Need the professional engine builders advice.

I've got a Dart Little M on the way (iron caps) and I'm wondering how many cubic inches I should build.

I've been looking at doing something like a 377 but with a little more stroke (3.500, 3.562 or something similar). 5.7" rod, and probably a small dished piston.

Motor will probably be 9.5:1 and see a bottle it's first time through then it will get a procharger.

A lot of ppl tell me to do a 420" motor but my friend tells me that it is worthless to throw all the weight around of the extra stroke.

Looking for advice guys!

Thanks

 

the rotating assemblys are close to the same weight plus there is no replacement for displacement.leave it at 4.125 bore for later builds.400 ci should be enough cubes,especially when under pressure.

 

For that block:
Max Bore 4.185". Max Stroke 3.750"

You won't be dissappointed going more cubes. Believe me when I say I wish I still had my 406 small block. I ended up selling it to my brother for his wagooooon project. That block has great capability...use it. Then the next time a ricer or other car you disslike pulls up next to you, you won't have to worry about if "u got enough".

It's always a nice comfortable feeling.

 

Is the max stroke for that block really 3.75" I thought I could stuff a 4.00" or 4.25" stroke in there if I wanted to.

Huh?

Thanks!

 

Clearance is an issue. With machining, you can run any stroke you want. I would check with Dart on the max. stroke. I quickly looked at a few source books and I'm getting 2 different answers. One book says 3.75, the other says 3.875. Here is a GREAT article, nice build up:

http://www.chevyhiperformance.com/techarticles/90719/

edit: I know for a fact the Motown blocks can use up to 4.000'' stroke without clearancing the block.

 

hey man.....

here's a short rundown of my motor. i am changing over to a Fast Times custom turbo spec cam first, but eventually when i get the turbo system on and going, i will freshen the motor and bring the CR down and give the heads some attention. as you can see, mine has a 4" stroke and it did need a little bit of clearancing even with the spread pan rails of the Rocket block. this motor is being copied for the most part from a TT427, also built by the same Fast Times mine was built by, and made just shy of 1200hp and 1000lbft at the flywheel.........on 92 octane!!! you can check it all out at www.montygwilliams.com

-Dart rocket block with splayed billet caps, wide pan rails, raised cam, 4.120 bore and 9.300 deck height!
-Callies 4" stroke internally balanced 4340 crankshaft.
-Crower 6.125" billet rods.
-JE 2618 10.5:1 compression custom FORGED PISTONS.
-Billet solid roller cam.
-.658/.683 lift, 256/264 duration at .050, 108 lobe sep.
-Childs & Alberts rings
-Comp cams offset roller lifters(The expensive ones).
-DART 18 DEGREE HEADS.
-Did I mention it has Dart 18 degree heads!! (untouched, out of the box)
-1.625 comp cams 998-16 valve springs.
-Manley Severe Duty stainless 2.15/1.625 valves.
-Comp cams titanium retainers.
-Crower 1.70:1 ratio stainless shaft rocker system.
-Manley 3/8” pushrods
-Chevy Bowtie nascar type valve covers.
-Siemans 83 lb.hr injectors. (low imp.)
-Billet 2000CFM DOMINATOR THROTTLE BODY.
-ACCELL DFI 7 DIGITAL SEQUENTIAL FUEL INJECTION SYSTEM.
-Holley hall effect crank trigger.
-Holley hall effect phaasable ident distributer.
-WEIAND aluminum waterpump.
-STREET & PERFORMANCE alternator bracket.
-1 7/8” 18 degree headers
-Fluidamper.
-Billet pulleys.
-POWERMASTER racing alternator.
-AGR racing power steering pump.
-TCI racing starter
-16” K&N Dominator air cleaner
-Moroso 7 quart rocket block oil pan

there's some misc. stuff in there because i copied and pasted it from elsewhere. but i hope that helps. and btw, agreed........"there's no replacement for displacement"! especially with TURBO'S!!!!!

later,
Dave

 

Go big bore and short stroke. RPM the hell out of it.

My DART has a 4" stroke with aluminum rods. No clearance problems.

 

The rocket block and the iron eagle block seem to take special parts right?

Madman is there anything wrong with rpm'ing the hell out of it?

 

not a thing wrong with it if you put the right parts in it. mine took some special pieces, but that's because it has spread pan rails and a raised cam location, not to mention the 18* heads. i personally am not comfortable with a high winding motor, but that's just preference. if i was to build an all out drag motor, that would be one thing. but i'm interested in building one of the baddest street motors ever, especially for a small block. just something i'd like to do and hopefully one day show it some when it's done and perhaps get a photo shoot in a mag. that'd be cool!

Dave

 

I'm a believer in high winding sbc. I shift mine at8800rpm and cross at 9000rpm. If you have the right parts then the motor will love the rpm.

 

I'm assuming a billet crank and alum rods.....

A little too much for me.

 

have you looked at the dyno graph of that 1200hp/1000tq street car? 1201 hp comes in at only 6600rpm and 986 lbft by 6200rpm! personally, i would not change a thing. and to get all that power so quickly is unbelievable. but to each his own.

Dave

 

400-427 ci,8.5 cr o ring block and a t-88,thats what i want to build anyway.

 

Max recommended stroke for the Dart Little M block is 3.875. 4.155 bore unshrouds intake quite well, providing a potent 420 CI package.

 

Assuming all other conditions are equal(CR,head flow, etc.), a larger motor will make almost the exact same power as a smaller one, but the larger motor will make the power earlier than the smaller one, and the larger one will have more torque. Cubic inches also help tame large cams, so if you plan on driving it on the street, then I say go with more cubes. If it's just for race, then make it big anyway and RPM the hell out of it like that. Since you're talking about aluminum rods I hope you are just going to race it...

 

I won't do aluminum rods. I'm looking at 4340 crank, rods, and a good set of pistons.

Like I said, first time around the motor will see a fogger, then a pro charger. I don't want to over bore if it I don't have to to give myself some room for rebuilds and such.

I'm still up in the air as far as stroke.

it will be 90% street, with the occasional race on the weekends.

Thanks

 

BTW, what kind of clearance work (if any) needs to be done on the Little M with a 3.875" crank and big h-beam rods?

 

Nothing to clear the crank throws, but may need to clearance block for rod bolts. Recommend running a small base circle camshaft, frees up some additional space so top side of rod does not need extensive machining. I used Carrillo rods with Bryant cranks in two engines, one with a 3.600 stroke, the other a 3.875. Expensive, even twelve years ago, but never had an internal failure.

 

Start with a 4.140 bore and go from there. This will give you opportunity to do multiple rebuids, before reaching 4.185 limit.