400 strokerbuild -> torque

[Igor]

Hey guys,

I'm really a newbie in all this engine stuff and all these different options how to build a motor.
I'm asking for your opinions and suggestions about stroking a 400 block.

It should be a street car on pump gas (95/98) and it should be a durable build.

I'm looking for max torque in the lows and mids.

Would you go with a 512 stroker kit by 440source?
If yes, which parts would you combine?
w or w/o EFI
Heads, cams, etc

Thanks for your ideas and explanations

 

[Yatzee]

Mine is a 400 with a 512 stroker final. I bought my own parts from various suppliers because I wanted it strong. Even went with a lower girdle for stoutness. I ended up at 628 HP and 615 ft/lbs torque (dynoed). You'll need a quality torque convertor at about 3400 stall to get the performance and trust me, a stock 727 ain't gonna cut it nor will the stock drive shaft and u-joints. An 8 3/4 is a must for that much power. Do it and you'll never look back except to see the looser in your rear view mirror. TBI the beast and it'll do what ever you want, whenever you want, carbs just can't maintain the right AF ratios to get the most out of the engine. Good luck!

 

[niteshift70]

Keep the stroke to 4.25 or less in order to avoid going to external oil lines for the oil pickup. Avoid the kit that requires the support ring for the oil rings. It's an extremely short piston with the oil ring groove crossing the wrist pin area. It's fine for racing and short trips but expect shorter engine life and increased oil consumption. Other than that just make sure you have enough available airflow to feed all those cubes. Trick Flows or Stealth CNC ported heads oughta be good. Be sure and save plenty budget for tires!

 

[Cranky]

Are you going to build this yourself? And I'm a carb guy. My most consistent drag strip cars were carbed.....

 

[Xp29h]

Went 440source 512 kit for my 400. Planned on less than 10:1 cr. Came it at 9.7 runs great on 93 pump gas. Better when I add some octane boost and yet better on no ethanol gas.
Went with 571 440source hydraulic roller and their stealth CNC heads. Runs cool, with alum water pump and pulleys from 440source. Absolutely no complaints. Havent been able to light it up for long because the steering is a little crazy. But that's getting fixed next week as firm feel box is arriving soon!

I upgraded to all Arp bolts and upgrades from the ones 440 supplies.
Revmax 3000 stall 4:10 gears.

Good luck
Don't hesitate to pm. If you have any more questions on parts used for my build. I'll try to locate my parts ordered list.

 

[68 HEMI GTS]

Source 512 kit is nice. It'll still need pin fit done by a machine shop. Big motors need heads that can breathe. Street motor, T/F 240's would be my choice. Keep the cam and converter reasonable. You don't need fuel injection but it's a pretty neat way to go if you can afford it.

My source 512

 

[Igor]

Thanks guys.

I thought an EFI could handle these engines better and quicker...

BTW: I'm running now with the 3.23 and a 727 with an unknown shiftkit. Wanted to keep this setup. Would you?

 

[ibsorgn]

Hey guys,

I'm really a newbie in all this engine stuff and all these different options how to build a motor.
I'm asking for your opinions and suggestions about stroking a 400 block.

It should be a street car on pump gas (95/98) and it should be a durable build.

I'm looking for max torque in the lows and mids.

Would you go with a 512 stroker kit by 440source?
If yes, which parts would you combine?
w or w/o EFI
Heads, cams, etc

Thanks for your ideas and explanations

Call me old fashion but I believe in making sure that I know what I'm getting myself into before I start writing checks, I would suggest you read material on building performance Big Block Mopars from authors like Andy Finkbeiner or Chuck Senatore. You will be suprised in what you DON'T know and how important it is that parts fit and work well together. I wanted to build my own motor and after educating myself, I finally had to admit that 1) didn't have the special tools to put together and verify the assembly, 2) too much detail machining, 3) uncertain about parts selection and how well they may or may not work together and complement each other, 4) risk of purchasing unnecessary parts and their costs and finally 5) staying within a reasonable budget and obtaining the performance and mannors I wanted.

 

[Igor]

I'm not building it alone. I've got somebody nearby, who built several engines for other guys around.
I've already ordered some books to get into this stuff.

That is why I'm asking for your advice and your experiences with severeal parts, because I'm not sure which parts work well together.
I don't belive this is mentioned in any book, is it?

 

[ibsorgn]

I'm not building it alone. I've got somebody nearby, who built several engines for other guys around.
I've already ordered some books to get into this stuff.

That is why I'm asking for your advice and your experiences with severeal parts, because I'm not sure which parts work well together.
I don't belive this is mentioned in any book, is it?

Might try reading my post on this site to get a better insight into my 526ci RB http://www.forbbodiesonly.com/mopar...g-trials-tribulation-results-and-video.75804/

These books will give you outlines on builds not part numbers. However I do remember one of Larry Shepard's books defining a dozen builds on small blocks that even specified part numbers so I'm sure they are out there.

I know of number of guys that threw parts together and assembled in their backyard with varing degrees of success. Some were pretty impressive some where a joke. What I found most interesting was the variation in cost which did not necessarily have a relationship to performance. Some refused to have their motors dyno'd and I'm sure you can guess why.

Do yourself a favor and once you feel that you have a handle on what you would like to build make up a parts list down to every nut, bolt, gasket, and include a little margin for screw-ups and don't forget machine work and dyno time. Try to be honest with yourself and this exercise should give you a pretty good idea of what this motor is going to cost. Don't forget to set yourself goals like minimum octane and vacuum requirements, what converter stall you will need, compression ratio, hp and and torque levels hoped for, engine (starting and running) behavior, cooling requirements etc.

 

[Cranky]

Best thing you can do is talk to someone that really knows cams. Not talking about a cam manufacturer either but someone that can talk with you about what will work best for what you are trying to do and be ready to give that person ALL the info about your drive line which includes the heads, intake, exhaust system, trans, rear end gears, car weight and on and on including how you plan on driving it. The cam is the heart of the engine and everything around it will mean a lot to how well it runs. It can run like crap if everything isn't matched up....

 

[66Satellite47]

Thanks guys.

I thought an EFI could handle these engines better and quicker...

BTW: I'm running now with the 3.23 and a 727 with an unknown shiftkit. Wanted to keep this setup. Would you?

A pro built 727 by a real Mopar guy is critical. You can do your own if you learn all the important stuff. Shift kits are always questionable IMO. Pro auto shift or manual auto shift are the way to go. My manual shift valve body worked just great on the street. The 500" motor had no problem starting from a standstill in 2nd or even 3rd. Good luck figuring out what the EFI wants.

 

[Igor]

OK, so what do you think how much torque is possible our of a 512?
And which parts would work together to achieve a durable torquebased engine?

Thanks for a few examples. I'm still figuring out the overkill of aftermarket parts

 

[drobertson]

Went 440source 512 kit for my 400. Planned on less than 10:1 cr. Came it at 9.7 runs great on 93 pump gas. Better when I add some octane boost and yet better on no ethanol gas.
Went with 571 440source hydraulic roller and their stealth CNC heads. Runs cool, with alum water pump and pulleys from 440source. Absolutely no complaints. Havent been able to light it up for long because the steering is a little crazy. But that's getting fixed next week as firm feel box is arriving soon!

I upgraded to all Arp bolts and upgrades from the ones 440 supplies.
Revmax 3000 stall 4:10 gears.

Good luck
Don't hesitate to pm. If you have any more questions on parts used for my build. I'll try to locate my parts ordered list.

I have always heard that octane boosters are a gimmick. I guess that might be wrong? What booster are you using? Thanks.

 

[66Satellite47]

My 512 is an RB. It did 675 Ft-Lbs @4400 RPM on the dyno. I suspect a fair amount more below 4400. Pulls the front wheels pretty good in the 3700 # car.

 

[SlinktRR]

600lb-ft is pretty straightforward with big block stroker 470+ ci with any basic aluminum heads like edelbrock, stealth, or trick flow 240. If you want more than that you will need bigger heads (Indy).

potential overkill stuff is rocker arms, roller cams, external oiling etc. If you stay in 600hp range you can get a lot of engine for the money.