can some one drop me the goods on this motor?

I might be getting one for my bronco. and I need to know the good side and bad side of this engine.


thanks ahead of time



If it is still running. you didn't try hard enuf!

 

well to start off the m in my opinion is the strongest engine ford made. they aint the best on mpg but they get the job done and plus. they are very cold blooded though. the one problem i have seen in many is that the oil pump if prone to go out. i suggest replacin with quality high volume pump. the 351m puts out a tremendous deal of torque and hp for the cubes though. what is your trucks main application? towing? pullin? highway? if i left anything out just say so

 

general daily use with mild to moderate off roading.

looking to drop lockers in.

If it is still running. you didn't try hard enuf!

 

>well to start off the m
>in my opinion is the
>strongest engine ford made.
>they aint the best on
>mpg but they get the
>job done and plus.
>they are very cold blooded
>though. the one problem
>i have seen in many
>is that the oil pump
>if prone to go out.
> i suggest replacin with
>quality high volume pump.
>the 351m puts out a
>tremendous deal of torque and
>hp for the cubes though.
> what is your trucks
>main application? towing? pullin? highway?
> if i left anything
>out just say so

-----------------------------------------------------------------

Got a good chuckle outta that one!!! LOL!!!

the 351/400M motors are basically a tall deck Cleveland motor. They share bore spacing and head bolt pattern and no too much more. They have larger main bearings and all have the 429/460 bellhousing pattern. It shares the terrible oiling design of the Cleveland that has to be fixed(restrictors) for any high RPM use.

They also all have terrible open chamber smog heads that in factory trim made them dogs!! The HP comment is what got me laughing!!! There is things you can do but there are other easier/cheaper alternatives for a M swap. Mainly a 429/460!!!

 

>
>Got a good chuckle outta that
>one!!! LOL!!!
>
>the 351/400M motors are basically a
>tall deck Cleveland motor. They
>share bore spacing and head
>bolt pattern and no too
>much more. They have larger
>main bearings and all have
>the 429/460 bellhousing pattern. It
>shares the terrible oiling design
>of the Cleveland that has
>to be fixed(restrictors) for any
>high RPM use.
>
>They also all have terrible open
>chamber smog heads that in
>factory trim made them dogs!!
>The HP comment is what
>got me laughing!!! There is
>things you can do but
>there are other easier/cheaper alternatives
>for a M swap. Mainly
>a 429/460!!!


Well you're close. They are basically a tall deck Cleveland and they do share an oiling system but there's absolutely NOTHING wrong with the heads. The heads are the best part of the M series since they're really just 2V Clevelands and flow like crazy right out of the box. They blow most other Ford heads away. The reason the M series is so under powered is the low C.R., anemic cam and the fact they only came with 2V carbs.

 

I respectfully disagree. The GIANT combustion chamber causes the lower CR and even with the lower CR these junk heads have a tendency to cause detonation, EVEN WITH THE LOWER CR.

The Australian small chamber heads with the 2 BBL valve sizes are much more desireable but still not up to the current aftermarket.

The 351/400M heads are a dime a dozen! They bolt onto a Windsor block with ONE EASY modification. Why aren't they used instead of the more expensive aftermarket Windsor heads?

What is your definition of good flow?

These motors were built during a sad time for Ford fans with a 150hp 400 CID screamer and the junk heads didn't help the cause!

 

>I respectfully disagree. The GIANT combustion
>chamber causes the lower CR
>and even with the lower
>CR these junk heads have
>a tendency to cause detonation,
>EVEN WITH THE LOWER CR.
>
>
> The Australian small chamber heads
>with the 2 BBL valve
>sizes are much more desireable
>but still not up to
>the current aftermarket.
>
>The 351/400M heads are a dime
>a dozen! They bolt onto
>a Windsor block with ONE
>EASY modification. Why aren't they
>used instead of the more
>expensive aftermarket Windsor heads?
>
>What is your definition of good
>flow?
>


You can disagree however you want but you're still wrong. The low compression ratio is caused by the dished pistons not the open chamber heads. Putting a set of flat top pistons in gives an easy 9:1 comp. ratio which really wakes the motor up. Of course closed heads will raise the C.R., so does decking the block or milling the heads. What's your point?

2V Cleveland heads which are identical to M heads flow better out of the box than any stock Windsor head ever made. Clean them up and they flow as good as most hi po aftermarket Windsor heads. That's why there aren't many aftermarket Cleveland heads, the factory pieces are just that good. Want some flow stats? Check out:

http://www.waldens.com/351heads.htm

Notice that right out of the box the 2V heads flow well. Add 4V valves and look at the numbers. Do a little bowl blending (which isn't on the chart) and then test them.

Yes it is very easy to put a set of C or M heads on a W block although it takes more than "ONE modification". The problem is that the custom intake manifold is extremly costly as well as needing custom pistons so most people just go out and get aluminum aftermarket Windsor heads and a cheap intake.

For more info on the "Clevor" check out:

http://www.themustangshop.com/clevor.cfm

 

[font size="1" color="#FF0000"]LAST EDITED ON 29-Jan-01 AT 01:14 PM (EST)[/font][p]>I respectfully disagree. The GIANT combustion
>chamber causes the lower CR and even with the lower
>CR these junk heads have a tendency to cause detonation,
>EVEN WITH THE LOWER CR.

Hey now, maybe they need a little help, but I wouldn't call them junk, especially compared to the even (proportionately) bigger chambers in '78-up 460 heads (96cc) and '72-up 429 heads (91cc).

>The Australian small chamber heads with the 2 BBL valve
>sizes are much more desireable but still not up to
>the current aftermarket.

If you look at the flow numbers in the URL Bill posted, you'll see they are quite comparable w/ aftermarket SB Ford units. I have personally seen stock untouched M-block heads measured at 186/152 cfm @ 28" H2O (0.500 valve opening).

Also, the small chamber Aussie heads have 58cc chambers. That's so small, even the truck pistons with an 8.8cc dish would give 10.27:1 compression ratio in a stock-bore 400!

>The 351/400M heads are a dime a dozen! They bolt onto
>a Windsor block with ONE EASY modification.

Maybe easy if you do a lot of custom performance engine work, but not easy for the DIY guy, or if you have to pay the pros to do it with a non-pro wallet.

>Why aren't they used instead of the more expensive aftermarket >Windsor heads?

By the time you add up costs of doing the modifications, they are about the same as the cost of aftermarket heads.

>What is your definition of good
>flow?

See above.

>These motors were built during a sad time for Ford
>fans with a 150hp 400 CID screamer and the junk
>heads didn't help the cause!

Yeah, and they were built at the same time the 460 was wheezing out a mere 195-210 hp.

Don't forget, by 1978, 400s in cars were using a piston with a huge 32.45 cc dish for a compression ratio of only 7.33:1 and they still coughed out 160 hp!

BubbaF250

1980 F250 4x4 Custom, 351M/NP435/NP208/D44HD-TTB/D60-FF/3.55s 6750 GVW, Rust & White.

 

>can some one drop me the
>goods on this motor?
>
>I need to know the good
>side and bad side of
>this engine.

jopey,

The bad side is that the 351M doesn't have a lot of high performance potential.

The good side is that all you need to turn the 351M into a 400 is the 400 crankshaft and pistons. The 400 has a lot of performance potential, easily double the factory numbers for torque and horsepower.

You can get inexpensive flat-top pistons for the 400 to get the compression ratio up to 9.0:1, and there are a lot of good cams for this engine.

Cam it right and get the compresion up and your 400 can make some real power, like 450+ ft/lb torque and 375+ hp.

BubbaF250

1980 F250 4x4 Custom, 351M/NP435/NP208/D44HD-TTB/D60-FF/3.55s 6750 GVW, Rust & White.

 

well it is looking that I will decide against it.

I got a buddy that says for around $1000 he can build me a better windsor than a 351M. with around 400lbs torque. think he is out of his mind?


If it is still running. you didn't try hard enuf!

 

>well it is looking that I
>will decide against it.
>
>I got a buddy that says
>for around $1000 he can
>build me a better windsor
>than a 351M. with around
>400lbs torque. think he
>is out of his mind?

I wouldn't say he's out of his mind but it's easy to spend someone else's money. Let's say you get a junkyard 351W for a song...say $150. That leaves you only $850 for all the rest of the work. In order to get 400 ft.lbs of torque out of it you're gonna need to make the heads breathe a whole bunch better than they do now which means either exten$ive porting, bigger valve$, etc ($$$) OR aftermarket heads which run around $800-$900 for cast iron complete, maybe $600 bare. Well there went your budget and we haven't even got to the bottom end machining yet, camshaft, intake, carb, etc. Now maybe if he said $2000...

 

>I got a buddy that says
>for around $1000 he can
>build me a better windsor
>than a 351M. with around
>400lbs torque. think he
>is out of his mind?

jopey,

What are you starting with? Do you have a decent running 351W now? If so, you might be able to get the right parts for another $1K to get 400 ft/lb torque out of it.

If you're starting from scratch and paying reasonable prices for parts, there's no way you can get a 400 ft/lb 351W for $1K. That would barely buy you a stock-level rebuilt long block, with maybe 300 lb/ft torque if you've already got all the late-model EFI goodies to go on it.

You didn't say what year your Bronco was, but the 351M/400 was available only in '78-'82 Broncos (only the 351M was a factory option from '80-'82). If your truck's newer than '82, you're probably better off with the 351W for legality reasons.

BubbaF250

1980 F250 4x4 Custom, 351M/NP435/NP208/D44HD-TTB/D60-FF/3.55s 6750 GVW, Rust & White.

 

85 bronco

I already have a 351 that will be ready to build up. but I am still in the thinking phase. any and all info/pointers are welcome.

thanks for all of the info so far.


If it is still running. you didn't try hard enuf!

 

>85 bronco
>
>I already have a 351 that
>will be ready to build
>up. but I am
>still in the thinking phase.
> any and all info/pointers
>are welcome.
>

The only reason I can think of to put an M block in your Bronco would be for the extra cubes that a 400 would give you. You'd still have to swap the tranny to a big block bolt pattern so why not slap in a 460?

So that leaves you and your rather optimistic friend looking at building a 351W which isn't a bad thing. If you're going to do a complete rebuild then I can guarantee it's going to cost substantially more than $1000. If you're just trying to increase the output of the one you have then you have a slim chance at success but it's going to take some judicious planning and a lot of work. There are "bolt on" parts you can get to increase the power like a camshaft, carb & intake, small tube headers and a good exhaust system but I don't think they're going to get you to the magic 400 ft.lbs of torque number you're looking for especially down low where you need it.

The real power of any automotive gasoline engine is in the heads. Engines are big @ss air pumps so the best thing you can do is make them breathe better. That means either modify the existing heads which isn't expensive if you do the work yourself but very co$tly if you have it done OR bolt on some aftermarket heads. The problem is that if you make the top end strong then the bottom end is likely to go out on you if it hasn't been re done. I don't mean to sound like a pessimist because I have no doubt whatsoever that 400 ft. lbs is available in a 351W but I think the price tag you're looking at is too low.


I'd start with a new cam, carb & intake and headers, you know all the standard stuff as well as a new timing set that will allow you to move the torque peak as low as possible by using the different keyways on the crank gear. That's definitely in your price range and fairly easy to do. If that don't cut it then move on to the higher ticket stuff.

 

Got ganged up on by the Bubba and Bill show!!!!

Good links all!!

But you guys are knowledgeable enough to realize thet flow #'s are just one part of the equation. One of the links even states that the M heads have giant ports. C'mon guys, I'm the biggest Ford fan there is but you've got heads out there that have smaller valves, less port size AND flow more with smaller CC out of the box for less than $1000. Equal flow with smaller ports = a better performance head.(velocity)

I'll back off and not call them horrible anymore! LOL!! And I never said that any stock Windsor head was better(even though the GT-40's are admirable and in the same 180CFM range that Bubba states) But the M's are 30 year old technology and I have heard that the large chamber heads are prone to detonation EVEN with low compression.

Believe me guys. The people I hang with that build Mustang race cars(me included) wouldn't think twice about different pistons or drilling a few water passages or two if we thought it would give us an advantage.

Now the Yates heads with the revised exhaust ports and .......well that's a Cleveland head. Show me the money!!