1980 F 150 Engine wake up
#1
#3
I agree, turn it into a 400; the modifications you speak of will lighten your wallet several thousand dollars and you'll still have the stock low-compression pistons.
Look in the sticky, do some homework on making your 351M a 400 with a straight-up timing set, different cam, and TMI pistons (amongst other things like intake and exhaust).
Look in the sticky, do some homework on making your 351M a 400 with a straight-up timing set, different cam, and TMI pistons (amongst other things like intake and exhaust).
#4
. The EFI will do next to nothing powerwise or MPG-wise... these were horrible engines stock from the 1970's "Dark Ages of Engines"... actual compression ratio down in 7's, despite what Ford claimed... retarded cam timing at the chain...
. Like the guys said, adjustable timing chain/sprocket set, RV cam/lifters, 400 crankshaft, TMI pistons for a 400" (there's no good pistons for the 351M and no other good pistons for the 400)... externally, 4 bbl. intake, 4 bbl. carb, headers, dual exhaust can be added later as budget/time allows... triples your HP... better MPG... night and day difference from what you have now... doesn't cost all that much if doing it yourself... lots of other threads right here about doing this... basically makes your engine run like a 2015 one...
. Wouldn't bother with the Eddy heads unless you have money to burn... if you do, check out the CHI heads...
. Like the guys said, adjustable timing chain/sprocket set, RV cam/lifters, 400 crankshaft, TMI pistons for a 400" (there's no good pistons for the 351M and no other good pistons for the 400)... externally, 4 bbl. intake, 4 bbl. carb, headers, dual exhaust can be added later as budget/time allows... triples your HP... better MPG... night and day difference from what you have now... doesn't cost all that much if doing it yourself... lots of other threads right here about doing this... basically makes your engine run like a 2015 one...
. Wouldn't bother with the Eddy heads unless you have money to burn... if you do, check out the CHI heads...
#5
ck out this websitehttp://www.fordmuscle.com/archives/2007/02/Ford400/index.php
these engines with the large ports , big valves and low compression only ask for one thing a wake up call , a cam,4bbl intake and at least 9.5:1 , will make a ton of ford power yes there are still pistons around ,search the web I found this site in mins.
these engines with the large ports , big valves and low compression only ask for one thing a wake up call , a cam,4bbl intake and at least 9.5:1 , will make a ton of ford power yes there are still pistons around ,search the web I found this site in mins.
#6
. That site only mentions the off-the-shelf popularly-priced TMI pistons that I already just mentioned above... and they only fit the 400" version... not the 351"M(unless converted to 400)... they are the only pistons worth bothering with at reasonable price... they come in three slight variations depending on heads used and RPMs range...
. There are some cheap general 'rebuilder' pistons available for both engines, but they're even worse than the crappy stock pistons... sit even further down in the cylinders... give 1930's Ford flathead V8 compression ratios...
. Of course, you can also go $600 custom pistons from other sources (like comes in the TMI 434" kit)... if want to go that route... TMI doesn't sell them separately...
. This has been well researched around here over and over...
#7
. That site only mentions the off-the-shelf popularly-priced TMI pistons that I already just mentioned above... and they only fit the 400" version... not the 351"M(unless converted to 400)... they are the only pistons worth bothering with at reasonable price... they come in three slight variations depending on heads used and RPMs range...
. There are some cheap general 'rebuilder' pistons available for both engines, but they're even worse than the crappy stock pistons... sit even further down in the cylinders... give 1930's Ford flathead V8 compression ratios...
. Of course, you can also go $600 custom pistons from other sources (like comes in the TMI 434" kit)... if want to go that route... TMI doesn't sell them separately...
. This has been well researched around here over and over...
. There are some cheap general 'rebuilder' pistons available for both engines, but they're even worse than the crappy stock pistons... sit even further down in the cylinders... give 1930's Ford flathead V8 compression ratios...
. Of course, you can also go $600 custom pistons from other sources (like comes in the TMI 434" kit)... if want to go that route... TMI doesn't sell them separately...
. This has been well researched around here over and over...
don't all 351-c 351-m 400 type engines use the same pistons stock 4" bore with the same pin height ,just different compression height ,domed ,dished or flat top I know yrs ago stuff for these engines was everywhere , now its like there extinct early 70's boss 351-c and 351-c h.o. had a wide range of comp ratios , I remember the closed chamber 4bbl Cleveland heads made 1.5 points compression when bolted on a block with the big open 8:1 heads, and they bolt on the 351 m-400 , tell you what every valve cover sticker I looked at stated engine displacement 351-m/400 cid so how does a person know its a 351 or 400 another thing I read somewhere is a 351-m is a 400 block with a 351-w crankshaft because they use the same size crank, journals with different rod length to give it 1/2" less stroke
Trending Topics
#8
don't all 351-c 351-m 400 type engines use the same pistons stock 4" bore with the same pin height ,just different compression height ,domed ,dished or flat top I know yrs ago stuff for these engines was everywhere , now its like there extinct early 70's boss 351-c and 351-c h.o. had a wide range of comp ratios , I remember the closed chamber 4bbl Cleveland heads made 1.5 points compression when bolted on a block with the big open 8:1 heads, and they bolt on the 351 m-400 , tell you what every valve cover sticker I looked at stated engine displacement 351-m/400 cid so how does a person know its a 351 or 400 another thing I read somewhere is a 351-m is a 400 block with a 351-w crankshaft because they use the same size crank, journals with different rod length to give it 1/2" less stroke
But, I did note before I quit a lack of understanding of the 335 Series engines. The 351C pistons use a different pin size than the M & 400, and it has shorter rods due to the shorter deck height. But the only diff between an M and a 400 is the crank and the pistons. The rods are the same, so the piston pin has to sit higher on the piston.
So, an M can be made into a 400 with a crank and piston change - and TMI has both, and the only good 400 pistons. But if you want to keep it an M you can run pistons from a C with the pins bushed.
#9
Yes, I agree with Gary... the way you're writing makes it hard to read and figure out what you're trying to say... which will keep people from even trying to figure it out and talk back to you...
#10
Oh, did he say something about "engine family"? I quit reading before the end of the 2nd line.
But, Chris is certainly right. Both Dad's truck and Rusty have a label saying that the engine comes from the M/400 family. But there is further info on the truck that provides the specifics on which of the two engines the truck came with. However, if someone has changed the crank and pistons, as I'm doing, there is no way to tell from the outside visually. The easiest is to put a straw in a spark plug hole and measure the stroke. While not all that accurate the 1/2" difference between an M and a 400 is pretty obvious.
But, Chris is certainly right. Both Dad's truck and Rusty have a label saying that the engine comes from the M/400 family. But there is further info on the truck that provides the specifics on which of the two engines the truck came with. However, if someone has changed the crank and pistons, as I'm doing, there is no way to tell from the outside visually. The easiest is to put a straw in a spark plug hole and measure the stroke. While not all that accurate the 1/2" difference between an M and a 400 is pretty obvious.
#11
. pin height/compression height kinda the same thing to most people...
. I've searched through the entire Silvolite catalogue for stock pistons for every brand and model of engine and couldn't find any comparable to the 351"M pistons with their huge compression height... as the guys said, the tall block 400 and the later 351 Modification of it use the same rods, so the 1/2" shorter stroke was compensated for entirely by an unusually tall (by automotive standards) compression height piston...
. The 4 bbl. 351C closed chamber heads raised compression, but had way too big, misshapen ports for a 351" that flowed really poorly... ports big enough for 600 HP, but only flow well enough stock for 300-400 HP... turbulence kills their flow and torque producing characteristics... the usual solution is to make them smaller via aftermarket 'port plates', epoxy, or welding for a street engine... or make them straighter for an all out race engine...
#12
#13
. The TMI pistons are basically 351C pistons with an already enlarged piston pin hole for a 400... another solution most wouldn't want to be bothered with is using stock 351C pistons and bushing the 351M/400 rods smaller to fit the 351C pins... especially since either off-the-shelf pistons are about the same price...
. Using 351C pistons in a 351M would prolly give about 4:1 compression ratio... 75 HP... would start and run fine...
#15