The Stovebolt Site Forums The Shop Area Engine Shop 2.5 liter desperate

After 635,000 miles of stallward service my beloved 2.5 liter iron duke has kicked up it's heels. I'm trying to find another one to drop in while I rebuild the original, and suddenly they seem to be the invisible engine. No one seems have one and they don't want to look for one from anything but my year and model of truck.I've been tempted to tell them ANY 2.5 from after 1980, but I've heard horror stories about ones used in front wheel drive apps. cracking heads and putting rods thru cylinder walls and that some were using forged cranks and rods, rather than the cast I know and love. Is any of this true and is there any way to know which engines are the real deal, or an "also ran" turkey. I'm gettin' desperate here, so any help would be really appreciated.

From what I heard, the rear drive style engines are different than the front drive engines and it's the front drivers that had the head cracking problems.The cracked heads leaked coolant into the oil ,gumming up the lubrication system and ruining the bearings.The thrown rods were generally in the Fiero models, they could generate enough cornering G's to starve the oil pick up,a rod bearing spins from lack of lube,the rod welds to the crank,breaks, goes through the block folloewd by a few quarts of oil which catches fire on contact with the hot exhaust.
So it seems the S10 style 2.5 is the better of the bunch, but won't fit in a front drive model situation.

Do you know how these blocks can be told apart? Is there a block code that separates them from the others or is the difference easy to spot? And is there any truth to this forged steel components stuff? Maybe those were the ones that made it into the Fiero, a friend told me they might be used in cars that were built offshore for sale in the U.S. Many thanks for the info

If there were factory forged steel parts, they'd probably be a lot stronger than the standard cast versions.

I may be wrong on the year but, I had one of these in my AMC Spirit, 1982 ? It was the Pontiac motor I believe. Maybe you can find one of these.

You might try Pennock's Fiero Forum

(www.pennock.nl/forum/htm)

Go into the "mall" section and see if you can get one there.

What is this going into, A front driver car, or a S-10? I belive the S-10 Blocks can be ID because they have the holes on the side for the side type motor mounts, but the front driver engines are mounted on the front and rear of the engine, with no bolt holes on the sides of the block. (I think!!)

This should be a very easy engine to find, try car-part.com

Sorry about that, the vehicle is an S-10 from 88, and you would think it would be a simple find wouldn't you? But apparently not in southern AZ.

I've see quite a few in the St. Louis area, so they are out there. Most of them I've seen are early-'80s, though.

Is it true that some of the 2.5 Iron Duke engines have a serpentine belt system that can be retrofitted onto an L22 inline 6 (194/230/250/292)? I have heard a rumor to that effect.

Hey Dutch,
A friend of mine in Orlando showed me a project he was working on: a '30s Model A phaeton w/ an L4 2.5 liter mill, he said came out of a '90s Grand Am or Omega. He said even though the engine was configured for front wheel drive, he was able to "swing" it 90 degrees and use it in a rear wheel drive application. He also said that all the accessory bolt holes for a rear wheel drive application were still on the block and in the right places.

Dutch--you really put me to shame. The first new vehicle I bought was a 1979 Chevy Monza 2+2 hatchback with that very same 2.5 liter (aka 151) inline 4 engine. I found out a year after I bought it that it was a Pontiac engine; they used them in Chevy Monzas, Buick Skyhawks, Plymouth Astres, Pontiac Sunbirds, what have you. I'd be more than willing to sell you mine, but I traded in my '79 in October 1990 after 222,822 (more or less) worry-free miles. I NEVER had any mechanical problems with that engine, never had anything done other than replacing several oil seals at the 100k mark. Other than replacing the carb at 150k and the clutch at 172k, and upteen sets of tires, that car more than paid for its $5800 sticker price. I am not surprised that you got 635000 miles out of it, congratulations. You might let me know if your vehicle had a 4 or 5 speed trans in it. My Chevy had a 4 speed and that was the only thing I didn't like about it, I couldn't shift into 4th gear any slower than 40 mph or the engine would start to lug.