348 assembly

[nana1962409]

Now that looks familiar! I did the same thing when I was getting mine ready setup and built my own intake. I used large port heads so I started with a factory dual quad intake for my base. It wasn’t the prettiest thing when done but it worked. I thing all the small port blower intakes made are based off the offy intake

 

[Hods1222]

Any pics of your setup? Any advice for someone heading down this particular road? I had also read somewhere on here that a 440 Chrysler manifold had the right port spacing just needed the flanges reworked for angle/bolt holes.

 

[La Hot Rods]

http://www.348-409.com/forum/threads/slow-build-1962.33603/

 

[427John]

So I may be getting a little ahead of myself but I mocked up the heads with the huffer on top of a 409 manifold I have. It seems a blower manifold for these engines is as scarce as proverbial hens teeth. Since I have a 3 axis VMC at my disposal and an ac tig welder I was thinking of machining/welding up my own custom manifold. Anyone have any experience in doing this? Is there a good manifold to start from? I had heard that back in the day blower manifolds were made from an offy manifold to suit the bill.

I could see where the offy manifolds would be favored as a starting point,with their low profile single level design.I've seen examples where they milled a flat surface to mount the pop off valve chamber to,bored thru the top of the plenum to match the bottom of the chamber and the only welding was basically for any bolt bosses needed to mount it.

 

[Don Jacks]

Mrhp can tell you where he got his .His is a modified Offy.

 

[nana1962409]

Here is my thread with the blower and intake build. The one James posted is mostly my car thread. As far as advice I just kinda winged it and it worked. I did a lot of mocking up to make sure distributor and thermostat housing cleared good before I made anything permanent. http://www.348-409.com/forum/threads/junkyard-find.36516/page-2

 

[Hods1222]

nana1962409, I just looked over your build thread and that is exactly what i was looking to do. What thickness was the plate you milled to accept the blower?

 

[Hods1222]

Alright. I went and picked up my crank today and everything looks great. While they were balancing it I had them cut the 2nd keyway in. You were right about the pistons being heavy as they had to put 2 slugs in to balance it out. The journals just took a polish and I should be able to run standard bearings. I assume the the specs are the same as a bbc with the mains at .0025 - .0033 and the rods at .0022 - .0027. Any recommendations on clearances/bearings to help this live with the blower?

 

[La Hot Rods]

I would would go for some hard race bearings.

 

[Hods1222]

I put the main bearings in last night and the rod bearings will go in tonight. I went with mahle cb743h tri metal bearings and the clearances are in the .0022-.0025 range with the rear at .003. I will probably set my sights on the cam and lifters next. Do you guys recommend grooving the lifter bores to guard against lobe failure? I attached a pic from a David vizard book I have on building BBCs.

 

[Don Jacks]

If you're going flat tappet,it wouldn't hurt but since that book was written there have improvements such as oiling holes and or grooves added to some lifters that do the same thing.If you're going roller it's not needed.

 

[Hods1222]

I had some shop time today and was able to get the rotating assembly put together. Now to get a cam coming and an oil pump so I can button up this bottom end and put the pan on. Since this is going into a belair, I am probably going to have to modify the pan to clear the drag link, either that or bite the bullet and get a stefs pan for it.

 

[63impalass409]

What pan do you have?

 

[La Hot Rods]

Looking good, make sure you have the correct oil pump driveshaft before you button the pan up.

 

[Hods1222]

The one I have looks to be from a 409, it has the dipstick on the passenger side unless the 348 truck ones were on the passenger side. I picked up a melling drive shaft from summit so I should we good to go on that one. Which pump would you guys recommend?

 

[63 dream'n]

I’m sure the smart guys will chime in here soon Ronnie Russell used to always say that there was nothing wrong with the 409 oiling system .......But they’re always used to be problems with ordering the oil pump that they would always send the small block Chevy driveshaft with it and the 409 or the W motor is specific

 

[Don Jacks]

Get with Show Cars and get the correct part now.If the shaft that you have now came in the box with the pump you have the wrong shaft,,it's too short.The Melling M-55 will work fine.

 

[Hods1222]

The driveshaft that I ordered from summit is MEL-IS-55A and they specifically listed 348-409. Hopefully this is the right one.

 

[Hods1222]

Hey Don, I came across this cam and wanted to get your take on it. I am looking to run BBC roller rockers with it which will decrease the lift a little. Will the .505 intake lift be compatible with my stock valve notches?

 

[Don Jacks]

It'll be suitable from that stand point but the intake to exhaust is too wide.Call Howards cams and have them copy these spec's;lobe seperation-113,lobe centerline-109,;lift-.519 in.,.525 exhaust,Duration at ..050 218in.,224 ex.This is a proven grind in a 380[ask MRHP] and will work on a 348 just fine.I would not exceed 220 duration intake at .050 on one of these engines without notching,ugly things can happen if you do.