Twom turbo 440vs451

[trc54]

My friend has his 440 from a 70s rv he wants to sell me for $500. It comes with a 727.
I want to do a really mean twin turbo motor that could make some serious power. Would I be better off doing my 400 to a 451 or doing the 440 up for boost.

 

[Photon440]

Well I suppose you could do either. It depends on what you mean by 'serious power'. A single turbo with 7 pounds of boost can give you a 440 with 650 ft/lbs of torque. Your stock block won't handle the power possiblilities of a twin turbo. Nor will the 727.

Your 400 is already low compression, why not lightly boost that and go from there?

We don't know your budget, the intended platform, or expected use. But if you want to put a turbo into a motorhome, you'll find plenty of room for the plumbing!

 

[trc54]

Going into a 73 charger. Serious power is 1000rwhp

 

[fourforty6pac]

Going into a 73 charger. Serious power is 1000rwhp

WOW. That's gonna rip that block apart. LOL. Not to mention the unibody. Your gonna need different trans., a four link out back would help keep everything planted, and maybe a good brake upgrade would be helpful. Keep us posted!

 

[dellortox4]

Thats a lot of horsepower to be reaching for
I was going the same way , twin turbo 440, a while back and have since changed directions.
Two hx35 turbos would give you more than enough to have fun with.
If your 440 has cast pistons and is std bore, i still have a new set of 2266 trw pistons std
and a used claysmith high volume race , That I was going to use
Let us know how your build goes

 

[Moparmatt72]

Some people half fill the block to support that kind of power. But some have made it with a steel crank forged h beams and forged pistons. Main girdle is recommend along with some billet steel main caps. Heads is up to you again depending on budget, aluminum heads always better but can be done with cast iron ones as well aleast ported and polished. Cam profiles are different when going forced induction. I would have the 727 rebuilt better but they can handle it either find a shop or buy one from a good reputable place. Good luck

 

[MoparBillTX]

My friend has his 440 from a 70s rv he wants to sell me for $500. It comes with a 727.
I want to do a really mean twin turbo motor that could make some serious power. Would I be better off doing my 400 to a 451 or doing the 440 up for boost.

I'm working out plans for a 440/496 MPFI, twin turbo stroker, projected hosepower is estimated to be on the topside of 800 with torque around 950. It's not going to stress the block, as a matter of fact it's going to be easier on the block than building it "all motor". I've been working on it with my buddy that has worked with really high horsepower Mopar motors. The only reason I'm going with the stroker crank is all I have is a bare block and I need a rotating assembly. I considered the low deck block, but the intake I want is only made for RB motors.

You should put a roll cage in, as well as subframe connectors. A 4 link isn't necessary, but helpful if you're build a straightline racer. I'm going with XHD MP leaf springs, relocated 3" with sliders.

Get on theturboforums.com there are quite a few guys on there building Mopar turbo motors, very knowledgeable and helpful. Good luck with the build!

 

[Meep-Meep]

A buddy of mine has a turbo set up on his Ford 351W and it seems to handle 550 RWHP quite well. Through his experience he seems confident that a deep skit MoPar block would safely handle 900 RWHP and says that would be pretty easy to get out of 440 inches. If you want some insurance for the bottom end get the Pro-Gram cross bolt main cap conversion and a K1 crank and H beam rods slinging lightweight pistons.

 

[RustyRatRod]

The 400 might make for a good turbo motor. Since the piston sits way down in the hole. I think they say that promotes big time cylinder filling on a turbo motor.

 

[racedodge]

just wouldnt want to use cast pistons on that puppy with all that cylinder pressure... he hits the high rev's and its grenaded motor methinks....