Hot Rods Can you guys take me to early Hemi school?

I have a nice 1930 Model A coupe- it's chopped, channeled, etc. It has a ZZ4 small block Chevy in it with a 700R4 trans. I'm bored with the somewhat generic look of the small Chevy, and want to replace it with an early Hemi. The small Chevy has about 370HP as it sits, and that's more than sufficient. I'm not racing it, it's more a cruiser.

I have an opportunity on two Hemi engines. The first is an intact Chrysler 331 without the extended bellhousing. It's as removed, everything included, It turns over and the owner says it runs. He wants $2500 for it. The second is a 354, disassembled, all parts complete and accounted for. He wants $1500 for that one. This is too long a story to exlain, but suffice to say, I am very confident that both engines are damage free, as far as cracked blocks, heads, etc. Both will need rebuild.

I'd be interested in which of these you guys think would be the better one to purchase? I don't need the 370HP of the Chevy is necessary, but I'd like to get as near to 300 as possible. I don't want to break the bank on this enigne. Of course I fully realize that Hemi's are NOT cheap, and it is considerably more than a Chevy to build, I'm not blind to that fact. I don't necessarily have a set budget amount for this, whatever it takes is what it'll be. That said I would like to somewhat contain costs where I can. My main concern is the almost absurdly low compression ratio these engines came with. I can't imagine you can make any power at all with the 7.5:1 to 8:1 they came with. I'll definitely go with a roller cam, I'm not going to even thinkn about messing with flat tappets at this point in time, it's not worth the break in stress and headachesthey bring to the table.

Any and all info and suggestions would be greatly appreciated. Which engine? Are these decent prices for these engines? What to equip them with? Power levels attainable without huge expenditures? Where to get new and used parts? I'm aware of Hot Heads in NC, anywhere else? Any and all info appreciated?

 

If you don't want to "break the bank", a roller setup for an early hemi is probably counterproductive. Also, "the owner said it would run" is worth almost as much as a styrafoam coffee cup. Maybe, maybe not. When paying that much for a used engine lying on the garage floor, you've got to assume the worst. A friend just paid good money for a '61 Pontiac 389 tripower engine that "ran when he pulled it", and you don't want to know what was lurking inside that engine.

 

If you can swing it, I would buy both! Yes, expensive to build but nothing looks like a hemi!

Dave

 

You can crunch some numbers and do a bit of research to answer your questions fairly easily. Assume both engines need to be rebuilt at the least. Call around to your local machine shops and get a couple quotes regarding honing/boring all the necessary surfaces, decking the block and heads, and a valve grind. Then you can do a little Google-fu and add up new bearings and rings at the very least and see where you land. That would be a best-case-scenario, low-buck rebuild. Then add 10% to that price because that's how it works. That should give you a fairly good idea what the cheap end of the spectrum will run you. I wouldn't bother spending the money on a roller setup if you're trying to pinch a couple pennies or at least make your dollar stretch a little further.

Those prices don't seem terrible, BTW, but you should know what you're up against budget-wise before you pull the trigger. That $1500 331 deal could turn into a $10k nightmare! Do a search here and gather as much info as you can. Good luck!

Here are a few links of Hemi build stuff I've done in the past...

https://clampdowncomp.com/tech/how-to-select-the-proper-pistons-for-a-vintage-engine/
https://www.motortrend.com/how-to/1009cct-50s-hemi-engine-21st-century-technology-build/
https://www.motortrend.com/how-to/0810sr-331-chrylser-hemi-engine-build/
https://www.motortrend.com/how-to/0811sr-chrysler-331-hemi-engine/

 

The price to rebuild the 331 and 354 will be exactly the same assuming condition of both motors is the same. There would be no real advantage to building the 331, so why not go for the cheaper and larger 354?

 

Don't forget the Hemi Tech Index . . . . lots of reading there.

HEMI Tech- INDEX | The H.A.M.B. (jalopyjournal.com)

 

Get ready to fork out some serious cash. Whatever you think it will cost multiply that by 3. This is coming from a Cadillac guy.

 

The machine work should be the same no matter what engine it is.... Parts are where the expense comes in... Hot Heads is the go to place for hemi stuff...You can get a good set of roller lifters for around 400$...You can run up to 11 to 1 compression with no detonation due to the hemi head....I like mine...

 

1) Check the engine numbers to see if they're industrial or truck engines.
2) Don't be surprised if you spend nearly $10K on an engine that weighs 160 lbs more than your SBC and makes about the same peak HP.
3) All else being equal, I'd buy the 354. For one thing, it can be bored 0.0625", allowing use of stock 392 pistons, so you spend less $$ while increasing the compression ratio.
4) Get educated. Get a copy of Ron Ceridono (sp?)'s book, "The Complete Chrysler Hemi".

Those are my lessons learned. I bought a truck 354" (Chrysler Hemi #1619829), originally installed in a Dodge school bus and a set of #555 354 car heads. I have no regrets.

Before & after:

 

Get the 354, an adapter, and put it in front of the 700R4.

 

ONLY if the block has been sonic checked for core shift first.

It is rare, but the chances are never zero.

 

You’re embarking on a $20k venture. You could do it for less, but you want higher compression and a roller cam, so you won’t. You’ll make 40 fewer hp and weigh 200lbs more. It’s not for everyone. Build the 354.

 

300hp is totally do-able.

That might mean pistons, as the stock compression is quite low.

That, and a decent cam. While I do have a roller cam in my blown 354, I do not have one in my unblown 354.

You can save some major coin by just running a hydraulic flat tappet cam. They are not the nightmare that they are being played up to be. A good roller cam and lifters can push you towards $1k.

If you do want to go that route, look for an off-the-shelf grind. A custom grind will drive up the price. Herbert Cams made my custom grind from an 8620 steel billet. My roller lifters are Johnson's.

Whatever cam you are looking at, it cannot even approach 0.500" without rocker stands with altered geometry.

Even the factory 4-barrel manifold is pretty good. It's just got the heavy. Put a thin adapter plate on that, and you have all the carburetor choices you want.

Don't forget, if the ZZ4 is in good shape, you can sell that.

 

If he's got a good machine shop, one that does not charge rich-man rates, it won't be $20k if he's careful, and takes sound advice.

I have about $25k in one of my 354's, but the only thing inside the block that is original is the crank, and there is a 6-71 on the top.

 

When you are writing checks for the expensive parts, watch this video. It will ease your pain.

 

I like it too!

One day I will have time to work on this....

 

Thanks guys. My fault that I didn’t articulate clearly- I have no intention of running the 331 as is. The chances of it running are pretty good, the chances of it running well are likely zero. I’m thinking the 354 is probably the better deal as you all said, they’ll both need to be rebuilt anyway. The comment about the 392 pistons is a good one. What compression does a stock set of 392 pistons in a bored 354 typically yield?

 

I read that about the stock 392 ‘s .
It’s true as far as money goes,,,,but you still won’t have any compression .
Bore it and buy some good Ross pistons,,,,with at least ,,10.5 to 1 .

If you are worried about lifters , you can have your originals resurfaced,,,,,,they recrown the face ,,,,,work just like new .
The cam can be reground as well,,,,,if you are nervous about trusting stuff .
But,,,,,,,you can buy brand new from Hot Heads,,,,,,and they will work great .

As a matter of fact,,,,if you will get on their website,,,,they can supply anything you need for an early Hemi,,,,including the Ross pistons !
Check it out !

Tommy

 

Holy Mackeral - I just looked on line for the book that Gary recommended. Amazon has a used one for $680.00. No one else seems to have one at all.
I knew Hemi stuff was pricey but that's a bit much, no???

 

The 354 is far easier to adapt to what you already have.

You might not even need to mess with the firewall.

 

There's one on eBay for $994.94! LOL

Didn't realize they were that scarce, but I know Ron has been toying with the idea of doing an updated version of the book for awhile now.

 

Help a “know nothing about Hemi” guy, why is the 354 easier to adapt than the 331?

 

If the 331 is from 1951-53, it's got an extended block like a pre '49 flathead, or early Olds V8. '54 and up 331s are basically the same as a 354.

 

It's definitely not an extended bell version. I have no interest in the challenges that they present.

 

Yeah, I saw that. I was answering Budget36's question.

 

I got a lot of parts and info from Bob Walker at PowerPlay/ Hot Hemi Heads. He claimed stock 392 10:1 cast pistons yield ~10.3:1 in this combo.

The rest includes stock 354 rods & crank, 340 oil pump and Hot Heads filter adapter. Cam is a 280 hydraulic grind: 224*@0.050/0.435” lift/108*LSA; I’m pretty sure it’s a Schneider. The top end has stock rocker assemblies, new adjustable pushrods and new ss valves.

A few more thoughts:

If using a trans adapter, ensure it positions the starter on the passenger side. Steering, exhaust, and brake (and clutch) linkage makes for a really tight fit on the driver's side, especially since your coupe is channeled.

Find an experienced and trustworthy machinist. I wanted someone I could count on, not just a "good buddy deal" or an inexperienced shop hoping to use my project to expand its repertoire.

You have to pay to play. I'm on a modest "Dad's monthly allowance" budget and Hemis are really expensive, but it's exactly what I want for my project and I couldn't be happier. Once I quit fretting over the cost, I enjoyed the process a lot more. You could do it for less $ if you have the technical expertise to assemble it yourself and use stock (cast iron) parts.

Hope this helps.

 

There is always the dodge and desoto engines . The dodge engines can be in the SBC weight range or a 330 desoto is lighter than a 331 Chrysler

 

Most 331's have an integrated bellhousing.

As far as I know, nobody makes an adapter that would bolt on to the front pump bolts of his 700R4, after he carefully sawed off the existing bell housing.

That style adapter only exists for a Chrysler 727, and that is a 3-speed automatic, without an overdrive gear, and he not only doesn't have a car set up for one, he doesn't own one.

Or, he would need to run a manual transmission.

 

If that's the case, either one works.

So long as the block has been checked for core shift, you can bore a 331 for 354 pistons.

 

^All great advice, don't get hung up on compression ratios, these Hemis were torque monsters from day one, and they're more than enough, even in stock form, for almost any HAMB era car. Also, the stock exhaust manifolds are more than enough for even "Hot" built engines. Unless you need headers for fitment or style choices, the stock ones work perfectly and are naturally pretty tight to the block.

Ultimately, I wouldn't go crazy with parts and upgrades, a simple refresh with new bearings, rings, pistons, etc... will be more than potent enough to blast around in a lightweight hotrod or custom. Keep in mind these engines were designed for cars weighing 3700-4400lbs!

Shoot me a PM if you have any questions or need recommendations, I've built/worked on dozens of Hemi's since I could barely walk, so I know what you're getting into.

~Peter