Strange Chrysler Hemi number

Everyone has a different approach when it comes to projects like this. Having absoultely NO history on the engine, I would be hard pressed to ****on it up and try running it. There are too many variables. I want to know everything that I can so that a rational decision can be made for 'what to do now / next'. Pull the cam so you can inspect it, check lobe condition and depending on the markings, ID it. Questionable Markings? Then send it out to someone with a Cam Doctor. Pull every bearing cap and inspect both the insert and the shaft. Pull the cover plate on the oil pump and check clearance. All basic stuff, yes. Time consuming, yes. But with the price of Hemi parts being what it is, can you afford to ****on it up and take a chance ?
Use a standard 392 head gasket.

 

Okay... I'll poke and prod and see what I come up with. Thanks for the advice! Still very curious what's barried in there!

 

Oh, one more thing!

Is it possible these are stock replacement high(er) dome CAST pistons? That 392 marking sure looks cast to me. I guess I just didn't realize that anyone made a domed top cast piston setup for an +.040 over-bore.

 

All 354-392 piston will have a dome similar to what your pictures show. The compression is dependant on the height of the dome above the wrist pin. Different mfgrs use various shapes for the dome and shoulder. Upon removal, place a stock 354 piston on a common wrist pin with the 392 piston then compare the two dome shapes and heights. A down fill check is the only way to really know actual compression. If you need help with the process, call and I'll walk you through.
Upon removal, look inside of the piston, cast or forged will be evident.

 

Okay! So it's possible that these just may be stock replacement cast pistons? I've not looked at anything other than 331 pistons and they are flat, so wasn't sure.

 

Started taring it down last night. Here's what I found:

Still ***embly lube in the valley area...



This piston wiped right off...



All the cylinders look like this one...



I randomly pulled this lifter and took a peek...





No visible ware on the cam side...



Just looking down at the lobes through the lifter bores they look good. Still going to pull the front cover and see what the cam is none the less.

 

The lifters may have given trouble. They have a narrow oil supply groove. The lifters drop down in their bores when a high lift cam is used. These lifters will sometimes not pump up as the supply is above the groove when they want to take on oil. Also fill the rocker shafts with oil before re***embly.

 

Scooter, looks like you got a freshly built motor there. Congrats! I think I'd still have the bores sonic checked just to make sure it's OK. I'm not sure, but I think most of the bore could be checked without the pistons being removed, just roll the crank so each piston is at the bottom of it's stroke, and you should be able to get most of each bore checked.

 

Definitely a good point on filling the rocker shafts and an interesting statement about the narrow oil grooves on the lifters. Hmmm... are these the stock style hydraulic lifters? I don't have one to compare to.

I don't know what the cam is or if it has anything more than a stock lift, but I'm going to hopefully find out very soon. If it has high lift I need to look at the guides to make sure I'm not bottoming out too.

 

looks good man.. i say ****on it back up and run it!! if you break it you break it.

 

Brotha' bean! HAHA!

So... should I send the bill to your house or over to the shop for replacement hemi parts if it breaks?

 

I don't know if this has come up. A 392 has a different piston pin heigth than a 331-354. It is higher so a 392 piston will not come up as far. The compression wil be lower.

 

Yep! I noticed that. I'm guessing 8.5:1 or so with the way it sits right now. That also explains the ring at the top of the bore.

 

Okay, a little update for you guys. The motor is apart as much as it's coming apart now. It turns out this things is SUPER clean inside! Pistons are definitely new, the timing chain appears to be new (although it's a stock type replacement), I'm going to check out the lift on the cam tonight, but it appears to be stock specs if not actually THEE stock cam.

I got ahold of the guy that build it in Lake Havasu and he said he thinks he rebuilt it about 5 years ago and he just ran it to show the guy he sold it to and that guy never ran it since.

SO! The plan is to regasket, put it back together and just run it as is. Not expecting much performance out of it, but it will be great for shaking down my Model A. In the mean time I'll build what I REALLY want from one of the other blocks I have.

Here's some pictures of what I found when I dropped the pan and pulled the front cover.



Crank still has the markings from the machinist on it.



Oil pump looks new and the pickup was very clean as well



The pistons are DEFINITELY new and are made by HY DUTY and are cast pistons. Anyone ever heard of that maker??



Stock type timing chain, but only had .094 deflection to it. Appears to be perfectly good as well. I would rather it be a double roller, but it will work.



The pan looked clean inside with just a nice collecion of ***embly lube sort of gumming up the bottom. No dirt or sparkly things in the pan, or evidence of water getting in there. Oil looked good when I drained it as well.

I'm going clean it up, repaint, put it back together, and run it pretty much as is. Changing the intake and valley cover, but other than that, gonna leave it alone and just run it.

 

Scooter, since I used to be a distributor for HyDuty many many years ago I should have recognized the top...this getting old is pure ****...I don't recommend it. Good pistons, very heavy, as in over 900 grams, but very durable. The entire HyDuty operation was sold to Badger to augment their production but Badger never offered the Hemi parts. Ultimately, the molds ended up at Egge and that is what you buy today. Interesting that the current production pistons DO NOT make advertised compression. Be advised.
With regards to the lifters, and as previously noted, it appears that the builder may have used a B-RB lifter instead of the A-LA piece. The oil feed groove appears very high and will not oil properly. Suggest changing them.

 

I'm going to have to get all that duct tape back or charge you a core charge, you know. I'm so glad everything seems to be checking out. I hope I'm as lucky with mine.
cheers.

 

Wait a second... so these pistons are ****? My lifters are not correct either? I had another HAMBer compare these lifters to a set he had laying around and he said they appear to be exactly the same as a stock 331 (or maybe he had 354).

I'm very reluctant to put money in this motor and I'm not changing the pistons. I'm not looking for any real performance out of this motor. If it runs and drives effeciantly that will be good enough for what I want to do with it. HOWEVER, if the lifters are wrong than I will replace them.

Since we're on the subject of lifters, are they the same as a Slant-6 motor? I think I heard that once.

EDIT: I just reread what you said Gary. HA! I thought you meant the pistons ****ed. Looks like you're saying they're fine but they just aren't the compression that's advertised. Cool. I can live with that.

 

HAA!!! You rock!! Coming to breakfast tomorrow??

 

fresh! that thing is real clean, glad youre gonna have some fun with er.

 

Just took a couple measurements off the lifters. The groove starts at 1.430 from the tappet/cam face and the oiling hole is actually at 1.500 (to the center) from the tappet/cam face. They do not appear as if they would ever come out of the lifter bore, but from what I gather of the things I'm reading is that they do not dip LOW ENOUGH to collect oil and pump up the lifter therefore throwing off valve clearances and such. Is that what we're saying here?

 

(talking to myself here. HAHA!)

I just got some solid measurements from another HAMBer. He meausered his 1954 331 lifters and got the EXACT same measurements as mine including diameter.

So what would I buy if THESE aren't the right ones??? Are the truck blocks different in the lifter department??

 

Scooter, pictures can be deceiving, the numbers don't lie. Your 1.5" is dead on, no issues. As for interchange, ALL Mopar engines use the same diameter lifter ( AMC and some others also) the difference is in the location of the oil groove. If the groove is too high then it will not 'see' the window in the block long enough to get pressured.
The A-LA is the closest we get to the original VL-8 part.
The pistons are not junk, but a 392 piston in a 354 block will drop compression to 8.5:1 or so. Who knows, maybe it will be cheaper to burn kerosene than gasoline....
As for differences in the truck blocks, most had a thicker rear main cap, this means a 1/4" longer intermediate drive shaft.

Cheers

 

Alright! Thank you for clearing that up Gary!! I'll run 'em. I'll get on the horn right now and order me some gasket and freeze plugs and get 'er goin!!

I'll post an update when it's all back together and lookin' purdy!

 

I & many others have used the 361-413 lifters w/o problems. I was thinking 331-354s had the swinging oil pump pick-ups instead of the screw in type.

 

This whole motor is just weird! HAAH! Would surprise me to hear that something else is weird also...

 

There is no adjustment in the valve train. A high lift cam has a reduced bace circle as already discussed. It also increases the distance between the lifter and the rocker. If you determine that you have a high lift cam, check the clearances at the valve to see if you need adjustable push rods.

 

I'm ahead of ya'! The motor already came with adjustable pushrods. They look to be in perfect shape too.

I didn't get time to check out the cam tonight, but tomorrow for sure.