As suggested I'm reposting in the appropriate thread. Can y'all help me with these questions?

Hi guys. I purchased a 79 F150 recently and just wanted to check some of my facts. They are peiced together from various sources (books and internet).
The powerplant is 351W with a compression ratio of 8.2:1 and produces approx. 200HP @ 3800 RPM and approx 300ftlb @ 2800 RPM.
The engine tag on the valvecover has the number "W9F5884D" but its nearly unreadable and all the smaller numbers for carb designation and manufacturing plant and all that are completely gone. I'm presuming that it is the original cover based on the previous owner's usage of it.


I need some help with the transmission, I don't see a tag on it anywhere. It does have "S4A" molded into the housing in big raised lettering. Without the tag I'm just shooting in the dark, any info to help narrow it down would be appreciated.
(sorry about the tranny question in the engine thread).

Could someone refresh my memory about the two engine measurement systems. CID is actual dispalcement of the cylinders? and I think I remember someone telling me once that the 5.8L measure has something to do with volume of air moved through the engine during a spefic time period?

8.2 seems like a pretty low compression ratio to me. Why so low, are thier benefits (extended engine life)? Wouldn't a higher ratio get better performance out of the engine? Even a modest increase to 8.5 or 8.8? How would that be achieved? smaller compression chamber? lengthen piston stroke? different pistons? increase airflow?

I plan to go over the engine thouroughly, check the plugs and timing and replace vacuum hoses, pvc valves and things like that, if they need it. Basic tune up stuff. Is there anything specific you guys think I should check while I'm at it that isn't included in this category (general maintenance, that is)?

 

I have a 79 F150 w/ a 302 in it and an overdrive manual 4sp. I'm suspicious of a 351W being the stock from the factory motor in a 79. Are you sure it's not a 351M which was common in 79's?I don't believe that 351W were used in pickups till later in the 80's. A Windsor has the same heads essentially as a 302 w/ an interchangable valve cover. Does your valve cover have 6 bolts or more... the M has either 7 or 8 (I can't remember exactly). Also the intake manifold differentiates these motors. The Windsor has a thermastat housing similar to the 302 where it's part of the front of the intake manifold with the hose comeing straight forward. The M has a thermastat housing in the block itself. As far as 5.8 thats just the Metric equivalent of 351cid.... it's rounded off to 5.8L. 7.5's are 460s 5.7 is Chev's 350..... 5.0 is a slight exageration of a 302 and closer to Chevy's 305. The 300 I6 is a 4.9L The newer 4.6L is about 280cid About your transmission, give us a hint, is it a manual or automatic? 3sp-4sp, 4sp w/ granny low, or Overdrive. If you have a 351M w/ automatic, I'd say you probably have a C6. If it's a 351w w/ automatic, it could be either C4 or C6.. a C4 has a separate bellhousing, the C6 is integral. Manuals may have been T18 or NP 435 if granny low 4sp... the 3sp+OD 4sp overdrive is known as a RUG.. it's very similar to the 3sp toploader, w/ a bulge on the passenger side of the caseing. Mine has external shift linkages... models from the 80's had shifter towers.

 

Because of your statement that 351W didn't come stock in 79s I went out and checked. The valve covers have 8 bolts in them. The engine appears to belong to the truck. The VIN engine key is an "H" which indicates either a 351W or 351M. The book I have says they were both produced in trucks that year. The engine tag indicates its a windsor from production plant 2. Conflicting information with what you told me (a Windsor engine would have 6 bolt v-covers)? In other words, no I'm not sure its a 351W.

The transmission is a 3 speed automatic. I'll check the bell housing tomorrow during the daylight. If its integral I'll go on that its a C6.

What I mostly need is points of reference for service and parts. The worst that happens is I get the wrong part and have to exchange it, right?

 

I don't suppose the truck has a vin number?

Daywalker
92' F-250 351 4x4 xlt 4.10 5spd supercab longbed

 

Displacement is figured by taking the volume of the compression chamber at TDC. This is then multiplied by the number of cylinders. The compression ratio you mention is stock and common. You can increase the compression by doing a couple of things: Get new pistons that have raised tops. This will allow the same amount of air to be pulled in on account that air cannot completely fill the cylinder on the intake stroke, but it will compress that air more than a stock piston. You can get a set of Federal Mogul Zero-Gap rings. Both Compression rings have two pieces that make a complete circle around the cylinder walls. You can also cut the head and block decks, but be warned that unless the machine shop is real good, the piston will hit the head and your head and block is shot.
To get more air you could get a new carb (fuel injection kit if you can afford it) and intake manifold. If you can afford it buy new high-flow heads or you can port the stock ones but this probably won't produce the results you want. You could bore it but I wouldn't go too far because you will probably run into cooling problems.
As for checking tune-up things. Chech your vacuum routing. I have found that the haynes emission-controls book is the vacuum control Bible. Buy yourself to check the vacuum routes. Replace the hoses one at a time while your at it. Clean the EGR valve and tubes.

 

yep, the trucks VIN is
F15HRDJ7062

 

Displacement has nothing to do with the "volume of the compression chamber at TDC"

Displacement= bore X stroke x (3.14) X # of cylinders.

 

>Displacement= bore X stroke x (3.14)
>X # of cylinders.

Not quite. Displacement = bore^2 x pi / 4 x stroke x # of cyl

1979 F150 Custom: 75 351W, Edelbrock & Holley
1987 F150 XLT Lariat: 88 351W EFI
Chevy 454: waiting for a truck (Mazda?Nissan?)

 

I was going to say you definitely have a 351M. But it also
could be a 400. Do you know the history of the truck? Anything
could happen. Guys change motors and drivelines all the time.
With 8 bolts on the valve cover it has to be a "cleveland" style
head.

 

[font size="1" color="#FF0000"]LAST EDITED ON 27-Feb-01 AT 08:04 PM (EST)[/font][p]>>Displacement= bore X stroke x (3.14)
>>X # of cylinders.
>
>Not quite. Displacement = bore^2 x
>pi / 4 x stroke
>x # of cyl
>
>1979 F150 Custom: 75 351W, Edelbrock
>& Holley
>1987 F150 XLT Lariat: 88 351W
>EFI
>Chevy 454: waiting for a truck
>(Mazda?Nissan?)
----------------------------------------------------------------


Sorry, Thanx.

It's weird that both formulas work the same for a few motors.

 

[font size="1" color="#FF0000"]LAST EDITED ON 27-Feb-01 AT 11:21 PM (EST)[/font][p]I found out today the engine was rebuilt but thats all, not who did it or when or any other details. My wife told me the previous owner told her while I was out of the room. He also told her the transmission was "replaced". Its not difficult to believe someone would put clevland heads on during a top end rebuild. But swap the engine sticker too?

Which is what I keep getting stuck on. The sticker says it's a W, the valvecover bolt pattern indicated C or M, the VIN says W or M.

Are all the heads interchangable on the 351s and 400 (since they are the same block)?

Aside:
the formula for volume of a cylinder is
Pi x R^2 x h

 

quoted from the 351M/400 thread.

"The 302/351W have 6 valve cover bolts, the 351C/351M/400 have 8 valve cover bolts.

It only takes 10 minutes to change a valve cover, so valve cover ID tags are not very reliable.

BTW: 351C pistons will work in a 400, so piston ID is not necessarily a sure way to tell either.

You can distinguish between the 351C and 351M/400 engines by the block casting number, located on the side of the block, under the rear of the right cylinder bank (just above where the starter mounts).

Both 351M and 400 engines use the same blocks. The most certain identification of the 351M/400 engines is the crankshaft casting number. In fact, identifying the crankshaft is really the only way to positively distinguish between the 351M and 400, as all their external components are the same.

Another way to distinguish between 351W and 351C/351M/400 engines is the location of the thermostat housing.

The 302/351W have a "wet" intake manifold, with coolant flowing through the manifold. The 302/351W thermostat housing attaches to the front of the intake manifold (like FEs and 429/460 big blocks).

The 351C/351M/400 engines have a "dry" intake manifold, with no coolant flow through the manifold. The 351C/351M/400 thermostat housing attaches to the top of the block, in front of the intake manifold.

BubbaF250

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

 

John, are you still wondering between a M or W??? Not only is all the above info correct(the valve cover bolts should be the easiest) The next easiest way is the fuel pump mounting bolts. The W will have the bolts in a horizontal plane, the C/M has the fuel pump bolts in a vertical plane.


What does r and h represent in your formula???

 

lvstang, yes and no. What I need to do is spend an hour and compare all the info from here to the parts and numbers on the truck. (and write them down for future reference) My guess right now is I have some combination of parts because of the rebuild.

R is radius (distance from the center of a circle to the outside edge) and H is height...in this application R would be 1/2 the bore and H would be the stroke.