400 stroker options

[wagonman]

Trying to make a game plan for a 400 stroker build. The block is at the machine shop for inspection to see what bore it will go ect. Have a set of 440 source heads new OOTB. Looking at their roller rockers, anyone use them? Good, bad, junk? Also looking a their 500in kits same questions? Thanks.

 

[IQ52]

OOTB 440 Source Stealth heads and 440 Source rocker arms with a 500" engine is like Jelly Beans with Prime Rib. By the time you spend the money to make Stealth heads appropriate for 500" you could have purchased Trick Flow heads.

I have used 440 Source stroker kits. I purchase them unbalanced and have my machine shop do the balancing. The piston pins need to be checked for proper clearance and the rods honed to fit. Pretty normal stuff for a stroker kit. I haven't had to send any cranks back for journals being too far out of tolerance. They aren't perfect, but have been serviceable.

 

[wagonman]

Thanks IQ52. Got the heads as a package deal with the 400 block. I pulled the valves and was supprised to see crappy bowl blend in the seat to casting area, well maybe not supprised. Has a ledge about 1/16th under the seat. A little time with a dremmel should clean that up. Then off to the machine shop to check guides and seats. I have a set of Isky ductile rockers I can use instead of the others. Thanks for the headsup on the kits. More Qs to come as this progresses

 

[Steve009]

you will probably get a tone of different opinions on here about what stroker kit to use with different heads. Im currently building a 400 to 470 stroker using the 440 source kit. from what ive researched and chatted with my engine builder about in his experience, 500ci+ is too much for a 400 block simply because of the piston skirt size. some have seen these short skirted pistons create slap over time (some haven't). since mine is mainly for street use I was fine with not going over 470 and getting a longer skirted piston. for a drag only car I would have went 512 for sure. I think the trick flow 240s are the best bang per buck on the market and that's what I will be using. I was told to not trust 440 source for anything besides stroker kits, its their specialty and they should stick with that. lots of bad stories about the 440 source heads, rockers, etc., but everyone has their own opinion I guess.

 

[wagonman]

Thanks Steve, Yes there are many opinions and options. Doing my research and as You I am also considering the 470 kit as well. It is going to be for a street car so good street manners and longevity are needed and lots of low end torque. The heads were almost free with a project I got. I will see what my machine shop says, not going to put a ton of $ in these things but they should be better and lighter than cast iron. Pocket port and gasket match and let them fly.

 

[5.7 hemi]

You won’t be disappointed if you do a 470, they rev like a rice rocket and have tons of torque! Buy good tires, you’ll need em’.

 

[Garys1969RR]

I'm also planning another 500 inch build. Taking the bottom end out of a 496, and will use it in a 400 block to come up with a 512. I will need new pistons, of course. I have a set of Stealth heads on the 496 now, and it seems to run out of breath about 5000 RPM or so. Torque falls off, and it just wont go much faster. So, as has been said, a head that will only flow enough air to get a 500 cubic inch motor up to 4500 or 5000 RPM before torque falls off, doesn't make sense. Especially in a drag race motor. Most heads in production form usually can't supply the flow needed to make them run well at higher RPMS. So off to the professional porter they go, to make them flow more air. I'm sure there is a formula that shows how much intake flow is needed to get a 500 cubic motor to produce maximum torque at say, 4500 RPM. DOES ANYONE KNOW HOW TO DETERMINE THAT? And would you please let us know? Then we can find a head that will flow the right amount of air to make the 500 inch monster run like it is supposed to. Thanks

 

[Garys1969RR]

I currently have a set of Stealths , and a set of Mopar Stage VI HEADS. I don't think either one, in present form, is up to the task of supplying a 500 inch motor enough air to run well at 5000 + RPM.

 

[68 HEMI GTS]

I'm also planning another 500 inch build. Taking the bottom end out of a 496, and will use it in a 400 block to come up with a 512. I will need new pistons, of course. I have a set of Stealth heads on the 496 now, and it seems to run out of breath about 5000 RPM or so. Torque falls off, and it just wont go much faster. So, as has been said, a head that will only flow enough air to get a 500 cubic inch motor up to 4500 or 5000 RPM before torque falls off, doesn't make sense. Especially in a drag race motor. Most heads in production form usually can't supply the flow needed to make them run well at higher RPMS. So off to the professional porter they go, to make them flow more air. I'm sure there is a formula that shows how much intake flow is needed to get a 500 cubic motor to produce maximum torque at say, 4500 RPM. DOES ANYONE KNOW HOW TO DETERMINE THAT? And would you please let us know? Then we can find a head that will flow the right amount of air to make the 500 inch monster run like it is supposed to. Thanks

Pretty hard to put to much head on a 500 ci motor if its gonna have any suds. I run a standard port window on my 511 (good flowing heads) with a matched cam for the combo and it’s over about 6200. Torque is brutal mid 4’s on up. Only reason I didn’t go max wedge port is the six pack. Other wise it’s a no brainer. The other thing about 500 ci motors is they like lots of carburator. I had a 1050 dominator on the runner I was tuning for a different car, it was incredibly fast with that carb and still had great street manors. And the runner is not a race car. It’s a 4000# with me, heat working, stock suspension, drive it to work kinda car.

Flow sheet on my SR’s

 

[Bighead440]

We used the 440Source crank and rods but got Ross pistons for our 471. I liked the 6.535" (.400" long BBC) rods for a more stable piston skirt, but the 6.700" rods would work as well, just a shorter piston. Buy the chamfered main bearings from 440Source, regular bearings won't clear the crank radius on the mains, trust me.

 

[IQ52]

I'm also planning another 500 inch build. Taking the bottom end out of a 496, and will use it in a 400 block to come up with a 512. I will need new pistons, of course. I have a set of Stealth heads on the 496 now, and it seems to run out of breath about 5000 RPM or so. Torque falls off, and it just wont go much faster. So, as has been said, a head that will only flow enough air to get a 500 cubic inch motor up to 4500 or 5000 RPM before torque falls off, doesn't make sense. Especially in a drag race motor. Most heads in production form usually can't supply the flow needed to make them run well at higher RPMS. So off to the professional porter they go, to make them flow more air. I'm sure there is a formula that shows how much intake flow is needed to get a 500 cubic motor to produce maximum torque at say, 4500 RPM. DOES ANYONE KNOW HOW TO DETERMINE THAT? And would you please let us know? Then we can find a head that will flow the right amount of air to make the 500 inch monster run like it is supposed to. Thanks

For the purpose of response I'm going to consider the Stealth head and the Edelbrock RPM head the same, as we can get the same air flows from each head.

I think maximum torque rpm is going to be determined more by the camshaft than the cylinder head flow, and then to a lesser degree, by the intake manifold design.

We ran a 451 stroker with 452 iron heads that flowed around 302 cfm @ .600" and a 496" stroker with Edelbrock RPM heads that flowed 309 cfm @ .600" lift.

The 451 used a Comp Cams solid roller 254/260, .582/.588, 110 LSA.
The 496 used a Lunati solid roller 249/255, .585/.600, 110 LSA.

451 made max torque of 588 lb-ft @ 4,600 rpm and 621 HP @ 6,100 rpm
496 made max torque of 642 lb-ft @ 4,600 rpm and 642 HP @ 5,800 rpm......so we know that 300+ cfm will get a 451-496 engine to max torque with that kind of cam around 4,600 rpm.

Then we used the 451 and a 500" with the same pair of 906 iron heads that flowed 340 cfm and both used the same solid roller 280/288 @ .050, .800/.800 lift.

451 made max torque 548 lb-ft @ 6,200 rpm and 694 HP @ 6,900 rpm
500 made max torque 599 lb-ft @ 6,200 rpm and 730 HP @ 6,600 rpm

What can the well ported (340+ cfm) Edelbrock/Stealth heads do on a 451? With a solid roller 278/280 @ .050 and .780/.780 lift, just one of many dyno sheets from 11/29/09 says.............601 lb-ft @ 5,800 rpm and 773 HP @ 7,200 rpm. I can only guess what the 500" engine would do with the same heads, we never tried them.

 

[hemiman426]

I have 2 400 stroker,one is 500 ci,another is 540ci,also I have a 230 block going to do a 500 ci,try ohio crankshaft for a stroker kit,they can put together anything you want,also 30 years ago builts a 451 stroker from a 400,ross pistons,stock yl 440 rods,steel 440 crank cut down,with steel heads,ran 10.30s on alky

 

[wyrmrider]

couple of tips
plenty of good info already
did they mention the pinfit and go through the heads for concentricity and guides? verify quality seals like viton
do not bore any more than absolutely necessary the cubes are not worth it but cylinder wall strength is
run tight quench
run a little less cam and compression- let the cubes do the work for a street build

 

[wagonman]

couple of tips
plenty of good info already
did they mention the pinfit and go through the heads for concentricity and guides? verify quality seals like viton
do not bore any more than absolutely necessary the cubes are not worth it but cylinder wall strength is
run tight quench
run a little less cam and compression- let the cubes do the work for a street build

Have not ordered a kit yet but will verify pin fit when I get it. Heads are at machine shop to check guides and seats and will have to see if they need a cut for the seals, came with regular seals that wont fit with a double spring if used. I want to keep the bore at 035 max if possible. Looking at 10.5 compression and a Comp XE 525 Hi Lift or ? Havent really got that far and will ask about that as the build continues. Thanks.

 

[Garys1969RR]

My plan is to run flat top pistons and a .oo6 positive deck height. With a 4.375 bore, 4.25 stroke, 75 cc chambers (Stage VI ), and a .039 head gasket I will have .033 quench and 13 to 1 C Ratio. It's a strip only motor, and we really need that extra squeeze at 5400 feet. The 496 in the Valiant now supposedly has 14 to 1. Ill find out when I disassemble it.

 

[Garys1969RR]

Is there any reason one should NOT run a slightly positive piston to deck clearance on a 400 stroker? I think Chrysler actually produced one with the piston .010 above the deck. What was that, a 69 440 6 pack motor? Does anyone know what engine it was, that had a piston extending slightly above the deck?

 

[moper]

Given the piston/stroke choice - you need another .010 of head to piston clearance IMO. The short pistons rock a lot at TDC. I always run "tight" quench if it's possible and routinely run +.005 above deck. But I think a 1.32" piston height with a 4.38 bore will rock too much for under .040" quench at any real rpm.

 

[68 HEMI GTS]

It’s like mopar says, you gotta maintain a enough clearance between the piston and head. Big bore with a short skirt piston it’s critical. I’m out on my 511, used a .050 gasket to keep it in check. Back to around .040. Smaller bore engines like 4.6L fords you can run tighter. I’ve ran them in the .030 range and have seen guys run those even tighter than that.

 

[Bighead440]

Is there any reason one should NOT run a slightly positive piston to deck clearance on a 400 stroker? I think Chrysler actually produced one with the piston .010 above the deck. What was that, a 69 440 6 pack motor? Does anyone know what engine it was, that had a piston extending slightly above the deck?

Some 340s and a few years 383HP had positive deck height, no 360 or 400's.

 

[Garys1969RR]

Trying to make a game plan for a 400 stroker build. The block is at the machine shop for inspection to see what bore it will go ect. Have a set of 440 source heads new OOTB. Looking at their roller rockers, anyone use them? Good, bad, junk? Also looking a their 500in kits same questions? Thanks.

My current 496 stroker in the Valiant has Stealth heads, and roller rockers from 440 Source on it. No issues so far. It also has a roller cam of unknown origin. Valve lift about .630"
The motor sees 6000 plus RPM at the drag strip, and the Source roller rockers seem to be working well. When I adjusted the valve lash, and tightened the lock nut, the lash didn't change. I had that issue with the nodular iron rockers. The lash would change slightly when you tighten the lock nut. So the Source roller rockers work fine for my use. As for the Stealth heads, they are working good enough to get this old Plymouth down the strip at 11.20 and 118 MPH. And that's with a lot of leak down past the rings, and 5400 feet elevation. As has been said, if you use the heads you have, get them checked over first.