Pirate4x4.Com : 4x4 and Off-Road Forum

Pirate4x4.Com : 4x4 and Off-Road Forum (/forum/)
-   Ford (http://www.pirate4x4.com/forum/9-ford/)
-   -   whats the better motor? 351m or 400m? (http://www.pirate4x4.com/forum/ford/983514-whats-better-motor-351m-400m.html)

xxxfordmafia 05-31-2011 04:44 PM

whats the better motor? 351m or 400m?
 
Alright, my current 78 ford has a 351m. Only thing i have done is install a edelbrock performer manifold and an edelbrock 600cm carb. motor is for sure not the power house but does the job. heres why i ask.

here in my town, we do a demo derby for the 4th of july. This year they have decided to do fullsize trucks. well i have a 78 F250 thats rusted out, and needs a motor. Now i also have a 400m all stock with 35k original miles runs perfect. What motor do i install in the derby truck and what motor do i run in my truck? keep my 351m in my truck and install 400 in derby machine? now remember the motor is for sure going to be overheated, will be ran hard, will for sure be running stacks out the hood and is not going to be treated well. i dont care what motor goes in the derby truck, im more concerned about the better motor to put in my truck.

82F100SWB 05-31-2011 04:53 PM

The 351M is essentially a destroked 400(no M.) No sense to kill a perfectly good 400 and save the M, more cubic inches in the same package is always better, and you probably won't notice a lick of difference in the fuel mileage, but the difference in power will be noticeable.

xxxfordmafia 05-31-2011 05:03 PM

yes i was thinkin the same thing. the 400 only has 35k miles and was running perfect when pulled. I realize the the few extra cubic inches should help out with power. neither motor is really a power house. I do daily drive my truck and run about 25 miles a day to and from work and im averaging about 13mpg now.

Westernair 05-31-2011 05:24 PM

If the prices are close and the 400 has such low miles, I would only consider the 400.

cobramustang331 05-31-2011 05:25 PM

just buy a 460

xxxfordmafia 05-31-2011 07:44 PM

the 351m is already installed and running in my truck. Ive also got the 400m. no money involved it all stuff i got. Im just wondering if its work the time to pull my motor from my truck and then do the labor to swap it into the other truck. all id be gaining in my truck is a few cubic inches. is it really worth all the time and effort. i could get away with putting the 400 into the derby truck and go that route. granted the 400 is low mileage and a good motor.

FORDTECHGURU 05-31-2011 07:57 PM

it's not the cubic inch so much as the stroke benefit, put the 400 in the d.d., while it is out, slide a decent cam in it too..

xxxfordmafia 05-31-2011 08:25 PM

Quote:

Originally Posted by FORDTECHGURU (Post 12955753)
it's not the cubic inch so much as the stroke benefit, put the 400 in the d.d., while it is out, slide a decent cam in it too..

With the 400 can i expect to get around the same 13mpg im getting now. its my daily/weekend wheeler. my commute is about 25 miles a day right now.

SAY789 05-31-2011 08:35 PM

As stated before, put a 460 in it actually both. Its hard to kill a stock 460 even overheating it. Just as long as you put oil in it, it will run.

Dr.Danger 05-31-2011 09:32 PM

Quote:

Originally Posted by SAY789 (Post 12955945)
As stated before, put a 460 in it actually both. Its hard to kill a stock 460 even overheating it. Just as long as you put oil in it, it will run.

There was a guy I remember from 460ford several years ago who ran an odd figure 8 race track. All the guys were running 460 powered metric big body cadillacs, because the rules were '79 and up vehicles. The reasoning was that the caddy was the heaviest car you could get, and the 460's were powerful enough and damn near indestructible even without cooling systems and could go several races before needing a rebuild.

In this case, I would never waste any good money on a destruction derby car. Take the 400, slap a decent cam in it and throw it in the driver. Put the 351 in the junker and have some fun. Make sure you guard the hell out of the dizzy, that's the easiest way to kill a Ford with it being up front. Damn chebby guys have it easy, all they do is cut a hole in the firewall so it won't get crushed when the engine is inevitably pushed back.

FORDTECHGURU 06-01-2011 08:44 AM

Quote:

Originally Posted by xxxfordmafia (Post 12955892)
With the 400 can i expect to get around the same 13mpg im getting now. its my daily/weekend wheeler. my commute is about 25 miles a day right now.

yep, or better, torque moves your junk...

highboy4sure 06-01-2011 09:43 AM

I will share my experiences with the 400 for you and my knowledge of the 351m.The 351 is the junkmotor,the big problem is to make a 351 out of the 400 block they moved the pin way down on the piston,that motor uses a oddball piston setup and really is a pretty half assed motor.The 400 was the basis for Jon kass,sorry probably wrong spelling,winning engine masters challenge for a few years,he used a factory ford 400 block and crank with chi cylinder heads and won a few years I believe.The 400 can be a monster if built correctly,the biggest draw back to both motors is the low compression,maybe 8.0-1 on a good day,run plenty of timing they like lots of timing with the big open combustion chambers.My biggest advice is do not turn any rpm at all with the stock or stock stlye valve springs.I broke a valve spring and ruined my motor,my buddy broke a ford motorport valve spring in the 400 in his race car,destroyed the motor,so the 400 is the good motor,get some valve springs on it put some timing in it and enjoy it. Oh and also I do love a good 460 a great motor just like the cleveland,one thing to keep in mind though is a 460 is 150 pounds heavier than a 400 and has a shorter stroke so the 400 has potential to make more torque earlier in the revs,a very underestimated motor for sure.

Proeliator 06-01-2011 04:36 PM

There is no replacement for displacement.

Especially true when we are talking essentially about the same motor except one is a destroked pussified version of the other.

xxxfordmafia 06-01-2011 04:48 PM

well sounds like i got some work to do haha. im going to pull the 351m and put that into the derby machine and put the 400 into my truck haha. 4th of july is like a month away and i havent even started lol.

redpitbull44 06-01-2011 08:31 PM

Quote:

Originally Posted by xxxfordmafia (Post 12959578)
well sounds like i got some work to do haha. im going to pull the 351m and put that into the derby machine and put the 400 into my truck haha. 4th of july is like a month away and i havent even started lol.

haha, lol, hurry up!:flipoff2:

5BrothersFabrication 06-02-2011 08:22 PM

Swap the intake and carb first. BTW, I've revved the SHIT out of my modified, and it never let me down. However, the trans and power steering pump have, quite a bit. From experience, replace the rag joint with a knuckle ($25 at any race shop), run an a/c condenser (and a shit-ton of fluid) as your trans cooler (if you're running a manual, forget it. You lose. Period.), and make "slider" motor and trans mounts with a square drive shaft. You get hit in the front, IF the crank doesn't break, it should slide back and not break the distributor off like the GM bastards. :flipoff2:you guys!

Dr.Danger 06-02-2011 11:53 PM

Quote:

Originally Posted by 5BrothersFabrication (Post 12965045)
Swap the intake and carb first. BTW, I've revved the SHIT out of my modified, and it never let me down. However, the trans and power steering pump have, quite a bit. From experience, replace the rag joint with a knuckle ($25 at any race shop), run an a/c condenser (and a shit-ton of fluid) as your trans cooler (if you're running a manual, forget it. You lose. Period.), and make "slider" motor and trans mounts with a square drive shaft. You get hit in the front, IF the crank doesn't break, it should slide back and not break the distributor off like the GM bastards. :flipoff2:you guys!

I wonder if his rules would allow him to build a protective bar that ties in to both motor mounts and guard the crankshaft pully. If he could get away with it, he wouldn't have to worry about breaking the crank as much.

mustange70 06-04-2011 08:15 PM

400s are great motors, and theres a shit ton of parts out there, just gotta know what swaps over from the other family's ;). They are pretty indestructable too, granted the cyclinder walls don't like it when a hypereutectic piston explodes at 7000rpms . . . . crank didn't mind it thou . . . lol.


I would do what you're planning, put it in the DD and use the 351 in the derby rig, invest in a comp cams 255 DEH and a 4bbl intake with a 750 carb, good exhaust and you're off to the races.

If you want some reading on building one check out my thread in the mud section on my 800hp (on the giggle gas, bout 700 est before the shot) stroker ;).


All times are GMT -7. The time now is 11:57 PM.

Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0 ©2011, Crawlability, Inc.