Mopar 400 2bbl

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MRL Performance

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Here is our latest endevor, a BBM 400. Its a bit of a "Sleeper" as it is a stock looking 400 2bbl. The HP manifolds make it look a little better. Here is the run down, well as much as Im willing to tell yall anyhow.

400 BBM
4.375" bore 3.38" stroke
Stock 383 516 2bbl heads and intake
Heads were not ported, only a blend for the new seats that we installed
Super light weight valvetrain, Beehive style springs, light weight valves
10 to 1 compression
2.08/1.60 valves
Holley 4412 500 2bbl carb
Super light weight internals, 2066g bob weight
Lunati Voodoo 60303 cam
MP iron adjustable rockers
Top end oiling mod
A few tricks here and there ;)

Ran the water pump with the crank, not electric drive, and a real life 175* water temp. Timing was set to 34* total, A/F was 12.4-13.0.

Factory 400 4bbl rating is 190hp/305tq, and thats with a 4bbl

Any guesses on power output???????
 

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"A few tricks" might mean that carb is flowin 700 CFM. I'm sayin 395 and 425, respectively.
 
Nothing done to the carb, its bone stock out of the box, except for a jetting change. At max rpm we measured 500cfm going thru the engine.

I will post the dyno sheet later.
 
I'll also be curious if a carb spacer was used......would kinda take away from the sleeper aspect, but i'm gonna take a wild guess and say with those cubes and that size carb that mixture velocity would reak havoc with the carb that close to the plenum floor?
P.S....and my guesses here will probably be about as good as my lottery picks:D
 
Remember that 190 figure is NET, and you are probably measuring GROSS.

The 74-77-ish van 400 I ran in my 70 Bee felt MUCH more powerful than 190 (or 228 if you add the 20% back to simulate gross)

I'll say 340 HP and 410 TQ.
 
He's looking at a fast reving and maybe high reving engine with the lightweight rotating assembly and valvetrain. I'd also expect a ton of torque because of the smaller valves and intake/carb setup. I'd say 415hp and about 480tq
 
...whoops, didn't see the 10:1 part...now saying 380 HP and 430 TQ.
 
falston1 said:
He's looking at a fast reving and maybe high reving engine with the lightweight rotating assembly and valvetrain. I'd also expect a ton of torque because of the smaller valves and intake/carb setup. I'd say 415hp and about 480tq
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If Mike gets these numbers out of it\\:D/.
 
Well, 400+HP from unported 383 2bbl heads and intake with stock exhaust and 2" pipes and a 226/234* @ .050" cam? With headers, maybe, but not these manifolds.

We ended up with 357HP @ 5200 rpm and 455TQ @ 3000rpm

It ran strong, pulled hard and sounded great. It had 16-17inches of vacuum at 800rpm, no vacuum advance. With a 4bbl intake and headers, this engine would make another 100hp easy.

Any way you look at it, its making a lot more power than a stock 400, with smaller heads, smaller intake, smaller carb. The advantages are, more compression and a mild performance cam, lighter pistons and valvetrain and few *Special* mods.

Oh yeah I forgot to mention something. Remember my thread on what would be better, the center dump truck manifolds vs the HP manifolds in this thread?- http://www.forabodiesonly.com/mopar/showthread.php?t=185840

Well I tested the theory and you wont believe it. The HP manifolds were good for another 0 HP and 0 TQ. Thats right, NOTHING at all. It made the same HP and TQ with both manifolds. We didnt have time to test headers, but Im guessing that would be worth another 30-50HP. We left the HP manifolds on because thats what the car is setup for, so its a drop in.
 

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OldmanRick said:
Hp 345@5200 / tq 415@3400
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BSFC numbers were more consistant then i thought they would be.....nice job and big torque. I'll assume a build like this would only be cost effective for someone doing a resto type build. But then again a early 4bbl or T/Q intake and corresponding carb would surely pump the HP up 25 or so.
 
The HP manifolds didnt help because it was only a 2 barrel cant get much air in. In order for the HP manifolds to make a difference you need the have a lot of air coming in to have a lot of air comming out.
 
74DartSwinger360 said:
The HP manifolds didnt help because it was only a 2 barrel cant get much air in. In order for the HP manifolds to make a difference you need the have a lot of air coming in to have a lot of air comming out.
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That may be so, but Im not going to believe it until I see it, and right now, Im not seeing it. I have a a few people tell when they swapped out the stock manifolds to the HP's, they felt no gain. But going from HP's to headers was a big kick in the pants.

This engine is for a circle track racer that has to run in a stock class and has to run a 2bbl carb. His SBC competition wont know what hit them.
 
Nice job. I was hoping this was destined for a '73 Newport or something...lol
You've posted as a sleeper... Now it's a NASCAR spec build? Two vastly different animals. I'd like to hear much more on the lower end. How was the bobweight reduced?
And on the manifolds bit - I agree with 74Dart and I keep shaking my head as to why you might believe otherwise...lol. I'm told I'm stubborn but you're resetting the bar ...lol
 
MRL Performance said:
His SBC competition wont know what hit them.
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You got that right......neither will anything else. lol Just a question.....is this so proprietary that you cannot give a parts numbers list? I am gathering parts now for a B engine and this looks like a good direction to follow. Like pistons. Did you use KB240s?
 
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