Teardown of the T has begun....got engine questions

[unclenick2004]

Ok, have already done some research on this but cant find a final answer.

The engine on my T-bucket is a 400 small block, but what did it come out of as I want to know all about this thing in detail before I go ordering parts and such.

Casting date -1/72

Casting number- 3951511

Here is where the question is. Some sites say it is from a truck, some say it is from a b-body, some say it is from a chevelle or monte carlo....I dunno.

Engine Suffix Code/Date- T0906CSA

4 Bolt main-bore:4.126/ main cap:2.65

The carbs are twin Holley 4160's - 390cfm, list # 8007

Edelbrock Trix intake with tunnelram setup....

So what do you all think this boat anchor came out of?

I need to find out somehow because I want to refresh the engine while it is out of the bucket for the blower setup I want to buy. But if this is a 175HP motor...it is going to the curb( Craigslist).

Any suggestions?

 

[bill4u6]

mor tec says its a sbc 400ci 1970-1973 4 bolt main

 

[RPM]

Where is this curb? That sounds like a good motor to work with. Probably all you will use is the block. That is all I used when I built my blower motor. Everything else is aftermarket stuff. When you build it be sure to get a double key crank and a blower drive hub, don't use the stock balancer. The cast iron balancer won't live very long.

 

[MDANIELSON55]

3951511....400...70-73...4...Some replacement blocks had 2-bolt main caps this is what u got a good motor. check with mortec engine castings, if u dont like the 400 check with ur local good dirt tracker and ime sure he will trade u something. me personally. id rather have the 400 mike

 

[Mike]

Wow, nice catch. A 400 4-bolt block that is still standard bore? We knew there had to be one out there somewhere. I'm sure there will be enough taper that it will require being bored, but don't take it any further than necessary.

As RPM mentioned, that crank needs to find its way into someone else's hands, but you've got a good block for starters.

 

[old round fart]

Back in 1972 when I was messing with a blown motor on the street in a bucket, I was advised by "Sneaky" Pete Robinson and Hoyt Grimes (two of the pioneers of drag racing in the early days) to go to the junk yard and get a truck motor that had 8:1 compression in those days, bolt the blower on it and drive it until it failed then go get another one. I didn't listen of course and built a 4 bolt 350 and ran it for a couple of years at 20% under crank speed, then tried 1:1 and liked that so the last 8 years I ran it at 20% OVER crank speed. That will really get your heart started! I needed all 144" of wheelbace to keep that sucker headed in the right direction. Oh for the days of .39 cent gas!!!

 

[RPM]

Mine is 10% under driven, and it has more than enough power for the street. You can get in trouble with it real quick.

 

[unclenick2004]

Hmmm, I was always told the 400 sb had overheating problems.....I'll take you guys word for it.

I need some ideas for the carb/intake set up. I might not go with a blower but it looks so damn cool.

The twin carb/tunnel ram air cleaner set up is so mickey mouse right now, barely bolts on, has some type of v-bowl under air cleaners to make it fit.

Let me see some ideas here so I can decide what to do. Thanks :welcome:

 

[Hotrod46]

Unclenick

Sounds like a good catch.

The machined pad on the front of the passenger side deck should have a serial number stamped on it. That should break down to tell you what it was intended for(truck or car). I believe if it has a "T" prefix it was a truck motor.

One thing to check on a 4 bolt 400 is the webs where the main caps bolt. The 4-bolt blocks were bad about cracking in this area according to the guy at my local machine shop.

Mike

 

[unclenick2004]

Now I'm thourlghy confused. I called Summit and they are telling me the block is definatly a 400 chevy small block, but the oil add tube is in front on the front of the intake. Is this not an Olds engine? Man, I'm getting brain fried here and just might yank this thing out and kick it to the curb if I cannot figure out what The hell is on this car. Man it is a small block GM emgine...getting frustrated now....

Notice the location of oil filler tube next to thermostat, what do you guys think?

So we know it is a 400 SB(what kind)...who knows as the intake is for a ??????

 

[tfeverfred]

mor tec says its a sbc 400ci 1970-1973 4 bolt main

Yup. Here's the link:
http://www.mortec.com/castnum.htm

That manifold may have came with the oil fill tube in it after market. I'd go by the casting #. If it runs good and the internals are good, go for the rebuild. No need to scrap it.

 

[tfeverfred]

Wikpedia says they were produced for 10 years and the initial years were 265HP. Considering the year of your casting it's a safe bet it is NOT one of the gas crunch motors that had low HP ratings.
http://en.wikipedia.org/wiki/Chevrolet_Small-Block_engine

I'd keep it. Regardless of year, it's a good motor with a lot of potential.

 

[tfeverfred]

Do you have a lead on where the engine came from when you got the car?

 

[Mike]

The oil fill tube has nothing to do with the engine itself. That intake is older than the hills and was cast with the provision for the early-style oil fill.

Does it have a PCV valve in each valve cover? If so, then you might want to put a good breather on one side. That might help a bit with the oil leaks you mentioned. The old style fill tube breather work, but just. I've seen guys cram those breathers down so hard, they virtually make it impossible for the breather to actually move any air. If you want to re-use that intake at any time, just remove the tube and knock a freeze plug into its place.

If you plan on driving it, as-is, for a while, you will realize a bit of power with a header that utilizes a collector. There will be some guys that are clutching at their chests as they read this , but the collector on a header will actually help a naturally-aspirated motor breath. The weedburners are OK for a blown application, but they're going to be down on power for what you currently have. Remember, at overlap, the header, the cylinder and the intake are all one, long tract, so you want them working together to produce maximum cylinder fill.

 

[unclenick2004]

Alright, then I'm going to order everything off the fact it is a 72 400 sbc.

Going to buy a new intake, carbs and different air cleaner set up, new valve covers and a felpro engine gasket kit.

Thanks for keeping me sane...

 

[RPM]

Alright, then I'm going to order everything off the fact it is a 72 400 sbc.

Going to buy a new intake, carbs and different air cleaner set up, new valve covers and a felpro engine gasket kit.

Thanks for keeping me sane...

OH go ahead and buy the blower set up. I bought a new Weiand kit for mine when I did it. I bought it thru Advance Auto Parts.....They keep them in stock in their warehouses and got it the next day. No shipping charges and for less money than Jegs or Summitt.

 

[Mike]

If you're planning on doing any machine work whilst it is apart (and I suspect it will need some), don't order things like pistons and/or rings until you know what bore you're going to end up with. Same with bearings. Get that crank checked, so you will know if it's going to need turned and/or polished.

 

[old round fart]

That looks like a pre-pcv valve intake. That won't shed any light on the origin of the motor as most SBC stuff is interchangeable.

 

[RPM]

It really does not matter what it came out of or what HP it was from the factory. Tear it all down and rebuild it and it is a custom hot rod motor. With a blower it could make 700hp or more. A factory 4 bolt block is all you need in a street motor.

 

[unclenick2004]

Got quite a bit done tonight after work. Got it down to the block minus starter, alt and water pump...Man I got a real bad case of "while I'm in there" right now. :lol:

Going to my local hot rod place tomorrow in the am and am going to go nuts...my parts list is already 2 pages long.

I sure need one now.

Going to get rid of the points dist and go hei with an msd, also a blower is in order....my wife is going to :lol: when she sees the credit card bill this month!

Oh well, you only live once.

Will post more tomorrow when I yank the engine out in the am!