400 Magnum.. To Buy or not to Buy?

[SirNik73]

While at the Car show this weekend I went all over the swap meet. I met a guy who was selling the 400 Magnum out of his 73 charger... its only 300 smackeroos... for everything. air cleaner to oil pan... now... I have a 400 in my charger... it runs and drives.. I also have a rather large stack of parts for the 400 (cam, intake, carb, re-machined heads... ect) now the question is... should i spend the 300 for this 400, its a Magnum, so its got the stronger cranks and rods, and he said it only had a little over 130k miles on it.. and was running strong when he pulled it in order to drop in a 440.
i want to clean my engine compartment up, and get the engine together, I'm thinking of an engine rebuild... nothing serious, just a face lift... pull it apart deglaze the cylinder walls and install new rings and the install my new parts. (that is is the cylinder walls are in good shape)
so, should i go ahead with my current engine... and pull it and give it the face lift? or pay the 300, not have to pull it just yet, (keeps the car drivable in case my dad makes me move it) and get the better parts...
I have a friend with a 68 who wants a big block and was talking to me about me building my 400 into a 451 stroker for my car , so i might be able to sell him my current 400...
also, i have an old 413 industrial with the forged crank and rods... i was going to use it in a 451 project a few years a go before that 400 block got stolen from the engine lab at school... so i could pass that along to my friend if he really wants to do the 451 project....

or i could go ahead with the 451 project with my current 400 and drive the magnum...

what do you guys think?
should I buy the 400?

[Nacho-RT74]

being cheap as he is selling I would go for it, whatever you do, a driver or stroker.

[RD]

its a Magnum, so its got the stronger cranks and rods,

false, those rods are no different from regular rods.  The crank is still a cast crank unless it came out of a 4 speed.

[rt green]

is your 400 orignal to your car? if so, get the new 400, biuld that one and keep your orignal motor under wraps. you never know, you might get a lead foot some nite and pop your modified engine. 10 years from now, you might still have the car,{i hope you do]  and big blocks might be very hard to find. you;ll have your a** covered.

[MassCharger73]

is your 400 orignal to your car? if so, get the new 400, biuld that one and keep your orignal motor under wraps. you never know, you might get a lead foot some nite and pop your modified engine. 10 years from now, you might still have the car,{i hope you do]  and big blocks might be very hard to find. you;ll have your a** covered.

  what he said.

[Big Lebowski]

  Yep, there's no difference between the 2 400's. They're both low compression, smog headed toads.

[TruckDriver]

The Term "Magnum" means no more then "Hemi" on the new cars. Just a name.

[SirNik73]

the engine is out of a 4 speed car. which is another thing it didn't think of... is it true that only the 4 speed engines have the hole in the crank for the pilot bearing?

[Todd Wilson]

  Yep, there's no difference between the 2 400's. They're both low compression, smog headed toads.

Only good enough to anchor a boat!!!!!!


Todd

[Lowprofile]

You can build almost any engine to be a monster.....$300 dosen't sound like such a bad deal for a complete engine..........See if you can talk him down $50-$75 bucks! Spare parts are a good thing....ask twilt!!   

[Big Lebowski]

the engine is out of a 4 speed car. which is another thing it didn't think of... is it true that only the 4 speed engines have the hole in the crank for the pilot bearing?

  I believe all cranks have a hole, but the auto's were not machined out all the way for the bushing sleeve. Am I wrong? You guys are digging real deep in 'ol duders head today.

[694spdRT]

The main problem with the cast crank is it is externally balanced so you can't use common flywheels like you can with steel cranks. For $300 it probably is not a bad deal with the steel crank especially if you are going with a 4 speed.

[SirNik73]

so the only differences from the standard 400 i have now is that the crank is steel and has the pilot bearing hole machined out for the 4 speed and its internally balanced...

well i was looking for 4 speed parts when i came across the engine... I have a 4 speed transmission, but still looking for all the othere peices.

[Chargerguy74]

for 300 I would have bought it already

[RD]

so the only differences from the standard 400 i have now is that the crank is steel and has the pilot bearing hole machined out for the 4 speed and its internally balanced...

well i was looking for 4 speed parts when i came across the engine... I have a 4 speed transmission, but still looking for all the othere peices.

what I said was that the rods and cranks were no different, the motors themselves are.  The 400 magnum is a 4bbl version that had a different camshaft profile than the 2bbl version 400.  The 400 Magnum, if I remember correctly (nacho can help out here), had 8.5 to 1 compression rather than the claimed 8.2 to1 compression (was more like 7.8 to 1 or 8 to 1) of the 400 2bbl version.  The 400 magnum in 72 put out around 255 hp, whereas the 72 400 2bbl only put out 185hp I believe.  This is from memory though.

[Nacho-RT74]

I'm  sure about camshaft, springs, windage tray, and HP exhaust manifolds, beside the of course 4 bbls intake manifold. As far I know and what this table copied from the old board shows, compression is the same ( I copied several tech archives from the old board ), is 73 engines... I guess at least similar on 74 and laters, even I think since 74 and laters, cams are the same than "standart" engines

Engine Bore Stroke Horsepower Torque Compression Barrels
198 3.400 3.640 95 @ 4000 150 @ 1600 8.40 : 1 1
225 3.400 3.640 105 @ 4000 185 @ 1600 8.40 : 1 1
318 3.910 3.310 150 @ 3600 265 @ 2000 8.60 : 1 2
318 3.910 3.310 170 @ 4000 270 @ 1600 8.60 : 1 2
340 4.040 3.310 240 @ 4800 295 @ 3600 8.80 : 1 4
360 4.000 3.580 170 @ 4000 285 @ 2400 8.40 : 1 2
400 4.340 3.380 175 @ 3600 305 @ 2400 8.20 : 1 2
400 4.340 3.380 185 @ 3600 310 @ 2400 8.20 : 1 2
400 4.340 3.380 220 @ 4000 310 @ 3200 8.20 : 1 4
400 4.340 3.380 245 @ 4800 325 @ 3200 8.20 : 1 4
400 4.340 3.380 260 @ 4800 335 @ 3600 8.20 : 1 4
440 4.320 3.750 215 @ 3600 345 @ 2000 8.20 : 1 4
440  4.320 3.750 220 @ 3600 350 @ 2400 8.20 : 1 4
440  4.320 3.750 280 @ 4800 380 @ 3200 8.20 : 1 4

[SirNik73]

OK, so I'm thinking that since this engine was in front of a 4 speed from the factory, and i want to put a 4 speed in my car it makes since to get this engine. what I'm also thinking is that i don't have a flywheel yet, and if the engine is externally balanced then i need the correct fly wheel, is it easy to get the flywheels, are they of predetermined weights, or are diffrent amounts of weight added to each engine?

[RD]

OK, so I'm thinking that since this engine was in front of a 4 speed from the factory, and i want to put a 4 speed in my car it makes since to get this engine. what I'm also thinking is that i don't have a flywheel yet, and if the engine is externally balanced then i need the correct fly wheel, is it easy to get the flywheels, are they of predetermined weights, or are diffrent amounts of weight added to each engine?

if it was in front of a 4 speed, it will have the forged crank in it I believe.  Look at the balancer to see if it is "thin" or "thick".