who knows 400ci chevys?

[WayFast84]

I have a question for yah, but I would like to talk to you privately, so either post up in here so I can PM or IM you or pm me and or im me at warningitwayfast.

thanks

[johnjzjz]

The Pluses we raced them great power --- the negatives -- they run hot - the load on the cylinder walls is greater than any other SBC ( reason ) all except the 400 uses a 5.7 length rod the 400 has a 5.56 length rod, every one we had cracked the # 6 cylinder wall -- they don't rpm in stock form -- and the 2 bolt blocks turned out to be stronger for us than the 4 bolt -- jz

[johnjzjz]

If you can remove a valve cover and the best deal would be its real clean like new if not -- than its not or at least buy any one in the business standard of a rebuilt motor --- look at the overall condition of the detail on it as well -- ( NOTE ) the head gaskets for a 400 are $48.00 bucks EACH -- everything else is the same except internal stuff to any 350 Chevy -- and almost all the stuff sold in jegs or who ever 55 to 79 SBC is what you will be buying --- the flywheel flex plate for the starter is special to the 400 be sure not to bend it up -- jz

[1QWIKBIRD]

I have a question for yah, but I would like to talk to you privately, so either post up in here so I can PM or IM you or pm me and or im me at warningitwayfast.

thanks

what do you want to know???? I have one in my 70 Nova and have a couple of cranks, a spare block etc......good motor that got a bad rap early on because of overheating issues...use a 5.7 or a 6.0 rod, but be sure to check rod bolt to cam clearance, go with a studded 2-bolt main block if you can find it. A 4-bolt block is good for street/strip applications as well. Look for a two freeze plug block (2-bolt) versus the three freeze plug block (4-bolt). They can't generally take more than .030 overbore without sonic checking them first. With the proper head they'll spin plenty of RPM. Cubes=Power.......The balancer and the flexplate/flyweel are specific to the 400. 4.125 bore * 3.75 stroke in stock form. All factory cranks were cast iron and have a 2.65 in main versus the 2.45 main in the rest of the original SBC family. If you are buying one used, make sure it passed a magnaflux test prior to plunking down cash.....if it was ran hot, it could have split the cylinder walls...

not to beat a dead horse but cubes=torque and torque*rpm=horsepower more cubes = more power (generally speaking....)

chris

[WayFast84]

basically I wanted to have a private convo but o well,

I need to know what to look for about buying a used one, soposedly its rebuilt for a mild rebuild.. im gonna pop the valve covers off it their arent any to see the condition, if its bad, ill say for get about it, and if its ok ill set up a way to get it to my house..

[BonzoHansen]

Chris echoes a lot that I have read a lot of posts all over about bad 400 cores - core shift (not even sure what that entirely means) and problems with cyl wall thickness (need to sonic check). Oddly enough, it seems a lot of builders avoid 4 bolt 400s like the plague and would rather have a 2 bolt block and add splayed caps. I guess the 4 bolts crack at the webs. And cracks in the lifter valley. All sorts of wierd ****.

A destroked 400 (377) always sounded like a piss load of fun in a light car. :)

I'm betting you could read about 400s for 2 days at Team Chevelle.

[WayFast84]

i went on team chevelles, woah they have like 6xx ci motors, i found verry little info on 400's but lots of 400vs402 threads

[WildBillyT]

There are still bigger than 6xx inch motors. Pat Musi and his guys (among others) build 707+ big blocks.

Regarding the 400, most of what I know has been said- they have siamesed cylinders so they run hot, they won't take much of an overbore, 2 bolt blocks are stronger than 4 bolts.

If you can, get a 509 or 511 block over an 817. Not that there is anything really wrong with the 817 but they are more failure prone.

400s are also externally balanced.

[WayFast84]

Casting #: 3951509
Engine ID #: F0305TLS
Head Casting #: 3973493 (1.94/1.5 valves, 76cc chambers)

[Tru2Chevy]

Hit me up on AIM if you have any more questions man....

- Justin

[WayFast84]

I will tomorrow.

what trans is good to run with theese motors? it comes with th350..should I keep it, use the 700r4 or what? im prolly gonna install a shift kit on what ever im gonna use

[Tru2Chevy]

For a mild 400, stick with the 700R4. Much better first gear + OD = FTW.

- Justin

[Untamed]

Is there a way to upload documents? I have a PDF of the Pontiac 400 (W72) - don't know how much different that is from the Chevy or if it would be useful at all. :shrug:

[Tru2Chevy]

Is there a way to upload documents? I have a PDF of the Pontiac 400 (W72) - don't know how much different that is from the Chevy or if it would be useful at all. :shrug:

Nope, pretty much the only thing they have in common is that they are v8s.....

- Justin

[hardline_42]

The Pluses we raced them great power --- the negatives -- they run hot - the load on the cylinder walls is greater than any other SBC ( reason ) all except the 400 uses a 5.7 length rod the 400 has a 5.56 length rod, every one we had cracked the # 6 cylinder wall -- they don't rpm in stock form -- and the 2 bolt blocks turned out to be stronger for us than the 4 bolt -- jz
I'm a little biased but I have to chime in with a few corrections. 400's DO NOT RUN HOT! The issue with overheating is not due to the siamesed bores (every bowtie block would be having the same problem if that were the case) but mainly because of the fact that people swap 350 heads on to them without drilling the steam holes. I have drilled them myself on all of my 400s and never had a single overheating problem running a stock radiator and water pump. Stock 400s do have short rods and will not hold up at higher (above 6k) RPMs. A common upgrade is to go with 5.7" or 6" rods which may cause clearance issues (not always). Two bolt blocks are known to be stronger than four in the case of the 400s. The casting numbers in order of strength are 817, 511, and 509, the 2-bolt version of each being stronger than the 4. ANY STOCK BLOCK IS GOOD UP TO 400HP. Anything more and you will want the better castings.

[WildBillyT]

I'm a little biased but I have to chime in with a few corrections. 400's DO NOT RUN HOT! The issue with overheating is not due to the siamesed bores (every bowtie block would be having the same problem if that were the case) but mainly because of the fact that people swap 350 heads on to them without drilling the steam holes. I have drilled them myself on all of my 400s and never had a single overheating problem running a stock radiator and water pump. Stock 400s do have short rods and will not hold up at higher (above 6k) RPMs. A common upgrade is to go with 5.7" or 6" rods which may cause clearance issues (not always). Two bolt blocks are known to be stronger than four in the case of the 400s. The casting numbers in order of strength are 817, 511, and 509, the 2-bolt version of each being stronger than the 4. ANY STOCK BLOCK IS GOOD UP TO 400HP. Anything more and you will want the better castings.

hard, are you saying the 817 is the strongest of the 3? Not trying to argue but that's contradictory to what I've found.

[hardline_42]

hard, are you saying the 817 is the strongest of the 3? Not trying to argue but that's contradictory to what I've found.
Sorry, I should have said "in order of strength from weakest to strongest." That would make the 817 the weakest, followed by the 511 and the 509 being the strongest. The 2-bolt versions of each casting are stronger, making the strongest stock block the 509 2-bolt block, which is the block that WayFast is asking about. The 400 debate has been gone over countless times at nastyz28 but here's a recent thread: http://www.nastyz28.com/forum/showthread.php?t=66006. Pay special attention to Marv D's comments on anything 400 related and Dirt Reynolds' comments on anything Vortec 400 related. They know they're shizzle.

[WildBillyT]

Sorry, I should have said "in order of strength from weakest to strongest." That would make the 817 the weakest, followed by the 511 and the 509 being the strongest. The 2-bolt versions of each casting are stronger, making the strongest stock block the 509 2-bolt block, which is the block that WayFast is asking about. The 400 debate has been gone over countless times at nastyz28 but here's a recent thread: http://www.nastyz28.com/forum/showthread.php?t=66006. Pay special attention to Marv D's comments on anything 400 related and Dirt Reynolds' comments on anything Vortec 400 related. They know they're shizzle.

Yep, Dirt and Marv know their stuff cold. :mrgreen:

[johnjzjz]

i never owned a street 400 SBC in my shop we only ever built them to race, and the steam hole angle is very important 1/8" hole and the gasket as well -- we must have over the early years broke 20 / 30 of them before the boe ty - became available -- had to go and look at the one today i saved its been years since i looked at a stock 4 bolt 400 block and its really not what is known today as a Siamese cylinder -- not like the newer stuff anyway - we used 8 EGTs years back than to try and figure out what was up with the engine temp problem and what we found in the 80s was running a water line front to rear of the manifold really helped ( air was traped in the block tops of the deck ) but the temps of the motor at the turnaround at the track end was still 240 / 260 -- alloy radiator helped as well it all seamed to on the drive back to bring the engine temp down quicker -- but the overall high temp never came down to what a 540 BBC would be 210 maybe on gas alky no engine has a heat problem --- the issue with using 350 heads the iron 492 head 64 cc Flat piston 2 valve relief .039 head gasket and a zero deck netted 11 to 1 with a 406 motor as the best out of all of them -- iron heads in drag racing means more consistent times alloy heads car is faster is it the weight of head the difference ??/ never got an answer that made sense to that question its been better than 12 or 15 years since we used a 400 block and would never go back we broke every part in them every time we made it work with a MOD something else failed of course you may have had better luck --- not us -- jz

[hardline_42]

i never owned a street 400 SBC in my shop we only ever built them to race, and the steam hole angle is very important 1/8" hole and the gasket as well -- we must have over the early years broke 20 / 30 of them before the boe ty - became available -- had to go and look at the one today i saved its been years since i looked at a stock 4 bolt 400 block and its really not what is known today as a Siamese cylinder -- not like the newer stuff anyway - we used 8 EGTs years back than to try and figure out what was up with the engine temp problem and what we found in the 80s was running a water line front to rear of the manifold really helped ( air was traped in the block tops of the deck ) but the temps of the motor at the turnaround at the track end was still 240 / 260 -- alloy radiator helped as well it all seamed to on the drive back to bring the engine temp down quicker -- but the overall high temp never came down to what a 540 BBC would be 210 maybe on gas alky no engine has a heat problem --- the issue with using 350 heads the iron 492 head 64 cc Flat piston 2 valve relief .039 head gasket and a zero deck netted 11 to 1 with a 406 motor as the best out of all of them -- iron heads in drag racing means more consistent times alloy heads car is faster is it the weight of head the difference ??/ never got an answer that made sense to that question its been better than 12 or 15 years since we used a 400 block and would never go back we broke every part in them every time we made it work with a MOD something else failed of course you may have had better luck --- not us -- jz
I guess everyone has different experiences with the 400s. As far as I know, siamesed blocks are siamesed blocks. It just means the area between the cylinders has no water jacket, just solid metal. It's interesting that you mention the steam being trapped at the top of the deck because that's exactly what the steam holes are there for - to vent the steam. Maybe there were problems aligning the holes in the head/gasket/deck? IMO, 64cc heads are a great upgrade to a stock 400, and as long as the quench is about .040, you can stay out of detonation. As far as iron vs. alum. heads, the iron heads keep a little more compression but weigh more. The aluminum heads allow you to run higher compression since they bleed off more heat and they weigh less. Not sure how the two compare under equal circumstances.

[johnjzjz]

i never really understood the steam hole location that is recommended we always felt the air that is trapped is at top in the V -- all the deck crack i have found have been in the center bolt area at the top of the thread going vertical --- ( As far as I know, siamesed blocks are siamesed blocks. ) -- i was talking about the thickness of the area at the barrell centers the new stuff is 700 thick in this area and solid as a rock -- the stock blocks are at best flakey and thin -- ( we after braking both sliced the blocks on a band saw to see what the real deal was ) SORRY I DID NOT EXPLAIN CORECTLY -- jz