Moparts

400 stroker

Posted By: DusterKid

400 stroker - 10/13/17 01:29 PM

Will be building my 1st mopar stroker engine this winter and would like some input. Will be using a 400 block, 440 source heads that have been reworked and flow:

Head flow numbers
100 lift 77cfm
200lift 161cfm
300lift 230cfm
400lift 271cfm
500lift 283cfm
600lift 287cfm
700lift 285cfm

Engine will be going in a 3200 lb car with driver and hoping to get to the 6.2s-6.4s range in the 1/8. Not looking to turn a bunch of rpm, would like to shift around 6000 and not twist it over 6500. Looking to be around 10.5:1 compression. For the moment will probably stay with a mechanical flat tappet camshaft. My questions are:

What are the pro/cons of the 512/500/470 kits?
Obviously more cubic, but would one be better suited than the other for what I'm trying to do?

As far as block prep:
Should the block be atleast partial filled?
Do I need just main studs or main studs and a girdle or go ahead and get 440 source main caps with studs and girdle?

Any other helpful tips and suggestions are appreciated. Thanks.
Posted By: Thumperdart

Re: 400 stroker - 10/13/17 05:04 PM

I squeaked out a 1.33 60 ft. and a 6.15 @ 109 slightly lifting last time out at around 3050 lbs making around 700 hp but w/way more than you are planning. I'm at 12.1.1 comp, .680-.660 276-281 @ .050 solid roller and heavily ported RPM heads with 2.19 intake valves non filled and non bushed block. The low rpm's you are suggesting may not be the ticket as I spin mine past 7000 to get the et's and shifting lower killed em but your cam choice and head flow will dictate some of that.........either way good luck........... thumbs
Posted By: JohnRR

Re: 400 stroker - 10/13/17 05:15 PM

Bigger cubes the lower the peak RPM so if you want a 6000/6500 rpm motor then I myself would probably build a 470 considering the flow of your heads, maybe go 500ish if you think you might put a better head on down the road?

Studs, alum caps ... or Ductile iron ... bush the lifter bores if you are going with a mechanical flat tappet and thinking of running a cam that will take advantage of the .904 lifter size, does Hughes still sell HTL cam ?
Posted By: rickseeman

Re: 400 stroker - 10/13/17 05:26 PM

I think you are asking a lot from a pump gas, flat tappet. Go 512. My buddy's Dart (weights are close) can barely do what you are asking with unported B-1 B/S's, more compression and a light duty roller cam. You will have to have a well working combo.
Posted By: Cab_Burge

Re: 400 stroker - 10/13/17 06:22 PM

Have your block sonic tested before doing any machine work on it scope Look for at least .140 cylinder wall thickness AFTER boring on both the major and minor thrust surfaces, cam side and motor mount sides scope
If it tests good, most do, then look at either using studs with either aluminum or ductile iron main caps, NOT STEEL tsk (I like and use Ductile iron but I don't think you can buy them now whiney )
The advantage of increasing the stroke is to increase the bottom end torque up
As far as your goals on limiting the RPM the cam, headers, intake and carbs., converter, tranny gear ratios and rear gear ratio and tire size will dictate where the motor wants to be shifted to go as fast as it can shruggy
Maybe you should shoot for between 6000 and 7000 RPM shifting and crossing the 1/4 mile at work
My first 400 pump gas stroker motor(511 C.I. with a low deck Eddy six pack intake and carbs) made peak torque at 4500 RPM and peak HP at 5500 RPM on the dyno and it ended up liking to be shifted above 7000 RPM at the track to go as fast as it could shock shruggy
Last thing do not waste your money on filling the block tsk If your current block is not good enough to use as is, find a better one up
Posted By: AndyF

Re: 400 stroker - 10/13/17 06:24 PM

You might want to sell the 440Source heads before you use them and use the cash for a set of Trick Flow 240 heads. The better heads will make the rest of the problem easier to solve.
Posted By: rb446

Re: 400 stroker - 10/13/17 07:04 PM

Crunching some numbers with the spec you gave of 287cfm heads@.600, 10.5:1 and 3200lbs race weight, a 470 would probably not squeeze the 630ish hp needed to run 6.30's-1/8th and 10.0's in the 1/4 with a solid FT cam
With 630hp-4.10's and a 30" tyre it should trap around 6150+slip, 4.30's = 6450+. A bigger motor for more torque to help with the hit with say 4.10's (for low rpm) would be better but your heads could then be a bit restrictive and top end power could dwindle before time, so really the issue is its not enough head as I see it to reach your goals with a 470 at least. Now if you ran a roller cam and got some more out of those heads?.

One combo that I can quote you from the track if it helps is>
440ci, 12.7:1CR, 320cfm heads, .590/312 purple solid, 3150 r/weight, 10.1's @131 = 600hp, 4.56 w/31" tyre 5000 stall, shift at 6400, trapped at 6800
Posted By: AndyF

Re: 400 stroker - 10/13/17 08:12 PM

My pump gas 470 makes over 700 hp running unleaded premium. That is why I suggested he switch to the TF heads. The Wilson ported intake that I used on my 470 is for sale in the race section so all a guy needs to do is build a 470 short block with flat top pistons then buy 240 heads from Summit and add the intake that I have for sale. That will give you 700 hp which should run low 10's or high 9's depending on how well the car is set up.
Posted By: DusterKid

Re: 400 stroker - 10/13/17 08:52 PM

Originally Posted By AndyF
My pump gas 470 makes over 700 hp running unleaded premium. That is why I suggested he switch to the TF heads. The Wilson ported intake that I used on my 470 is for sale in the race section so all a guy needs to do is build a 470 short block with flat top pistons then buy 240 heads from Summit and add the intake that I have for sale. That will give you 700 hp which should run low 10's or high 9's depending on how well the car is set up.


Was any work done to the TF 240 heads or they pretty much OOTB?
Posted By: AndyF

Re: 400 stroker - 10/13/17 10:29 PM

My heads are OOTB except for a valve spring change. The TF heads are CNC ported and flow really well out of the box.
Posted By: gregsdart

Re: 400 stroker - 10/13/17 11:41 PM

IMHO go 512 with better heads, if possible. A fully ported set of Indy SR heads would be a minimum ( about 340 cfm flow at .700). The reason for the much better heads is that with less flow, the whole car combo will need to be spot on to reach your goal. What altitude do you race at?
Posted By: 67mprfan

Re: 400 stroker - 10/14/17 12:04 AM

Originally Posted By AndyF
My pump gas 470 makes over 700 hp running unleaded premium. That is why I suggested he switch to the TF heads. The Wilson ported intake that I used on my 470 is for sale in the race section so all a guy needs to do is build a 470 short block with flat top pistons then buy 240 heads from Summit and add the intake that I have for sale. That will give you 700 hp which should run low 10's or high 9's depending on how well the car is set up.



Andy is that intake limited to just the trick flow heads or can they be used with something else
Posted By: AndyF

Re: 400 stroker - 10/14/17 02:40 AM

Originally Posted By 67mprfan
Originally Posted By AndyF
My pump gas 470 makes over 700 hp running unleaded premium. That is why I suggested he switch to the TF heads. The Wilson ported intake that I used on my 470 is for sale in the race section so all a guy needs to do is build a 470 short block with flat top pistons then buy 240 heads from Summit and add the intake that I have for sale. That will give you 700 hp which should run low 10's or high 9's depending on how well the car is set up.



Andy is that intake limited to just the trick flow heads or can they be used with something else


That intake would work with any standard port cylinder head. It will work better if the heads have been ported by someone who knows what they are doing.
Posted By: Dragula

Re: 400 stroker - 10/14/17 05:19 AM

Originally Posted By DusterKid
Will be building my 1st mopar stroker engine this winter and would like some input. Will be using a 400 block, 440 source heads that have been reworked and flow:

Head flow numbers
100 lift 77cfm
200lift 161cfm
300lift 230cfm
400lift 271cfm
500lift 283cfm
600lift 287cfm
700lift 285cfm

Engine will be going in a 3200 lb car with driver and hoping to get to the 6.2s-6.4s range in the 1/8. Not looking to turn a bunch of rpm, would like to shift around 6000 and not twist it over 6500. Looking to be around 10.5:1 compression. For the moment will probably stay with a mechanical flat tappet camshaft. My questions are:

What are the pro/cons of the 512/500/470 kits?
Obviously more cubic, but would one be better suited than the other for what I'm trying to do?

As far as block prep:
Should the block be atleast partial filled?
Do I need just main studs or main studs and a girdle or go ahead and get 440 source main caps with studs and girdle?

Any other helpful tips and suggestions are appreciated. Thanks.


Going to need better heads than that to go 6.2 at that weight..

512 with light weight crank option is best....Definitively use a girdle, and no need for any fill.
Posted By: B3422W5

Re: 400 stroker - 10/14/17 07:41 PM

Originally Posted By AndyF
My pump gas 470 makes over 700 hp running unleaded premium. That is why I suggested he switch to the TF heads. The Wilson ported intake that I used on my 470 is for sale in the race section so all a guy needs to do is build a 470 short block with flat top pistons then buy 240 heads from Summit and add the intake that I have for sale. That will give you 700 hp which should run low 10's or high 9's depending on how well the car is set up.


If its making a " track proven" 700, a 3200 pound car will run well down in the 9's easily.
My old w5 motor " made" 708 on a dyno and backed that up running low 9.60's at 140 in good air on 002/003 leafs and cheap shocks. So nothing trick about the car setup at all.
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