So... a 351m... displaces 351 cubic inches
and... a 351m/400 displaces 400 cubic inches

if that isn't correct plz help

If correct.... I am wondering if there is any block casting number or sign displaying this difference.

I have a local junk yard pal of mine offering a 400 that smokes for $100.... I am wondering if anyone has a breakdown or if anyone knows how to read casting numbers so I can know exactly what I am getting.

any help is excellent

 

>So... a 351m... displaces 351 cubic inches
>and... a 351m/400 displaces 400 cubic inches

A 351M is +/- 351 CID, a 400 is +/- 400 CID. There's no such thing as a 351M/400.

>if that isn't correct plz help
>
>If correct.... I am wondering if there is any block casting
>number or sign displaying this difference.

The 351M and 400 share the same block. All you have to do is swap the crank & pistons and you can change from 1 to the other.

>I have a local junk yard pal of mine offering a 400 that
>smokes for $100.... I am wondering if anyone has a breakdown
>or if anyone knows how to read casting numbers so I can know
>exactly what I am getting.
>

Since they share the same block the only sure way to tell the difference is to pull the pan and check the casting code on the crank. 5M, 5MA, 5MAB is a 400. 1K is a 351M.

If you plan on rebuilding this motor then I suggest you go to [link: motorhaven.autoanything.com|MotorHaven.com] and pick up the book by Tom Monroe called How to Rebuild Your Ford V-8 351C, 351M, 400, 429, 460. It has a complete breakdown of all the casting #s for the major parts.

 

[updated:LAST EDITED ON 30-Nov-01 AT 10:12 AM (EST)]thanks for the information, I ordered the book you said.

I just talked to comp cams about a cam for the exact build-up out of hot rod for the 400.
They refered me to the 265 DEH grind series. I don't think actually knew anything about the engine besides what the computer screen said.

He also said that they dont make an extreme cam for that engine.

I looked on their website and found a specialty cam for the 400
actually i found a few.. two of them were the 268 grind. the only difference is the lobe seperation angle. I am planing on putting this in a light car. what would be a good cam for up to 5500 max rpm and what would be the difference between a 108 and 110 degree cam when everything else is the same on the cam. anything noticeable or did someone get bored.

thanks
this is the catalog page for the cams
http://www.compcams.com/catalog/224.html

 

>thanks for the information, I ordered the book you said.
>
>I just talked to comp cams about a cam for the exact
>build-up out of hot rod for the 400.
>They refered me to the 265 DEH grind series. I don't think
>actually knew anything about the engine besides what the
>computer screen said.

I believe the cam in the Hot Rod article was a custom grind.

>He also said that they dont make an extreme cam for that
>engine.
>
>I looked on their website and found a specialty cam for the
>400
>actually i found a few.. two of them were the 268 grind.
>the only difference is the lobe seperation angle. I am
>planing on putting this in a light car. what would be a
>good cam for up to 5500 max rpm and what would be the
>difference between a 108 and 110 degree cam when everything
>else is the same on the cam. anything noticeable or did
>someone get bored.

Lobe separation is what determines the effective compression ratio of the cam by controlling valve overlap. The narrower the lobe sep. the farther up the bore the piston will be when the intake valve closes so the lower the E.C.R. would be (Maximum E.C.R. is acheived by closing the intake valve at BDC). In some cases this isn't a bad thing because it helps prevent detonation.

Bottom line, if you were to run a 108 and 110 cam on the Desktop Dyno they'd be virtually identical.

Here is a short list of the cams that made the final cut in my selection for my 400. I eventually went with the Crower. Haven't got my engine on the dyno yet so I can't say how well it will perform.

[link:home.pacifier.com/~bbeyer/Cam_Comp.htm|Cam Comparison]

 

cardude,

As Bill mentioned, the cam used in the HR article was a custom cam, so it will not be in any of their catalogs. If you want it, you must ask for grind number FC5433/280H-3. (If you can get someone who's familiar with it, they should recognize the reference to the HotRod article.)

In general, smaller lobe separation angles produce lower effective compression at low rpm, for the reasons Bill stated.

However, at high rpm, when the intake F/A charge has more momentum (inertia), the narrower lobe separation angle has less effect on the effective CR. Indeed, the higher rpm you want to run the engine (and get good power), the later you want to close the intake valve on the compression stroke so you get maximum F/A charge in the cylinder.

When comparing lobe separation angles, a narrower angle will "bleed off" some low rpm compression, perhaps at the expense of idle quality and idle vacuum. A wider lobe separation angle will give better idle quality and vacuum, but at the expense of some high rpm performance potential.

 

>When comparing lobe separation angles, a narrower angle will
>"bleed off" some low rpm compression, perhaps at the expense
>of idle quality and idle vacuum. A wider lobe separation
>angle will give better idle quality and vacuum, but at the
>expense of some high rpm performance potential.

Excellent point. That's why higher RPM "race" cams use a 108 lobe sep. vs. 110 to 112 for street/torque motors.

 

[updated:LAST EDITED ON 30-Nov-01 AT 11:07 PM (EST)]you guys rule!

I just found out my father in law is giving me a 78 galaxie with 60000 miles. Its either a 400 or a 460.

i hope

thanks again

now that i think about it, it may not be a galaxie... but it is a 78 with 60000 orginal miles

 

does anyone know what the journal sizes for the 351m/400 cranks.

 

>does anyone know what the journal sizes for the 351m/400
>cranks.

Main 3.00" Rod 2.311"

 

First of all I want to say is I am new to this site, and it's awsome I have picked up alot of useful information!!!

I have a 1977 F-150 with a 351M and C6, 3" lift, and within the last year, installed another 351M/400, which came out of a Mercury, or (please don't laugh) what I thought was a 351M. Let me explain further....

I know from reading this thread and others that there is no such thing as a 351M/400, only one or the other. On the valve cover of the engine I recently installed, the sticker read:

351M/400 (2CV1)
400 C.I.D.
D7AE-9C485-ABA

I have a 400, correct? or would i still have to remove the pan to get the casting codes off of the crank to verify this? Is the later set of numbers a casting code? Help!

 

>I know from reading this thread and others that there is no
>such thing as a 351M/400, only one or the other. On the
>valve cover of the engine I recently installed, the sticker
>read:
>
> 351M/400 (2CV1)
> 400 C.I.D.
> D7AE-9C485-ABA
>
>I have a 400, correct? or would i still have to remove the
>pan to get the casting codes off of the crank to verify
>this? Is the later set of numbers a casting code? Help!
>

Unless someone switched the valve covers that's a 400.

 

Thanks Bill!

 

The 400 block is basically the same as a Cleveland block. The differences are The deck height is approx one inch taller on the 400, So that means an aftermarket intake is a must if you want a 4bbl. Another difference is the Crankshaft, the 400 has a longer stroke of 1/2 in., Also the main journals are bigger on the 400. The 4bbl was listed only 1 year that was in 1970. All 400s used 2vCleveland heads. Then there is the 351M . M stands for Modified. The 351M is a 400 block that was modified by Ford to put the 351W crankshaft in the 400 block. Therefore that is where the name comes from. The 351M has been in prodution since 1975. They also used the 2v cleveland heads and 4bbls were not produced.It uses the same intake as the 400. Hope this helps

 

>The 400 block is basically the same as a Cleveland block.
>The differences are The deck height is approx one inch
>taller on the 400, So that means an aftermarket intake is a
>must if you want a 4bbl. Another difference is the
>Crankshaft, the 400 has a longer stroke of 1/2 in., Also the
>main journals are bigger on the 400. The 4bbl was listed
>only 1 year that was in 1970. All 400s used 2vCleveland
>heads. Then there is the 351M . M stands for Modified. The
>351M is a 400 block that was modified by Ford to put the
>351W crankshaft in the 400 block. Therefore that is where
>the name comes from. The 351M has been in prodution since
>1975. They also used the 2v cleveland heads and 4bbls were
>not produced.It uses the same intake as the 400.
>Hope this helps

It would be much more helpful if it was correct.

First of all 4V 400 intakes seem to be about as plentiful as unicorns. No one seems to be able to come up with a factory 4V manifold or even a FoMoCo part #.

Second, the 351M/400 motors used heads which are very similar but not identical to 2V Cleveland heads. Of course they will interchange but then again so will the 4V Cleveland heads.

Third, M may very well stand for Modified but there isn't any documentation from Ford that says so.

Fourth, the 351M and 351W do not share a crankshaft. They have different castings with different counterweights and different snouts.

Hope this helps.