hey guys whats up. i just decided that im going to move up in cubic inches. i bought this motor on monday. its a small block chevy 400. its a 1971 four bolt main. my first plan was to bore it .030 over(406ci). when i got home i found out that the motor was already bored 30 over. so i went over to my machinist's house and was talkin to him about it. the first 2 cyclenders are rusty but he said that he would try to hone it out. if not im going to go 60 over (408ci i think). i cant wait until i get the motor finished. by the way im not going to leave it orange. i just going to strip it down at shoot it with some black spray paint. well, i just had to tell some one. let me know what you guys think. heres some pics.

 

heres another

 

heres a shot of the heads(wich are original 400 heads)

 

oops. i guess the pic would help

 

and heres the last one

 

wow thats alot of orange. i cant wait till i get a new motor for mine i was thinking 400 but not sure now. goodluck man hope it turns out pretty sweet

 

hey, did a 400 myself this summer. .60 over? wow, thats not much room left. i looked at mine which is still std and that was close. i cant imagine what anything bigger would look like. guess i'm used to the space on my old 305 . good luck with the build, wow do these things sound good when you start em up for the first time

 

oh, and if you think orange is bad, how about canary yellow? my poor block was yellow! its black now and all better

 

looks like a sweet project hehe any plans for head/cam combos or is it goin in stock like that?

hope you are going to change that transmission... i heard some bad things about a lot of power put into a T5, but i could be wrong . anyway, good luck man lol

 

CAM,p3RO, do you have any cooling problems? I heard these motors like to run hot, how's yours doing? Any times for him to shoot for? good luck with the swap heavy!

 

I'm in the middle of a 400 build right now, I too had to have mine bored .060 over which by the way equates to 412 cid not 408. from what Iv'e heard the only problems people have with overheating is due to not drilling the steam holes in the heads, if I were you i'd trash those "882" heads and opt for some decent heads, I hear the "882" really choke the crap out of these motors. I am waiting for my new pistons which should be here monday, by the way you may also want to consider going to 5.7" rods insted of the 5.56" factory rods, these motors have a tendency to push short rods through the side of the block if stressed too much.

 

Does the 400 4 bolt block have 3 freeze plugs per side?I'm told that's the way to tell a 4 bolt 400 from a 2 bolt 400.SBC 400 4 bolts are extremely rare. Are the heads actually 882's? I read once that early 400's used #441 castings with a 1.6 exhaust valve.I have #441's on my 2nd gen Z28 but they were/are 1.5's.

 

yes, the 4 bolt blocks have 3 freeze plugs per side. I have heard that they (4 bolt blocks) are weaker than the 2 bolts because the extra bolt weakens the web that holds the main cap, it is my understanding that both the "882" and "441" are about the same performance wise, the biggest factor is the runner design along with the valve size. by the time you spend the money to get them somewhat usable (performance wise) it wouldn't be that much more to get a good set of aftermarket heads.

 

hey guy thanks for all the imput. i talked to mymachinist(also the guy whose going to help me build this motor) and he said that ill be fine if i have to go 60 over. me and my machinist talked alittle about cams, but were going to wait to start ordering stuff because im supposed to go with him today to have it checked for cracks. *** i hope it is not cracked. thanks so much for all the tips, keep them comin. i'll leep you guys posted

 

400 small blocks run hot from the get-go..Boring them 60 over will make them run hott all the time... not a smooth move

 

i know 400 are not really known well for there "coolness" but why can u not just go overkill on the radiator and fan setup to fix that problem?

 

Just finished my 406 small block swap into my 86 z28.. heres a few things that might help you out when you get ready to put your engine in.... If you are running a t-5 trans you will need to get a 305-350 flywheel and have it unbalanced for the 400 becasue all of the 400 flywheels are 14 inch and they will not fit into the stock t-5 bellhousing. Now because you have to use the smaller 153 tooth flywheel to fit in the bellhousing you have a starter problem now..... 400 blocks are made for a stagered mount starter and 99% of the stargered starters are for 168 tooth flywheels... i am almost positive they do not make one but i could be wrong.. so what i ended up doing is drilling and tapping my block and it worked out real good. Also drilling the heads is no big deal i have 1969 64cc gm heads on mine off a 350 and all i did was put an old 400 head gasket on with a couple head bolts to hold it in place and drilled them. You will love the power of the 406, agree def get rid of those stock 400 heads!

406:
5.7 eagle SIR rods
Comp cams 268XE .477/.480 lift
Keith black 30 cc dish pistons
64 CC heads 1.94 intake 1.50 exhaust
Edelbrock performer intake
Edelbrock 750cfm carb
Stock crank
hedman headers
Accell ignition
1..5 ratio Roller tip rockers

 

outside pic:

 

last one.. inside pic:

 

I know all about the overheating problems these 400's have. It's not because the big bore that these things overheat, it's all the scale and junk that builds up inside the block, in the jackets and all the passages. These engines came from the late 70's and were used mostly in trucks, they were neglected alot and the crap built up inside them. Just get the blocks hot tanked and clean out the water jackets the best you can and put the steam holes in the heads. Remember that most people have cooling problems too because they use the stock cooling system, big no no.
I know this because I've owned 4 400 blocks now and everyone of them was all cruded up. I used one block and built a 427 small block out of it and it never had a cooling problem, and it used a 2 core radiator and a 180 thermostat.

So get the cooling passages clean and drill the steam holes, use a good cooling system and you'll be fine.

Joe

 

well, sorry this took so long. i havent really had the engine running long. i had probs with my rebuilt (wont do it myself again) 700r4, so i gotta put the th350 in. it was really hot when i first started her up, but i think thats just because there was still air in the block. who knows. i'm hoping to be hitting low 14s with the setup, maybe i'm being overly optimistic. really wanna throw some vortec heads on this motor, should send it very close to the 400 hp goal i'm goin for. i'm also lucky enough to have one of the two bolt blocks, but its nothin special at the moment

 

camarokev400, i like the look of the engine bay! Is that how you kept it or is that just primer? I like that look how the whole bay is flat black and there is this bright orange motor with chrome on it right in the middle! nice

 

yep that is how i left it, i undercoated the whole engine bay then went over it all with some high temp engine paint seems to be holding up pretty good so far. Ill have some more pics of the egine bay soon i had a battery blow up and the acid got all over everything so im trying to clean it all up again.