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351 Ho?

23K views 17 replies 7 participants last post by  pmeisel 
#1 ·
Okay, a guy I work with has a 79 Ford Pickup that he's thinking about getting rid of, I may pick it up cause it has some parts on it I'd want for the 69, disc brakes, pbrakes etc. Anyhow he says it has a 351 HO, now I did a search on google for it, and basicaly all I found out was that it was a Ford Crate motor that was pretty much a de-tuned Boss engine. My ford engine interchange guide doesn't make any mention of this engine at all. If anyone knows if this might be worth fixing up or any details about it I would appreciate it. Thanks.
 
#2 ·
The 351HO in the late 70's and 80's really lacked the HO part... It is NOT the 351C HO from 1972, that was the slightly detuned Boss 351 (72 was the only year that motor was available). The later HO is Windsor and made just a bit above 200HP, and wasn't really anything but a bigger version of the 5.0HO. Only worth botherin' with if you're just gonna start from scratch IMO, its a smogged out low-compression engine.
 
#3 · (Edited)
351 HO

The difference between a 351 W HO and the standard 351 W is a 4 bbl intake from the factory, and a lot larger cam, as far as carbureted versions were concerned. At least any built past 1970. According to my books, the HO option didnt come out til 84, which at that time they also put in a larger cam, .445/.453 lift; 206/221 duration @ .050", vs .416/.416 lift; 195/195 duration @ .050" with the standard cam. The last year the smaller cam was used was in 85. These stats pertain to the pickups.

In cars the larger cam was used starting in 80 and the last year the smaller cam was used was in 88.

The HO had various ratings of HP from 84 on up, from 185 HP to 210 HP. While that may not sound like much, they put out an extreme amount of torque.
IF you didnt do anything but pump up the compression a notch to about 9-9.5:1 and do a little bowl blending, you would have a very respectable running, 5000 RPM engine on your hands. A good exhaust would put you close to 1 HP per Cubic Inch.
IF you want to know about Ford engines, ask Ford People.
Been there done that.

Its a good possibility that truck could have a 351 M. While these were a little lacking, as was the 351 W, back in the 70's, it does have more potential than does the Winsor due to its having the 2 bbl Cleveland heads on it. The 351 M weighs 575 lbs, vs the 351 w, which weighs 525 lbs.

The 351 M was not an HO engine, but its HP was about 20 or so hp more than the 351 W and corresponding amount of torque.

There are several differences in the 302 and the 351 W. Deck height on the 302 is nominally 8.2; 351 W is 9.5 inches. The cranks are different, due to the 351 having larger mains.
Cams, heads, timing cover interchange. Intakes wont, due to the 351 having, roughly, a 2 inch wider intake.

A good way to tell the difference between a 302 and a 351 W.
If the water pump ports in the timing cover are flush with the deck of the block, its a 302; if the deck is 1.3 inches above the water pump ports on the timing cover, its a 351.
 
#5 ·
351 HO?

Youre welcome. As I mentioned earier. The HO with a little boost in compression, and some minor porting, and headers will be a very lively engine. Even with the stock cam, intake, etc. Putting a set of the early 1.85/1.56 valves in it will really wake it up, but if you dont plan to turn it over 5000 RPM, then putting the bigger valves in wont do all that much.

Any 351, Winsor or M block can be turned into a really good stump puller, especially the Winsor, where the M block (Midland), can be made to turn some serious RPM.
 
#7 ·
360 vs 351

The 360 is a very good engine, inspite of its weight (635 lbs). Its an FE and most anything that fits a 332- 427 FE will fit on them as well. A 4 bbl and manifold off of a 390 will do wonders. There are a lot of junkyard goodies out there that can make your 360 turn into a real runner. The 360 has a 4.05 bore and 3.5 stroke.
My Step Dad had a 360 in a 74 F-250. Whenever he would take it in to have it tuned up, it would run like a slug. I would reset the distributor at 15 degrees initial advance, and then it ran like a scalded cat.
 
#8 ·
I agree with the timing, I set mine at about 10 BTDC, runs MUCH better now. I am in the market for a 4BBL intake for it another ford guy I know just got rid of the last of his 390s a few months before I went out to see him. Would you reccomend a factory 390 intake or one of the Edelbrock Performer 390s (non-EGR) ....#2105? I really appreciate all your help, I'm trying to figure out what I'm going to do with my motor situations because I will be going back to school soon full time and my time will be limited so I really do appreciate this, thanks.
 
#9 ·
FE intake

Edelbrock EDL-2105, is about as good as any. Weiand also offers intakes for the FE, but I dont have a part number on them.
Even though they weigh about 75 lbs, the stock 390 4 bbl intake flows well and is as good as any other than the weight. The intake from a 410 or 428 will work as well. You might even accidently come across a 4 bbl intake for a 351. Same deal with it.
If you come across a Holley intake, I honestly dont recommend it as I dont think Holley does as much R&D on Ford stuff as they do Bow Tie stuff.
One advantage of an aluminum intake is you will lose about 40 lbs from your intake. I would run a Holley carb of 500-600 CFM max.

As for cost, a 390 stock 4 bbl intake will be your cheapest bet.

That was supposed to read 352 intake; not 351.
 
#10 ·
If you are looking at an engine to rebuild and you have the 360, I would advise running with the 360 over a 351 windsor especially if you already have the 360 installed. The 360 generally runs a 2.02inch intake valve and a 1.55inch exhaust valve with ports running2.34*1.34inch intake and1.84*1.34inch exhaust
compare this to the windsor 351 that at best will give a 1.84inch intake and 1.54exhaust valves with1.94*1.76inch intake, 1.24*1.00inch exhaust ports

my personal opinion would say a little bit of porting on the 360 heads, a decent dual plane intake and a 650 cfm vaccume secondary carb, and a bit bigger cam- about a 224 duration on 110 degree split. You should be seeing 350 horsepower or so at a mild 8.8:1 compression get the compression up to the 9.2 range and 400 is quite possible

This is what I gather from crunching alot of data in an effort to put together a 350 hp 351w with stock heads, on 87 octane fuel. whenever I look at the numbers I wish that I had an FE to put together instead of a windsor.


I would love to hear your take on my numbers keith, you seem to sound like you know your stuff.
Scott
 
#11 ·
heavy breathing

ScotRod you have obviously been doing your homework. The 360 does have more potential by a long shot, over the 351W, when running stock heads.
There again the biggest drawback is with the 360 being over 100 lbs heavier.
I know this may sound strange, but if I had no engine in my vehicle, and had a choice of these 3 engines and limited resourses to work with, I would go with a 351M, as of the three, it has the most potentia. Theres just no way to get around those awesome Cleveland heads, and the M block is only 50 lbs heavier than the Winsor.
That being said, any of those engines can be made to get up and move.
I wouldnt have a problem building a 360, at all. Being that is a truck engine, the biggest drawback is the compression.
If a major overhaul is in order, 390 Pistons are the same as for the 360, and there are a myriad of those on the market. However, a simple .030" cut off the deck of the heads would yield a good 9.5:1 compression, and that would be about as high as I would go with any street engine.
As for intakes, naturally a dual plane 4 bbl intake is the order of the day, however since its not a 6000 RPM engine, I would elect to go with a carb in the neighborhood of 550 to 600 CFM, vacuum secondary. An aluminum intake will drop about 40 lbs off the weight of an FE block on average.
The FE heads were notorious for good flowing from the factory and I would only do a mild bowl blend on them, and if they have the air injection tonsil in the exhaust port, would grind that out first.
I would run a cam in the neighborhood of 210-220 degrees duration at most, Since with an engine of that displacement, when you start getting over 220degrees, you start getting into cams that are more for high rpm, and lower end torque will start to suffer, and lower end grunt is what an engine needs 99% of the time, especially for stop and go driving, and hauling loads. even running the stock cam isnt all that bad if some of these other things, like good exhaust, a little more compression, some mild port work, and a good intake and carb are applied. Its not difficult to add about40 hp with those things alone. The same applies with the Winsor and M block as well.
On defense of the Winsor, dont let the small valves fool you. Those heads, while having small valves and a somewhat restrictive exhaust port in stock configuration are very efficient. The key there is to know what you are dealing with and how to make it work best. It is not that difficult to get 1 HP per cube out of a "stock" head 351W, going with 1.94/1.6 valves will help a lot if you have ported the heads out, but going to the larger valves in them selves wont see a thing over stock, if you havent worked the heads over. Going to larger valves, IE 2.02/1.60, requires flycutting the pistons to clear the valves, the 1.94 being as large as you can go with the stock valve reliefs.
Also keep in mind that the smaller valves along with the smaller passages make for some nominally better bottom end power as your velocities are higher, with the fuel air mixture, and unless you are running an open chamber head, going to the biggest valves can actually hurt you due to shrouding, on production heads. Your cam choice of 224 degrees with 110 lobe separation is a good choice, that being as big as I would go though. The narrower lobe separation definatelly has it advantages for bottom end power.
Rule of thumb, when looking at cams. Figure what you want for peak RPM then get a cam that has its power band about 500 to 1000 RPM lower. Remember that a stock cam in the earlier engines usually had a power band of 0-3500 and the engines often made their peak power at around 1000 rpm over that. A classic example of this was with the 271 and 306 HP 289's. They ran a solid lifter cam with 228 degrees and put out peak power at over 6000 RPM. When comparing cams, it generally takes 10 more degrees of duration on a solid lifter cam to operate in the same power curve as a hydraulic lifter cam.
IE a 240 degree solid lifter and a 230 degree hydraulic, generally have the same power band.
 
#12 ·
Max Keith said:
Any 351, Winsor or M block can be turned into a really good stump puller, especially the Winsor, where the M block (Midland), can be made to turn some serious RPM.

Max, no big deal, but I know you're an old Ford head. Where did you pick up the 351M=Midland terminology? I always heard M=Modified -- but the people I know who would know for sure are mostly long retired......

BTW, I was in the Cleveland Casting Plant today. They are doing a major ($100 million) clean air project, so it looks like there will be Cleveland cast iron blocks for a few more years!
 
#13 ·
The 351M is ( i think) a Modified cleavland- being that it has a taller deck height than the cleavland in order to decrease compression- it makes it a low end grunter for trucks. The Midland term comes from the plant where it was produced I think.

And if we are talking about turning a M into a powerful engine, we should look at the 400m- its got the longer stroke with those awsome cleavlands atop it. Great breathing, the longest stroke in the ford family at 4.00". This is THE factory stroker and widely overlooked hotrod engine.

I would build any of these engines over the windsor if it wernt for the pesky little 302, which I hold very dearly as it is currently the powerplant in my 1970 F100 and the reason I will be building a 351W this spring. it bolts in with the stock motor mounts.
 
#15 ·
The Mystery of M block

As for the actual designation of Midland for the M block, several years ago, I read an article which stated that the M blocks were forged in Midland, Kansas. This supposedly started with the inception of the M block. So, that being the case, Ive always referred to the M block as Midlands, rather than Modified. I realise that this has probably never been a widely advertized thing, and has gotten me some quizical looks in the past. But then I enjoy doing that for no other reason than to confuse people.
 
#16 ·
The Mystery of the M block designation

ScotRod, you are a man after my own heart. I would go for the 400 M any day over the 351 M, providing I didnt have a displacement rule dropped on me, and if that were the case, I would opt for a 351W, if an SBF stroker wasnt allowed.
As for the actual reason for producing the M block, to begin with, your guess is as good as mine. My reasoning has always been that the Clevelands (bless their hard running little hearts), seemed to have problems with core shifting and lateral thrust wear from pistons on the cylinders. I dont think it was a compression issue, as Clevelands were made with compression ratios all the way from 8.7:1 to 11:1, and its a lot cheaper to make a dished piston and lower compression than to just add another inch to the top of the block.
I am also fairly certain that the 400 M actually came out first and that the 351 M was brought out the next year, when some slide rule geek discovered that the Cleveland block foundering system was being sent to Australia, since Ford of Australia didnt have a proprietary engine.
The sad thing is that there isnt more interchange between the two engines. Seems to me it would have been smarter to have stayed with the 912 wristpin of the Cleveland, rather than have gone to the 975 wristpin.
On a side note, M block rods can be used in an FE block by doing a .10" offset grind, stroking the engine a total of .20", and using any of a number of stock FE pistons to finish the job, since both use the same wrist pin size. The M block rods are also .10" longer than the FE rods.
More crazy ideas from your friendly poor broke white trash for getting some more low dollar cubes.
 
#17 ·
Max Keith said:
The difference between a 351 W HO and the standard 351 W is a 4 bbl intake from the factory, and a lot larger cam, as far as carbureted versions were concerned. At least any built past 1970. According to my books, the HO option didnt come out til 84, which at that time they also put in a larger cam, .445/.453 lift; 206/221 duration @ .050", vs .416/.416 lift; 195/195 duration @ .050" with the standard cam. The last year the smaller cam was used was in 85. These stats pertain to the pickups.

In cars the larger cam was used starting in 80 and the last year the smaller cam was used was in 88.

The HO had various ratings of HP from 84 on up, from 185 HP to 210 HP. While that may not sound like much, they put out an extreme amount of torque.
IF you didnt do anything but pump up the compression a notch to about 9-9.5:1 and do a little bowl blending, you would have a very respectable running, 5000 RPM engine on your hands. A good exhaust would put you close to 1 HP per Cubic Inch.
IF you want to know about Ford engines, ask Ford People.
Been there done that.
I believe the cam was the same as used in the 82 to 84 Mustang. Again, I believe the cam was a marine cam. replace the stock heads like you said with at least the E7 Mustnag head or GT40 head and it would be a great street motor with tons of torque.

The stock carb is a 4180, 575 CFM Motorcraft that is very similar to the Mustang version. This is a very decent carb and will run very well with a little tuning. This is a Motorcraft spec carb made by Holley. Despite looking like a Holley, almost nothing will interchange. I belive just the jets and rear metering plate and nothing else, not even float boals or throttle plate. Ditch the factory cast iron intake, I think Ford did something funky with the EGR set up as I recall.
 
#18 ·
ScotRod said:
The 351M is ( i think) a Modified cleavland- being that it has a taller deck height than the cleavland in order to decrease compression- it makes it a low end grunter for trucks. The Midland term comes from the plant where it was produced I think.
And if we are talking about turning a M into a powerful engine, we should look at the 400m- its got the longer stroke with those awsome cleavlands atop it. Great breathing, the longest stroke in the ford family at 4.00". This is THE factory stroker and widely overlooked hotrod engine.

I would build any of these engines over the windsor if it wernt for the pesky little 302, which I hold very dearly as it is currently the powerplant in my 1970 F100 and the reason I will be building a 351W this spring. it bolts in with the stock motor mounts.
no -- Ford has no midland plant -- the 351C, 351M, and 400 blocks were all made at Cleveland Casting Plant -- the big foundry between the two engine plants, across the railroad tracks from Cleveland Hopkins airport........
 
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