Machine Shop Questions

[Jeffrey Osstyn]

I need some work done on a 348 block. Align bore mains, had a cracked cap, found a replacement. Possibly need cylinders bored. So there is one machine shop near me, and Tucson is 70 miles away which probably has several. Assume the shop close to me has zero experience on the 348, what would I need to be aware of, or to explain them exactly how to proceed? I will do the assembly. I keep reading about guys going to great lengths to have their blocks done at a shop with experience on the 'W' motor. What do I need to watch for?

 

[Ishiftem]

As far as block machining, that is something any good reputable shop can do. Nothing special about it.

 

[bwell]

I used Automotive Machine of Scottsdale for my 409, was very pleased with their work.
They did boring, decking, cylinder sleeve, balancing and head work.
The drive is a little farther than Tucson but the work was good!

 

[MRHP]

Make sure they do not rebore the counterbore, or your compression will suffer a .5 loss.

 

[427John]

Some boring bars require adapters to mate to the 74* deck surface if they have those chances are its not their first rodeo.While these engine types are by no means common,between the fairly mainstream 348,rarer 409's and the long production of the lincoln MEL motors(another non 90* deck surface block),if a shop has been in business for a while chances are they've run into them before.

 

[Phil Reed]

Day Automotive here in KC has a CK-10 Sunnen boring machine which does not need the boring plates.

 

[models916]

Ask the shop if they have a torque plate for boring?

 

[El Rat]

I used the torque plates on all my hemi rebuilds. I would swap the sleeves out and hone again. Eventually I would leave my friendly machine shop with one block and 20 or so sleeves.

 

[Jeffrey Osstyn]

Thanks for all the responses.

 

[Jeffrey Osstyn]

Make sure they do not rebore the counterbore, or your compression will suffer a .5 loss.

So I go to the local machine shop to discuss working on a 348 block which is already .030 over bored. He advised he could hone to .040 over but he would bore the combustion chamber (counterbore?) .060 over that so you can get a ring compressor in there.
I didn't agree with him as I have another block I had bored .080 over and I don't believe the combustion chamber was over bored, just the top of the main bore had a slight chamfer on it and I was able to install the rings with out a compressor.
The machinist advised he had only done 2 other 'W' blocks, so maybe I should go some where else?
Is he right?

 

[Don Jacks]

YES!!!!!!!!!!!! go somewhere else.

 

[Fathead Racing]

I have never used a ring compressor on a 348 or 409.

 

[Phil Reed]

NO.....HE IS NOT RIGHT!!!!!!!! I mean the machine shop you went to.

 

[Don Jacks]

On my 380,we simply took an old style band type ring compressor,turned it upside down,and installed the piston,ring,and rod assembly.Piece of cake.

 

[Jeffrey Osstyn]

So that leads back to my first post, do I need to seek out a shop with experience on the 'W' block and how do you know they are telling the truth? So 'bewell' advised of a shop in Phoenix, 200 mile drive one way for me, that did his. So now I know about the combustion chamber counterbore, if I tell the shop not to touch it what else is there to tell them. Or do I just go to another shop and ask their procedure? Will honing from .030+ over to .040 over give good results? No boring (cutting) involved. Guess if it's straight it's good to go?

 

[Don Jacks]

Jeff,that depends on the type of hone being used.Honing is simply meant to prepare the walls for the type of ring being used,not to take out that much material.Often times,any thing more than .004-.005 will lead to the walls being "burnished" up to the point that the rings won't seat right.If it were me,I'd be making that 200 mile drive.

 

[dm62409]

Rear cam bearing needs some special attention for proper oiling. using Durabond small block cam bearings , & redrilling the oil holes on the rear bearing.

 

[dm62409]

Double important.

 

[Tom Kochtanek]

A few years ago we picked up a truck 409 short block, supposedly rebuilt by a reputable machine shop familiar with 409s.

Had a stock 409 crank, BBC rods and KB-Icon forged pistons. Machine shop bill (labor and components, including rods and pistons, bearings, etc) was about what he was asking, so we made the deal, brought it home and set it aside.

Two years later we have a purpose for it (ongoing 1962 Impala convertible project) so James pulls it out of storage and notes that one of the rods was assembled improperly, which would have caused catastrophic failure if fully assembled as was .

Moral of the story, don't believe all that you hear from a seller, check things for yourself and be prepared to disassemble any assembly that you purchase from somewhere other than your own trusted machine shop.

TomK

 

[Jeffrey Osstyn]

First time I have heard about the rear cam bearing mod. Hopefully the 348 I am running now will survive, I doubt this was done in mine but I am not running those spring pressures mentioned for sure. Do stock cam shafts come fully grooved, or do you need to special order it? Before I moved to AZ. I had some issues with work done by the shop that machined my block and they were the go to place for all the local racers so highly recommended. Problems were not in the machining but in the inspection process, they were not used to dealing with 50 + year old blocks and missed some rust issues early on, but did get it worked out to my satisfaction.
So far it looks like I will need to look for another shop to do work on my next project, just wish I could find a place closer than an 8 hour round trip drive!
Thanks for all the tips on the rebuild! All good info. I'm making a list!