Lets talk about building a 400 stroker.......

[BEEP383]

Well just got me another motor.......a nice 400! Thinking about a stroker this time and well I'm really open for suggestions on this subject. Has anyone built a 451? Or do you have a better stroker combo?! Please let me know or e-mail me. THANKS.

[440 Jim]

For discussion definition, I think we can talk about the two most popular stroker combos for the 400 block:

1) 451 CID - 4.340+0.035 bore x 3.750 stroke
2) 474(471)CID - 4.340+0.035 bore x 3.915 stroke

The 451 is a 440 crank turned on the mains to fit the 400 block. Either 400 or 440 rods can be used, but pistons for the 440 rods may be more available.

The 474 not only turns the mains down, but offset grinds the rod journels to BB Chevy size (2.200) giving 3.915 stroke. I hear Eagle makes rods specifically for this.

Well if we are talking aftermarket rods, why not put a MP 4.15 stroke crank in. The pistons require a 0.990 wrist pin so either bush 440 rods, or use aftermarket. That has been called a 496 (I calculate 498 at 4.37 bore).

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440 Jim
E-Body Fish

[This message has been edited by 440 Jim (edited August 15, 2000).]

[440 Jim]

Here is a start on some parts:

Ross Pistons for 400 block, 440 rod length, 3.75 stroke (451)
#99499 4.375 bore, 0.990 pin, 1.320 comp ht, 551 grams
#99500 4.375 bore, 1.094 pin, 1.320 comp ht, 537 grams

Keith Black Pistons for 400 block, 400 rods, 3.75 stroke (451)
#215 Quench dome, 10.6 CR with 85cc head

Manley Rods for BB Chevy journel in Mopar engine (474)
#14279 6.766 length, 0.990 pin, 888 grams



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440 Jim
E-Body Fish

[dartboy71]

440 Jim--A couple questions for clarification. . .

Will the block have to be notched for the bigger rods on the offset ground crank? Also, is it feasible to think about using stock heads with some good port and bowl work on this kind of setup (if its for a dual purpose ride)? Obviously, the stroker will want to breathe better, but will bigger than stock valves be necessary?

[340king]

Typically, longer stroked engines respond to better head flow rather well, but they really respond to low lift flow improvements. This is due to the rate the cylinder depression(vacuum) is developed. Any improvements in low lift flow will do wonders for performance. Coincidentally, low lift flow usually adds up to better high lift flow to a point.

[440 Jim]

Originally posted by dartboy71:
440 Jim--A couple questions for clarification. . .

Will the block have to be notched for the bigger rods on the offset ground crank?

You mention a good point. According to the Chuck Senatore book, to put the 440 crank into the 400 block either the block must be ground for a little clearance or (as recommended) the crank small counterweights must be beveled about 3/8" wide (45 degrees).
He has a good picture on page 35 of the HP book, "Big-Block Mopar Performance". Don't let this scare you. A die grinder and careful fitting can generate the required clearance, about 0.060. If you don't want to do it, a performance machine shop should be willing to do it relatively cheaply, just some die grinder work on the block or lathe grinding the crank. Not too big a deal, especially if you have them grind the mains.

By-The-Way (BTW), he also has some good and easy tips on improving oiling in the B/RB Mopar such as 1/2 NPT hemi oil pickup and 17/64 oil passage from the lifter gallery to the main bearings.

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440 Jim
E-Body Fish

[This message has been edited by 440 Jim (edited August 15, 2000).]

[This message has been edited by 440 Jim (edited August 15, 2000).]

[440 Jim]

You guys bring up another good point about head flow. IMHO, any big block stroker bigger than say 490-500 CID needs aftermarket heads if you want RPM above say 6500.

Remember, big displacement and high RPM need big flow heads! However, most of us humans will be happy with 451 CID, 6000-6200 RPM, and 475-525 HP with ported cast iron heads.


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440 Jim
E-Body Fish

[DartGT66]

I have built a couple of 451's and they are great engines. I think that the 4.15" crank in the 400 block is not a good idea, you have to compromise everything in doing that (rod length, compression height etc.) If you want a bigger engine than the 471, rather use the RB block especially in street applications.

[451boy]

I agree with DartGT66 on the 4.150 issue. It is just too big to fit in a 400 block. I've built a motor that way and it ate the piston skirt in short order.

I wrote an article several years ago on the 451 engine. It is still alive in cyberspace if you want to read it. Go to yahoo and search for 451 stroker engines.

[23T-Wedge]

Hey 451Boy,

I was just trying to find that article when I saw your post, really, really great info...saved it as one of my favorite places...the URL I'm showing is
http://www.phoenix.net/~atc347/451/

Hey Beep, I take it you may not be looking for a 383 steel crank anymore...Lemmeknow...

Ronny
Waymaker Racing
John 14:6

[440 Jim]

451boy, Great article!

For piston choices check these web sites:
www.rosspistons.com/chrstock1.htm

www.kb-silvolite.com/page41.htm

www.brcpistons.com/pist_chrysler.html

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440 Jim
E-Body Fish

[This message has been edited by 440 Jim (edited August 16, 2000).]

[440 Jim]

What are people's thoughts on rods?

Stock 400, 6.358", 812 grams
Stock 440, 6.768", 846 grams
Eagle
Manley

Anyone have experience if the piston pin reaches the oil ring groove with the 440 rod?


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440 Jim
E-Body Fish

[Brian_wo]

Personally I think the 400 rods is a bad idea,I have a 431(383+.030 and 383 rods) and I have a 450 (400+.030 and 440 rods) and never again will I build one of those with a 400 rod,I feel that you lose to much,the 383-400 rod makes the piston much larger and heavier and the whole reason(for me) to build a low deck stroker is to get a lighter rotating assembly and the 383-400 rod almost offsets that.

I am about to fire up the 450,it's going in my ramcharger,well it's there now but just found out I can't use the headers I have so I just ordered a new set,my guss is that this motor is going to be a real screamer,even in this heavy pig.

[440 Jim]

I see your point (Brian_wo). An example:

Ross #99535 (new #) pistons, 608 grams, 400 rod
Ross #99494 pistons, 525 grams, 440 rod

Even though the 440 rod adds 34 grams, you save 83 grams with the pistons, net 49 grams.

[BEEP383]

All I have to say is WOW!!!!!!!! Hey 451boy do you have the general instructions on building this combo. I have pulled the 452's off flipped it over to yank the caps & crank.........whats next!!!! Thanks.

[Brian_wo]

here are a few pictures of my 450 that I just built for my ramcharger,it has Keith Black quench dome pistons and is 9.5:1

<img src=http://www.geocities.com/wo23dodge/crank.jpg>

<img src=http://www.geocities.com/wo23dodge/452.jpg>

<img src=http://www.geocities.com/wo23dodge/450.jpg>

[BEEP383]

Brian_wo
Did you port those heads or did you have it done? I was thinking porting mine myself, looked in Summit Racing catalog they have mandrel porting kit but is rated to be with an electric grinder & not an air die grinder which I have.....Thanks.

[blowncuda]

I have just finished building a 451 and a 474
" engine for my new car. I had a few problems with some Eagle rods,5 sets to be exact,they would not retorque to spec consistantly. I ended up using Manley's in both engines and am glad I did. I also recommend using the 440 length rod to reduce piston weight. I used JE pistons in both,just my preference,think they are the best pitons out there. You are also better off having the crank throws turned down instead of grinding the blocck,once again to get rotating weight down,makes for a quicker reving combo that is easier on parts. Both engines are equipped with Indy Heads. Don't know if I answered any questions just wanted to share my experiences.

[Brian_wo]

Originally posted by BEEP383:
Brian_wo
Did you port those heads or did you have it done?

To be honest I just left them alone and the reason is that this is a motor that most likely will never see over 5000rpm because it is going in my tow vehicle,the cam is tiny at .430 lift so I am looking for all low end power.

Everything Blowncuda said on building these motors are the only way I will build mine,I am started on a 500 cube Indy headed motor now and they are at MM being ported now,sure hope I can afford to get them back

[440 Jim]

Originally posted by BEEP383:
I was thinking of porting mine myself, looked in Summit Racing catalog they have mandrel porting kit but is rated to be with an electric grinder & not an air die grinder which I have.....Thanks.

BEEP383,
The home porting topic has lots of opinions, but here is mine... I did a set of 452 casting heads using the MP templates as a guide. I didn't bother to grind/sand/polish every surface from the intake flange to the valve. I just made the templates fit, smoothed the transitions, and matched the intake port to the gasket. I did smooth most of the exhaust port surface to prevent carbon build-up. This was relatively easy with a couple size grinding stones in an air die grinder, and some sanding rolls; thats all I used.


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440 Jim
E-Body Fish

[440 Jim]

Brian_wo,
Please clarify some crank questions using the 440 crank in a 400. What clearance does the reduced 7.25" dia crank counter weight give (with the 1/16" chamfer)? Where is the closest point and is it at the chamfer? Since the stock 440 crank is about 7.5", I was wondering if a dia between the two with a bigger chamfer would get the job done.
For balancing, how do you calculate the bob weight? In general, does the 7.25" leave a little weight for the balance shop when using stock 440 rods (say 830g, 600g big+230g small end), KB 280 pistons (550g + 191g pin), rings (say 65g?), and bearings (?g). What do the Manley rods with 2.200" journal weigh, 888g?

I have another steel 440 crank and rods without a block, so picking up a 400 block has appeal for my next motor! I can turn the counter weights on a lathe, but I don't want to take off too much before balancing!


[This message has been edited by 440 Jim (edited August 19, 2000).]

[Brian_wo]

[QUOTE]Originally posted by 440 Jim:
Brian_wo,
Please clarify some crank questions using the 440 crank in a 400. What clearance does the reduced 7.25" dia crank counter weight give (with the 1/16" chamfer)? Where is the closest point and is it at the chamfer?
I don't put the chamfer on the edge of the counterweights,on the two stroker motors I have built so far I just turned the crank down to the 7.25 and with the stock 440 rod and a KB 280 the crank had to be drilled a little bit more to get the weight out but it was not a lot.
Since the stock 440 crank is about 7.5", I was wondering if a dia between the two with a bigger chamfer would get the job done.
maybe but part of the reason for cutting the counters down is to take weight out of the crank,if not you would have to swiss cheese the counters and it would not be pretty,also my machinest uses a lathe also to do this.
For balancing, how do you calculate the bob weight? In general, does the 7.25" leave a little weight for the balance shop when using stock 440 rods (say 830g, 600g big+230g small end), KB 280 pistons (550g + 191g pin), rings (say 65g?), and bearings (?g). What do the Manley rods with 2.200" journal weigh, 888g?
I have no idea what the manelys weigh but they would be a bit more,well maybe not because you are talking about the chevy length so maybe they would be close to the same as the stock 440 rod,as soon as I can find my numbers(weights)I will post them but I seem to have misplaced them.

I have another steel 440 crank and rods without a block, so picking up a 400 block has appeal for my next motor! I can turn the counter weights on a lathe, but I don't want to take off too much before balancing!
If you cut the counters to 7.25 and use a 440 rod and a kb 280 or lighter piston the crank will still be a little heavy,I should have taken a few pictures of what little drilling was left on the crank to get it to weigh but I didn't think about it and now it's in the truck so I really can't.

For the most part all I did was read 451boy's page that he wrote and did what he said,I had been hearing of these motors for a long time and had read as much as I could,then I got on the net and watched the posts of several and could tell 451 knew what he was talking about so I just took his numbers to my machinest and everything came out just like he said it would,he has said over and over that it would balance out around 2400 with the counters cut to 7.25 and you see the number on my crank and to get that it had to be lightened just a bit.

[440 Jim]

451boy, I should have asked you my crank questions (Aug 19 below) too!

Brian_wo, thanks for your input.

I like to save money by doing some things myself, when equipped (basic lathe, mill); and paying the machine shop with what they do best. Every $50-$100 adds up...

[440 Jim]

Well, to keep this thread going I have a question. The Keith Black Silvolite pistons for the 440 rods, KB 280, require the quench dome to be machined for each engine. What do people think of the acceptable quench distance? For those who did it, what dome height did you leave and what was your piston to deck, head chamber distance and resulting volume?



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440 Jim
E-Body Fish

[CrazySpdz]

What's the expected hp/torque out of a a stroked 431/451/496? Thanks!

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73 Charger 400
94 ZJ Limited 318

[DartGT66]

440Jim, Although I have never used those KB pistons, I have built other '451's with quench chambers. For the quench to be effective, it should be less than .080". If you do it properly, you have to machine the blank side of the chamber so that they are parallel to the deck level and in the same depth. Then you try to adjust the dome to about .040" distance including gasket thickness. It doesn't have to be this scientific and it still will work, but this is how it should be done.
Can't say anything about the torque figures of the different combos, because there are so many other things that influence them than the displacement. Compared to a similar size and similarily built 440, you always win with the '451' because of the lighter reciprocating an d rotating assembly and stiffer, lighter and externally smaller block.

[RPM/M]

I have been reading into 451 strokers for a while now. I first came across 451boy's article a long time ago. But since my knowledge of internal components and definitions is still limited I have a hard time understanding what is actuall being said. Would 451boy's article be exactly what I need to take to my machinist to prep my crank and engine? If not, is there any other articles, besides this one here, that I can use to achieve a better understanding of the whole process? Any assistance would be much appreciated.

[440 Jim]

Although putting a 440 crank into a 400 block is one of the easiest strokers currently being done, I advise the following:

If you are not ready to take the full responsibility for every aspect of the engine build-up, then find an engine builder that has done this before and pay him to do everything at least up to assembling the short block.

I think any engine build up needs "blue print" type assembly and checking. When you change the factory set up in any way, then even more has to be checked so something doesn't get overlooked and bite you for $$$$.

Good Luck with your build up. I am not trying to scare you, just be careful.

[Brian Mills]

I just dragged home a 74 400 2bbl complete from a car, and a 78 400 4bbl complete from a 1 ton cube van. I have been given a baffed 440 from a 78 motorhome, supposed to have a good crank and rods, I'll pick it up soon.

I am catching some interest in a 451, I guess I'd put it in my ramcharger 4x4, don't want a real screamer. I was going big block anyway, think the 451 is way more fun, or is the stock 400 enough. The fun to drive factor is all that counts here, this vehicle is a spare. It has 360 4bbl and headers now, needs some engine attention.

PS If anyone is interested, the 1 ton van is equipped with the factory hydraulic brake booster. The power steering pump has 2 sets of lines, 1 to the steering box, and 1 to the brake booster. If interested let me know.

[Brian_wo]

well I am building another of these motor but this one is kind of odd and throws a monkey wrench in to the whole deal.


First I have a set of Ross pistons I bought off the net,we measured the CH the other night and if I remember right they were 1.81.

Then I just picked up a set of .100 long hemi rods(.200 longer than 440)

the pistons have the 1.094 pin and the rods are bushed for .990 but doing a little math in a 400 block with a 440 crank it looks as if the pistons would stick out of the block about .050,this is where my machinest gets creative,he is going to bore the bushings from 1.094 to .990 but will offset bore and actually shorten the rod by close to .050,what ever we don't get there we will shave off the top of the piston to get a zero deck,then who knows,maybe edelbrock will have their new heads out and I can give them a try?


BTW,if it was not for picking up the Ross for $300 and the Manley Rods for $400 I would not be doing this combo because of the extra cost of the machining but I saved enough on those to more than offset the cost of the extra machine work.