Rebuilding the 348

58Apache · November 27, 2010, 07:44:00 PM

Hi,
I have my truck most of the way disassembled so it was time to find out what a rebuild on the 348 is going to cost me. It's a 58 348 and in the dually with big gears it doesn't need to have a lot of HP or torque. I trade top speed for the gears.

Anyway I know one of the freeze plugs are leaking and I felt some vibrations in it, so while I have the truck apart I figured I would see what it's going to cost me. It has a manual tranny in there and I think I will keep it in there right now. So maybe the vibration was something other than the internal engine?

A local racing shop recently sent me a quote of $3,6xx.xx plus $300 more if I want a custom ground cam.

I just sent an e-mail to Egge to get some info on parts. I may just take it down to the local machine shop for the things I can't do and do the assembly myself.

Thoughts or tips?

phat rat · November 27, 2010, 08:34:26 PM

The price the shop gave you w/cam is about what I just paid for a 454/489 stroker to be built. This includes the stroker kit, and all new parts including all bolts plus balanced and blueprinted. The only used items were the block and bare heads

58Apache · November 27, 2010, 09:29:26 PM

Yeah and crate engines new from the factory are always an option and may be close in price if you shop around? But this 348 is "different" when you look under the hood.

So for the unique and "cool" factor I am going to see what options I have and try to get the costs down.

wayne petty · November 27, 2010, 10:09:46 PM

just curious.

how are your engine building skills...

you always have the option of the ring and bearing the motor and a decent valve job... with possible new hard seats and valves.. ... a reground cam and new lifters... new timing set and oil pump...

in my looking around... there is talk of going stainless valves and NOT hardened insert seats... but this takes more research...

if the bore is NOT that worn.. you can get away with it..

its not a race car...

i would look around to other manufacturers of 348 pistons if you need it bored... if there are any...

http://www.hotrod.com/techarticles/engine/hrdp_0810_edelbrock_409_chevy/je_forged_pistons.html

http://www.chevyhiperformance.com/tech/engines_drivetrain/shortblock/0907chp_chevy_348_big_block_engine_restoration/index.html

http://www.maxchevy.com/tech/2008/iii_4-head-3.html

http://www.hotrod.com/techarticles/engine/hrdp_1012_walden_world_products_w_series_409_chevy_engine_block/index.html

http://www.carcraft.com/techarticles/ccrp_0802_409_chevy_engine/index.html

Rrumbler · November 28, 2010, 04:26:48 AM

One thing to rmember about the 348 and 409 "W" engines is that the combustion chamber is in the cylinder instead of in the head; the deck does not sit at 90 degrees to the bore axis, so machining takes some attention to detail - more than normal.

58Apache · November 28, 2010, 01:15:27 PM

Thanks guys. My engine building skills aren't that great ...I put one back together once and it ran, but that didn't mean I knew what I was doing.

Good points, I may be able to get away with an "overhaul"...but how could I tell if it needs a re-bore?

Thanks for the links. I will check them out.

bowtietillidie · November 28, 2010, 02:10:34 PM

I read this whole post and all the stuff Wayne posted . it was all very interesting...... But If you aren't well versed on assembly of the W motor.
Do not try using the thin ring compressor that was talked about . It is VERY easy to break a ring with it . Many years ago I raced these W motors and overhauled lots of them. At that time Lyle made a special ring compressor for the W motors . It had a tail on one side that went down into the combustion past the valve releif and protected the ring pack till everything was safely in the bore. with out this ring compressor it so easy to brake a ring on assembly .

348tripower · November 28, 2010, 04:02:37 PM

There are some bearings that interchange from the SBC. And i think the oil pumps. It has been some time since I have done one of these. But the look is cool.

Jokester · November 28, 2010, 04:38:24 PM

There's one for sale over on the HAMB. It's in Ohio, don't know how far from you.

http://www.jalopyjournal.com/forum/showthread.php?t=532179&highlight=348

I have no connection with the seller or the HAMB, just happened to see it after I saw your post.

.bjb

kb426 · November 28, 2010, 05:34:21 PM

In answer to your question as to tell how if you need to bore it or not: the best way is to use a dial bore gauge. This will allow you to see if the cylinders are out of round and if they have taper. A street engine can tolerate a little out of round but the taper is the killer. The taper won't allow the rings to seal from top to bottom of the stroke. The crank and connecting rods all have to be miced to see if they are round. One other thought: is this a truck or passenger engine. There are 2 different deck heights. The truck engine is a tall deck height. From what I remember that is a poor performing street engine. One other thought about round cylinders: The vacuum in the cylinder is what causes it to fill as best as it can. When the cylinder is out of round or tapered, it will not be able to create as much vacuum to fill properly.

58Apache · November 28, 2010, 08:20:25 PM

I believe I ran the numbers and found it to be a truck engine. This will be in a 1 ton dually with low gearing so it don't have to be a high performance engine. Just run and be reliable.

WOW that one over at the HAMB looks like a fairly good deal ....depending on how much you can trust the guy...but how much abuse had it taken? I wasn't sure if this guy selling it said that HE wen through it or what. Anyway, not sure I could come up with that sum right now or I could get this one rebuilt

Ok sounds like with those rings there are some things I need to watch out for. Leaning back towards having it rebuilt for me, but I will have to save up a while.

Thanks guys,

junkyardjeff · December 07, 2010, 11:36:26 PM

Is the racing shop the one off 35 in Beavercreek?,there is a little two man shop thats been around since the 50s that you might want to check into. I am going to have them do the machine work on the Y block I will be buillding and assembling it myself since I dont want another fiasco with wrong parts like with the 351 I had done. PM me and I will get the phone number for you.

58Apache · December 08, 2010, 01:13:15 AM

Yeah that's the place I got the quote from. I know there's a small machine shop in Beavercreek that I may use if I can get help with assembly. I have a mechanic friend in Indiana I may talk into coming over, but not sure of his experience with these engines. Some good info on things to watch out for in here. I'm not real knowledgeable on engine rebuilding details and the unique things about these W motors, but I understand the basics.

wayne petty · December 08, 2010, 09:47:38 AM

the problem that has seemed to put a stop to you is what bowtietillidie said about not using a thin ring compressor... as it can slide down under the step in the relief in the bore...

what is exactly wrong with this motor?

/

is it down on power...

does it smoke...

is it misfiring/missing....

have you gone through the basics... points.. condenser. timing. wires... carb kit.. compression test.... if a low cylinder is found...a single squirt can pump of oil to see if it is the rings or the valves. a cylinder leak down test.. after running the engine to get rid of the oil..

checking the timing chain for SLACK.. by rocking the crank back and forth to see/feel how much slack there is before the cam starts to move...

low oil pressure...

cam gone flat???

smoke from the tail pipe???

or.. just wanting to freshen it up ...

the idea of building an out of the normal build motors.. download the various parts catalogs.. and put together a list of parts including the catalog page.. so you have several catalog brands pages covering each part... if its not a conventional part.. there are in some catalogs more foot notes than others...

i posted the various 348 and 409 builds to familiarize you with the way its done... sort of a class in W motors... i realize that not every tiny problem is covered in every article..

the only thing different i see on assembly.. is dealing with the angled deck when installing the pistons.. so you might want to use a plier type ring compressor... perhaps with a modification to one of the bands to hook it like bowtietillidie described.. i wonder if he has one of those left... he might live close enough to you .. that you might ask him for help on assembly day... driving the motor to him.. or having him come to you .. seems he has some experience with these...

there are also some more articles on the heads... where the heads are done.. thats going to be the real costly part besides the pistons..

i would bet that there are a few you tube videos on installing the pistons in a W motor..

a few old time machine shops will have the 74 degree adaptor for the W motors and the MEL ford motors to bore the blocks with a boring bar... the current crop of really expensive machines can handle it.. but not every machine shop has a rottler CNC boring machine.. ( i personally would like one right in my living room .. just as a conversation piece)

Beck · December 08, 2010, 02:02:05 PM

If I recall the BBC crank will fit into the 348 just like it does in the 409. The crank snout needs to be turned down. This would increase the motor stroke considerably.
If you really don't want to spend the big bucks I would check it out like others here have suggested. If it aint broke don't fix it. Hone it and put rings and bearings in it. A new timing set and oil pump is always a good idea.