Chevy 348 Engine...Advice Needed.

Long story short, a few years back I purchased a 1960 Chevrolet Brookwood (Factory 2-door wagon). It was an original 6 cyl. car, but the PO had pulled that and replaced it with a 348 (engine manufacture date unknown). To the best of my knowledge the engine install was never completed and the 348 never ran in the Brookwood. I have sold off the wagon to my dad, since I acquired my '51 Shoebox and the 348 was sold to a friend. I was originally planning on dropping a '66 327 300hp in the Shoebox, but now I'm considering buying back the 348 and installing that instead. Price of the 348 is $300. The 348 is stuck and no components have yet been removed to inspect the internal condition.

So my questions are, when rebuilt how reliable can these engines be and how costly are they to rebuild. I've done some research and noted that some regular maintenance items interchange with SBC/BBC parts.

On a side note, the 348 has a factory 4bbl intake on it, but a factory 3x2 intake would be included with the sale as well. I'm thinking even if the engine is found to be not rebuild able, I could recoup some of the cost by selling off the 3x2 intake.

ANY advice on just general information for the Chevy 348 would be greatly appreciated and I welcome all opinions on the matter. Thanks!

 

If you're just going to drive it, reliability is as good as your re-build. I had one in a 58 Apache, drove it for 2 or three years, no problems, was a gas hog. They are good engines but heavy and not noted for gobs of easy horsepower. But they look cool. But only when you have the hood open. Re-build will not be cheap, and should only be done by someone who knows these engines well. There are a few interchange issues, mostly with '58 348's I believe. If it was me, I'd sell it, build a SBC like I want, put it in in a day, and have some cash in my pocket. Cool-looking engines really need a hoodless car IMO. Can't wow the troops with the hood down.

 

When I rebuilt my 348 it turned out to cost about roughly twice what a SBC cost. But a SBC is the cheapest engine to rebuild so that may not be a good yardstick to measure by. I think I put about 1500 in parts in it but I didn't keep receipts and that was over a period of time. I think I rebuilt it cheaper than most because I searched for bargain prices over time. Mine was bored with new pistons/rings, new cam/kit, rebuilt heads, just your standard rebuild, not really hot rodded. I found a bargain on a 3x2 setup and found Showcars Inc had the best prices on rebuilding parts.
Check the block sides under the head mounting surface in the middle for freeze cracks. They are quite prone to crack there. If its cracked, that may help you decide.
Go here and start reading:
http://www.348-409.com/forum/forums/348-and-409-engines.4/

 

I totally understand where you're coming from. The car is being built up to just be a good-running, reliable cruiser. It's not going to be a show-stopper/ trailer queen but It would be nice to have something other than "just another SBC" under the hood. On the other hand, I do realize that sometimes practicality can greatly trump the desire to be different. It would be nice to be able to pop the hood and have something somewhat different to show though. Thanks for your input.

56don, thanks for the link. I've visited that site before, but had totally forgotten about it. Theres tons of great information there. Thanks again.

I'm really on the fence about motor selection at this point. I guess it'll all depend on what kind of condition the 348 internals are in, then go from there.

As for as machining the 348 block for a rebuild, is there any special tooling needed for these engines? I'm aware that the deck surface isn't the 90 degree norm.

 

Ask your machine shop if they have ever done a W motor before because like you stated, the block is different in that it contains the combustion chamber and requires a knowledgeable machinist to properly set up and bore one of these blocks.

 

Find a machine shop that knows these engines.
If you want more power get a 409 crank and some custom pistons and it will be a big wake up for it.

 

If you haven't been, go to www.348-409.com everything you would ever want to know!

Stan

 

I would think twice about this. The 348 won't perform as well as a 350. They wouldn't even perform as well as a 283, when new. You could spend a lot of money on a heavy, obsolete engine and not get anything to show for it.

I could see it if you were restoring a 58 - 64 Chev but not for anything else.

 

That's a valid point. From what I've researched so far, it appears you can squeeze some horsepower out of these engines. If a basically stock spec rebuild would run 2-3 times as much as a SBC rebuild, I'd hate to foot the bill for a horsepower-driven build on one of them.

 

They cost about the same to machine as any other engine so your real cost is going to be the hard parts. Figure the price of BB parts and add about a third to cover your bases.

They are as reliable as a hammer when properly assembled., @ 300 and you get the tri power you really can't go wrong. Both the 3x2 and the 1x4 intakes are desirable intakes and if the 4 bbl is stock you got a good one to start with.

 

Rusty, stop throwing road apples at 348's, my first car was a 61 Impala, 348/3 speed.
That car would play well with my buddies' 57 wagon with a 283/4 speed.
I doubt the OP is going to go after any national records with this car.

 

porknbeaner, thanks for the input. I'll probably end up getting it back from my buddy, put it off in the corner and do a little more investigating on the internals to see if it'd be worth rebuilding or not. I guess I could always part it out if the block is too far gone.

 

Like PnB said, at $300 it seems like a good deal. When rebuilt correctly it should be as reliable as any other engine. I guess you have to ask yourself if you want to make the investment. Sure the $$ per horsepower can't compete with the SBC but using that yardstick no one would build bangers or flathead Fords either and you know how popular they are. I vote you dig a little deeper into your wallet and do the 348. It will only add more cool to your already cool project.

 

LOL that is the John Holmes yard stick, a short little guy with too muck moxie. Good thing that we are not all measured by that yard stick.

 

Build it!

The 348 is a great motor but you have to do your homework. As mentioned previously the W-engine is a chamber in block design meaning the combustion chamber is in the block and the cylinder heads are similar to a diesel with a flat deck and small reliefs for the valves. The first thing I would do is run the casting numbers to determine if you have a passenger car block or a truck block. The truck block can be built up but you are at a slight disadvantage as a result of the relief cut into the block to lower compression.

As far as cylinder heads are concerned the 348's highest output was 350 hp with the 3 deuce setup and 11.0:1 compression so unless you invest in a set of modern aluminum heads and/or do some port work you will be pretty limited in terms of output. You could build a stroker but that is probably not in the budget and even with the increase in cubic inches you are breathing through a straw figuratively speaking.

348's are more affordable than 409's and if you are willing to spend a little more money you can get some serious power out of them, especially with stroker cranks and new piston and cylinder head options. Plus who can deny the cool factor!

Good luck

 

The 348 blocks do not have near the value of the 409 so keep that in mine if you are thinking of resale.

 

I replaced the 283 in my truck with a "warmed over " 348 (3x2, mild cam, etc.). Three things I would say from the experience:
1. They are more expensive to re-build, but all the parts are available.
2. It powers my 1957 Chevy 4WD NAPCO truck way better than the 283 (I do have low gearing 3:38).
The torque is great.
3. People seem to really enjoy seeing a "W" motor, they look different, in a good way. For the uninitiated,
they spend a lot of time trying to figure out what it is, but they all seem to like it.
As far as myself, I wanted a 348 for my own reasons, and I don't apologize for it. I realize some other choices make better sense from a variety of perspectives, but this was my choice for my reasons.
don

 

I have run several 348 motors thru the years,,Pistons are the highest cost.water pumps are higher also,I had a 11:1 30 over 348 with tri power 4 speed and 4:11 gear Guarantee it would kick a 283 ass, A few people with 350's scoffed at the Garbage Truck motor but were surprised when they got out run also,, They were truck motors first, made good low end torque and quit making power about 5500...

 

Well one could loose the cool factor all together in exchange for zot and find a set of porcupine heads for it.

Here is the thing and anyone who races and has for more then 10 minutes is that speed costs money. Period. You can make a 348 compete or as my friend salt flats can attest to you can make a 409 compete if you throw enough money at it. No W motor is competitive by today's standards as they come. But you can throw modern rods and cranks, heads, pistons rings and induction at one and make one helluva motor at it.

Personally I think that when you do that it is like putting a zoot suit on a millennial. Looks cool on the outside but in the inside it is not a zooter nor does it even understand what a zoot suiter is. Or you can just take it for what it is build it and have fun.

Just for clarification it is pretty much the same for any of our old mills built the old way, they are just not going to compete on a 21st century level. They will be fun but that is pretty much where it stops, fun. personally I like fun, but I have paid my dues and am back to fun.

 

Thanks to everyone for their advice and input, both encouraging and discouraging opinions are appreciated.

If I go the 348 route, I'm thinking a mostly stock build with a mild cam running the 3x2 intake. With that being said, the 3x2 intake is missing the original carbs. What would be an appropriate carb package to either hunt for or purchase off the shelf? Anyone know what the factory carb manufacturer/model/CFM was?

 

Couldn't agree more. My car is being built up to be a cruiser and that's it, period. When it's all said and done I want to have something that's a little unique, but reliable enough to jump in and make a couple hundred mile stretches at a time. If I wanted 21st century performance, I'd be dropping an LS between the frame rails and that's just not my style. I tend to believe that and "old car" should have and "old engine". I probably wouldn't have that mindset if it weren't for the H.A.M.B., but I'm not complaining about that one bit.

I'm thinking the way I'd like to build up this 348, it'll be just as reliable as any other engine from that period whether it be a SBC or whatever. Upgrade the internals to today's standards for reliability and I'm thinking it'll do everything I ask of it. In the back of my mind I just keep thinking how cool it would be to lift the hood and not see "another SBC" there.

 

I may be wrong but I think that they were 4 bolt intakes and would have run Rochester 2Gs. Gm ran a lot of Rochester and carter carbs over the years.

if it were mine I would tweak the 4bbl intake and run a single Carter AFB on it. Holleys got a lot of press back then and I am a natural Holley guy but I have been known to pull a Holley in favor of the Carter. Depends on the mill and I know for a fact that the W motor responds well to the Carter and looks good doing it.

 

They were rochester 2g's from the factory. The outter carbs had no idle circuits and the base plates were different. If you try to run normal 2g's on the outter carbs it will not work. You will have vacuum leaks and the engine will run way rich!

There are a few kits you can purchase to convert normal 2g carbs for use as the outter carbs. The center carb is just standard 2g. I don't know where you would purchase said kits off the top of my head but I'm sure someone will chime in.

The original carbs are very hard to find and priced accordingly.

 

Thanks. The 4bbl intake has the original carb still with it. Rebuild and I think it'll be good to go. May run that at first and just keep the 3x2 intake on the shelf for now.

 

They used 2CGs as said the outer carbs do not use the power valve or power pistons how ever you want to call them.
Speedway sells the kits to cover the outer carbs yo just have to look the the small carbs.

 

Actually all three carbs need to be modified, they use longer throttle shafts. There is a carb guy on here that does the modifications and does a way better job then the speedway kits, I don't recall who he is though. Someone will chime in with the proper introduction I am sure.

Contrary to popular belief you can run three center carbs, you just have to run the idle circuit. it take a different tune up then to run the outer carbs dead. I would want to run the correct type of outer carbs but if I couldn't I would not be afraid to run them the other way.

 

Dickster27

 

Yep that's the guy. You would think that I could remember a name like that.

if I wanted end carbs I would send my stuff to him.

Thanks GV

 

Great guy, helped me sort out the 3X2's on the 348 in the T. He also owns a 27 with a 348 in it so he knows his way around that set up.

 

Nice! Thanks for the info, guys.