Gents, I'm a diehard Olds and Chevy motor fan. I did alot of chatting with my bud who wants to build up a Ford for his older Mustang. Although, I'm very ignorant to Fords, I am the only help that my friend can get to build his engine. After some intense reading, I've decided to recommend the 400 to my bud. The reason is torque! Thats the name of the game on the street. Looks to me the 400 can build a mountain of torque and can rival my stock 455 Olds motor in my Cutty. I've noticed that the street camshaft offerings are over .500" lift with a fairly short duration...what a torque monster but I can see to make things work we need compression. Here's my question...I don't know exactly what the deal is with 351C flat top pistons in the 400. Or...are there 400 flat top pistons out there. I've also noticed that replacement pistons seem to be down in the bore a semi significant amount. I havent decided if we are going to go the Aussie 2V head route with stock dish pistons or go the cheap way and get flat top pistons with stock 2V open chamber heads. Can any of you gents steer me and my bud in the right direction? If I flub up on this, it'll ruin a friendship. Of course, I could always play it safe and go the Windsor route but I can't help but see "gold" in one of those old 400s!

 

Read past posts in here for a while b4 you settle on any engine specs or parts. There is a ton of information to digest. Remember your pump gas won't allow you to run much more than 9:1 compression without detuning the engine which is not efficient.

 

I hear what you're saying about compression but I run a Chevy 383 in my 4 speed 80 Camaro that I built up for a thousand bucks. With it's flat top pistons (that are a measured .020" down the bore and stroker crank, it's got to be running 9.5 or there abouts compression. The motor won't run on regular gas but will run just fine on mid grade. The heads are old stock smoggers that I did a home port and polish job on. I really think that a set of Aussie closed chamber heads, resulting in a decent squish, would be just the ticket for a daily driven 9.5 compression 400. It should be able to run regular with a bit of mid grade gas thrown in because of it's better squish design than my open chamber Chevy heads. I'm just thinking out loud here. If I'm off the mark, feel free to blast me. Lord knows, if I build an engine for my friend with his hard earned money and it pings even on high test, I'll never live it down! I'd rather be in trouble with my wife than my friend! But then again, I sleep with my wife...I take that back...I'd rather be in trouble with my friend!

 

Read...

 

and read,
https://www.ford-trucks.com/forums/s...hreadid=200521
polish the cambers, that seems to help pinging.

 

The ford 400 is one of the best motors ford ever put in to production. But alot of people avoid them because they were build during the emission choked 1970s.

I have done alot of reseach on how to make alot of useable power out of these motors. And my current 400 I'm building should have more torque than a well built 460 (but with out the 250 or so pounds of extra metal of the 460). There are alot of performance parts out there for the 400. You just need to know were to look.

First thing I would do is ditch the stock cast iron 2V intake. There are two non EGR intakes available. Edelbrock makes a low rise dual plane intake, part #2171. It makes good torque and horsepower, and has a useable power band from idle-5500rpm. If your looking for a little more power, Weiand makes a high rise dual plane intake, part #8010. It makes good torque and and horsepower, and has a useable pwoer band from idle-6000rpm. Both intakes work well. If you want to use a more wild single plane intake Weiand makes spacers, part #8205 that allow any of their 351C intakes to be bolted to the 351M/400 heads. But for best results I would stick to the dual plane design.

A number of different cams are available for the 400 as well. Comp Cam, Edelbrock, Lunati, Crane, Speed Pro, Summit, etc make all sorts of cams.

If you are looking for a High compression flat top pistion Badger makes a set of OEM design replacement pistions for the 1971 400. This is the only year the 400 had a flat top pistion. Part #40010F-030 (.030 oversized) is idea. You can get a full point in compression by just using these pistions, and with milling of your head you can get even more.

High energy ignition systems are also a good way to make power. Accel, and MSD both have kits that are ready to make you 400 scream.

Exhaust systems can also make power when made right. Dual exhaust that includes headers, low restriction pipes, mufflers, and a cross over not only sound cool. They make some sweet horsepower, and torque inprovements.

My 400 should be done here some time next week, and it should make over 425HP, and over 475 lb/ft torque. Here is all that I used in my build up.

-bored .030 over.
-Badger flat top pistons. BADGER #40010F-030
-Weiand Action Plus intake. Part #8010
-Edelbrock 750cfm carb. Part #1407
-Comp Cam Magnum 280H camshaft. Part #32-225-4
-Rebuild kit from Speed works (includes bearings, and head kit).
-Double rollor timing set.
-Headman Headers. Part #89260 (77-79 2wd F-series).
-Accel billet distributor. Part #71202E
-Accel 300+ Racing igniton system. Part #49320.

Adam Hanson

1 fast F-100.

 

The problem with trying to get Horse power out of any large cube motor is the difficulty in getting air in and out at high RPMs. The 400's heads are good for a production motor, but need a lot of porting work for real power. There are some aftermarket heads available that will really light up a 400 motor. I am working on such a motor, built for street use.

Bore 4.030
Stroke 4.0
Pistons - Ohio Flatops
Rods - Stock
Heads - Cylinder Head Innovations 3V Aluminum heads 64cc Combustion Chambers (10.35:1 CR).
Cam - Preditor Hydraulic Roller 281 Adv Duration 0.595 lift.
Roller Rockers - 1.7 ratio
Double roller timing chain
Intake - Edelbrock Streetmaster Single Plane
Carb - Carter 750 CFM
Exhaust - Sanderson FC3 Block huggers
Distributor - Mallory Unilite
Coil - Mallory Promaster
Spark - Holley Annihilator

According to Dyno 2000, this makes 540 HP@6000 RPM and 539 ft-lbs Torque@ 4500 RPM.

You cannot get Quench on a 400 motor with any off-the shelf piston, because the stock piston sits 0.0565 in down the cylinder. Replacement pistons are even worse. You can run reasonable compression ratios, if your cam's IVC is late enough to keep the cylinder pressure down.

 

i'd like to find a inverted dome (not dished)piston that can bring the deck clearence to .000. then use these heads http://www.airflowdynamics.com.au/cleve2V.html
it would have good Quench
351M has 10.297 deck
400s has 10.292 - 10.302 deck
rods are 6.58"
stock piston CH
351M 1.947
400 1.647 (same as 351C)
if the 400 block was decked to 10.292
deck clearence would be .065". so we would need a piston with 1.717 CH to get .000 clearence
you would need and -18CC piston the get 10:1 CR, and a -23CC to get 9.6:1 CR, flat top piston would be about 12:1.
custom pistons can be made.

 

And what are you guys going to run for gas in these high HP monsters?

 

93 Octane

 

See if AFD has any input for this, it should be a common question. They were also talking about designing a 70+cc chamber version for stroker Clevelands.

The chamber shape is a lot different than the factory "D" shape quench chamber. I would think custom pistons are needed for best results. The only off the shelf, 22cc reverse dome I remember was from Wiseco with a 1.430" CH and .927" wrist pin. I'll dig up the part # if interested, it's not in their current catalog.

 

You may have to de-tune them to run on 93 octane, and 93 octane is not available in many places. 91 is premium pump gas here.

 

Can't we dream a little?

 

Dreaming is nice as long as everyone understands what is involved and don't throw big $$$ down a rathole building an engine that won't work well for their application.

 

Wow, what a lot of input. And all it took to bring it all out was for someone to say they were a Chevy guy.