Mopar 396 SB Stroker is off the Dyno & in the Books

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MRL Performance

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Here is a "Special" engine we made with a 3.825" stoker crank and a R block. It turned out pretty good.

MP R block, Magnum style converted to shaft oiling, Yes we do this in house
Older forged 3.825" stroker crank
6.250" rods, SBC style
RaceTec flat top pistons 4.060" bore
Ported ProComp head w/2.08-1.60 valves
Eddy SV intake
Lunati solid roller cam 273/281 @ .050"
Kevko 6qt Kick Out oil pan
QF Black Diamond 950 carb
ProGram 4 bolt main caps w/studs on all 4
11.2 to 1 compression

It made 600+HP from 5950-6800 rpm peaking at 612HP around 6300 rpm. It will pull hard all the way to 7000 rpm.

It also made 500+TQ from 4100-6400 rpm peaking at 550TQ around 5000-5400 rpm

This thing sounds super Bad ***, has a real Crisp throttle response and the power curves are never ending. It held peak TQ for 400+ rpm and peak HP for almost 1000 rpm!!!!

Its super efficient as well. The Volumetric Efficiency was 100%+ from 4600-6800 rpm peaking at 106% from 5000-5900 rpm. BSFC was .410-.463 and the A/F ratio was a solid 11.9-12.7
 
Thanks for posting the specs on your engines. I really enjoy seeing you choices/decisions.
 
[ame]http://youtu.be/9zwM6HqS3KA[/ame]
 

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Wow, kinda hard to believe the hp & tq are so high.
Good work!

Thanks. Not hard to believe. It actually made a little less than I was hoping for. I was shooting for 625HP, but this is what it made and Im pretty happy. If I would have spent 6-12hr porting the intake, I would have got it, but its a cost vs gain thing, just wasnt worth it.
 
Motor sounds great in my Duster with and without exhaust. I still grin every time I think about it!

I can't wait to post reports once we thaw out and I can get it out on the street and track for some testing !

:burnout:
 
Did you flow the Procomp Heads?

Post up some numbers on them. I am sure guys would like to get their hands on a set of them!
 
Motor sounds great in my Duster with and without exhaust. I still grin every time I think about it!

I can't wait to post reports once we thaw out and I can get it out on the street and track for some testing !

:burnout:

Lucky dog. What a screamer!
 
i've always wondered why the 4" crank has been the 'go to' stroker build when the 3.75 seemed to be a better choice.
 
Nice! What did you run for fuel? I see comp is high. What do you have going on for quench?
 
i've always wondered why the 4" crank has been the 'go to' stroker build when the 3.75 seemed to be a better choice.

If the crank companies would make one that was not a $1500 piece more people would run them, but the 4.00" is the standard and that the way it goes. I would build more of them, but after you factor in the custom pistons and cost of the crank it puts it out of the budget for most people.

Did you see the videos Jim posted with it in the car? Made the hair stand up on the back of my neck!
 
i should have been clearer...i'm wondering why the manufacturers chose the 4" piece.
..especially with the success of the generals' 383.... from mild to wild.
Would the 3.75" stroke out perform the 4"square bore/stoke at all rpms?
 
i should have been clearer...i'm wondering why the manufacturers chose the 4" piece.
..especially with the success of the generals' 383.... from mild to wild.
Would the 3.75" stroke out perform the 4"square bore/stoke at all rpms?

Try putting a 4 inch crank in an OEM sb chevy block...you will see why the manufactures chose 3.75...the OEM sb mopar is a much easier engine to stroke .
 
If the crank companies would make one that was not a $1500 piece more people would run them, but the 4.00" is the standard and that the way it goes. I would build more of them, but after you factor in the custom pistons and cost of the crank it puts it out of the budget for most people.

Did you see the videos Jim posted with it in the car? Made the hair stand up on the back of my neck!

a 3.79 crank is available for not all that much money

http://www.molnartechnologies.com/molnar-cranks.html

that just leaves the custom pistons unless there is some oddball chevy rod that would make this work with a piston intended for a 4"crank with a chevy pin.
 
If the crank companies would make one that was not a $1500 piece more people would run them, but the 4.00" is the standard and that the way it goes. I would build more of them, but after you factor in the custom pistons and cost of the crank it puts it out of the budget for most people.

Did you see the videos Jim posted with it in the car? Made the hair stand up on the back of my neck!


Nope, how about a link:cheers:
 
I had the video's on my facebook which isn't public. I'll have to figure out another place to host them, or maybe I can get Mike the video's or have him grab them off my Facebook and post them on the MRL Youtube ?

Mike ?
 
Youtube is good. I dont know to or if i can grab them off FB. You can email them to me and I can put them up on youtube.
 
Ok here is the first one with Open headers. You can smell the high octane fuel!

[ame]http://youtu.be/bVU0lwK66Cs[/ame]
 
This one is out the exhaust system. Man it sounds so goooood!

[ame]http://youtu.be/9BZoldXr78o[/ame]
 
i've always wondered why the 4" crank has been the 'go to' stroker build when the 3.75 seemed to be a better choice.

I agree 110%
I really like my 3.79 Molnar Technologies Crank

I think the 4" stroke is just a "Mines Bigger than Yours" deal
 
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