Okay-we finally got around to running the modded 77 F-250 400 against the 93 chevy ex-cab dually w 400sbc(delayed due to rod out side of block of chevy and long argument with rebuilder), we tested both with and without trailers and---

If your game is 0-60 the Ford wins every time. The difference is more pronounced from 0-30 and dead stops going uphill. It's not by much at this point as the Chevy is by the box on the Ford by 55 and almost but not quite even at 60.
After 65 the chevy 400 has more throttle response and is better able to maintain 75 mph highway rolling hill speed, however the chevy has the 4l80E od and it is 2mpg ahead of the 400 Ford.

If you are running around town towing I'd rather have the 400M. Sharp throttle response, better torque much easier to get moving all around below 55 mph. Better city mpg

If running the hwy the 400 chevy does better here. It gets 13 mpg to the Fords 11 on the hwy, maintains speed with less throttle. However the the chevy runs at 215 degrees with a 180 thermostat, and Ford runs 185 with a 180 so I suspect durability will be greater with the Ford IMO

 

Both 400's...Ford and Chevy were slugs IMO....much like other engines of their time period. They were used...1970's... because cars were heavy, emissions were taking a real toll on HP and manufacturers needed big cube engines to overcome all the emission controls that tended to sap the power out of power plants back then.

Many of the applications for low performance 400 cube engines then, were also coupled with axle ratios in the 2.73...2.75...sometimes axle ratios around 2.56, etc....a recipe for sluggish acceleration.

I had rides in both Chevy and Fords (when they were new) powered by their respective 400 cubic inch engines...they were underwhelming when it came to acceleration....they were both truly bad....compared to what say a 390 FE or a 396 Rat motor could do...just a few years previously....before stringent emissions, etc.

I enjoy of reading debates as to whether a 180 hp Ford 400 vs a 170 hp Chevy 400...somehow makes the Ford 400 a better engine. Both of the old '70's emission strangled 400's were not great performance engines.

If you're going to have a engine debate....maybe choose something like the Ford 428 Cobra jet or Ford 427/425 hp Fe side oiler vs the Chevy Rat 427/425 hp...L72...now you have some material to debate about.

BTW...these 400 blocks were not designed to be high performance engines by the factory, however many years later...400 engines with the benefit of modern technology and hot rod experimentation have made these engines a good choice for hot rodding and modification.

 

I know this is an older thread and all, but I was gone a long time!

This is very surprising to me. I would have expected the opposite to be true, with the Ford 400 having more top end, what with it's better breathing heads and it's better rod length to stroke ratio.

This is because, as you mentioned, this particular Chevy 400 had the benefit of a overdrive.

That's the Ford's superior rod ratio at play here. Better rod ratios make for a much lower friction engine!

Thanks for posting the results!

I was simply pointing out that it was in fact the 400 Ford that made more power, and did so with half the carburation! I was also setting the record straight that it was the Ford that made more power, however small it was, not the Chevy.

Very few of us will ever have one of those engines. This thread was created to talk about two engines that we DO actually have actual access to! Other threads already existed that debate those other engines.

Plus, see below.

A better choice in fact, than the FE based 427s and 428s have proven to be!

Regards,
Eric

 

One thing about the SBC 400, in order to get the need bore size the cylinders are "siamesed", meaning there is no water between them. It gives the block great strength for hopping up, but does make them run hotter.

My son had my old 390 powered 77 F-150 for a few years, he finally had to get rid of it because it was a standard cab and once his son was born it wouldn't carry all 4 of them. A number of years later he bought a 77 Chevy 4WD with a built 400. The 390 and C6 got 16-17 mpg solo on the highway, Chevy got 7-8 with a TH400 and pinged horribly with any kind of load. When I explained to him about the cylinder design then he understood the problem.

Moving from Washington state back to Texas, since he was doing it mid-winter (gotta love Army PCS orders) he went down I-5 to I-10 so he wouldn't need to deal with snowed in passes. He called me at one point because he was afraid of damaging the engine pulling his camper over the bottom end of the mountains. I told him to try retarding the timing just a bit. He was able to just guess at where to move it as all his tune-up stuff was buried. Ran 1000% better, the guy he bought it from apparently had jacked the timing way up. He still only got about 5 mpg on that trip though. Old 390 would deliver about 10 mpg with a similar load (big Wolverine slid-in flat towing an Omni).

 

Oh yeah, the siamesed cylinders! That does indeed contribute to hot running as well.

Really a miserable engine overall! I just really despise it! That's why I was so vocal here on this thread! I'm just as quick to bad mouth Ford though when they mess up too, as can be seen by some of my other posts around here! But for me, this one is a no brainer: 400 Ford all the way!

Regards,
Eric

 

You guys mention siamesed cylinders, but it depends how much they "overlap" over each other (how much they interfear). Chrysler 2.2 and 2.5s had siamesed cylinders and I've known people who got plenty of miles out of them. Jaguar V12s also had siamesed cylinders and they did well in racing. Many new aluminum block cars have gone this route as well, and see how many of these new cars pass 250 , even 300,000 miles ?

A slight amount shouldnt matter, the amount of thickness could be less than the cylinder wall thickness.

The Ford 400 does have potential, my grandson and I built a strong running 72 400 for a big 72 Galaxy and with the exception of them being hard on the rod bearings they are good engines. If my 351M ever gives out, I'll drop in a 400 crank and rebuild that. Engine Masters magazine had a guy who won one year in a buildoff with a 400Ford and made surprising horsepower.


As much as it hurts to say, circle track guys love the Chevrolet 400 they seem to do well.

 

I did already mention in an earlier post that the 400 Ford has won more of those Engine Masters competitions than any other engine.

Short track guys love Chevies in general, not just the 400. But in the lower more stock classes, the Fords at my local track prevailed. Factory Stock div. was owned by a 351W powered Crown Vic! Ironically, the driver of that car drove a Chevy in a higher division! (El Cajon, now closed. The track where Jimmy Johnson, another Chevy guy, got his start!) Chevies prevail in the upper classes simply because they enjoy better aftermarket support. It's tough to overcome, and it's self perpetuating. Nobody dares to be different cause it's too expensive to build a non-Chevy!

Regards,
Eric

 

Three items, I would like to see how Jaguar v12s have siamesed cylinders considering they are a wet sleeve engine (I used to work for a Jaguar dealer).

Second, yes there is a heck of a lot more aftermarket support for those French engines. It takes brains to build a Ford or Chrysler engine.

As far as the 2.2L Chrysler, I know about them, see my screen name. 135 ci, 200 HP at 14 psi boost. Next up for that, 2.5L with SRT 4 DOHC head and turbo, should be able to get 400 HP out of that combination.

 

Quote:

Originally Posted by Holiver31

You must be high. The 351M/400 are "small blocks". Saying they are small/big block is incorrect as well. Ford does not determine engines by small/big but by series or initials. Ex.- 335 Series-351M/400. FE-390/360. They were based on the 351C which is a "small block" and given a taller deck height. The only reason they share 385 Series bellhousings is because they were created to phase out the 390/360's. Also another flaw in your "idea" is carrying the M with the 400. The only ford engine to carry the M is the 351 from the 335 series. It stands for modified, not midland, not Michigan, its Modified. Don't fight it either, ford literature proves it. Contact NumberDummy if you don't believe me.

This is what happens when one tries to apply chebbie terminology to everyone else's product. While Ford lumps the 351C, 400 & 351M in the same 335 design engine family (initially the "small block" 351C); they also specify the 2 later blocks as using a C6 transmission, originally for FE big blocks. To add to the confusion, Ford then (briefly) cast a 400 block for the FMX having a small bellhousing; definitely "small" block. Due to the 400/351M having a much higher deck & the vast majority of them using "big block" (FE, 385) bellhousings/transmissions, it's hard to classify them as small. In other words, TOSS all chebbie references into the garbage WHERE THEY BELONG & start using Ford terminology (Y-block, MEL, FE, Windsor, 385, 335)!

 

Holy thread resurrection, Batman!!!

While I'll agree the big block/small block debate is mostly a Chevy thing, there is no arguing it has crossed over to the Ford camp.

IMHO, bellhousing bolt pattern has nothing to do with the designation. The simple fact that the 335 motors use the same bore spacing as the 221, 255, 260, 289, 302, 351W makes it a "small" block if they're going to be called anything.

Being able to basically bolt a canted valve "Cleveland" head on any of the above motors also bolsters the argument for small block.

 

Ok, heres my contribution to an old thread. The 400 Ford isn't exactly a small block, nor is it exactly a big block. Unlike Chevy and Mopar, Ford built engines along family lines. The physical size between these various engines and the competition placed it in-between the size of SB and BB engine. The 400 was part of the 335 "Cleveland" family. BTW it wasn't really supposed to be called 400"M". The "M" was actually applied to the 351"M" and meant "Modified" to help distinguish it from the 351"W" and 351"C"

I've heard some say the "M" stood for "Marine" but that wasn't the case either as they were intended for trucks and larger cars, not boats. "Modified" is exactly what it meant. The 351M came about by destroking the 400. At the time, Ford ended the production of 351C's and replaced them with 351W's. They began running short on this displacement. The 351M filled in the void. Since the 400 wasn't altered or "Modified" and was designed to replace the older 390 FE, the "M" doesn't actually apply to the 400. Of course numerous typos over the years has it that this engine is also referred to as the 400M.

In a general sense, Ford's approach to producing engines along family lines meant that each engine is optimally designed for it's displacement, whereas, a singular sb or bb design meant that you eventually reach the design limits of a particular block design. The 400 Chevy was pushing the limits of the SBC engine block. But Chevy had one big advantage, and that was parts were always cheaper for SBC parts. This wasn't by accident. With a common design, parts were easy to mix and match and prices reflected that. The 400 Ford may have been optimally designed for it's intended displacement, but the engine lacks aftermarket support and unfortunately it was intro'ed during the 70's fuel crisis/emissions/smog engine era. The engine was relegated to larger cars and trucks that had no real performance image to worry about. By about 1980 it was all over. The 351M/400 was replaced by the 351W as Ford ramped up production for that engine, and the 460 became the sole large displacement engine

​​​​​​​Ed

 

The other item, the 351M/400 was designed to share the back of the block bolt pattern with the 429/460 engines so for a full size Ford or Mercury in 1972, engines were for the Ford, 240, 302, 351M, 400, 429 Mercury, 302, 351M, 400, 429. I had a 1971 Colony Park, engine choices were 351W, 426 2V or 429 4V whereas a Ford Country Sedan, base engine was a 240.