400 sbc

[neonclown]

Im getting a 400 sbc from the junkyard tomorow, I dont know much about it other than it came out of a 76 Blazer.
I was wondering if anyone can send me a link to any information or know of anything about this engine... Ive looked everywhere.
Thanks in advance.
-Vince.

[Firstbornbone]

The 400 SBC is just like any other SBC as far as size weight etc... The big difference is that the cylinder bores are simeased with no water jackets between them.

[Redhead]

400's are known to run hot in cars. Trucks had more room but some still ran hot. Big cumbustion chambers (76cc) were detonation prone. Thin cylinder walls only allow a .030 overbore, do not trust a .060 over bore cylinder wall on a 400 no matter who or whom says. Some 400's had 4 bolt main caps. If the timing chain cover is off, there are three sets of 3 digit numbers inside there. The middle one is nickle content. When peope say "I got a 030 block" (joking) that's a high nickle content. Most were 010. Were not talking Bowtie blocks here of course so high nickle in a stock production block is much different but still, an 030 block will hold a better cylinder wall then a 010. You can clearly see the difference between the two. Nickle added to cast iron makes it more dense, harder, better....

400's were torque monsters. Not quite like a big block but pretty good. Building one into a hot engine you gotta watch the cam lobe clearence-to-connecting rod bolt. I know it sounds strange but in all chevies the cam lobes come real close to the connection rod bolts. Chevy never put a forged crank is a 400. They weren't know to have crank problems though.

[jhnyquest]

Quote: Originally Posted by neonclown

Im getting a 400 sbc from the junkyard tomorow, I dont know much about it other than it came out of a 76 Blazer.
I was wondering if anyone can send me a link to any information or know of anything about this engine... Ive looked everywhere.
Thanks in advance.
-Vince.

Here you go check out this site. Will tell you about everthing for your blcok and heads. http://www.mortec.com/castnum.htm

[neonclown]

Awesome thanks guys.

[sbctimh]

1 400s are not detonation prone big open chambers are the best insuance against detonation

2 400s do not over heat because of there siam bore, most pro engine builders use block filler down there anyway, and it's simply a non-issue with modern radiators/coolant

3 only way to know how far over you can go is sonic checking it, not random internet advice

personaly, I'd start with new pistons and rods
stock rods are to short and the piston has to become extra heavy to make it to deck, the horrible rod angle promotes wear at even low rpms, and makes the heads seem even smaller than they are

the heads(usualy 882 castings)are small even for the 350s they were made for, on the 400 they run out of air very early

the right set of heads will make or break the build


realy a 400 Chrysler is the way to go
huge 6.7+rods
stroke is less then 350 chevy
2.14 1.81 valves fit in stock heads 2.18 1.81 in others
bore/stroke and rod/stroke angles are better than 327 chevy

[Redhead]

1) The further the flame front travels, the worce detontation is (two flame fronts occure and colide causing detonation). Hint: Notice how newer engines with 11.1 compression do not have detonation problem's. New heads have 57cc cumbustion chambers. Better spark control really has nothing to do with flame fronts coliding. The further the flame front travels, the more detontation you get. I know it was once thought that large cumbustion chambers meant lower compression therefore less prone to detonation and cleaner emissions. It was wrong-way engineering. Those big 76cc heads were also weak & cracked between the valve seats. Seen too many like that to just ignore it. All chevy heads with dual heat riser ports crack, avoid them altogether.

2) It is because of the seimeased cylinders that 400's run hot. No water circulation between the bores. Pretty easy to understand that one.

A street engine filled with block filler is certain death to piston rings. Heat causes rings to relax and loose tension. I mean do what you want. It's only money.... If you decide to put something together to last, it's a whole different deal. I built an engine for the engine masters series. It was a 355 chevy that made 560hp on pump gas. I probably don't know what I'm doing, just kind of bump into walls to find my way to this watchamacallit internet thingy. I'll be the last person to tell you not to spend money, it's keeping the economy alive and people iinto jobs. My reason for posting here was to at least let the guy know some truths about 400's. Hey I like the engine, I've built several that made great torque for puller tractors. I used standard bore blocks because the 400 has thin cylinder walls. Don't take my word for it though, sonic check and read the numbers, not just find thick material. What do you consider thick? is a .065 cylinder wall thick? What does boring a cylinder do? I'll answer that one. It increases the swept volume. This raises compression. Why? Because the volume is still compressed into the same area.

Some things are easier to understand then others.

[pushing413]

The 400 is a very good enigne. If you really want a good hard turning engine then take the 400 that you are getting and destroke it. The 400 is very bad for spinning bearings if you are not carefull. By destroking the engine you can turn it harder and faster.

[super_chevy]

You motor is a 2 bolt main...correct?? yeah i got a 400 SBC and it is bored 030 over in my 89 Dime and i'm getting my radiator cleaned out tom. becuz I'm running a little hot. but that is becuz my radiator is very dirty. then I'll let you guys know if it has heating problems. I have a 3 core radiator to help with the heating prob. it is suposibly suppose to have. I haven't spun ne bearings yet either. I have had some cam probs though. sucked one valve, fuked up a couple lobes on the cam. Lifters in mine are noisy already not even 200 miles since I last heard them.

[neonclown]

Yeah 2 bolt, Ive got it stripped down almost to the block, by the end of tomorow it should be at the machine shop to see what needs to be done Ill keep it posted.

[Redhead]

Thinking back, I'm pretty sure the 4-bolt 400's had 2 freeze plugs in the side of the block, the 2-bolts had 3. Or vice-versa....

[neonclown]

4 Bolts had three, at least I hope cause I have a 2 Bolt with 2 freeze plugs and I ran the numbers at the machine shop ha