting?

The ITMs are newly made. Probably their own improved design.
You can see a picture of them on ebay or on ITM's website...
http://www.itmengine.com

[john keefe]

Hey Brad, Had to replace mine a couple years ago. Went with these on eBay (very good rep, gave a lot of info before I purchased) :
https://www.ebay.com/itm/NEW-2-9-FORD-C ... XQPGJSNzr4

They changed their description a bit, and now list these as being manufactured by ProStar. I don't recall if they were ATK or Pro Comp at that time. Nicely finished heads, though. Surfaces all checked out nice and flat. No problems installing, or since, except for the early (typical) valve cover leak, and later a small leak at or near the distributor. Replaced the Dizzy o-ring, same small leak, so probably a weakness in my gluing the back of the intake manifold gasket. I wouldn't expect that to be a fault with the heads.

Don't recall if I used ARP or FlePro head bolts, and if they were Torque-to-yield or not. but I rechecked torque after about 100 miles, and no issues. Exhaust bolts were a PITA, so I rechecked those. I think one or two had backed out slightly, but that could again be installer error.

Has run great since.

[brokencase]

They look like a good price for a pair assembled. Should use torque to yield.

[PetroleumJunkie412]

The newly made ITM heads appear to have square pedestals.

Like the ones shown above, on the right? Or an entirely different casting?

Been meaning to post this for a while, but if you do upgrade from the 86TM to 89TM heads, be sure to get the correct rocker shaft assemblies.

The heads on my 2.9 are from J&C Enterprises in Fairmont, WV, and are their improved "performance" design. I learned the hard way that you MUST either bore out and chamfer the 86TM pedestals to accept the increased oil flow from the 89 heads, or get the correct pedestals and assemblies. The correct ones will have pedestals that match the profile of the improved heads.

There is a machine shop in Chicago, Windy City Engine, that carries refurbished sets for $90 or so.

[DPDISXR4Ti]

It's been suggested that 1989 MY Scorpios got the improved head from the factory. Yes, no, maybe???

[john keefe]

I heard the same thing regarding later Ranger 2.9L's, and thought that might be the case for '89 Scorpios. Same with the notorious cracked heads on my old Jeep Grand Cherokee 4.0L... But, never found a superceding part number for either, just the aftermarket solutions. You'd think between either the 2.9L or the 4.0L, they both had such long production runs that they must have made some improvements in later years, especially to address as big a warranty issue. On the other hand, like the millions of solid rear axles FOMOCO had in stock, it was probably easier to just find ways to use up what's in stock until you're forced to start planning/designing for all new engine architecture.

[brokencase]

I guess revised designed heads are a good thing.

But the only reason a head (any head) cracks is because the engine overheated.
In the Scorpio that most likely happened because the temperature gauge sensor failed, or the coolant level sensor failed - and the owner did not know it was overheating or was low on coolant. Another issue is air trapped in the cooling system during refill.

Overheating is bad for so many other reasons. It's not like you're going to install the revised heads and say "Great I can now safely overheat my engine.."

Like I've always said - Flush coolant system every couple of years. Install a 185F Thermostat (drill an 1/8th inch bypass hole so air won't get trapped in the cooling system. Use water wetter. Done.

The "Condenser fan on when A/C clutch on" modification also helps to keep engine temp under control.

[DPDISXR4Ti]

The good news is that identifying which heads you have is as easy as popping off the covers and looking. Agree that it's not a panacea; it just buys a little more margin against failure should something go wrong. The reality is that when/if the time comes to replace the heads, you'd just want to make sure to go with the later/better ones.

[Ed Lijewski]

But the only reason a head (any head) cracks is because the engine overheated.

The "Condenser fan on when A/C clutch on" modification also helps to keep engine temp under control.

Replacing the fan clutch at ~50 K (they typically last longer but to be safe/sure...) is good protection against overheating.

Condenser fan on when A/C clutch engaged is likely to result in the deicing switch frequently cutting off the compressor resulting in less effective dehumudification of the cabin during most outside ambient conditions where A/C is desired.

I also note that my '88 Scorpio condenser fan temperature switch operated exact as expected with A/C running while at Carlisle last month. It switched on the condenser fan (to low speed) once engine temps were up to normal while moving in slower traffic with ambient temp ~90*.

YMMV

[brokencase]

Agreed - a failed viscous fan clutch is another big contributor to cracked heads.