400/406 Builds

[Captainfab]

Anyone building a 400/406 this Winter?

[Captainfab]

Any completed 400/406 builds or new builds going on?

[DBD]

Originally Posted by D.PASSMORE

I believe the fella is telling his story and looking for advice. No need to be critical. Were not professionals, just hobbyist.

You live and learn, my first attempt lasted around 10k and nuked. Tried again, and it lasted 100K plus.

David

not being critical...but if a bolt won't torque just leaving it is pretty bad and that's all I was saying. sometimes the way people learn is having mistakes pointed out; that's how I learn

if the threads pulled it was even worse because there was no way it would seal - but if the head had been pulled no matter what was wrong could have been caught and fixed...just leaving it was a bad call, no matter what the issue was.

im calling it out so people can learn from it - that's it.

[Marv D]

The deck on the 511 casting is thin to begin with. If someone 'cleaned the threads' with a standard tap.... and old corroded bolts were used.... good chance he pulled the threads out of the deck. New bolts or studs ain't gonna fix that!

The 400 deck and bolt holes are a weak link for sure, Here's a 509 casting that was making just over 650 at the crank, was pushing the head up hard enough to pull the deck, cracking it from the bolt to the water ports and it pinched the piston enough to turn it to junk. Sometimes 'studs' work too good LOL

http://www.small-block-chevy.com/ima...0/400blk_a.jpg

http://www.small-block-chevy.com/ima...0/400blk_b.jpg

Think maybe we discussed this early in this thread (or in another),, sorry if it creates an echo

[bigmac73]

here is what I am working with -

Dart Short block 400 (03114002)
AFR 195 or 210 head eliminator street head
Howards OE style lifters (91113)
Howards Roller Cam either a 180885-10 or a 180265-10
Comp Ultra Pro Rocker Arms (1602-16)

any more thoughts on the cam selections please feel free

[68nou1]

Got my 408 back together and headed to the engine dyno on the 18th for break in and tuning. New speed pro pistons, 5.7 eagle rods, ARP head studs, and a set of Blue Print Engines Aluminum 195 heads. Should be a little of 10:1 compression. Lesson learned, trying to do it right this time.

[68post]

Originally Posted by 68nou1

Got my 408 back together and headed to the engine dyno on the 18th for break in and tuning. New speed pro pistons, 5.7 eagle rods, ARP head studs, and a set of Blue Print Engines Aluminum 195 heads. Should be a little of 10:1 compression. Lesson learned, trying to do it right this time.

Good luck, and please let us know how great it did !

[68nou1]

Originally Posted by 68post

Good luck, and please let us know how great it did !

Thanks, will do. Hopefully ill get plenty of pictures and a video or two.

[ol84]

I am building a street/strip engine for my 64 Chevy II. Let me know what you think.
.40 over 509 block
Comp 280h
Scorpion 1.6 Rockers
GMPP FastBurn Heads yielding approx. 11.2 compression
Edelbrock Vic Jr
Holley 750 HP
TH350 with 3000stall

What do you think of the cam selection? Any recommendation for better choice? I already have all of this on the shelf.

Rusty

[Captainfab]

The 280h is a bit of an old school grind by today's standards, but I totally understand the want to use what you already have. Have you calculated your dynamic compression to see if you can run the fuel that you want to with that cam? You may need a different cam or pistons with a dish to get your dynamic compression where you need it.

[68nou1]

Back from the dyno the other day. Brian and Chris at DynoTune Engineering in Paris, TN are great to work with and anyone local that is wanting to dyno their motor I would recommend them. We went through a couple different setups and I ended up with 445 HP and 485 ft/lbs of torque. Not breaking any records but I'm pretty pleased with it. Should be fun in a little 4 speed car.

[Marv D]

Originally Posted by 68nou1

Back from the dyno the other day. Brian and Chris at DynoTune Engineering in Paris, TN are great to work with and anyone local that is wanting to dyno their motor I would recommend them. We went through a couple different setups and I ended up with 445 HP and 485 ft/lbs of torque. Not breaking any records but I'm pretty pleased with it. Should be fun in a little 4 speed car.

Thats going to be a nice street motor!! Almost 500 pounds of torque will put a smile on your tire dealers face for sure.

Can you give us the cam specs you used?

[68nou1]

Originally Posted by Marv D

Thats going to be a nice street motor!! Almost 500 pounds of torque will put a smile on your tire dealers face for sure.

Can you give us the cam specs you used?

Sorry it has taking me so long to get back with the specs. Been laying hardwood after a water leak and taking care of things around the house. Anyways the cam is a Comp xe274h 230/236 @ .510/.520 lift with 110 LSA

[Cautrell05]

Im in the early stages of putting one together for my 47/S10 build. somewhat low buck build.

2 bolt .020 over 400. dont remember casting number.
fully rebuilt and ported cammel backs. 292 I believe
ported, cast 327, holley flange stock intake
2 inch ram horns for now, 2 1/2 if I find a set for cheap.
Not sure on cam yet. open to suggestions
600 vac secondary holley

Not looking for a full race motor but would be happy with 400HP. Not sure if I will get there with that intake and exhaust but will see what happens. the truck will only be around 3000 pounds so it wont take much to be quick.

Nick

[Captainfab]

With the small combustion chamber on those heads, you must use a dished piston. A 600 cfm carb is a bit small for a 404 cu in engine. For a cam I would suggest something similar to the one I used in the build in post #1.

[ol84]

Should be a great combo 68nou1.

I ran the numbers and seems my compression is higher than I would like. A little more research to be had on my end on DCR. I could bump up to a larger comb chamber (72cc-76cc) head and that might solve the problem. Definitely want it streetable. My 84 C10 engine is a beast and I want this to more street friendly. What kind of cam profiles does one look at to bleed off DCR?

Thanks,
Rusty
Posted via Mobile Device

[68nou1]

Originally Posted by ol84

Should be a great combo 68nou1.

I ran the numbers and seems my compression is higher than I would like. A little more research to be had on my end on DCR. I could bump up to a larger comb chamber (72cc-76cc) head and that might solve the problem. Definitely want it streetable. My 84 C10 engine is a beast and I want this to more street friendly. What kind of cam profiles does one look at to bleed off DCR?

Thanks,
Rusty
Posted via Mobile Device

Sure will. I can't rattle off all the specs but will get them as soon as I can and don't want to give you any wrong info. My compression was a little higher than I would like but is still streetable, just need to have a good octane boost additive with pump gas. I had a set of heads that were 74 cc on the combustion chamber but from what ive read the 400's like to breath and those heads were really choking it down. From what we found I could be over 500hp if I had them worked. but like I said I am happy with it for now at least. Any recommendations on a good octane booster in a bottle would be helpful though.

[Marv D]

Originally Posted by 68nou1

.... good, .... octane booster in a bottle.... would be helpful though.

Yeah if you find one that has any PROVEN effect on a 16 gallon tank of 91 pump gas let us know.

99% of these miracles in a bottle are nothing but Toluene and Zylene and they have a dramatically reduced effect on the 10+% ethanol fuels at the US pumps today.

Only thing 'I' know of to make a true 95+ octane (MON,, no one cares about RON or the 'pump' names),, Here's what I mix up for my 11.5:1 sand buggy.

5 gallons of VP C-12 (108 motor octane and 4.23g lead per gallon)
+ 10 gallons of Pump 91 (most is motor octane of less than 89)

mix well and enjoy with a frosty glass of iced-T



BTW here's some interesting reading on blending octane boosters with pump fuels. You have to make believe you understand the technical crap and the references to the Aussie fuels, but interesting stuff starting around page 16

[burnin oil]

I cammed my motor back a little and run a 274 duration solid cam. The 830 double pumper is barely to big for this cam but worked well with the old one. I ran around for about 2 months on the primaries only, disconnected the secondaries, while tuning and it ran alright. Once I rehooked the linkage I gained a mile to the gallon and it runs a lot better. She just wants more than 400cfm that is available on the primaries. Do some digging and you will find that the Holley vac secondaries will never hit the full potential unless you run the lightest spring. The heaviest spring will nearly never open the back side.

[bigmac73]

post #88 no inputs or opinions, come on guys give me your thoughts....

[Captainfab]

I think we need a little more info such as pistons being used, what trans and stall converter as well as your intended usage. Also what fuel you want to run.

Originally Posted by bigmac73

here is what I am working with -

Dart Short block 400 (03114002)
AFR 195 or 210 head eliminator street head
Howards OE style lifters (91113)
Howards Roller Cam either a 180885-10 or a 180265-10
Comp Ultra Pro Rocker Arms (1602-16)

any more thoughts on the cam selections please feel free

Originally Posted by bigmac73

post #88 no inputs or opinions, come on guys give me your thoughts....

[bigmac73]

http://www.summitracing.com/parts/drt-03114002
what ever pistons come with the short block, and I have a 2200 RPM stall now and a built 350TH, which is fine with the howards 180885-10 cam , and I already run premium 91 with my current engine now(per Manufaucture)

[Captainfab]

I agree with burnin oil. You will need all the info necessary to be able to calculate the dynamic compression. You will also need to know what combustion chamber sizes are available from AFR on those heads. I'm not an expert, but I believe the AFR heads' flow ratio between intake and exhaust is so good that a split pattern cam is not necessary. If the dynamic compression is too high with the Howards 180885-10 cam, you will have to go with a cam that has a later intake closing to bleed off some cylinder pressure. This is often a more radical cam such as the 180265-10, but cams designed specifically for N2O or boost, will have a later intake closing and bleed off cylinder pressure without having a higher operating range.

Originally Posted by bigmac73

http://www.summitracing.com/parts/drt-03114002
what ever pistons come with the short block, and I have a 2200 RPM stall now and a built 350TH, which is fine with the howards 180885-10 cam , and I already run premium 91 with my current engine now(per Manufaucture)

[burnin oil]

Flat tops will build some serious compression in a 400. You really need to know the cc's of the reliefs and how far down the deck the pistons go along with head gasket thickness. In HS I had a warm 400 that had hyp flat tops and 76cc iron heads that ran detonation free on 87. The only issue was intermediate dieseling at shut off. Tighter heads will shoot the compression really quick, especially with a zero deck height. Don't forget that hyper piston are not very tolerant of detonation so stay conservative on the timing curve and add some till it runs the best.

[Cautrell05]

anybody know what the dish size was on the stock 400 pistons?