Customer dropped off a 472 Crate Hemi--tag says Cummins last digits are 666 AC--it is several years old been sitting since bought--what are the things if any that need a look on this before install--I know the older units had problems -crate says dyno but looks like a few minutes on a test stand to me--pulled intake and covers--pushrods all have room--cam and lifters look like they have run some and look great! Retainers look wimpy and do not fit the single spring--does it need a different spring and retainer--single seems like borderline on this to me--Thanks for the help!

My 528 Cummins assembled engine had several problems the biggest being the finish on the cyl walls was too rough and wore the rings square. These engine were not run, just spun to test for oil pressure, etc. Eventually Ray Barton rebuilt my enigine on Chryslers tab, it's been right ever since.

Yes the retainers are slightly smaller than the springs this is not a problem. The factory valve job is also questionable.

The head gaskets were also rubbing several pushrods.

there were a lot of issues with those engines. i don't run a shop, but if i did, and someone brought one of those in, i'd point him to some of the past threads on this and probably other sites, and then tell him that unless it is torn down and completely inspected, i either don't want to do it, or won't guarantee anything.

You probably don't want to hear this from me ... but tear it down

The engine was run , not sure how long mine had black residue in the exh ports.

I have a 426 , the ID of the springs are about .090 bigger than the retainer step , the valve guide clearance is all over the place , I think my heads have bronze liners now.

the head gaskets have red RTV around the the big water ports, mine had RTV in at least 2 cylinders they put on so much. The #1 exhaust pushrod rubbed on the head gasket enough to keep the lifter from rotating when I spun it over by hand. When I matched the gasket to a steel shim gasket the exh pushrods holes were not in the exact same spot and they were both felpro gaskets.

All the ring gaps were lined up over each other on at least 5 pistons , not sure how much that matters though.

I never checked rocker geometry , After seeing the pushrod and spring issue I pulled the heads and found the head gasket issue so I just tore it down to a bare block.

On the 472 Cummings built Hemi's I dealt with, 528 head gaskets used on some of the 472's before Cummings caught it, resulting in blown head gaskets, or coolant leaks, really nice after it's in the car..,.according to Ernie at Cummings, approx 50+ 472's went out with a bad batch of Comp Cams castings (China),....got one ,....also the rocker adjuster screws weren't tempered right, too hard and brittle, either end will break off,...2 out of 3 engines had the rear main crank seal installed backwards.....



Tear it down, and go thru the whole thing, run the block number thru Cummings, they'll inform you of potential problems, warranty on the Engine is 90 days from purchase,....so that's out the window for your customer's engine



Mike

My Cummins 528... Crap springs retainers, locks. Valve guides so sloppily oversized that three exhaust valves were bent. Deck surface looks like it was done with a file. Not honed with torque plates and oversize to boot. Above mentioned silicone issues, no windage tray installed and rod bearings chamfered for radius clearance with what looked like a stone axe! Please tear that Hemi core down, it is not worth taking a chance!

Tore it down all the way today--I think we had one of the decent units that would have done fine--Guy at Mopar was very helpful over the phone and took his time to help establish which unit we had--approx date of build etc--had lots of specs on that unit THANKS! BG gave some good input as well as others--this engine was run a very short time--Had Engle cam not Comp Yea!!! It looked good--cylinder wall finish looked good, bearings were fine and overall pretty clean build--cam did have oil groove on the correct journals--retainers were weak at best--did NOT fit the spring which was in at 100 seat and 250 open--will see about that after bottom is back together- no protective shim under springs--those flat wound dampers can bore a hole in a head so that will be addressed-no pushrod rubbing, correct head gaskets, billet seal retainer--no windage tray, overall what I would expect for a factory type crate--some of the bearings showed that the crank was a tad fat near the chamfer etc but they always are--would have run forever just like it is--intake was loose , plugs were loose, the RTV deal on the waterholes looked fine to me --heck I would have used more than they did--have not got to the guides etc yet but have to say it all looked like a decent deal to me. Looks like some gaskets , oil , filter, paint , retainers locks and away we go. Thanks for the input

What Mopar number did you call to get all the info on your engine?

well Cummins had a # on the yellow tag ofthe engine-- they don't have the business I guess so it forwarded to Mopar directly--nice man--did not get his name was very helpful--seemed to know much about what was made where and was in each one--said Memphis units were not good that Canada built stood a better chance

I would also recommend a tear down and inspection. I also purchased a used but what seemed like an awesome running 426 Hemi crate engine last fall. This engine had great oil pressure (65-70 psi) cold to hot and the water temp held steady at 180 degrees once warmed up when tested in the car that the engine was in. We ran this engine for nearly 45 minutes. Even so, knowing these engines had issues a full tear down for an inspection was in order before installing it into my Charger. No major issues have been found but lots of small issues that left unattended would have resulted in bigger problems in the near future. So far we found one of the lifters snap ring in the oil pan and another about ready to let loose. The bronze intermediate shaft bushing was seized to the intermediate shaft. The timing chain was stretched. The engine was obviously put together dirty as all the main and rod bearing had lots of very tiny scratches on them. Also, this engine had a windage tray installed and 7 of the 8 rods have hit the windage tray as we found very small scuff marks on the tray. Next is the tear down of the heads. I'm very happy with the decision to tear down and inspect this engine. For the small amount of money I'll be spending to correct these issues I'll feel confident knowing that everything is up to par and it will reduce the chances of having to pull the engine back out anytime soon.

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