I was wondering if there are any kits or at least a crank out there to stroke a 400 i Know the 400 is a stoked 351m

 

The 400 was introduced in MY1971, and the 351M was introduced in MY1975. The 351M is actually a de-stroked 400.

Do a search on the topic. There have been numerous posts about the subject in this forum.

In a nutshell, there are no aftermarket stroker crankshafts for the 400, but you may be able to adapt one made for another engine, such as the 351W.

 

Here is a web page I found that offers a stroker kit for the 351m/400.
http://www.strokerkits.com/351___400m.htm

 

look up shazam here in FTE. He is the Stroked 400 king. More HP than you would even think was possible out of that motor.

 

Anyone named Bubba is always right.

 

ahhhhh shazam has(had) a compition(only) stroked 400, custom made, i beilve he said(wrote) apx 15 thousand dollars worth of motor
but as soon as i get my 79 straightened out and get a parcel of land and homestead i am building one
alas until then i will stick to my rebuilt little-400 (351m)

 

Remember too, if you stroke the engine, you add cubic inches, which adds compression ratio. You will then have to either dish the pistons, double the head gasket, or drop the piston in the hole to lower the CR, to run the available pump gas. It's foolish to build more than 9:1 into a street motor, as spark knock becomes a problem, especially with a heavy truck lugging a lot of weight.

I'd build a stock 400 before a stoked 400. But if you have the coin and time, have at it !

 

400's have pinging problems enough with 8 to 1 comp ratios. You don't have to go as high as 9 to 1 to have this problem. If you did stroke it say .050 and swapped to a set of aussie quench 2bbl heads, you would increase the comp ratio but also increase the motor's resistence to pinging. I worked it out before and you would need to run a piston with about a 13 cc dish ( or reverse dome) to run this combo ( 4.03 bore X 4.05 stroke with aussie 63 cc chambered heads) You don't want to drop the piston down the hole, doing so will destroy the quench the aussie heads combined with the near zero deck pistons at TDC will provide vs the stock 400's "zero" quench.

 

To have pinging problems at 8:1 there are other issues with the ignition advance curve, timing, etc. Most of the time they come from a bad EGR or disconnecting the EGR without the required changes to the distributor or A/F ratios etc. The 400 engines ran great OEM stock with 9:1 compression and 89/90 octane gas.

 

Oh really? I've got a 400 in a 77 F100 with 8 to1 comp ratio and zero quench because of the fact that the pistons are .050 down the bore at TDC, no matter what you set the timing at it pings. And the air fuel ratio is fine, in fact a little on the rich side with a Holley 500 cfm carb. And no EGR ( who needs it) I had a friend in high school that had a 71 custom with the 400 and it also pinged every time you naile the gas. This was back in the mid 70's before the drop in octane ratings on pump gas. The 400's well known pinging problems had nothing to do with A/F ratios, EGR problems or dist advance curves ( if anything retarding the **** out of the advance curve to rid the motor of pinging, would hardly be called an advance curve) Their pinging problems are solely the fact that Ford goofed when they designed the pistons for these motors with insufficient deck height and open chambered heads to boot.

 

My 78 F250 400 at 8:1 with stock heads and dished pistons does not ping.

None of the 1971 Fords I drove (and I drove a lot) with 400's at 9:1 compression pinged either.

Regular gas back in 1970-71 was 89 octane (R+M)/2 where I am in KC. Today you would have to run "midgrade" in these engines here.

To get pinging at 8:1 you have other engine problems that have nothing to do with the design of the engine. Ford didn't "goof" at all, just some people can't get them to run properly, -operator error.

 

If your's doesn't ping then you've got the timing so far retarded that you could harly call it "performance" . Regular gas down in south Texas back in the 70's was 91 octane. Even Ford admitted they goofed when they designed the 400's with insufficient deck height. I built a 400 with a 9,7 to 1 comp ratio using 351C forged pistons, milled, ported and polished heads ( 2 bbl open) this motor would ping with 93 octane premium gas and 8 degrees initial timing. This 400 was pushing 425-450 hp and it still pings like the 8 to 1 400 it replaced.

 

My experience with zero decked "quench" heads has proven, there is no merit to that theory in reality in an engine running unleaded pump gas. I built zero decked engine in the 400-455 inch range, and 9.6-10:1 CR, they pinged like heck on 94 octane Sunoco.

There's been a lot of buzz on the net recently, concering quench heads, zero deck, and resistance to detonation. All I can say is, just try it, most likley the engine will ping anyway. That theory is tied into MODERN engines, with spark computers and knock sensors, that automatically sense ping and retard timing. With the old non-computer stuff, it just doesn't work.

If you build a 9:1 or lower engine, it WILL run on unleaded, and won't ping with pump gas. When we started building street V-8's back in 1982, we started with stock 10:1 motors with zero deck, and found out quick it just won't work. We reduced to 9.5 CR, and still had problems with ping. When we got down to 9:1, we found the engines ran ok with no ping.

There's nothing wrong with dropping the piston in the hole. The dished piston basically does the same thing, right ?? Engines like the MEL Lincoln and 348/409 Chevy had flat heads in the combustion chamber area, and the piston was dropped in the hole in a angled manner to create the chamber, down in the bore.

I've built a ton of engines with .060"-.125" deck height, stacking gaskets to reduce compression, no problems- and the big inch 460+ engines were real tire burners. CarCraft did a test on an engine, and started with 1 head gasket, and kept adding gaskets until they had 3 or 4 under each head, and kept dyno-ing the motor each time. Even the 8:1 motor made great power, around 350-400 HP, but basically there is a 20 HP drop in power for every point in CR lost from 11:1 down. So a 8:1 motor will make 60 HP less than an 11:1 motor.

So if given the choice between 9:1 or 9.5:1, it's only about a 10HP difference. That's not even a tenth in a quarter mile race, barely. Not worth it.

 

a well adjusted vacuum advance will take care of this. got more timeing adavance than I had ever thought. and that prooved to take off 2 tenths in the 1/4 mile.
its not the engines fault for pinging, its knowing how to tune it to get the best performance out of it.
no knock sensore here.

 

Like I said b4; "Ford didn't "goof" at all, just some people can't get them to run properly, -operator error."

9.6:1 is way too much compression on a iron head engine without electronic controls. Don't blame the engine design for your mistake and lack of research etc. -Again, operator error...

My engines run just fine