hot rodding a 351 m

[auron73mach1]

Just a curiosity but what can be done to hot rod a 351m 2v?

I might be in possession of a lifted 81 bronco soon, that will become a lake toy but want some more umph to turn and burn the 35x12.5 inch tires

 

[MotoArts]

Swap the stock heads for 2V Clevelands.

Change the stock timing gear set to non-retarded or adjustable.

 

[mustbrad]

timing chain, 260/270ish duration camshaft, 2v to 4v manifold torque is the key

 

[Totalled]

Make it a 400 with tmeyer pistons to get the compression up into the 9s.

 

[73MustangCoupe]

I agree. Add some Cleveland heads, cam, and maybe upgrade the lifters and switch to roller rockers. Aussie heads would be even better. Keep in mind, this is a truck so you'll want the cam, intake, and heads working to produce low and mid range torque. For that reason, a dual plane intake much better than a single plane intake. There was a discussion of this exact subject this week on another forum I visit frequently on the Ford Truck Enthusiasts website.

Good luck.

Make it a 400 with tmeyer pistons to get the compression up into the 9s.

X2. Stroking it to a 400 will help with that torque, too, and get the compression up to about 9.4 or so. Let you make some good power on pump gas.

No replacement for displacement.

 

[Paul of MO]

http://www.projectbronco.com/Technical_Articles/351m400_performance_build_up.htm

Pretty much sums it all up but I have not built a 351M or a 400.

Seems like he knows what he is talking about.

Paul

 

[wwhite72]

You mentioned it is for a lake property? You got a boat? Because the M makes a good anchor. The 400 has been used with success for modified competition, but not in vehicles.

 

[Kit Sullivan]

I too have always heard from engine builders who know that any variation of the 351M, 400M or 351/400M are terrible for many reasons. My old man memory thinks these are some of the reasons:

1) Terrible heads

2) Horrible valve train, weak emissions-oriented cam

3) Undersized journals

4) Crappy, low-compression dished pistons

5) Skinny and weak con-rods

6) Inadequate and failure-inducing oiling system

7) Heavy....just too heavy

Of course this may not be totally accurate, but I have heard these same complaints from many others who are familiar. All of these problems are curable: just throw cubic money at it until you have solved the issues. But why start with an engine that puts you so far behind the "8- ball"? I think it would cost considerably more overall in the long run than if you just started with a better candidate in the first place. Even if the "M" was free, I still it would end more expensive overall to do it right.

I once had 351/400M in 79 Lincoln MK-V, and it gave me dependable service up to about 200K before I sold it. However, it was a pooch...gutless in every sense of the word.

But hey! It may have had no power, but at least it drank a lot of gas! Typically 9-11 mpg, driving it very easy.

Overall I was very dissapointed in its performance, even in stock 2-V form.

I stick wjth engines I know are and that I am familiar with:

1) Any Ford "Windsor" except the horrific 255

2) a true "Cleveland" (335- series)

3) Any 385- series (429/460)

4) Most "FE" Fords

And of course:

1) the famed SBC...one of the greatest engines ever overall

2) the MK-IV "porcupines"...inspiration for Ford's 385- series.

Like most, I guess I just stick to what know.

But if you get that "M" done up right on a reasonable budget, share the recipe!

 

[Mister 4x4]

Why all the hate for the 351M? It's VERY Cleveland-like... in a de-tuned kind of way. A lot of Cleveland hot rod parts will work with them, and any de-tune deficiencies can be overcome with some research and smart building. 351C-2V heads, Edelbrock intake & carb, and some headers... just bolted on 80-90hp. Throw in a cam, flat-tops, and roller everything, another 50-70hp.

Wait a minute there, Mr. Auron-"car-ADHD-guy:" You've got a '73 Mach 1 to finish and 2 parts cars to strip and chop-up before too much longer.

And you're right... those Coke Zeroes in the fridge taste like ass. :dodgy:

 

[auron73mach1]

And you're right... those Coke Zeroes in the fridge taste like ass. :dodgy:

Ha told you and I was just curious because a guy is willing to trade the dually for it and I would like another truck that screams "ME!!!!!" that the wife would know how to drive while I'm gone (as in automatic) cause I can't stand to see my dear pickup sit for 7 months and not be driven or even started ( she can't seem to remember how to do that or take the key out)

 

[wwhite72]

if the 1981 351M made 200hp at the crank when new i'd be surprised. So Ford probably had a rotating assembly to match. That long stroke came with long rods...rated for under 200hp. Why build a top end when the bottom end would be expected to grenade immediately after?

 

[Totalled]

I too have always heard from engine builders who know that any variation of the 351M, 400M or 351/400M are terrible for many reasons. My old man memory thinks these are some of the reasons:

1) Terrible heads

yep

2) Horrible valve train, weak emissions-oriented cam

Cam sucks, nothing really weak other than long pushrods.

3) Undersized journals

No, oversized actually. The same as a 351W.

4) Crappy, low-compression dished pistons

Yep

5) Skinny and weak con-rods

Not really. They are actually pretty beefy. It was common to use them in long rod builds before aftermarket 6" rods became commonplace.

6) Inadequate and failure-inducing oiling system

Same oiling system as a 351C... because it's literally a tall deck cleveland with windsor main sizes.

7) Heavy....just too heavy

Could be. Plus side is a big block shares the bell pattern, so it's a bolt in with mounts.

Of course this may not be totally accurate, but I have heard these same complaints from many others who are familiar.

See responses in red.

 

[73MustangCoupe]

I too have always heard from engine builders who know that any variation of the 351M, 400M or 351/400M are terrible for many reasons. My old man memory thinks these are some of the reasons:

1) Terrible heads

2) Horrible valve train, weak emissions-oriented cam

3) Undersized journals

4) Crappy, low-compression dished pistons

5) Skinny and weak con-rods

6) Inadequate and failure-inducing oiling system

7) Heavy....just too heavy

Of course this may not be totally accurate, but I have heard these same complaints from many others who are familiar.

Of course, that's pretty similar to what the Windsor motor guys say about the 351 Cleveland motor, too.

And don't even ask what Chevy guys say about Ford motors.

But with the right parts, an old 351M can be brought to life and still be in the original package. For someone doing a restoration, that can be really desirable. The 351M isn't my favorite, but I know some guys who really like theirs. Just sayin'.

 

[wwhite72]

i never heard a windsor owner bad mouth a cleveland. most of them dont know what a cleveland is.

 

[mustbrad]

here is a good article for a 400 same engine just different Crank & Pistons under good power awesome torque

http://www.hotrod.com/techarticles/engine/hrdp_9809_ford_406_engine_build/viewall.html

 

[hyena429]

i never heard a windsor owner bad mouth a cleveland. most of them dont know what a cleveland is.

I have alot...Even the same thing from chevy guys...I had a 5.0 owner tell me that the reason the cleveland had bad oiling issues was cause of the head design "rolls eyes"..lol..Then i was told by a windsor guy who had a mustang coupe that he was glad his had the 351w and not a cleveland cause of the weak bottoms ends a cleveland has...I said..No they dont..They have a stronger bottom end than a Windsor...I said that 221 block design is old and cleveland is years beyond in tech...he did not like that i said it..lol

 

[wwhite72]

builders of racing engines have written that clevelands are prone to cracks in the main saddles and suggest grinding off the cast flashing. but no idea what kind of HP they were building or how many runs would produce these cracks. they might have been complaining that 850hp drag engines were only lasting half a season! But these engines seem to do fine in street cars up to 400hp without any problems. And brand new Mustang GT's boast they have 400hp now. ha ha

 

[coreysvt]

the 351m is a good truck motor. as far as hot rodding goes, just go about it like any other engine. since its a truck I doubt you'll be turning a ton of rpm so I really wouldn't worry about the bottom end.

 

[Stocktrader]

I second Tim Meyer

I'll scan my picture from circa 1982

My 1980 Bronco. First independent suspension lifted ford in the country with 40's on it.

Skyjacker copied the steering arm for their lift kit about 2 years later.