400 Stroker kits...451 c.i. or 500c.i. Is bigger always better

[AKcharger]

Is there a disadvantage to going with a 500 c.i. stroker kit over the 451...beside gas milage of course? For some reason I don't see big cubes as that important...or perhaps I'm prejudice that all 500+ engines I've known were  Caddy engines and couldn't get out of their own way

AK

[Runner]

if both engines are biult right the  500 incher will eat the 451 for lunch!

[firefighter3931]

If i was to build a lowdeck stroker, a 470cube combo is what i'd assemble. Better rod ratio, less side loading of the cylinder walls and a long enough skirt to keep the slug stable in the bore. A 499 lowdeck combo is more of a race engine, inmo. If you really want 500 cubes, build an RB block. 

Ron

[471_Magnum]

Firefighter pretty much hit it.

The 500 inch motor will compromise durability. In addition to the aforementioned side loading, Your wrist pin will be in the middle of the oil ring. Piston skirts will be real short so you'll have a bunch of piston rock. Pretty much impossible to build in good quench.

You'll spend a bunch more money building the 500 inch motor. It's overkill IMHO

The 471 combo is a much better set-up for the street/strip and there is no compromise on durability versus a standard-stroke combo.

Unless it's going in a race car, you won't miss the extra torque. 471 (or 451) cubic inches can obliterate a set of tires just as easily as 500.

The 471 will cost a bit more than the 451, but in addition to the cubic inches, you get a nice low bobweight and it will rev like a small block.

[Ghoste]

AK, I've been for a ride in 471's car and with four guys riding in it, the sucker PULLED!  Take his and Ron's advice and build that engine.

[doctorpimp]

The 471 will cost a bit more than the 451, but in addition to the cubic inches, you get a nice low bobweight and it will rev like a small block.

Where did you get this 471 stroker kit from?
I've only seen the 451 and 500 strokers from 440source.com

[471_Magnum]

Kits are for wusses  I assembled my own. Muscle Motors can probably set you up though.

The foundation is a RB crank offset ground to ~3.915", BBC H-beam rods (I used Eagle 6.535 rods), and a set of forged pistons (I used Ross).

Actual stroke will depend on who's piston you decide to use. The Diamond piston is made for 3.900 stroke IIRC.

Attached is the complete parts list from mine.

Some engine builders don't like the extra side play you get with the BBC rod, but I've never come across anyone who has ever had a problem that could be attributed to excess side clearance. There's just a little more oil slinging down below.

[Mefirst]

471_Magnum** Do you have any dyno numbers?

/Tom

[471_Magnum]

I had it on a Mustang chassis dyno a few weeks ago just as an exibition. I'll post the dyno sheet a bit later when I get home. Peak RWHP was 356 @ 5500 rpm IIRC.

Just bear in mind comparing chassis dyno numbers can be very misleading. At last check, I held the record on this particular dyno, but that record may have since fallen. Also, and I'm not making excuses, this dyno has proven to be very conservative, especially when compared to a Dynojet.

Wish I had some "real" timeslips to post, but my only trip down the track involved and electrical system failure where my ignition cut out at 3500 rpm netting me a 14.0 @ 87 mph with a 2.5 second 60 ft.  Against the G-tech, I've registered consistant 12.3 @ 115. I'll take another crack at the quarter mile at Nationals in a couple of weeks.

[471_Magnum]

Here's the dyno sheet. Not a real clean pull since I had a slight bog when the secondaries opened. It was hotter than heck too. Might have it back on the dyno again this weekend though in better conditions.

Some additional food for thought... I drive this car everywhere. Took it on a couple legs of the Hot Rod Power Tour this year. I drive it to Columbus for Nationals every year. Only time it goes on a trailer is if it's broken (which has been known to happen  ).

Point is: this motor is very streetable.

[Chryco Psycho]

If i was to build a lowdeck stroker, a 470cube combo is what i'd assemble. Better rod ratio, less side loading of the cylinder walls and a long enough skirt to keep the slug stable in the bore. A 499 lowdeck combo is more of a race engine, inmo. If you really want 500 cubes, build an RB block.  

Ron

this exactly my opinion as well , I believe rod ratio & longevity are more important than more CI to make the best power

[Ghoste]

What 471 Magnum hasn't told you is that when he's trailered it for being broken, it's things like a leaky water pump.  NOT for things like windowed blocks and so forth.

[AlaskanCharger]

I've had three 444 cu. in. stroker motors. 400 blocks punched. I quarter miled two of them many times, with no problems what so ever.
1. motor 512 H.P. 588 ft. lbs. trq.
2. motor 528 H.P. 614 ft. lbs. trq.
3. motor 520 H.P. 568 ft. lbs. trq.
I raced the first/second motor, 69' charger, complete car 12.80 @ 119 mph with 3.91 gears
I had the first motor in a 68' charger, no int. race seats car weighed under 3400 lbs.
I was in the process of building a 474 stroker, but sold it before I could even start it, no known specs on the motor.
Hope this helps somewhat, I have sold off my 426 Hemi parts as of two weeks ago now.
Building a 440 now, 0.60 over 10.5 to 1. 540 Crane cam 306 duro. Haven't chosen a head set up yet. 1 7/8 super comp hooker headers. 750 holley d.p. M1 intake d.p. Pete Jackson g.d.
Trani' is stage 2 with a 3000 stall TCI.
Thats all for now, goodluck
Mark

[AKcharger]

Wow

I haven't checked this thread in a bit...GREAT info 471, thanks for the info. I had the same question about where you were getting 471 CI from, yours seems to be a good combo. Thanks again

Hey Alaskan Charger...you almost stole my name!...AKchager Might be back "home" in May after retirement...we'll see what the AK job market looks like. I'd love to hook up with you a bout engine stuff. Ah...drag racing at Palmer

[CFMopar]

Whats the specs on that cam. Just trying to get an idea of what my 440 will put out the build is fairly similer everythign else wise besides block of course.

[AKcharger]

One more question. I was planning to use a ’76 400 block to build, but read somewhere that the cylinder walls were “thin”. Block is in good shape and I don’t expect to have to go more than .010 over…is this a big deal?

[471_Magnum]

No matter what vintage, have it sonic checked. Really no such thing as a thin wall block.

You will probably have to go with a 0.035 overbore. This is dictated by ring availability. 4.375 is a "common" bore size. Check the Childs and Albert catalog before you settle on your finish bore.

[Chryco Psycho]

I agree , have the block sonic checked

[AKcharger]

  copy all

Thanks

[C_stripes]

I know this thread is old as hell, but I would like to know more info about your build 471. How streetable is your engine? What trans where you running?

[471_Magnum]

I know this thread is old as hell, but I would like to know more info about your build 471. How streetable is your engine? What trans where you running?

It was very streetable. Daily driveable if you could afford the gas. Pretty much every component is list above. Mind you, when I built it in 2003, stroker kits weren't nearly as prolific. There were no cheap aftermarket cranks for Mopars.

That car is long gone from my garage. Mr Angry / NYCMille bought it and it became "Angrier". As far as I know, the motor still lives. Every time he quotes a horsepower number, it seems to go up. LOL.

[AKcharger]

I know this thread is old as hell, but I would like to know more info about your build 471. How streetable is your engine? What trans where you running?

Wow How rude of me! I started this thread 8 years ago and never wrapped it up!

I took everyone's advice and went with the 470 kit from 440 Source back in 2008. Since then I've put about 3000 miles on the engine with no problems and I'm very pleased. Rebuild was priced well, very streatable and has plenty of torque, sorry no #'s or times...perhaps next month when the track opens. I'm running a 727 with stock converter and 3:23 SG unit and get around 12-14MPG around town

I used my original Block (12/71)  and went with the 440 Source balance rotating assembly as well as their "cheater" aluminum heads. Additional parts were windage tray, aluminium water pump housing and Engle K-56H cam (.504 lift/ 272 duration) I have cast iron HP manifolds an old torqer intake with a "massive" Edelbrock 600...it really needs an 800 but since I don't really race it I'm not real worried

Lessons learned/what I'd do diffrent:
- Really only thing is the the upgraded valve keepers. I had to do that on mine after seeing the grief caused to some other engines from dropping a valve
- One thing perhaps out of the ordinary is when cold the engine has a slight knock, but when warmed up it goes away. Machine shop said that's standard for the pistons...well, hasn't cause any problems